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Porting to Qt 4

This document describes porting applications from Qt 3 to Qt 4. If you haven't yet made the decision about porting, or are unsure about whether it is worth it, take a look at the key features offered by Qt 4. See also Getting Ready for Qt 4 for tips on how to write Qt 3 code that is easy to port to Qt 4.

The Qt 4 series is not binary compatible with the 3 series. This means programs compiled for Qt 3 must be recompiled to work with Qt 4. Qt 4 is also not completely source compatible with 3, however nearly all points of incompatibility cause compiler errors or run-time messages (rather than mysterious results). Qt 4 includes many additional features and discards obsolete functionality. Porting from Qt 3 to Qt 4 is straightforward, and once completed makes the considerable additional power and flexibility of Qt 4 available for use in your applications.

To port code from Qt 3 to Qt 4:

  1. Briefly read the porting notes below to get an idea of what to expect.
  2. Be sure that your code compiles and runs well on all your target platforms with Qt 3.
  3. Add the line QT += qt3support to your .pro file if you use qmake; otherwise, edit your makefile or project file to link against the Qt3Support library and add -DQT3_SUPPORT to your compiler flags. (You might also need to specify other libraries. See What's New in Qt 4 for details.)
  4. Run the qt3to4 porting tool. The tool will go through your source code and adapt it to Qt 4.
  5. Follow the instructions in the Porting .ui Files to Qt 4 page to port Qt Designer files.
  6. Recompile with Qt 4. For each error, search below for related identifiers (e.g., function names, class names). This document mentions all relevant identifiers to help you get the information you need at the cost of being a little verbose.

The qt3to4 porting tool replaces occurrences of Qt 3 classes that don't exist anymore in Qt 4 with the corresponding Qt 3 support class; for example, QListBox is turned into Q3ListBox.

At some point, you might want to stop linking against the Qt 3 support library (Qt3Support) and take advantage of Qt 4's new features. The instructions below explain how to do that for each compatibility class.

In addition to the Qt3Support classes (such as Q3Action, Q3ListBox, and Q3ValueList), Qt 4 provides compatibility functions when it's possible for an old API to cohabit with the new one. For example, QString provides a QString::simplifyWhiteSpace() compatibility function that's implemented inline and that simply calls QString::simplified(). The compatibility functions are not documented here; instead, they are documented for each class.

If you have the line QT += qt3support in your .pro file, qmake will automatically define the QT3_SUPPORT symbol, turning on compatibility function support. You can also define the symbol manually (e.g., if you don't want to link against the Qt3Support library), or you can define QT3_SUPPORT_WARNINGS instead, telling the compiler to emit a warning when a compatibility function is called. (This works only with GCC 3.2+ and MSVC 7.)

If you get stuck, ask on the qt4-preview-feedback mailing list. If you are a licensed customer, you can also contact Trolltech support.

Table of contents:

Type Names

The table below lists the classes that have been renamed in Qt 4. If you compile your applications with QT3_SUPPORT defined, the old names will be available.

Whenever you see an occurrence of the name on the left, you can safely replace it with the Qt 4 equivalent in your program. The qt3to4 tool performs the conversion automatically.

Qt 3 class nameQt 4 class name
QIconSetQIcon
QWMatrixQMatrix
QGuardedPtrQPointer

The table below lists the enums and typedefs that have been renamed in Qt 4. If you compile your applications with QT3_SUPPORT defined, the old names will be available.

Whenever you see an occurrence of the name on the left, you can safely replace it with the Qt 4 equivalent in your program. The qt3to4 tool handles performs the conversion automatically.

Qt 3 type nameQt 4 type name
QApplication::ColorModeQApplication::ColorSpec
QButton::ToggleStateQCheckBox::ToggleState
QCursorShapeQt::CursorShape
QFile::FilterSpecQFile::Filters
QFile::PermissionSpecQFile::Permission
QFile::SortSpecQFile::SortFlags
QFile::StatusQFile::Error
QFileInfo::PermissionSpecQFile::Permission
QGrid::DirectionQt::Orientation
QGridWidget::DirectionQt::Orientation
QIODevice::Offsetqlonglong
QImage::ScaleModeQt::AspectRatioMode
QSize::ScaleModeQt::AspectRatioMode
QSocket::ErrorQ3Socket::Error
QSocket::StateQ3Socket::State
QStyle::SCFlagsQStyle::SubControls
QStyle::SFlagsQStyle::State
QTSQTextStream
QUrlDragQUriDrag
QWidget::FocusPolicyQt::FocusPolicy
Q_LLONGqlonglong
Q_ULLONGqulonglong
Qt::DockQt::ToolBarDock
Qt::MacintoshVersionQSysInfo::MacVersion
Qt::TextFlagsQt::TextFlag
Qt::WindowsVersionQSysInfo::WinVersion

Enum Values

The table below lists the enum values that have been renamed in Qt 4. If you compile your applications with QT3_SUPPORT defined, the old names will be available.

Whenever you see an occurrence of the name on the left, you can safely replace it with the Qt 4 equivalent in your program. The qt3to4 tool handles performs the conversion automatically.

Qt 3 enum value nameQt 4 enum value name
IO_AppendQIODevice::Append
IO_ReadOnlyQIODevice::ReadOnly
IO_ReadWriteQIODevice::ReadWrite
IO_TranslateQIODevice::Translate
IO_TruncateQIODevice::Truncate
IO_WriteOnlyQIODevice::WriteOnly
QAccessible::MoveableQAccessible::Movable
QApplication::CustomColorsQApplication::CustomColor
QApplication::NormalColorsQApplication::NormalColor
QButton::NoChangeQCheckBox::NoChange
QButton::OffQCheckBox::Off
QButton::OnQCheckBox::On
QChar::SingleQChar::NoDecomposition
QChar::byteOrderMarkQChar::ByteOrderMark
QChar::byteOrderSwappedQChar::ByteOrderSwapped
QChar::nbspQChar::Nbsp
QChar::nullQChar::Null
QChar::replacementQChar::ReplacementCharacter
QComboBox::AfterCurrentQComboBox::InsertAfterCurrent
QComboBox::AtBottomQComboBox::InsertAtBottom
QComboBox::AtCurrentQComboBox::InsertAtCurrent
QComboBox::AtTopQComboBox::InsertAtTop
QComboBox::BeforeCurrentQComboBox::InsertBeforeCurrent
QComboBox::NoInsertionQComboBox::NoInsert
QDir::DefaultFilterQDir::NoFilter
QDir::DefaultSortQDir::NoSort
QEvent::AccelQEvent::Shortcut
QEvent::AccelOverrideQEvent::ShortcutOverride
QEvent::CaptionChangeQEvent::WindowTitleChange
QEvent::ChildInsertedQEvent::ChildAdded
QEvent::IMComposeQEvent::InputMethodCompose
QEvent::IMEndQEvent::InputMethodEnd
QEvent::IMStartQEvent::InputMethodStart
QEvent::IconChangeQEvent::WindowIconChange
QEvent::LayoutHintQEvent::LayoutRequest
QEvent::ReparentQEvent::ParentChange
QFileInfo::ExeGroupQFile::ExeGroup
QFileInfo::ExeOtherQFile::ExeOther
QFileInfo::ExeOwnerQFile::ExeOwner
QFileInfo::ExeUserQFile::ExeUser
QFileInfo::ReadGroupQFile::ReadGroup
QFileInfo::ReadOtherQFile::ReadOther
QFileInfo::ReadOwnerQFile::ReadOwner
QFileInfo::ReadUserQFile::ReadUser
QFileInfo::WriteGroupQFile::WriteGroup
QFileInfo::WriteOtherQFile::WriteOther
QFileInfo::WriteOwnerQFile::WriteOwner
QFileInfo::WriteUserQFile::WriteUser
QFrame::GroupBoxPanelQFrame::StyledPanel
QFrame::LineEditPanelQFrame::StyledPanel
QFrame::MenuBarPanelQFrame::StyledPanel
QFrame::PopupPanelQFrame::StyledPanel
QFrame::TabWidgetPanelQFrame::StyledPanel
QFrame::ToolBarPanelQFrame::StyledPanel
QImage::ScaleFreeQt::IgnoreAspectRatio
QImage::ScaleMaxQt::KeepAspectRatioByExpanding
QImage::ScaleMinQt::KeepAspectRatio
Qt::IdenticalQKeySequence::ExactMatch
Qt::NoMatchQKeySequence::NoMatch
Qt::PartialMatchQKeySequence::PartialMatch
QLayout::AutoQLayout::SetDefaultConstraint
QLayout::FixedQLayout::SetFixedSize
QLayout::FreeResizeQLayout::SetNoConstraint
QLayout::MinimumQLayout::SetMinimumSize
QMacStyle::SizeNoneQMacStyle::SizeDefault
QSettings::GlobalQSettings::SystemScope
QSettings::UserQSettings::UserScope
QSize::ScaleFreeQt::IgnoreAspectRatio
QSize::ScaleMaxQt::KeepAspectRatioByExpanding
QSize::ScaleMinQt::KeepAspectRatio
QSizePolicy::HorizontalQSizePolicy::Horizontally
QSizePolicy::VerticalQSizePolicy::Vertically
QSlider::AboveQSlider::TicksAbove
QSlider::BelowQSlider::TicksBelow
QSlider::BothQSlider::TicksBothSides
QSlider::LeftQSlider::TicksLeft
QSlider::NoMarksQSlider::NoTicks
QSlider::RightQSlider::TicksRight
QSocket::ClosingQ3Socket::Closing
QSocket::ConnectedQ3Socket::Connected
QSocket::ConnectingQ3Socket::Connecting
QSocket::ConnectionQ3Socket::Connection
QSocket::ErrConnectionRefusedQ3Socket::ErrConnectionRefused
QSocket::ErrHostNotFoundQ3Socket::ErrHostNotFound
QSocket::ErrSocketReadQ3Socket::ErrSocketRead
QSocket::HostLookupQAbstractSocket::HostLookupState
QSocket::IdleQAbstractSocket::UnconnectedState
QSqlError::ConnectionQSqlError::ConnectionError
QSqlError::NoneQSqlError::NoError
QSqlError::StatementQSqlError::StatementError
QSqlError::TransactionQSqlError::TransactionError
QSqlError::UnknownQSqlError::UnknownError
QStyle::CC_ListViewQStyle::CC_Q3ListView
QStyle::SH_UnderlineAcceleratorQStyle::SH_UnderlineShortcut
QStyle::Style_ActiveQStyle::State_Active
QStyle::Style_AutoRaiseQStyle::State_AutoRaise
QStyle::Style_BottomQStyle::State_Bottom
QStyle::Style_ChildrenQStyle::State_Children
QStyle::Style_DefaultQStyle::State_None
QStyle::Style_DownQStyle::State_DownArrow
QStyle::Style_EditingQStyle::State_Editing
QStyle::Style_EnabledQStyle::State_Enabled
QStyle::Style_FocusAtBorderQStyle::State_FocusAtBorder
QStyle::Style_HasFocusQStyle::State_HasFocus
QStyle::Style_HorizontalQStyle::State_Horizontal
QStyle::Style_ItemQStyle::State_Item
QStyle::Style_MouseOverQStyle::State_MouseOver
QStyle::Style_NoChangeQStyle::State_NoChange
QStyle::Style_NoneQStyle::State_None
QStyle::Style_OffQStyle::State_Off
QStyle::Style_OnQStyle::State_On
QStyle::Style_OpenQStyle::State_Open
QStyle::Style_RaisedQStyle::State_Raised
QStyle::Style_RectangleQStyle::State_Rectangle
QStyle::Style_SelectedQStyle::State_Selected
QStyle::Style_SiblingQStyle::State_Sibling
QStyle::Style_SunkenQStyle::State_Sunken
QStyle::Style_TopQStyle::State_Top
QStyle::Style_UpQStyle::State_Up
QTabBar::RoundedAboveQTabBar::RoundedNorth
QTabBar::RoundedBelowQTabBar:: RoundedSouth
QTabBar::TriangularAboveQTabBar:: TriangularNorth
QTabBar::TriangularBelowQTabBar:: TriangularSouth
QTextEdit::MovePgDownQTextEdit::MovePageDown
QTextEdit::MovePgUpQTextEdit::MovePageUp
QToolButton::RightQToolButton::BesideIcon
QToolButton::UnderQToolButton::BelowIcon
QValidator::ValidQValidator::Intermediate
QVariant::IconSetQCoreVariant::Icon
QWidget::ClickFocusQt::ClickFocus
QWidget::NoFocusQt::NoFocus
QWidget::StrongFocusQt::StrongFocus
QWidget::TabFocusQt::TabFocus
QWidget::WheelFocusQt::WheelFocus
Qt::AlignAutoQt::AlignLeft
Qt::AltButtonQt::AltModifier
Qt::AscendingQt::AscendingOrder
Qt::BottomQt::DockBottom
Qt::BottomLeftQt::BottomLeftCorner
Qt::BottomRightQt::BottomRightCorner
Qt::BreakAnywhereQt::TextWrapAnywhere
Qt::ControlButtonQt::ControlModifier
Qt::CustomPatternQt::TexturePattern
Qt::DescendingQt::DescendingOrder
Qt::DontClipQt::TextDontClip
Qt::DontPrintQt::TextDontPrint
Qt::ExpandTabsQt::TextExpandTabs
Qt::IncludeTrailingSpacesQt::TextIncludeTrailingSpaces
Qt::KeyButtonMaskQt::KeyboardModifierMask
Qt::Key_BackSpaceQt::Key_Backspace
Qt::Key_BackTabQt::Key_Backtab
Qt::Key_MediaPrevQt::Key_MediaPrevious
Qt::Key_NextQt::Key_PageDown
Qt::Key_PriorQt::Key_PageUp
Qt::Key_aacuteQt::Key_Aacute
Qt::Key_acircumflexQt::Key_Acircumflex
Qt::Key_adiaeresisQt::Key_Adiaeresis
Qt::Key_aeQt::Key_AE
Qt::Key_agraveQt::Key_Agrave
Qt::Key_aringQt::Key_Aring
Qt::Key_atildeQt::Key_Atilde
Qt::Key_ccedillaQt::Key_Ccedilla
Qt::Key_eacuteQt::Key_Eacute
Qt::Key_ecircumflexQt::Key_Ecircumflex
Qt::Key_ediaeresisQt::Key_Ediaeresis
Qt::Key_egraveQt::Key_Egrave
Qt::Key_ethQt::Key_ETH
Qt::Key_iacuteQt::Key_Iacute
Qt::Key_icircumflexQt::Key_Icircumflex
Qt::Key_idiaeresisQt::Key_Idiaeresis
Qt::Key_igraveQt::Key_Igrave
Qt::Key_ntildeQt::Key_Ntilde
Qt::Key_oacuteQt::Key_Oacute
Qt::Key_ocircumflexQt::Key_Ocircumflex
Qt::Key_odiaeresisQt::Key_Odiaeresis
Qt::Key_ograveQt::Key_Ograve
Qt::Key_oslashQt::Key_Ooblique
Qt::Key_otildeQt::Key_Otilde
Qt::Key_thornQt::Key_THORN
Qt::Key_uacuteQt::Key_Uacute
Qt::Key_ucircumflexQt::Key_Ucircumflex
Qt::Key_udiaeresisQt::Key_Udiaeresis
Qt::Key_ugraveQt::Key_Ugrave
Qt::Key_yacuteQt::Key_Yacute
Qt::KeypadQt::KeypadModifier
Qt::LeftQt::DockLeft
Qt::MV_10_DOT_0QSysInfo::MV_10_0
Qt::MV_10_DOT_1QSysInfo::MV_10_1
Qt::MV_10_DOT_2QSysInfo::MV_10_2
Qt::MV_10_DOT_3QSysInfo::MV_10_3
Qt::MV_10_DOT_4QSysInfo::MV_10_4
Qt::MV_9QSysInfo::MV_9
Qt::MV_CHEETAHQSysInfo::MV_10_0
Qt::MV_JAGUARQSysInfo::MV_10_2
Qt::MV_PANTHERQSysInfo::MV_10_3
Qt::MV_PUMAQSysInfo::MV_10_1
Qt::MV_TIGERQSysInfo::MV_10_4
Qt::MV_UnknownQSysInfo::MV_Unknown
Qt::MetaButtonQt::MetaModifier
Qt::MinimizedQt::DockMinimized
Qt::NoAccelQt::TextHideMnemonic
Qt::OverlineQt::TextOverline
Qt::RightQt::DockRight
Qt::ShiftButtonQt::ShiftModifier
Qt::ShowPrefixQt::TextShowMnemonic
Qt::SingleLineQt::TextSingleLine
Qt::StrikeOutQt::TextStrikeOut
Qt::TopQt::DockTop
Qt::TopLeftQt::TopLeftCorner
Qt::TopRightQt::TopRightCorner
Qt::TornOffQt::DockTornOff
Qt::UnderlineQt::TextUnderline
Qt::UnmanagedQt::DockUnmanaged
Qt::WNorthWestGravityQt::WStaticContents
Qt::WRepaintNoEraseQt::WNoAutoErase
Qt::WStyle_DialogQt::WType_Dialog
Qt::WStyle_NoBorderExQt::WStyle_NoBorder
Qt::WType_Modal(Qt::WType_Dialog | Qt::WShowModal)
Qt::WV_2000QSysInfo::WV_2000
Qt::WV_2003QSysInfo::WV_2003
Qt::WV_32sQSysInfo::WV_32s
Qt::WV_95QSysInfo::WV_95
Qt::WV_98QSysInfo::WV_98
Qt::WV_CEQSysInfo::WV_CE
Qt::WV_CENETQSysInfo::WV_CENET
Qt::WV_CE_basedQSysInfo::WV_CE_based
Qt::WV_DOS_basedQSysInfo::WV_DOS_based
Qt::WV_MeQSysInfo::WV_Me
Qt::WV_NTQSysInfo::WV_NT
Qt::WV_NT_basedQSysInfo::WV_NT_based
Qt::WV_XPQSysInfo::WV_XP
Qt::WordBreakQt::TextWordWrap
Qt::IbeamCursorQt::IBeamCursor

In addition, the following window flags have been either replaced with widget attributes or have been deprecated:

Qt 3 typeQt 4 equivalent
Qt::WDestructiveCloseUse QWidget::setAttribute(Qt::WA_DeleteOnClose) instead.
Qt::WStaticContentsUse QWidget::setAttribute(Qt::WA_StaticContents) instead.
Qt::WNorthWestGravity
Qt::WNoAutoEraseUse QWidget::setAttribute(Qt::WA_NoBackground) instead.
Qt::WResizeNoErase
Qt::WRepaintNoErase
Qt::WPaintCleverUnnecessary in Qt 4.
Qt::WMacNoSheetUnnecessary in Qt 4.

Properties

Some properties have been renamed in Qt 4, to make Qt's API more consistent and more intuitive. For example, QWidget's caption property has been renamed windowTitle to make it clear that it refers to the title shown in the window's title bar.

The table below lists the Qt properties that have been renamed in Qt 4. Occurrences of these in Qt Designer .ui files are automatically converted to the new name by uic.

Qt 3 nameQt 4 name
QButton::accelQButton::shortcut
QButton::onQButton::checked
QButton::toggleButtonQAbstractButton::checkable
QDial::lineStepQDial::singleStep
QDial::maxValueQDial::maximum
QDial::minValueQDial::minimum
QDialog::modalQDialog::isModal
QLineEdit::editedQLineEdit::modified
QLineEdit::hasMarkedTextQLineEdit::hasSelectedText
QLineEdit::markedTextQLineEdit::selectedText
QObject::nameQObject::objectName
QProgressDialog::progressQProgressDialog::value
QProgressDialog::totalStepsQProgressDialog::maximum
QProgressDialog::wasCancelledQProgressDialog::wasCanceled
QPushButton::iconSetQPushButton::icon
QScrollBar::draggingSliderQScrollBar::sliderDown
QScrollBar::lineStepQScrollBar::singleStep
QScrollBar::maxValueQScrollBar::maximum
QScrollBar::minValueQScrollBar::minimum
QSlider::lineStepQSlider::singleStep
QSlider::maxValueQSlider::maximum
QSlider::minValueQSlider::minimum
QSpinBox::lineStepQSpinBox::singleStep
QSpinBox::maxValueQSpinBox::maximum
QSpinBox::minValueQSpinBox::minimum
QTabBar::currentTabQTabBar::currentIndex
QTabWidget::currentPageQTabWidget::currentWidget
QToolButton::iconSetQToolButton::icon
QToolButton::textLabelQToolButton::text
QWidget::captionQWidget::windowTitle
QWidget::iconQWidget::windowIcon
QWidget::iconTextQWidget::windowIconText

A handful of properties in Qt 3 are no longer properties in Qt 4, but the access functions still exist as part of the Qt 4 API. These are not used by Qt Designer; the only case where you need to worry about them is in highly dynamic applications that use Qt's meta-object system to access properties. Here's the list of these properties with the read and write functions that you can use instead:

Qt 3 propertyQt 4 read functionQt 4 write function
QSqlDatabase::connectOptionsQSqlDatabase::connectOptions()QSqlDatabase::setConnectOptions()
QSqlDatabase::databaseNameQSqlDatabase::databaseName()QSqlDatabase::setDatabaseName()
QSqlDatabase::hostNameQSqlDatabase::hostName()QSqlDatabase::setHostName()
QSqlDatabase::passwordQSqlDatabase::password()QSqlDatabase::setPassword()
QSqlDatabase::portQSqlDatabase::port()QSqlDatabase::setPort()
QSqlDatabase::userNameQSqlDatabase::userName()QSqlDatabase::setUserName()

Some properties have been removed from Qt 4, but the associated access functions are provided if QT3_SUPPORT is defined to help porting to Qt 4. When converting Qt 3 .ui files to Qt 4, uic generates calls to the Qt 3 compatibility functions.

The table below lists these properties with the read and write functions that you can use instead. The documentation for the individual functions explains how to replace them with non-compatibility Qt 4 functions.

Qt 3 propertyQt 4 read function (QT3_SUPPORT)Qt 4 write function (QT3_SUPPORT)
QMenuBar::separatorQMenuBar::separator()QMenuBar::setSeparator()
QPushButton::menuButtonQPushButton::isMenuButton()N/A
QTabWidget::marginQTabWidget::margin()QTabWidget::setMargin()
QWidget::backgroundBrushQWidget::backgroundBrush()N/A
QWidget::backgroundModeQWidget::backgroundMode()QWidget::setBackgroundMode()
QWidget::backgroundOriginQWidget::backgroundOrigin()QWidget::setBackgroundOrigin()
QWidget::colorGroupQWidget::colorGroup()QWidget::setColorGroup()
QWidget::customWhatsThisQWidget::customWhatsThis()QWidget::setCustomWhatsThis()
QWidget::inputMethodEnabledQWidget::inputMethodEnabled()QWidget::setInputMethodEnabled()
QWidget::ownCursorQWidget::ownCursor()N/A
QWidget::ownFontQWidget::ownFont()N/A
QWidget::ownPaletteQWidget::ownPalette()N/A
QWidget::paletteBackgroundColorQWidget::paletteBackgroundColor()QWidget::setPaletteBackgroundColor()
QWidget::paletteBackgroundPixmapQWidget::paletteBackgroundPixmap()QWidget::setPaletteBackgroundPixmap()
QWidget::paletteForegroundColorQWidget::paletteForegroundColor()QWidget::setPaletteForegroundColor()
QWidget::underMouseQWidget::underMouse()N/A

The following Qt 3 properties and their access functions are no longer available in Qt 4. In most cases, Qt 4 provides similar functionality.

Qt 3 propertyQt 4 equivalent
QButton::autoRepeatN/A
QButton::autoResizeCall QWidget:setFixedSize(QWidget::sizeHint()) whenever you change the contents.
QButton::exclusiveToggleSee QAbstractButton::autoExclusive.
QButton::pixmapUse QAbstractButton::icon instead.
QButton::toggleStateUse QCheckBox::setState() and QCheckBox::state() instead.
QButton::toggleTypeUse QCheckBox::setTristate() instead.
QComboBox::autoResizeCall QWidget:setFixedSize(QWidget::sizeHint()) whenever you change the contents.
QFrame::contentsRectUse Q3Frame::contentsRect() instead.
QFrame::marginUse QWidget::setContentsMargins() instead.
QTabBar::keyboardFocusTabN/A
QToolButton::offIconSetUse the off component of QAbstractButton::icon instead.
QToolButton::onIconSetUse the on component of QAbstractButton::icon instead.
QWidget::microFocusHintN/A

Explicit Sharing

Qt 4 is the first version of Qt that contains no explicitly shared classes. All classes that were explicitly shared in Qt 3 are implicitly shared in Qt 4:

This means that if you took a copy of an instance of the class (using operator=() or the class's copy constructor), any modification to the copy would affect the original and vice versa. Needless to say, this behavior is rarely desirable.

Fortunately, nearly all Qt 3 applications don't rely on explicit sharing. When porting, you typically only need to remove calls to detach() and/or copy(), which aren't necessary anymore.

If you deliberately rely on explicit sharing in your application, you can use pointers or references to achieve the same result in Qt 4.

For example, if you have code like

    void asciify(QByteArray array)
    {
        for (int i = 0; i < (int)array.size(); ++i) {
            if ((uchar)array[i] >= 128)
                array[i] = '?';
        }
    }

you can rewrite it as

    void asciify(QByteArray &array)
    {
        for (int i = 0; i < array.size(); ++i) {
            if ((uchar)array[i] >= 128)
                array[i] = '?';
        }
    }

(Notice the & in the parameter declaration.)

QAccel

The QAccel class has been renamed Q3Accel and moved to the Qt3Support module. In new applications, you have three options:

  1. You can use QAction and set a key sequence using QAction::setShortcut().
  2. You can use QShortcut, a class that provides similar functionality to Q3Accel.
  3. You can use QWidget::grabShortcut() and process "shortcut" events by reimplementing QWidget::event().

The Q3Accel class also supports multiple accelerators using the same object, by calling Q3Accel::insertItem() multiple times. In Qt 4, the solution is to create multiple QShortcut objects.

QAccessibleInterface

The QAccessibleInterface class has undergone some API changes in Qt 4, to make it more consistent with the rest of the Qt API.

If you have classes that inherit QAccessibleInterface or one of its subclasses (QAccessibleObject, QAccessibleWidget, etc.), you must port them the new QAccessibleInterface API.

See Virtual Functions for a list of QAccessibleInterface virtual member functions in Qt 3 that are no longer virtual in Qt 4.

QAccessibleTitleBar

The QAccessibleTitleBar has been renamed Q3AccessibleTitleBar and moved to the Qt3Support library.

QAction

The QAction class has been redesigned in Qt 4 to integrate better with the rest of the menu system. It unifies the old QMenuItem class and the old QAction class into one class, avoiding unnecessary data duplication and the need to learn two different APIs.

The old QAction and QActionGroup classes have been renamed Q3Action and Q3ActionGroup and moved to Qt3Support. In addition, the new QAction class has compatibility functions to ease transition to Qt 4.

See Virtual Functions for a list of QAction virtual member functions in Qt 3 that are no longer virtual in Qt 4.

QActionGroup

The QAction class has been completely redesigned in Qt 4 to integrate better with the rest of the menu system. See the section on QAction for details.

QApplication

The QApplication class has been split into two classes: QCoreApplication and QApplication. The new QApplication class inherits QCoreApplication and adds GUI-related functionality. In practice, this has no consequences for existing Qt applications.

In addition, the following API changes were made:

  1. QApplication::allWidgets() and QApplication::topLevelWidgets() used to return a pointer to a QWidgetList. Now they return a QWidgetList.

    Also, QWidgetList has changed from being a typedef for QPtrList<QWidget> to being a typedef for QList<QWidget *>. See the section on QWidgetList below for details.

    For example, if you have code like

            QWidgetList *list = QApplication::topLevelWidgets();
            QWidgetListIt it(*list);
            QWidget *widget;
            while ((widget = it.current())) {
                if (widget->inherits("MainWindow"))
                    ((MainWindow *)widget)->updateRecentFileItems();
                ++it;
            }
            delete list;

    you can rewrite it as

            QWidgetList list = QApplication::topLevelWidgets();
            for (int i = 0; i < list.size(); ++i) {
                if (MainWindow *mainWin = qobject_cast<MainWindow>(list.at(i)))
                    mainWin->updateRecentFileItems();
            }
  2. QApplication::setMainWidget() is no longer used. When all an application's windows are closed, the application will exit normally.

QAquaStyle

The QAquaStyle class first appeared in Qt 3.0, when the Qt/Mac port was first released. It emulated Apple's "Aqua" theme. In Qt 3.1, QAquaStyle was obsoleted by QMacStyle, which uses Appearance Manager to perform its drawing.

The QAquaStyle class is no longer provided in Qt 4. Use QMacStyle instead.

QAsciiCache<T>

QAsciiCache<T> has been renamed Q3AsciiCache<T> and moved to the Qt3Support library. It has been replaced by QCache<QByteArray, T>.

For details, read the section on QCache<T>, mentally substituting QByteArray for QString.

QAsciiDict<T>

QAsciiDict<T> and QAsciiDictIterator<T> have been renamed Q3AsciiDict<T> and Q3AsciiDictIterator<T> and moved to the Qt3Support library. They have been replaced by the more modern QHash<Key, T> and QMultiHash<Key, T> classes and their associated iterator classes.

When porting old code that uses Q3AsciiDict<T> to Qt 4, there are four classes that you can use:

For details, read the section on QDict<T>, mentally substituting QByteArray for QString.

QAsyncIO

The QAsyncIO class was used internally in Qt 2.x in conjunction with QImageConsumer. It was obsoleted in Qt 3.0. If you use this mechanism in your application, please submit a report to the Task Tracker on the Trolltech website and we will try to find a satisfactory substitute.

QBackInsertIterator

The undocumented QBackInsertIterator class has been removed from the Qt library. If you need it in your application, feel free to copy the source code from the Qt 3 <qtl.h> header file.

QBitArray

In Qt 3, QBitArray inherited from QByteArray. In Qt 4, QBitArray is a totally independent class. This makes very little difference to the user, except that the new QBitArray doesn't provide any of QByteArray's byte-based API anymore. These calls will result in a compile-time error, except calls to QBitArray::truncate(), whose parameter was a number of bytes in Qt 3 and a number of bits in Qt 4.

QBitArray was an explicitly shared class in Qt 3. See Explicit Sharing for more information.

The QBitVal class has been renamed QBitRef.

QButton

The QButton class has been replaced by QAbstractButton in Qt 4. Classes like QPushButton and QRadioButton inherit from QAbstractButton. As a help when porting older Qt applications, the Qt3Support library contains a Q3Button class implemented in terms of the new QAbstractButton.

If you used the QButton class as a base class for your own button type and want to port your code to the newer QAbstractButton, you need to be aware that QAbstractButton has no equivalent for the Q3Button::drawButton(QPainter *) virtual function. The solution is to reimplement QWidget::paintEvent() in your QAbstractButton subclass as follows:

    void MyButton::paintEvent(QPaintEvent *)
    {
        QPainter painter(this);
        drawButton(&painter);
    }
Q3Button functionQAbstractButton equivalent
Q3Button::autoResize()Call QWidget:setFixedSize(QWidget::sizeHint()) whenever you change the contents.
Q3Button::isExclusiveToggle()Use QAbstractButton::group() or QAbstractButton::autoExclusive() instead.
Q3Button::pixmap() constQAbstractButton::icon()
Q3Button::setAutoResize()N/A
Q3Button::setPixmap(const QPixmap &)QAbstractButton::setIcon(const QIcon &)
Q3Button::setState(ToggleState)See remark below
Q3Button::setToggleType(ToggleType)See remark below
Q3Button::state()See remark below
Q3Button::stateChanged(int)See remark below
Q3Button::toggleType()See remark below

Remarks:

  1. In Qt 3, QButton had a "toggle type", which could be QButton::SingleShot, QButton::Toggle, or QButton::Tristate. The new QAbstractButton class doesn't support "tristate" directly; this feature is implemented in QCheckBox instead. The two other "toggle types" (QButton::SingleShot and QButton::Toggle) are replaced by a QAbstractButton::checkable property.
  2. In Qt 3, QButton had a "toggle state", which could be QButton::Off, QButton::NoChange, or QButton::On. In Qt 4, this mechanism has been moved to QCheckBox.

See Virtual Functions for a list of QButton virtual member functions in Qt 3 that aren't virtual in Qt 4.

See Properties for a list of QButton properties in Qt 3 that have changed in Qt 4.

QButtonGroup

The QButtonGroup class has been completely redesigned in Qt 4. For compatibility, the old QButtonGroup class has been renamed Q3ButtonGroup and has been moved to Qt3Support. Likewise, the QHButtonGroup and QVButtonGroup convenience subclasses have been renamed Q3HButtonGroup and Q3VButtonGroup and moved to the Qt3Support library.

The old QButtonGroup, as well as Q3ButtonGroup, can be used in two ways:

  1. The button group is the parent widget of a number of buttons, i.e. the button group is the parent argument in the button constructor. The buttons are assigned identifiers 0, 1, 2, etc., in the order they are created. A Q3ButtonGroup can display a frame and a title because it inherits Q3GroupBox.
  2. The button group is an invisible widget and the contained buttons have some other parent widget. In this usage, each button must be manually inserted, using Q3ButtonGroup::insert(), into the button group and given an ID number.

Unlike Q3ButtonGroup, the new QButtonGroup doesn't inherit QWidget. It is very similar to a "hidden Q3ButtonGroup".

If you use a Q3ButtonGroup, Q3HButtonGroup, or Q3VButtonGroup as a widget and want to port to Qt 4, you can replace it with QGroupBox. In Qt 4, radio buttons with the same parent are automatically part of an exclusive group, so you normally don't need to do anything else. See also the section on QGroupBox below.

See Virtual Functions for a list of QButtonGroup virtual member functions in Qt 3 that are no longer virtual in Qt 4.

QByteArray

In Qt 3, QByteArray was simply a typedef for QMemArray<char>. In Qt 4, QByteArray is a class in its own right, with a higher-level API in the style of QString.

Here are the main issues to be aware of when porting to Qt 4:

  1. The QMemArray(int size) constructor has been replaced with QByteArray(int size, char ch). The second argument specifies which character should be used for initializing the array; pass '\0' if you have no specific needs.

    For example, if you have code like

        QByteArray ba(64);

    you can rewrite it as

        QByteArray ba(64, '\0');
  2. QMemArray::at() returned a non-const reference, whereas the new QByteArray::at() returns a const value. Code like
        ba.at(0) = 'X';

    will no longer compile. Instead, use QByteArray::operator[]:

        ba[0] = 'X';
  3. The QMemArray::contains(char) function has been renamed QByteArray::count(char). In addition, there now exists a QByteArray::contains(char) function that returns a boolean value. Replace old calls to contains() with either count() or contains(), depending on whether you care about the specific number of occurrences of a character in the byte array or only care about whether the array contains that character or not.
  4. The new QByteArray has no assign() function. Calls to QMemArray::assign(const QMemArray &) can be replaced by calls to QByteArray::operator=(). Calls to QMemArray::assign(const T *, uint) have no equivalent in Qt 4; if you use it, the solution is either to use QByteArray::fromRawData() and to call free() yourself to avoid a memory leak, or to use the QByteArray(const char *, int) constructor, which will take a deep copy of the data.
  5. QMemArray::bsearch() and QMemArray::sort() have no equivalent in the new QByteArray class. Use qBinaryFind() and qSort() if you need that functionality.

QByteArray was an explicitly shared class in Qt 3. See Explicit Sharing for more information.

QCache<T>

QCache<T> has been renamed Q3Cache<T> and moved to Qt3Support. The new QCache class has a different API, and takes different template parameters: QCache<Key, T>.

When porting to Qt 4, QCache<QString, T> is the obvious substitute for Q3Cache<T>. The following table summarizes the API differences.

Q3Cache<T> functionQCache<QString, T> equivalent
Q3Cache::Q3Cache(int maxCost, int size, bool caseSensitive)See remark below
Q3Cache::autoDelete()N/A
Q3Cache::count()QCache::count() or QCache::size() (equivalent)
Q3Cache::setAutoDelete()See remark below
Q3Cache::size()N/A
Q3Cache::statistics()N/A
Q3Cache::operator=()See remark below

Remarks:

  1. Q3Cache requires the user to allocate a specific number of buckets by passing a prime number (17 by default) to the constructor. In contrast, the new QCache's hash table automatically grows and shrinks as needed, and the constructor doesn't take a prime number.
  2. Q3Cache supportes case-insensitive lookups by passing false as second argument to the constructor. This feature has no equivalent in QMultiHash. Instead, call QString::toLower() before you insert or lookup a key in the hash.
  3. The Q3Cache::insert() function returns a bool value that indicates whether or not the item actually was inserted in the cache. If the item wasn't inserted, it was the caller's responsibility to delete the item. The new QCache::insert() function returns void and either adds it to the cache or deletes it right away. Old code like
        if (!cache.insert(key, object))
            delete object;

    becomes

        cache.insert(key, object);
  4. The new QCache class always takes ownership of the items it stores (i.e. auto-delete is always on). If you use Q3Cache with auto-delete turned off (the rarely useful default), you cannot use QCache as a direct substitute. One unelegant trick that works well in practice is to use QCache<QString, T *> instead of QCache<QString, T>. In that case, QCache owns the pointers, not the objects that the pointers refer to. For example,
            Q3Cache<QWidget> cache;
            cache.insert(widget->name(), widget);
            ...
            QWidget *foo = cache.take("foo");
            if (foo)
                foo->show();

    becomes

            typedef QWidget *QWidgetPtr;
            QCache<QString, QWidgetPtr> cache;
            cache.insert(widget->name(), new QWidgetPtr(widget));
            ...
            QWidgetPtr *ptr = cache.take("foo");
            if (ptr) {
                QWidget *foo = *ptr;
                delete ptr;
                foo->show();
            }

    An alternative is to stick to using Q3Cache.

QCacheIterator<T> has been renamed Q3CacheIterator<T> and moved to the Qt3Support library. The new QCache class doesn't offer any iterator types.

QCanvas

The canvas module classes have been renamed and moved to the Qt3Support library.

Qt 3 class nameCompatibility class in Qt 4
QCanvasQ3Canvas
QCanvasEllipseQ3CanvasEllipse
QCanvasItemQ3CanvasItem
QCanvasItemListQ3CanvasItemList
QCanvasLineQ3CanvasLine
QCanvasPixmapQ3CanvasPixmap
QCanvasPixmapArrayQ3CanvasPixmapArray
QCanvasPolygonQ3CanvasPolygon
QCanvasPolygonalItemQ3CanvasPolygonalItem
QCanvasRectangleQ3CanvasRectangle
QCanvasSplineQ3CanvasSpline
QCanvasSpriteQ3CanvasSprite
QCanvasTextQ3CanvasText
QCanvasViewQ3CanvasView

Qt 4.1 is expected to provide a replacement module for these classes, based on Qt 4's powerful new 2D paint system.

QColor

In Qt 4, QColor is a value type like QPoint or QRect. Graphics system-specific code has been implemented in QColorMap.

The numBitPlanes() function has been replaced by QColorMap::depth().

QColorGroup

In Qt 3, a QPalette consisted of three QColorGroup objects. In Qt 4, the (rarely used) QColorGroup abstraction has been eliminated. For source compatibility, a QColorGroup class is available when QT3_SUPPORT is defined.

The new QPalette still works in terms of color groups, specified through enum values (QPalette::Active, QPalette::Disabled, and QPalette::Inactive). It also has the concept of a current color group, which you can set using QPalette::setCurrentColorGroup().

The QPalette object returned by QWidget::palette() returns a QPalette initialized with the correct current color group for the widget. This means that if you had code like

    painter.setBrush(colorGroup().brush(QColorGroup::Background));

you can simply replace colorGroup() with palette():

    painter.setBrush(palette().brush(QPalette::Background));

QColorDrag

The QColorDrag class has been renamed Q3ColorDrag and moved to the Qt3Support library. In Qt 4, use QMimeData instead and call QMimeData::setColor() to set the color.

QComboBox

In Qt 3, the list box used to display the contents of a QComboBox widget could be accessed by using the listBox() function. In Qt 4, the standard list box is provided by a QListView widget, and can be accessed with the view() function.

See Virtual Functions for a list of QComboBox virtual member functions in Qt 3 that are no longer virtual in Qt 4.

QCString

In Qt 3, QCString inherited from QByteArray. The main drawback of this approach is that the user had the responsibility of ensuring that the string is '\0'-terminated. Another important issue was that conversions between QCString and QByteArray often gave confusing results. (See the Achtung! Binary and Character Data article in Qt Quarterly for an overview of the pitfalls.)

Qt 4 solves that problem by merging the QByteArray and QCString classes into one class called QByteArray. Most functions that were in QCString previously have been moved to QByteArray. The '\0' issue is handled by having QByteArray allocate one extra byte that it always sets to '\0'. For example:

    QByteArray ba("Hello");
    ba.size();             // returns 5 (the '\0' is not counted)
    ba.length();           // returns 5
    ba.data()[5];          // returns '\0'

The Qt3Support library contains a class called Q3CString that inherits from the new QByteArray class and that extends it to provide an API that is as close to the old QCString class as possible. Note that the following functions aren't provided by Q3CString:

The following functions have lost their last parameter, which specified whether the search was case sensitive or not:

In both cases, the solution is to convert the QCString to a QString and use the corresponding QString functions instead.

Also be aware that QCString::size() (inherited from QByteArray) used to return the size of the character data including the '\0'-terminator, whereas the new QByteArray::size() is just a synonym for QByteArray::length(). This brings QByteArray in line with QString.

When porting to Qt 4, occurrences of QCString should be replaced with QByteArray or QString. The following table summarizes the API differences between the Q3CString class and the Qt 4 QByteArray and QString classes:

Q3CString functionQt 4 equivalent
Q3CString::Q3CString(const char *, uint)See remark below
Q3CString::Q3CString(int)QByteArray::QByteArray(int, char)
Q3CString::leftJustify()QString::leftJustified()
Q3CString::length()QByteArray::length() or QByteArray::size() (equivalent)
Q3CString::lower()QByteArray::toLower()
Q3CString::rightJustify()QString::rightJustified()
Q3CString::setExpand()See remark below
Q3CString::simplifyWhiteSpace()QByteArray::simplified()
Q3CString::sprintf()QString::sprintf()
Q3CString::stripWhiteSpace()QByteArray::trimmed()
Q3CString::toDouble()QString::toDouble()
Q3CString::toFloat()QString::toFloat()
Q3CString::toInt()QString::toInt()
Q3CString::toLong()QString::toLong()
Q3CString::toShort()QString::toShort()
Q3CString::toUInt()QString::toUInt()
Q3CString::toULong()QString::toULong()
Q3CString::toUShort()QString::toUShort()
Q3CString::upper()QByteArray::toUpper()

Remarks:

  1. Q3CString(const char *str, uint max) constructs a string of length strlen(str) or max - 1, whichever is shorter. QByteArray(const char *data, int size) constructs a byte array containing exactly size bytes.

    For example, if you have code like

            QCString str1("Hello", 4);           // "Hel"
            QCString str2("Hello world!", n);

    you can rewrite it as

            QByteArray str1("Hello", 3);
            QByteArray str2("Hello world!");
            str2.truncate(n - 1);
  2. Q3CString::setExpand(uint index, char ch) has no equivalent in Qt 4.

    For example, if you have code like

            QCString str("Hello world");
            str.setExpand(16, '\n');            // "Hello world     \n"

    you can rewrite it as

            QByteArray str("Hello world");
            while (str.size() < 16)
                str += ' ';
            str += '\n';

Since the old QCString class inherited from QByteArray, everything that is said in the QByteArray section applies for QCString as well.

QDataBrowser

The QDataBrowser class has been renamed Q3DataBrowser and moved to the Qt3Support library. It is expected that Qt 4.1 will offer a replacement class. In the meantime, you can use Q3DataBrowser for creating data-aware forms or you can roll your own.

See QtSql Module for an overview of the new SQL classes.

QDataPump

The QDataPump class was used internally in Qt 2.x in conjunction with QImageConsumer. It was obsoleted in Qt 3.0.

    If you use this mechanism in your application, please submit a
    report to the \l{Task Tracker} on the Trolltech
    website and we will try to find a satisfactory substitute.

QDataSink

The QDataSink class was used internally in Qt 2.x in conjunction with QImageConsumer. It was obsoleted in Qt 3.0.

    If you use this mechanism in your application, please submit a
    report to the \l{Task Tracker} on the Trolltech
    website and we will try to find a satisfactory substitute.

QDataSource

The QDataSource class was used internally in Qt 2.x in conjunction with QImageConsumer. It was obsoleted in Qt 3.0.

    If you use this mechanism in your application, please submit a
    report to the \l{Task Tracker} on the Trolltech
    website and we will try to find a satisfactory substitute.

QDataTable

The QDataTable class has been renamed Q3DataTable and moved to the Qt3Support library. It is expected that Qt 4.1 will offer a replacement class. In the meantime, you can use Q3DataTable for creating data-aware forms or you can roll your own.

See QtSql Module for an overview of the new SQL classes.

QDataView

The QDataView class has been renamed Q3DataView and moved to the Qt3Support library. It is expected that Qt 4.1 will offer a replacement class. In the meantime, you can use Q3DataTable for creating data-aware forms or you can roll your own.

See QtSql Module for an overview of the new SQL classes.

QDateEdit

The QDateEdit class in Qt 4 is a convenience class based on QDateTimeEdit. The old class has been renamed Q3DateEdit and moved to the Qt3Support library.

See Virtual Functions for a list of QDateEdit virtual member functions in Qt 3 that are no longer virtual in Qt 4.

QDateTimeEditBase

The QDateTimeEditBase class has been renamed Q3DateTimeEditBase and moved to Qt3Support. Use QDateTimeEdit or QAbstractSpinBox instead.

QDateTimeEdit

The old QDateTimeEdit class has been renamed Q3DateTimeEditBase and moved to Qt3Support. The new QDateTimeEdit in Qt 4 has been rewritten from scratch to provide a more flexible and powerful API.

See Virtual Functions for a list of QDateTimeEdit virtual member functions in Qt 3 that are no longer virtual in Qt 4.

QDeepCopy<T>

The QDeepCopy<T> class in Qt 3 provided a means of ensuring that implicitly shared and explicitly shared classes referenced unique data. This was necessary because the reference counting in Qt's container classes was done in a thread-unsafe manner.

With Qt 4, QDeepCopy<T> has been renamed Q3DeepCopy<T> and moved to the Qt3Support library. Removing it from existing code is straightforward.

For example, if you have code like

    QString str1 = "I am a string";
    QDeepCopy<QString> str2 = str1;
    QString str3 = QDeepCopy<QString>(str2);

you can rewrite it as

    QString str1 = "I am a string";
    QString str2 = str1;
    QString str3 = str2;

QDial

See Virtual Functions for a list of QComboBox virtual member functions in Qt 3 that are no longer virtual in Qt 4.

See Properties for a list of QDial properties in Qt 3 that have changed in Qt 4.

QDict<T>

QDict<T> has been renamed Q3Dict<T> and moved to Qt3Support. It has been replaced by the more modern QHash<Key, T> and QMultiHash<Key, T> classes.

When porting old code that uses QDict<T> to Qt 4, there are four classes that you can use:

Qt 4 classWhen to use it
QMultiHash<QString, T *>Since Q3Dict<T> is pointer-based and allows duplicate keys, this is usually the most straightforward conversion.
QMultiHash<QString, T>If type T is an assignable data type, you can use T as the value type rather than T *. This often leads to nicer code.
QHash<QString, T *>If you don't use duplicate keys, you can use QHash instead of QMultiHash. QMultiHash inherits from QHash.
QHash<QString, T>

The APIs of Q3Dict<T> and QMultiHash<QString, T *> are quite similar. The main issue is that Q3Dict supports auto-delete whereas QMultiHash doesn't.

The following table summarizes the API differences between the two classes:

Q3Dict functionQMultiHash equivalent
Q3Dict::Q3Dict(int size, bool caseSensitive)See remarks below
Q3Dict::autoDelete()N/A
Q3Dict::count()QMultiHash::count() or QMultiHash::size() (equivalent)
Q3Dict::find(const QString &)QMultiHash::value(const QString &)
Q3Dict::remove(const QString &)QMultiHash::take(const QString &)
Q3Dict::resize(uint)QMultiHash::reserve(int)
Q3Dict::setAutoDelete()See discussion below
Q3Dict::size()QMultiHash::capacity()
Q3Dict::statistics()N/A
Q3Dict::operator[](const QString &)See remark below

Remarks:

  1. Q3Dict requires the user to allocate a specific number of buckets by passing a prime number (17 by default) to the constructor and/or calling Q3Dict::resize() later on. In contrast, QMultiHash's hash table automatically grows and shrinks as needed, and the constructor doesn't take a prime number.
  2. Q3Dict supportes case-insensitive lookups by passing false as second argument to the constructor. This feature has no equivalent in QMultiHash. Instead, call QString::toLower() before you insert or lookup a key in the hash.
  3. Q3Dict::size() and QMultiHash::size() have different semantics. The former returns the number of buckets in the container, whereas the latter returns the number of items in the container.
  4. If there are multiple items with the same key, Q3Dict::remove() removes only the most recently inserted item, whereas QMultiHash::remove() removes all items that share a particular key. To remove only the most recently inserted item, call QMultiHash::take().
  5. Q3Dict has only one [] operator (Q3Dict::operator[]()), providing const access to an item's value. QMultiHash also has a non-const overload that can be used on the left side of the assignment operator. If you use the [] operator on a non-const QHash with an unexisting item, QHash will created an element and initialize it to be a null pointer. For that reason, Q3Dict::operator[] should be converted to QMultiHash::value(), not QMultiHash::operator[].

If you use Q3Dict's auto-delete feature (by calling Q3Dict::setAutoDelete(true)), you need to do some more work. You have two options: Either you call delete yourself whenever you remove an item from the container, or you use QMultiHash<QString, T> instead of QMultiHash<QString, T *> (i.e. store values directly instead of pointers to values). Here, we'll see when to call delete.

The following table summarizes the idioms that you need to watch out for if you want to call delete yourself.

Q3Dict idiomQMultiHash idiom
    dict.replace(key, value);
    delete hash.take(key);
    hash.insert(key, value);
    dict.remove(key, value);
    delete hash.take(key);
    dict.clear();

(also called from Q3Dict's destructor)

    while (!hash.isEmpty()) {
        T *value = *hash.begin();
        dict.erase(hash.begin());
        delete value;
    }

In 99% of cases, the following idiom also works:

    qDeleteAll(hash);
    hash.clear();

However, it may lead to crashes if hash is referenced from the value type's destructor, because hash contains dangling pointers until clear() is called.

Be aware that Q3Dict's destructor automatically calls clear(). If you have a Q3Dict data member in a custom class and use the auto-delete feature, you will need to call delete on all the items in the container from your class destructor to avoid a memory leak.

Finally, QDictIterator<T> (renamed Q3DictIterator<T>) must also be ported. There are no fewer than four iterator classes that can be used as a replacement: QHash::const_iterator, QHash::iterator, QHashIterator, and QMutableHashIterator. The most straightforward class to use when porting is QHashIterator<QString, T *>. The following table summarizes the API differences:

Q3DictIterator functionsQt 4 equivalent
Q3DictIterator::count()QHash::count() or QHash::size()
Q3DictIterator::current()QHashIterator::value()
Q3DictIterator::currentKey()QHashIterator::key()
Q3DictIterator::isEmpty()QHash::isEmpty()
Q3DictIterator::toFirst()QHashIterator::toFront()
Q3DictIterator::operator()()QHashIterator::value()
Q3DictIterator::operator*()QHashIterator::value()
Q3DictIterator::operator++()See remark below

Be aware that QHashIterator has a different way of iterating than Q3DictIterator. A typical loop with Q3DictIterator looks like this:

    Q3DictIterator<QWidget> i(dict);
    while (i.current() != 0) {
        do_something(i.currentKey(), i.current());
        ++i;
    }

Here's the equivalent QHashIterator loop:

    QHashIterator<QString, QWidget *> i(hash);
    while (i.hasNext()) {
        i.next();                   // must come first
        do_something(i.key(), i.value());
    }

See Java-style iterators for details.

QDir

The following functions used to have a boolean acceptAbsPath parameter that defaulted to true:

In Qt 3, if acceptAbsPath is true, a file name starting with '/' is be returned without change; if acceptAbsPath is false, an absolute path is prepended to the file name. For example:

Current directoryFile nameacceptAbsPathFile path
/home/tsmithindex.htmltrue/home/tsmith/index.html
false/home/tsmith/index.html
/home/tsmith/index.htmltrue/index.html
false/home/tsmith/index.html

In Qt 4, this parameter is no longer available. If you use it in your code, you can check that QDir::isRelativePath() returns false instead.

For example, if you have code like

    QDir dir("/home/tsmith");
    QString path = dir.filePath(fileName, false);

you can rewrite it as

    QDir dir("/home/tsmith");
    QString path;
    if (dir.isRelativePath(fileName))
        path = dir.filePath(fileName);
    else
        path = fileName;

QDir::encodedEntryList() has been removed.

fileInfoList(), entryInfoList(), and drives() now return a QList<QFileInfo> and not a QPtrList<QFileInfo> *. Code using these methods will not work with the Qt3Support library and must be adapted instead.

See Virtual Functions for a list of QDir virtual member functions in Qt 3 that are no longer virtual in Qt 4.

QDir::match() now always matches case insensitively.

QDir::homeDirPath() has been removed. Use QDir::home() instead, and extract the path separately.

QDns

Qt 3 used its own implementation of the DNS protocol and provided a low-level QDns class. Qt 4's QHostInfo class uses the system's gethostbyname() function from a thread instead.

The old QDns class has been renamed Q3Dns and moved to the Qt3Support library. The new QHostInfo class has a radically different API: It consists mainly of two static functions, one of which is blocking (QHostInfo::fromName()), the other non-blocking (QHostInfo::lookupHost()). See the QHostInfo class documentation for details.

QDockArea

The QDockArea class has been renamed Q3DockArea and moved to the Qt3Support library. In Qt 4, QMainWindow handles the dock and toolbar areas itself. See the QMainWindow documentation for details.

QDockWindow

The old QDockWindow class has been renamed Q3DockWindow and moved to the Qt3Support library. In Qt 4, there is a new QDockWidget class with a different API. See the class documentation for details.

See Virtual Functions for a list of QDockWidget virtual member functions in Qt 3 that are no longer virtual in Qt 4.

QDragObject

The QDragObject class has been renamed Q3DragObject and moved to the Qt3Support library. In Qt 4, it has been replaced by the QMimeData class. See the class documentation for details.

QDropSite

The QDropSite class has been renamed Q3DropSite and moved to the Qt3Support library.

The QDropSite class has been obsolete ever since Qt 2.0. The only thing it does is call QWidget::setAcceptDrops(true).

For example, if you have code like

    class MyWidget : public QWidget, public QDropSite
    {
    public:
        MyWidget(const QWidget *parent)
            : QWidget(parent), QDropSite(this)
        {
        }
        ...
    }

you can rewrite it as

    class MyWidget : public QWidget
    {
    public:
        MyWidget(const QWidget *parent)
            : QWidget(parent)
        {
            setAcceptDrops(true);
        }
        ...
    }

QEditorFactory

The QEditorFactory class has been renamed Q3EditorFactory and moved to the Qt3Support library.

See QtSql Module for an overview of the new SQL classes.

QEventLoop

In Qt 3, QEventLoop combined the Qt event loop and the event dispatching. In Qt 4, these tasks are now assigned to two distinct classes: QEventLoop and QAbstractEventDispatcher.

If you subclassed QEventLoop to integrate with another library's event loop, you must subclass QAbstractEventDispatcher instead. See the class documentation for details.

QFileDialog

The QFileDialog class in Qt 4 has been totally rewritten. It provides most of the functionality of the old QFileDialog class, but with a different API. Some functionality, such as the ability to preview files, is expected to be added in a later Qt 4 release.

The old QFileDialog, QFileIconProvider, and QFilePreview classes has been renamed Q3FileDialog, Q3FileIconProvider, and Q3FilePreview and have been moved to Qt3Support. You can use them if you need some functionality not provided yet by the new QFileDialog class.

The following table lists which functions have been renamed or removed in Qt 4.

Old functionQt 4 equivalent
Q3FileDialog::addFilter(const QString &)See remark below
Q3FileDialog::addLeftWidget(QWidget *)N/A
Q3FileDialog::addRightWidget(QWidget *)N/A
Q3FileDialog::addToolButton(QAbstractButton *, bool separator)N/A
Q3FileDialog::addWidgets(QLabel *, QWidget *, QPushButton *)N/A
Q3FileDialog::dir()QFileDialog::directory()
Q3FileDialog::dirPath()QFileDialog::directory().path()
Q3FileDialog::iconProvider()N/A
Q3FileDialog::isContentsPreviewEnabled()N/A
Q3FileDialog::isInfoPreviewEnabled()N/A
Q3FileDialog::previewMode()N/A
Q3FileDialog::rereadDir()N/A
Q3FileDialog::resortDir()N/A
Q3FileDialog::selectAll(bool)N/A
Q3FileDialog::setContentsPreview(QWidget *, Q3FilePreview *)N/A
Q3FileDialog::setContentsPreviewEnabled(bool)N/A
Q3FileDialog::setDir(const QString &)QFileDialog::setDirectory(const QString &)
Q3FileDialog::setFilters(const char **)Q3FileDialog::setFilters(const QStringList &)
Q3FileDialog::setIconProvider(Q3FileIconProvider *)N/A
Q3FileDialog::setInfoPreview(QWidget *, Q3FilePreview *)N/A
Q3FileDialog::setInfoPreviewEnabled(bool)N/A
Q3FileDialog::setPreviewMode(PreviewMode)N/A
Q3FileDialog::setSelectedFilter(const QString &)QFileDialog::selectFilter(const QString &)
Q3FileDialog::setSelectedFilter(int)See remark below
Q3FileDialog::setSelection(const QString &)QFileDialog::selectFile(const QString &)
Q3FileDialog::setShowHiddenFiles(bool)showHidden()
Q3FileDialog::setUrl(const QUrlOperator &)N/A
Q3FileDialog::showHiddenFiles()N/A
Q3FileDialog::url()QUrl::fromLocalFile(QFileDialog::directory())
Old signalsQt 4 equivalent
Q3FileDialog::fileHighlighted(const QString &)N/A
Q3FileDialog::fileSelected(const QString &)QFileDialog::filesSelected(const QStringList &)
Q3FileDialog::dirEntered(const QString &)N/A
Q3FileDialog::filterSelected(const QString &)N/A

Remarks:

  1. The Q3FileDialog::addFilter(const QString &) function has no direct equivalent in the new QFileDialog. Use QFileDialog::setFilters() instead.

    For example, if you have code like

            fileDialog->addFilter(tr("JPEG files (*.jpg *.jpeg)"));

    you can rewrite it as

            QStringList filters = fileDialog->filters();
            filters << tr("JPEG files (*.jpg *.jpeg)");
            fileDialog->setFilters(filters);
  2. The Q3FileDialog::setSelectedFilter(int) overload has no direct equivalent in the new QFileDialog. Use QFileDialog::selectFilter(const QString &) instead.

    For example, if you have code like

            fileDialog->setSelectedFilter(3);

    you can rewrite it as

            fileDialog->selectFilter(fileDialog->filters().at(3));

See Virtual Functions for a list of QFileDialog virtual member functions in Qt 3 that are no longer virtual in Qt 4.

QFocusData

The QFocusData class is not available in Qt 4. Some of its functionality is available via the QWidget::nextInFocusChain() and QWidget::focusNextPrevChild() functions.

QFrame

The QFrame class has been made more lightweight in Qt 4, by reducing the number of properties and virtual functions. The reduction in the number of virtual functions is significant because QFrame is the base class of many Qt classes.

Here's an overview of the changes:

To help with porting, the Qt3Support library contains a Q3Frame class that inherits QFrame and provides a similar API to the old QFrame class. If you derived from QFrame in your application, you might want to use Q3Frame as a base class as a first step in the porting process, and later move on to the new QFrame class.

See Virtual Functions for a list of QFrame virtual member functions in Qt 3 that are no longer virtual in Qt 4.

QFtp

QFtp no longer inherits from QNetworkProtocol. See the section on QNetworkProtocol for details.

The old QFtp class has been renamed Q3Ftp and moved to the Qt3Support library.

QGLayoutIterator

The QGLayoutIterator class no longer exists in Qt 4. This makes only a difference if you implemented custom layout managers (i.e., QLayout subclasses).

The new approach is much simpler: It consists in reimplementing QLayout::itemAt() and QLayout::takeAt(). These functions operate on indexes, eliminating the need for a layout iterator class.

QGrid

The QGrid class is now only available as Q3Grid in Qt 4. You can achieve the same result as QGrid by creating a QWidget with a grid layout:

For example, if you have code like

    QGrid *grid = new QGrid(2, Qt::Horizontal);
    QPushButton *child1 = new QPushButton(grid);
    QPushButton *child2 = new QPushButton(grid);
    QPushButton *child3 = new QPushButton(grid);
    QPushButton *child4 = new QPushButton(grid);

you can rewrite it as

    QWidget *grid = new QWidget;
    QPushButton *child1 = new QPushButton(grid);
    QPushButton *child2 = new QPushButton(grid);
    QPushButton *child3 = new QPushButton(grid);
    QPushButton *child4 = new QPushButton(grid);

    QVBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(child1, 0, 0);
    layout->addWidget(child2, 0, 1);
    layout->addWidget(child3, 1, 0);
    layout->addWidget(child4, 1, 1);
    grid->setLayout(layout);

QGridLayout

See Virtual Functions for a list of QGridLayout virtual member functions in Qt 3 that are no longer virtual in Qt 4.

QGridView

The QGridView class has been renamed Q3GridView and moved to the Qt3Support library. In Qt 4, we recommend that you use QTableView or QAbstractItemView for presenting tabular data.

See Model/View Programming for an overview of the new item view classes.

QGroupBox

The QGroupBox class has been redesigned in Qt 4. The old QGroupBox class has been renamed Q3GroupBox and moved to the Qt3Support library.

The new QGroupBox is more lightweight. It doesn't attempt to duplicate functionality already provided by QGridLayout. For that reason, the following members have been removed:

Naturally, the columns and orientation properties have also been removed.

If you rely on some of the missing functionality in your application, you can use Q3GroupBox instead of QGroupBox as a help to porting.

See Virtual Functions for a list of QGroupBox virtual member functions in Qt 3 that are no longer virtual in Qt 4.

QHBox

The QHBox class is now only available as Q3HBox in Qt 4. You can achieve the same result as QHBox by creating a QWidget with an horizontal layout:

For example, if you have code like

    QHBox *hbox = new QHBox;
    QPushButton *child1 = new QPushButton(hbox);
    QPushButton *child2 = new QPushButton(hbox);

you can rewrite it as

    QWidget *hbox = new QWidget;
    QPushButton *child1 = new QPushButton;
    QPushButton *child2 = new QPushButton;

    QHBoxLayout *layout = new QHBoxLayout;
    layout->addWidget(child1);
    layout->addWidget(child2);
    hbox->setLayout(layout);

QHeader

The QHeader class has been renamed Q3Header and moved to the Qt3Support library. In Qt 4, it is replaced by the QHeaderView class.

See Model/View Programming for an overview of the new item view classes.

QHttp

QHttp no longer inherits from QNetworkProtocol. See the See the section on QNetworkProtocol for details.

The old QHttp, QHttpHeader, QHttpRequestHeader, and QHttpResponseHeader classes have been renamed Q3Http, Q3HttpHeader, Q3HttpRequestHeader, and Q3HttpResponseHeader and have been moved to the Qt3Support library.

QIconFactory

The QIconFactory is no longer part of Qt. It has been replaced by the QIconEngine class.

QIconView

The QIconView, QIconViewItem, QIconDrag, and QIconDragItem classes has been renamed Q3IconView, Q3IconViewItem, Q3IconDrag, and Q3IconDragItem and moved to the Qt3Support library. New Qt applications should use QListWidget or its base class QListView instead, and call QListView::setViewMode(QListView::IconMode) to obtain an "icon view" look.

See Model/View Programming for an overview of the new item view classes.

QImageDrag

The QImageDrag class has been renamed Q3ImageDrag and moved to the Qt3Support library. In Qt 4, use QMimeData instead and call QMimeData::setImage() to set the image.

QImageIO

The QImageIO class has been split into two classes: QImageReader and QImageWriter. The table below shows the correspondance between the two APIs:

Qt 3 functionQt 4 equivalents
QImageIO::description()QImageWriter::description()
QImageIO::fileName()QImageReader::fileName() and QImageWriter::fileName()
QImageIO::format()QImageReader::format() and QImageWriter::format()
QImageIO::gamma()QImageWriter::gamma()
QImageIO::image()Return value of QImageReader::read()
QImageIO::ioDevice()QImageReader::device() and QImageWriter::device()
QImageIO::parameters()N/A
QImageIO::quality()QImageWriter::quality()
QImageIO::read()QImageReader::read()
QImageIO::setDescription()QImageWriter::setDescription()
QImageIO::setFileName()QImageReader::setFileName() and QImageWriter::setFileName()
QImageIO::setFormat()QImageReader::setFormat() and QImageWriter::setFormat()
QImageIO::setGamma()QImageWriter::setGamma()
QImageIO::setIODevice()QImageReader::setDevice() and QImageWriter::setDevice()
QImageIO::setImage()Argument to QImageWriter::write()
QImageIO::setParameters()N/A
QImageIO::setQuality()QImageWriter::setQuality()
QImageIO::setStatus()N/A
QImageIO::status()QImageReader::error() and QImageWriter::error()
QImageIO::write()QImageWriter::write()

QIntCache<T>

QIntCache<T> has been moved to Qt3Support. It has been replaced by QCache<int, T>.

For details, read the section on QCache<T>, mentally substituting int for QString.

QIntDict<T>

QIntDict<T> and QIntDictIterator<T> have been moved to Qt3Support. They have been replaced by the more modern QHash<Key, T> and QMultiHash<Key, T> classes and their associated iterator classes.

When porting old code that uses QIntDict<T> to Qt 4, there are four classes that you can use:

For details, read the section on QDict<T>, mentally substituting int for QString.

QIODevice

The QIODevice class's API has been simplified to make it easier to subclass and to make it work more smoothly with asynchronous devices such as QTcpSocket and QProcess.

The following virtual functions have changed name or signature:

Qt 3 functionComment
QIODevice::at() constRenamed QIODevice::pos().
QIODevice::at(Offset)Renamed QIODevice::seek().
QIODevice::open(int)The parameter is now of type QIODevice::OpenMode.
QIODevice::readBlock(char *, Q_ULONG)QIODevice::read(char *, qint64)
QIODevice::writeBlock(const char *, Q_ULONG)QIODevice::write(const char *, qint64)

The following functions are no longer virtual or don't exist anymore:

QIODevice::getch()Renamed QIODevice::getChar() and implemented in terms of QIODevice::readData().
QIODevice::putch(int)Renamed QIODevice::putChar() and implemented in terms of QIODevice::writeData().
QIODevice::readAll()Implemented in terms of QIODevice::readData().
QIODevice::readLine(char *, Q_ULONG)Implemented in terms of QIODevice::readData()
QIODevice::ungetch(int)Renamed QIODevice::ungetChar() and simulated using an internal unget buffer.

The IO_xxx flags have been revised. Most of them have been elimiated, because errors are best handled by the actual QIODevice subclasses than through the base classes. The file access flags, such as IO_ReadOnly and IO_WriteOnly, have been moved to the QIODevice class to avoid polluting the global namespace. The table below shows the correspondence between the Qt 3 IO_xxx flags and the Qt 4 API:

Qt 3 constantQt 4 equivalent
IO_DirectUse !QIODevice::isSequential() instead (notice the not).
IO_SequentialUse QIODevice::isSequential() instead.
IO_CombinedN/A
IO_TypeMaskN/A
IO_RawN/A
IO_AsyncN/A
IO_ReadOnlyQIODevice::ReadOnly
IO_WriteOnlyQIODevice::WriteOnly
IO_ReadWriteQIODevice::ReadWrite
IO_AppendQIODevice::Append
IO_TruncateQIODevice::Truncate
IO_TranslateQIODevice::Text
IO_ModeMaskN/A
IO_OpenUse QIODevice::isOpen() instead.
IO_StateMaskN/A
IO_OkN/A
IO_ReadErrorN/A
IO_WriteErrorN/A
IO_FatalErrorN/A
IO_ResourceErrorN/A
IO_OpenErrorN/A
IO_ConnectErrorN/A
IO_AbortErrorN/A
IO_TimeOutErrorN/A
IO_UnspecifiedErrorN/A

QIODeviceSource

The QIODeviceSource class was used internally in Qt 2.x in conjunction with QImageConsumer. It was obsoleted in Qt 3.0.

    If you use this mechanism in your application, please submit a
    report to the \l{Task Tracker} on the Trolltech
    website and we will try to find a satisfactory substitute.

QLabel

QLabel doesn't enable word-wrap automatically anymore when rich text is used. You can enable it by calling QLabel::setWordWrap() or by setting the wordWrap property. The reason for this change is that the old behavior was confusing to many users.

Also, QLabel no longer offers an autoResize property. Instead, you can call QWidget::setFixedSize() on the label, with QLabel::sizeHint() as the argument, whenever you change the contents of the QLabel.

See also Virtual Functions for a list of QLabel virtual member functions in Qt 3 that are no longer virtual in Qt 4.

QLayout

QLayout setSupportsMargin()

The deleteAllItems() function is now only available if QT3_SUPPORT is defined. If you maintain a QList of layout items, you can use qDeleteAll() to remove all the items in one go.

See also the section on QLayoutIterator and the section on QGLayoutIterator.

QLayoutIterator

The QLayoutIterator class is obsoleted in Qt 4. It is available only if QT3_SUPPORT is defined. It can be replaced by the QLayout::itemAt() and QLayout::takeAt() functions, which operate on indexes.

For example, if you have code like

        QLayoutIterator it = layout()->iterator();
        QLayoutItem *child;
        while ((child = it.current()) != 0) {
            if (child->widget() == myWidget) {
                it.takeCurrent();
                return;
            ++it;
        }

you can rewrite it as

        int i = 0;
        QLayoutItem *child;
        while ((child = layout()->itemAt(i)) != 0) {
            if (child->widget() == myWidget) {
                layout()->takeAt(i);
                return;
            }
            ++i;
        }

QLineEdit

See Properties for a list of QLineEdit properties in Qt 3 that have changed in Qt 4.

QListBox

The QListBox, QListBoxItem, QListBoxText, and QListBoxPixmap classes have been renamed Q3ListBox, Q3ListBoxItem, Q3ListBoxText, and Q3ListBoxPixmap and have been moved to the Qt3Support library. New Qt applications should use QListWidget or its base class QListView instead.

See Model/View Programming for an overview of the new item view classes.

QListView

The QListView, QListViewItem, QCheckListItem, and QListViewItemIterator classes have been renamed Q3ListView, Q3ListViewItem, Q3CheckListItem, and Q3ListViewItemIterator, and have been moved to the Qt3Support library. New Qt applications should use one of the following four classes instead: QTreeView or QTreeWidget for tree-like structures; QListWidget or the new QListView class for one-dimensional lists.

See Model/View Programming for an overview of the new item view classes.

QLocalFs

The QLocalFs class is no longer part of the public Qt API. It has been renamed Q3LocalFs and moved to Qt3Support. Use QDir, QFileInfo, or QFile instead.

QMainWindow

The QMainWindow class has been redesigned in Qt 4 to provide a more modern look and feel and more flexibility. The API has changed to reflect that. The old QMainWindow class has been renamed Q3MainWindow and moved to Qt3Support. See the QMainWindow class documentation for details.

QMemArray<T>

QMemArray<T> has been moved to Qt3Support. It has been replaced by the QVector<T> class.

The following table summarizes the API differences between the two classes.

QMemArray::assign(const QMemArray<T> &)QVector::operator=()
QMemArray::assign(const T *, uint)See remark below
QMemArray::duplicate(const QMemArray &)QVector::operator=()
QMemArray::duplicate(const T *, uint)See remark below
QMemArray::setRawData(const T *, uint)N/A
QMemArray::resetRawData(const T *, uint)N/A
QMemArray::find(const T &, uint)QVector::indexOf(const T &, int)
QMemArray::contains(const T &)QVector::count(const T &)
QMemArray::sort()qSort()
QMemArray::bsearch(const T &d)qBinaryFind()
QMemArray::at(uint)QVector::operator[]()
QMemArray::operator const T *()QVector::constData()

Remarks:

  1. QMemArray::assign(const T *, uint) and QMemArray::duplicate(const T *, uint) can be replaced by QVector::resize() and qCopy().

    For example, if you have code like

            QMemArray<QSize> array;
            ...
            array.assign(data, size);

    you can rewrite it as

            QVector<QSize> vector;
            ...
            vector.resize(size);
            qCopy(data, data + size, vector.begin());
  2. QMemArray is an explicitly shared class, whereas QVector is implicitly shared. See Explicit Sharing for more information.

QMessageBox

The QMessageBox::iconPixmap() function used to return a "const QPixmap *". In Qt 4, it returns a QPixmap.

QMimeSourceFactory

The QMimeSourceFactory has been renamed Q3MimeSourceFactory and moved to the Qt3Support library. New Qt applications should use Qt 4's Resource System instead.

QMovie

The QMovie API has been revised in Qt 4 to make it more consistent with the other Qt classes (notably QImageReader). The table below summarizes the changes.

Qt 3 functionQt 4 equivalent
QMovie::connectResize()Connect to QMovie::resized()
QMovie::connectStatus()Connect to QMovie::stateChanged()
QMovie::connectUpdate()Connect to QMovie::updated()
QMovie::disconnectResize()Disconnect from QMovie::resized()
QMovie::disconnectStatus()Disconnect from QMovie::stateChanged()
QMovie::disconnectUpdate()Disconnect from QMovie::updated()
QMovie::finished()Use QMovie::state() instead
QMovie::frameImage()Use QMovie::currentImage() instead
QMovie::frameNumber()Use QMovie::currentFrameNumber() instead
QMovie::framePixmap()Use QMovie::currentPixmap() instead
QMovie::getValidRect()Use frameRect() instead
QMovie::isNull()Use QMovie::isValid() instead
QMovie::pause()Use QMovie::setPaused(true) instead
QMovie::paused()Use QMovie::state() instead
QMovie::pushData()N/A
QMovie::pushSpace()N/A
QMovie::restart()Use QMovie::jumpToFrame(0) instead
QMovie::running()Use QMovie::state() instead
QMovie::step()Use QMovie::jumpToFrame() and QMovie::setPaused() instead
QMovie::step()Use QMovie::jumpToNextFrame() instead
QMovie::steps()Use QMovie::currentFrameNumber() and QMovie::frameCount() instead
QMovie::unpause()Use QMovie::setPaused(false) instead

QMultiLineEdit

The QMultiLineEdit class in Qt 3 was a convenience QTextEdit subclass that provided an interface compatible with Qt 2's QMultiLineEdit class. In Qt 4, it is called Q3MultiLineEdit, it inherits Q3TextEdit, and it is part of Qt3Support. Use QTextEdit in new code.

QNetworkProtocol

The QNetworkProtocol, QNetworkProtocolFactoryBase, QNetworkProtocolFactory<T>, and QNetworkOperation classes are no longer part of the public Qt API. They have been renamed Q3NetworkProtocol, Q3NetworkProtocolFactoryBase, Q3NetworkProtocolFactory<T>, and Q3NetworkOperation and have been moved to the Qt3Support library.

In Qt 4 applications, you can use classes like QFtp and QHttp directly to perform file-related actions on a remote host.

QObject

QObject::children() now returns a QObjectList instead of a pointer to a QObjectList. See also the comments on QObjectList below.

QObject::killTimers() has been removed because it was unsafe to use in subclass. (A subclass normally doesn't know whether the base class uses timers or not.)

The QObject::name property has been renamed QObject::objectName.

QObject::objectTrees() has been removed because maintaining a global tree of all objects in a multithreaded application was judged too expensive. If you are primarly interested in widgets, use QApplication::allWidgets() or QApplication::topLevelWidgets().

QObjectDictionary

The QObjectDictionary class is a synonym for QAsciiDict<QMetaObject>. See the section on QAsciiDict<T>.

QObjectList

In Qt 3, the QObjectList class was a typedef for QPtrList<QObject>. In Qt 4, it is a typedef for QList<QObject *>. See the section on QPtrList<T>.

QPaintDevice

To reimplement painter backends one previously needed to reimplement the virtual function QPaintDevice::cmd(). This function is taken out and should is replaced with the function QPaintDevice::paintEngine() and the abstract class QPaintEngine. QPaintEngine provides virtual functions for all drawing operations that can be performed on a painter backend.

bitBlt() and copyBlt() are now only compatibility functions. Use QPainter::drawPixmap() instead.

QPaintDeviceMetrics

All functions that used to be provided by the QPaintDeviceMetrics class have now been moved to QPaintDevice.

For example, if you have code like

        QPaintDeviceMetrics metrics(widget);
        int deviceDepth = metrics.depth();

you can rewrite it as

        int deviceDepth = widget->depth();

For compatibility, the old QPaintDeviceMetrics class has been renamed Q3PaintDeviceMetrics and moved to Qt3Support.

QPainter

The QPainter class has undergone some changes in Qt 4 because of the way rectangles are drawn. In Qt 4, the result of drawing a QRect with a pen width of 1 pixel is 1 pixel wider and 1 pixel taller than in Qt 3.

For compatibility, we provide a Q3Painter class in Qt3Support that provides the old semantics. See the Q3Painter documentation for details and for the reasons why we had to make this change.

QPointArray

The QPointArray class has been renamed QPolygon in Qt 4 and has undergone significant changes. In Qt 3, QPointArray inherited from QMemArray<QPoint>. In Qt 4, QPolygon inherits from QVector<QPoint>. Everything mentioned in the section on QMemArray<T> apply for QPointArray as well.

The Qt3Support library contains a Q3PointArray class that inherits from QPolygon and provides a few functions that existed in QPointArray but no longer exist in QPolygon. These functions include Q3PointArray::makeArc(), Q3PointArray::makeEllipse(), and Q3PointArray::cubicBezier(). In Qt 4, we recommend that you use QPainterPath for representing arcs, ellipses, and Bezier curves, rather than QPolygon.

The QPolygon::setPoints() and QPolygon::putPoints() functions return void in Qt 4. The corresponding Qt 3 functions returned a bool indicating whether the array was successfully resized or not. This can now be checked by checking QPolygon::size() after the call.

QPopupMenu

For most purposes, QPopupMenu has been replaced by QMenu in Qt 4. For compatibility with older applications, Q3PopupMenu provides the old API and features that are specific to popup menus.

QPrinter

The QPrinter class now expects printing to be set up from a QPrintDialog.

The margins() and setMargins() functions are only available as compatibility functions.

QProcess

The QProcess class has undergone major improvements in Qt 4. It now inherits QIODevice, which makes it possible to combine QProcess with a QTextStream or a QDataStream.

The old QProcess class has been renamed Q3Process and moved to the Qt3Support library.

QProgressBar

The QProgressBar API has been significantly improved in Qt 4. The old QProgressBar API is available as Q3ProgressBar in the Qt3Support library.

QProgressDialog

The QProgressDialog API has been significantly improved in Qt 4. The old QProgressDialog API is available as Q3ProgressDialog in the Qt3Support library.

See Properties for a list of QProgressDialog properties in Qt 3 that have changed in Qt 4.

QPtrCollection<T>

The QPtrCollection<T> abstract base class has been renamed Q3PtrCollection<T> moved to the Qt3Support library. There is no direct equivalent in Qt 4.

See Generic Containers for a list of Qt 4 containers.

QPtrDict<T>

QPtrDict<T> and QPtrDictIterator<T> have been renamed Q3PtrDict<T> and Q3PtrDictIterator<T> and have been moved to the Qt3Support library. They have been replaced by the more modern QHash<Key, T> and QMultiHash<Key, T> classes and their associated iterator classes.

When porting old code that uses Q3PtrDict<T> to Qt 4, there are four classes that you can use:

(You can naturally use other types than void * for the key type, e.g. QWidget *.)

To port Q3PtrDict<T> to Qt 4, read the section on QDict<T>, mentally substituting void * for QString.

QPtrList<T>

QPtrList<T>, QPtrListIterator<T>, and QPtrListStdIterator<T> have been moved to the Qt3Support library. They have been replaced by the more modern QList and QLinkedList classes and their associated iterator classes.

When porting to Qt 4, you have the choice of using QList<T> or QLinkedList<T> as alternatives to QValueList<T>. QList<T> has an index-based API and provides very fast random access (QList::operator[]), whereas QLinkedList<T> has an iterator-based API.

The following table summarizes the API differences between QPtrList<T> and QList<T *>:

QPtrList functionQList equivalent
QPtrList::contains(const T *)QList::count(T *)
QPtrList::containsRef(const T *)QList::count(T *)
QPtrList::find(const T *)See remark below
QPtrList::findRef(const T *)See remark below
QPtrList::getFirst()QList::first()
QPtrList::getLast()QList::last()
QPtrList::inSort(const T *)N/A
QPtrList::remove(const T *)QList::removeAll(T *)
QPtrList::remove(uint)QList::removeAt(int)
QPtrList::removeNode(QLNode *)N/A
QPtrList::removeRef(const T *)QList::removeAll(T *)
QPtrList::sort()See remark below
QPtrList::takeNode(QLNode *)N/A
QPtrList::toVector(QGVector *)See remark below

Remarks:

  1. QPtrList::toVector(QGVector *) can be replaced by QVector::resize() and qCopy().

    For example, if you have code like

            QPtrList<QWidget> list;
            ...
            QPtrVector<QWidget> vector;
            list.toVector(&vector);

    you can rewrite it as

            QList<QWidget *> list;
            ...
            QVector<QWidget *> vector;
            vector.resize(list.size());
            qCopy(list.begin(), list.end(), vector.begin());
  2. QPtrList::sort() relied on the virtual comparedItems() to sort items. In Qt 4, you can use qSort() instead and pass your "compare item" function as an argument.
  3. QPtrList::find(const T *) returns an iterator, whereas QList::indexOf(T *) returns an index. To convert an index into an iterator, add the index to QList::begin().
  4. QPtrList::removeFirst() and QPtrList::removeLast() return a bool that indicates whether the element was removed or not. The corresponding QList functions return void. You can achieve the same result by calling QList::isEmpty() before attempting to remove an item.

If you use QPtrList's auto-delete feature (by calling QPtrList::setAutoDelete(true)), you need to do some more work. You have two options: Either you call delete yourself whenever you remove an item from the container, or you can use QList<T> instead of QList<T *> (i.e. store values directly instead of pointers to values). Here, we'll see when to call delete.

The following table summarizes the idioms that you need to watch out for if you want to call delete yourself.

QPtrList idiomQList idiom
        list.replace(index, value);
        delete list[index];
        list[index] = value;
        list.removeFirst();
        delete list.takeFirst();
        list.removeLast();
        delete list.takeLast();
        list.remove(index);
        delete list.take(index);
        list.remove(value);
        int i = list.indexOf(value);
        if (i != -1)
            delete list.takeAt(i);
        list.remove();

(removes the current item)

        QMutableListIterator<T *> i;
        ...
        delete i.value();
        i.remove();
        list.clear();

(also called from QPtrList's destructor)

        while (!list.isEmpty())
            delete list.takeFirst();

In 99% of cases, the following idiom also works:

        qDeleteAll(list);
        list.clear();

However, it may lead to crashes if list is referenced from the value type's destructor, because list contains dangling pointers until clear() is called.

Be aware that QPtrList's destructor automatically calls clear(). If you have a QPtrList data member in a custom class and use the auto-delete feature, you will need to call delete on all the items in the container from your class destructor to avoid a memory leak.

QPtrList had the concept of a "current item", which could be used for traversing the list without using an iterator. When porting to Qt 4, you can use the Java-style QListIterator<T *> (or QMutableListIterator<T *>) class instead. The following table summarizes the API differences:

QPtrList functionQListIterator equivalent
QPtrList::at()N/A
QPtrList::current()QListIterator::value()
QPtrList::currentNode()N/A
QPtrList::findNext(const T *)QListIterator::findNext(const T *)
QPtrList::findNextRef(const T *)QListIterator::findNext(const T *)
QPtrList::first()QPtrList::toFront()
QPtrList::last()QPtrList::toBack()
QPtrList::next()QPtrList::next()
QPtrList::prev()QPtrList::previous()
QPtrList::remove()QMutableListIterator::remove()
QPtrList::take()QMutableListIterator::remove()

Be aware that QListIterator has a different way of iterating than QPtrList. A typical loop with QPtrList looks like this:

        QPtrList<QWidget> list;
        ...
        while (list.current() != 0) {
            do_something(list.current());
            list.next();
        }

Here's the equivalent QListIterator loop:

        QList<QWidget *> list;
        ...
        QListIterator<QWidget *> i(list);
        while (i.hasNext())
            do_something(i.next());

Finally, QPtrListIterator<T> must also be ported. There are no fewer than four iterator classes that can be used as a replacement: QList::const_iterator, QList::iterator, QListIterator, and QMutableListIterator. The most straightforward class to use when porting is QMutableListIterator<T *> (if you modify the list through the iterator) or QListIterator<T *> (if you don't). The following table summarizes the API differences:

QPtrListIterator functionQt 4 equivalent
QPtrListIterator::atFirst()!QListIterator::hasPrevious() (notice the !)
QPtrListIterator::atLast()!QListIterator::hasNext() (notice the !)
QPtrListIterator::count()QList::count() or QList::size()
QPtrListIterator::current()QListIterator::value()
QPtrListIterator::isEmpty()QList::isEmpty()
QPtrListIterator::toFirst()QListIterator::toFront()
QPtrListIterator::toLast()QListIterator::toBack()
QPtrListIterator::operator()QListIterator::value()
QPtrListIterator::operator*()QListIterator::value()

Again, be aware that QListIterator has a different way of iterating than QPtrList. A typical loop with QPtrList looks like this:

        QPtrList<QWidget> list;
        ...
        QPtrListIterator<QWidget> i;
        while (i.current() != 0) {
            do_something(i.current());
            i.next();
        }

Here's the equivalent QListIterator loop:

        QList<QWidget *> list;
        ...
        QListIterator<QWidget *> i(list);
        while (i.hasNext())
            do_something(i.next());

Finally, QPtrListStdIterator<T> must also be ported. This is easy, because QList also provides STL-style iterators (QList::iterator and QList::const_iterator).

QPtrQueue<T>

QPtrQueue has been moved to the Qt3Support library. It has been replaced by the more modern QQueue class.

The following table summarizes the differences between QPtrQueue<T> and QQueue<T *>:

QPtrQueue functionQQueue equivalent
QPtrQueue::autoDelete()See discussion below
QPtrQueue::count()QQueue::count() or QQueue::size() (equivalent)
QPtrQueue::current()QQueue::head()
QPtrQueue::remove()QQueue::dequeue()
QPtrQueue::setAutoDelete()See discussion below

If you use QPtrQueue's auto-delete feature (by calling QPtrQueue::setAutoDelete(true)), you need to do some more work. You have two options: Either you call delete yourself whenever you remove an item from the container, or you can use QQueue<T> instead of QQueue<T *> (i.e. store values directly instead of pointers to values). Here, we will show when to call delete.

QPtrQueue idiomQQueue idiom
        queue.dequeue();
        delete queue.dequeue();
        queue.remove();
        delete queue.dequeue();
        queue.clear();

(also called from QPtrQueue's destructor)

        while (!queue.isEmpty())
            delete queue.dequeue();

In 99% of cases, the following idiom also works:

        qDeleteAll(queue);
        queue.clear();

However, it may lead to crashes if queue is referenced from the value type's destructor, because queue contains dangling pointers until clear() is called.

QPtrStack<T>

QPtrStack has been moved to the Qt3Support library. It has been replaced by the more modern QStack class.

The following table summarizes the differences between QPtrStack<T> and QStack<T *>:

QPtrStack functionQStack equivalent
QPtrStack::autoDelete()See discussion below
QPtrStack::count()QStack::count() or QStack::size() (equivalent)
QPtrStack::current()QStack::top()
QPtrStack::remove()QStack::pop()
QPtrStack::setAutoDelete()See discussion below

If you use QPtrStack's auto-delete feature (by calling QPtrStack::setAutoDelete(true)), you need to do some more work. You have two options: Either you call delete yourself whenever you remove an item from the container, or you can use QStack<T> instead of QStack<T *> (i.e. store values directly instead of pointers to values). Here, we will show when to call delete.

QPtrStack idiomQStack idiom
        stack.pop();
        delete stack.pop();
        stack.remove();
        delete stack.pop();
        stack.clear();

(also called from QPtrStack's destructor)

        while (!stack.isEmpty())
            delete stack.pop();

In 99% of cases, the following idiom also works:

        qDeleteAll(stack);
        stack.clear();

However, it may lead to crashes if stack is referenced from the value type's destructor, because stack contains dangling pointers until clear() is called.

QPtrVector<T>

QPtrVector<T> has been moved to Qt3Support. It has been replaced by the more modern QVector class.

When porting to Qt 4, you can use QVector<T *> as an alternative to QPtrVector<T>. The APIs of QPtrVector<T> and QVector<T *> are somewhat similar. The main issue is that QPtrVector supports auto-delete whereas QVector doesn't.

The following table summarizes the API differences between the two classes:

QPtrVector functionQVector equivalent
QPtrVector::autoDelete()See discussion below
QPtrVector::bsearch(const T *)qBinaryFind()
QPtrVector::contains(const T *)QVector::count(T *)
QPtrVector::containsRef(const T *)QVector::count(T *)
QPtrVector::count()See remark below
QPtrVector::insert(uint, T *)See remark below
QPtrVector::isNull()N/A
QPtrVector::remove(uint)See remark below
QPtrVector::setAutoDelete()See discussion below
QPtrVector::sort()qSort()
QPtrVector::take(uint)See remark below
QPtrVector::toList(QGList *)QList::QList(const QVector &)

Remarks:

  1. QPtrVector::insert(uint, T *) sets an item to store a certain pointer value. This is not the same as QVector::insert(int, T *), which creates space for the item by moving following items by one position. Use vect[i] = ptr to set a QVector item to a particular value.
  2. QPtrVector::remove(uint) sets an item to be 0. This is not the same as QVector::removeAt(int), which entirely erases the item, reducing the size of the vector. Use vect[i] = 0 to set a QVector item to 0.
  3. Likewise, QPtrVector::take(uint) sets an item to be 0 and returns the previous value of the item. Again, this is easy to achieve using QVector::operator[]().
  4. QPtrVector::count() returns the number of non-null items in the vector, whereas QVector::count() (like QVector::size()) returns the number of items (null or non-null) in the vector. Fortunately, it's not too hard to simulate QPtrVector::count().

    For example, if you have code like

            int numValidItems = vect.count();

    you can rewrite it as

            int numValidItems = vect.size() - vect.count(0);

If you use QVector's auto-delete feature (by calling QVector::setAutoDelete(true)), you need to do some more work. You have two options: Either you call delete yourself whenever you remove an item from the container, or you use QVector<T> instead of QVector<T *> (i.e. store values directly instead of pointers to values). Here, we'll see when to call delete.

The following table summarizes the idioms that you need to watch out for if you want to call delete yourself.

QPtrVector idiomQVector idiom
        vect.insert(i, ptr);
        delete vect[i];
        vect[i] = ptr;
        vect.remove(i);
        delete vect[i];
        vect[i] = 0;
        T *ptr = vect.take(i);
        T *ptr = vect[i];
        vect[i] = 0;
        vect.resize(n)
        while (n > vect.size())
            vect.append(0);
        while (n < vect.size() {
            T *ptr = vect.last();
            vect.remove(vect.size() - 1);
            delete ptr;
        }
        vect.clear();

(also called from QPtrVector's destructor)

        for (int i = 0; i < vect.size(); ++i)
            T *ptr = vect[i];
            vect[i] = 0;
            delete ptr;
        }

In 99% of cases, the following idiom also works:

        qDeleteAll(vect);
        vect.clear();

However, it may lead to crashes if vect is referenced from the value type's destructor, because vect contains dangling pointers until clear() is called.

Be aware that QPtrVector's destructor automatically calls clear(). If you have a QPtrVector data member in a custom class and use the auto-delete feature, you will need to call delete on all the items in the container from your class destructor to avoid a memory leak.

QPushButton

See Properties for a list of QPushButton properties in Qt 3 that have changed in Qt 4.

QRangeControl

In Qt 3, various "range control" widgets (QDial, QScrollBar, QSlider, and QSpin) inherited from both QWidget and QRangeControl.

In Qt 4, QRangeControl has been replaced with the new QAbstractSlider and QAbstractSpinBox classes, which inherit from QWidget and provides similar functionality. Apart from eliminating unnecessary multiple inheritance, the new design allows QAbstractSlider to provide signals, slots, and properties.

The old QRangeControl class has been renamed Q3RangeControl and moved to the Qt3Support library, together with the (undocumented) QSpinWidget class.

If you use QRangeControl as a base class in your application, you can switch to use QAbstractSlider or QAbstractSpinBox instead.

For example, if you have code like

        class VolumeControl : public QWidget, public QRangeControl
        {
            ...
        protected:
            void valueChange() {
                update();
                emit valueChanged(value());
            }
            void rangeChange() {
                update();
            }
            void stepChange() {
                update();
            }
        };

you can rewrite it as

        class VolumeControl : public QAbstractSlider
        {
            ...
        protected:
            void sliderChange(SliderChange change) {
                update();
                if (change == SliderValueChange)
                    emit valueChanged(value());
            }
        };

QRegExp

The search() and searchRev() functions have been renamed to indexIn() and lastIndexIn() respectively.

QRegion

The following changes have been made to QRegion in Qt 4:

QScrollBar

See Properties for a list of QScrollBar properties in Qt 3 that have changed in Qt 4.

QScrollView

The QScrollView class has been renamed Q3ScrollView and moved to the Qt3Support library. It has been replaced by the QAbstractScrollArea and QScrollArea classes.

QScrollView was designed to work around the 16-bit limitation on widget coordinates found on most window systems. In Qt 4, this is done transparently for all widgets, so there is no longer a need for such functionality in QScrollView. For that reason, the new QAbstractScrollArea and QScrollArea classes are much more lightweight, and concentrate on handling scroll bars.

QServerSocket

The QServerSocket class has been renamed Q3ServerSocket and moved to the Qt3Support library. In Qt 4, it has been replaced by QTcpServer.

With Q3ServerSocket, connections are accepted by reimplementing a virtual function (Q3ServerSocket::newConnection()). With QTcpServer, on the other hand, you don't need to subclass. Instead, simply connect to the QTcpServer::newConnection() signal.

QSettings

The QSettings class has been rewritten to be more robust and to respect existing standards (e.g., the INI file format). The API has also been extensively revised. The old API is still provided when Qt 3 support is enabled.

Since the format and location of settings have changed between Qt 3 and Qt 4, the Qt 4 version of your application won't recognize settings written using Qt 3.

QShared

The QShared class has been obsoleted by the more powerful QSharedData and QSharedDataPointer as a means of creating custom implicitly shared classes. It has been renamed Q3Shared moved to the Qt3Support library.

An easy way of porting to Qt 4 is to include this class into your project and to use it instead of QShared:

        struct Shared
        {
            Shared() : count(1) {}
            void ref() { ++count; }
            bool deref() { return !--count; }
            uint count;
        };

If possible, we recommend that you use QSharedData and QSharedDataPointer instead. They provide thread-safe reference counting and handle all the reference counting behind the scenes, eliminating the risks of forgetting to increment or decrement the reference count.

QSignal

The QSignal class has been renamed to Q3Signal and moved to the Qt3Support library. The preferred approach is to create your own QObject subclass with a signal that has the desired signature. Alternatively, you can call QMetaObject::invokeMethod() if you want to invoke a slot.

QSimpleRichText

The QSimpleRichText class has been renamed Q3SimpleRichText and moved to the Qt3Support library.

See Rich Text Processing for an overview of the Qt 4 rich text classes.

QSlider

The QSlider::sliderStart() and QSlider::sliderRect() functons have been removed. You can retrieve this information using QAbstractSlider::sliderPosition() and QStyle::querySubControlMetrics(), respectively.

See Properties for a list of QSlider properties in Qt 3 that have changed in Qt 4.

QSocket

The QSocket class has been renamed Q3Socket and moved to the Qt3Support library. In Qt 4, it has been replaced by the QTcpSocket class, which inherits most of its functionality from QAbstractSocket.

QSocket

The QSocketDevice class has been renamed Q3SocketDevice and moved to the Qt3Support library. In Qt 4, there is no direct equivalent to Q3SocketDevice:

QSortedList

The QSortedList<T> class has been deprecated since Qt 3.0. In Qt 4, it has been moved to the Qt3Support library.

In new code, we recommend that you use QList<T> instead and use qSort() to sort the items.

QSplitter

The function setResizeMode() has been moved into Qt3Support. Set the stretch factor in the widget's size policy to get equivalent functionality.

The obsolete function drawSplitter() has been removed. Use QStyle::drawPrimitive() to acheive similar functionality.

QSpinBox

See Properties for a list of QSpinBox properties in Qt 3 that have changed in Qt 4.

QSqlCursor

The QSqlCursor class has been renamed Q3SqlCursor and moved to the Qt3Support library. In Qt 4, you can use QSqlQuery, QSqlQueryModel, or QSqlTableModel, depending on whether you want a low-level or a high-level interface for accessing databases.

See QtSql Module for an overview of the new SQL classes.

QSqlDatabase

QSqlDatabase is now a smart pointer that is passed around by value. Simply replace all QSqlDatabase pointers by QSqlDatabase objects.

QSqlEditorFactory

The QSqlEditorFactory class has been renamed Q3SqlEditorFactory and moved to Qt3Support.

See QtSql Module for an overview of the new SQL classes.

QSqlError

The enum Type was renamed to ErrorType, The values were renamed as well:

QSqlFieldInfo

The QSqlFieldInfo class has been moved to Qt3Support. Its functionality is now provided by the QSqlField class.

See QtSql Module for an overview of the new SQL classes.

QSqlForm

The QSqlForm class has been renamed Q3SqlForm and moved to the Qt3Support library.

See QtSql Module for an overview of the new SQL classes.

QSqlPropertyMap

The QSqlPropertyMap class has been renamed Q3SqlPropertyMap moved to the Qt3Support library.

See QtSql Module for an overview of the new SQL classes.

QSqlQuery

QSqlQuery::prev() was renamed to QSqlQuery::previous(). There is a function call for compatibility, but if you subclassed QSqlQuery, you have to reimplement previous() instead of prev().

QSqlRecord

QSqlRecord behaves like a vector now, QSqlRecord::insert() will actually insert a new field instead of replacing the existing one.

QSqlRecordInfo

The QSqlRecordInfo class has been moved to Qt3Support. Its functionality is now provided by the QSqlRecord class.

See QtSql Module for an overview of the new SQL classes.

QSqlSelectCursor

The QSqlSelectCursor class has been renamed Q3SqlSelectCursor and moved to the Qt3Support library.

See QtSql Module for an overview of the new SQL classes.

QStoredDrag

The QStoredDrag class has been renamed Q3StoredDrag and moved to the Qt3Support library. In Qt 4, use QMimeData instead and call QMimeData::setData() to set the data.

QStr(I)List

The QStrList and QStrIList convenience classes have been deprecated since Qt 2.0. In Qt 4, they have been moved to the Qt3Support library. If you used any of these, we recommend that you use QStringList or QList<QByteArray> instead.

QStr(I)Vec

The QStrVec and QStrIVec convenience classes have been deprecated since Qt 2.0. In Qt 4, they have been moved to Qt3Support. If you used any of these, we recommend that you use QStringList or QList<QByteArray> instead.

QString

Here are the main issues to be aware of when porting QString to Qt 4:

  1. The QString::QString(QChar) constructor performed implicit conversion in Qt 3. Now, you will need a cast to convert a QChar to a QString.
  2. The QString::QString(const QByteArray &) constructor used to stop at the first '\0' it encountered, for compatibility with Qt 1. This quirk has now been fixed; in Qt 4, the resulting QString always has the same length as the QByteArray that was passed to the constructor.
  3. The QString::null static constant has been deprecated in Qt 4. For compatibility, Qt 4 provides a QString::null symbol that behaves more or less the same as the old constant. The new idiom is to write QString() instead of QString::null, or to call clear().

    For example, if you have code like

                str1 = QString::null;
                if (str2 == QString::null)
                    do_something(QString::null);

    you can rewrite it as

                str1.clear();
                if (str2.isNull())
                    do_something(QString());

    In new code, we recommend that you don't rely on the distinction between a null string and a (non-null) empty string. See Distinction Between Null and Empty Strings for details.

  4. QString::at() returned a non-const reference, whereas the new QString::at() returns a const value. Code like
            str.at(0) = 'X';

    will no longer compile. Instead, use QString::operator[]:

            str[0] = 'X';
  5. The QString::contains(x) function (where x is a character or a string) has been renamed QString::count(x). In addition, there now exists a set of QString::contains() functions that returns a boolean value. Replace old calls to contains() with either count() or contains(), depending on whether you care about the specific number of occurrences of a character in the string or only care about whether the string contains that character or not.
  6. Many functions in QString had a bool parameter that specified case sensitivity. In Qt 4, in the interest of code readability and maintainability, the bool parameters have been replaced by the Qt::CaseSensitivity enum, which can take the values Qt::CaseSensitive and Qt::CaseInsensitive.

    For example, if you have code like

                if (url.startsWith("http:", false))
                    ...

    you can rewrite it as

                if (url.startsWith("http:", Qt::CaseInsensitive))
                    ...
  7. The QString::setExpand(uint, QChar) function, which already was obsolete in Qt 3, is no longer available. Use QString::operator[] instead.

    For example, if you have code like

                str.setExpand(32, '$');

    you can rewrite it as

                str[32] = '$';
  8. The QT_NO_ASCII_CAST and QT_NO_CAST_ASCII macros have been renamed QT_NO_CAST_TO_ASCII and QT_NO_CAST_FROM_ASCII, respectively.
  9. The QString::data() used to return the same as QString::ascii(). It now returns a pointer to the Unicode data stored in the QString object. Call QString::ascii() if you want the old behavior.
  10. QString::simpleText() has been renamed QString::isSimpleText().

QStringList

QStringList now inherits from QList<QString> and can no longer be converted to a QValueList<QString>. Since QValueList inherits QList a cast will work as expected.

This change implies some API incompatibilities for QStringList. For example, at() returns the string, not an iterator. See the section on QValueList for details.

QStyle

The QStyle API has been overhauled and improved. Most of the information on why this change was done is described in the QStyle overview.

Since QStyle is mostly used internally by Qt's widgets and styles and since it is not essential to the good functioning of an application, there is no compatibility path. This means that we have changed many enums and functions and the qt3to4 porting tool will not change much in your qstyle code. To ease the pain, we list some of the major changes here.

QStyleOption has taken on a more central role and is no longer an optional argument, please see the QStyleOption documentation for more information.

The QStyle::StyleFlags have been renamed QStyle::StateFlags and are now prefixed State_ instead of Style_, in addition the Style_ButtonDefault flag has moved to QStyleOptionButton.

The QStyle::PrimitiveElement enumeration has undergone extensive change. Some of the enums were moved to QStyle::ControlElement, some were removed and all were renamed. This renaming is not done by the qt3to4 porting tool, so you must do it yourself. The table below shows how things look now.

Old nameNew nameRemark
PE_ButtonCommandQStyle::PE_PanelButtonCommand
PE_ButtonDefaultQStyle::PE_FrameDefaultButton
PE_ButtonBevelQStyle::PE_PanelButtonBevel
PE_ButtonToolQStyle::PE_PanelButtonTool
PE_ButtonDropDownQStyle::PE_IndicatorButtonDropDown
PE_FocusRectQStyle::PE_FrameFocusRect
PE_ArrowUpQStyle::PE_IndicatorArrowUp
PE_ArrowDownQStyle::PE_IndicatorArrowDown
PE_ArrowRightQStyle::PE_IndicatorArrowRight
PE_ArrowLeftQStyle::PE_IndicatorArrowLeft
PE_SpinBoxUpQStyle::PE_IndicatorSpinUp
PE_SpinBoxDownQStyle::PE_IndicatorSpinDown
PE_SpinBoxPlusQStyle::PE_IndicatorSpinPlus
PE_SpinBoxMinusQStyle::PE_IndicatorSpinMinus
PE_SpinBoxSliderQStyle::CE_SpinBoxSlideruses QStyle::drawControl()
PE_IndicatorQStyle::PE_IndicatorCheckBox
PE_IndicatorMaskN/Ause QStyle::styleHint() to retrieve mask
PE_ExclusiveIndicatorQStyle::PE_IndicatorRadioButton
PE_ExclusiveIndicatorMaskN/Ause QStyle::styleHint() to retrieve mask
PE_DockWindowHandleQStyle::PE_IndicatorToolBarHandle
PE_DockWindowSeparatorQStyle::PE_Q3DockWindowSeparator
PE_DockWindowResizeHandleQStyle::PE_IndicatorDockWindowResizeHandle
PE_DockWindowTitleQStyle::CE_DockWindowTitleuses QStyle::drawControl()
PE_SplitterQStyle::CE_Splitteruses QStyle::drawControl()
PE_PanelQStyle::PE_Frame
PE_PanelMenuQStyle::PE_FrameMenu
PE_PanelMenuBarQStyle::PE_PanelMenuBar
PE_PanelDockWindowQStyle::PE_FrameDockWindow
PE_TabBarBaseQStyle::PE_FrameTabBarBase
PE_HeaderSectionQStyle::CE_HeaderSectionuses QStyle::drawControl()
PE_HeaderArrowQStyle::PE_IndicatorHeaderArrow
PE_StatusBarSectionQStyle::PE_FrameStatusBar
PE_SeparatorQStyle::PE_Q3Separator
PE_SizeGripQStyle::CE_SizeGripuses QStyle::drawControl()
PE_CheckMarkQStyle::PE_IndicatorMenuCheckMark
PE_ScrollBarAddLineQStyle::CE_ScrollBarAddLineuses QStyle::drawControl()
PE_ScrollBarSubLineQStyle::CE_ScrollBarSubLineuses QStyle::drawControl()
PE_ScrollBarAddPageQStyle::CE_ScrollBarAddPageuses QStyle::drawControl()
PE_ScrollBarSubPageQStyle::CE_ScrollBarSubPageuses QStyle::drawControl()
PE_ScrollBarSliderQStyle::CE_ScrollBarSlideruses QStyle::drawControl()
PE_ScrollBarFirstQStyle::CE_ScrollBarFirstuses QStyle::drawControl()
PE_ScrollBarLastQStyle::CE_ScrollBarLastuses QStyle::drawControl()
PE_ProgressBarChunkQStyle::PE_IndicatorProgressChunk
PE_PanelLineEditQStyle::PE_FrameLineEdit
PE_PanelTabWidgetQStyle::PE_FrameTabWidget
PE_WindowFrameQStyle::PE_FrameWindow
PE_CheckListControllerQStyle::PE_Q3CheckListController
PE_CheckListIndicatorQStyle::PE_Q3CheckListIndicator
PE_CheckListExclusiveIndicato\o QStyle::PE_Q3CheckListExclusiveIndicator
PE_PanelGroupBoxQStyle::PE_FrameGroupBox
PE_TreeBranchQStyle::PE_IndicatorBranch
PE_RubberBandQStyle::CE_RubberBanduses QStyle::drawControl()
PE_PanelToolBarQStyle::PE_PanelToolBar
PE_ToolBarHandleQStyle::PE_IndicatorToolBarHandle
PE_ToolBarSeparatorQStyle::PE_IndicatorToolBarSeparator

The QStyle::drawControlMask() and QStyle::drawComplexControlMask() functions have been removed. They are replaced with a style hint.

The QStyle::drawItem() overloads that took both a pixmap and a string have been removed. Use QStyle::drawItemText() and QStyle::drawItemPixmap() directly.

The QStyle::itemRect() overload that took both a pixmap and a string is also removed, use either QStyle::itemTextRect() or QStyle::itemPixmapRect() instead.

QStyleSheet

The QStyleSheet and QStyleSheetItem classes have been renamed Q3StyleSheet and Q3StyleSheetItem, and have been moved to the Qt3Support library.

See Rich Text Processing for an overview of the Qt 4 rich text classes.

QSyntaxHighlighter

The QSyntaxHighlighter class has been renamed Q3SyntaxHighlighter and moved to the Qt3Support library.

See Rich Text Processing for an overview of the Qt 4 rich text classes.

QTabBar

See Properties for a list of QTabBar properties in Qt 3 that have changed in Qt 4.

QTabDialog

The QTabDialog class is no longer part of the public Qt API. It has been renamed Q3TabDialog and moved to Qt3Support. In Qt 4 applications, you can easily obtain the same result by combining a QTabWidget with a QDialog and provide QPushButtons yourself.

See also the dialogs/tabdialog example, which shows how to implement tab dialogs in Qt 4.

QTabWidget

See Properties for a list of QTabWidget properties in Qt 3 that have changed in Qt 4.

QTable

The QTable, QTableItem, QComboTableItem, QCheckTableItem, and QTableSelection classes have been renamed Q3Table, Q3TableItem, Q3ComboTableItem, Q3CheckTableItem, and Q3TableSelection and moved to the Qt3Support library. New Qt applications should use the new QTableWidget or QTableView class instead.

See Model/View Programming for an overview of the new item view classes.

QTextDrag

The QTextDrag class has been renamed Q3TextDrag and moved to the Qt3Support library. In Qt 4, use QMimeData instead and call QMimeData::setText() to set the data.

QTextEdit

The old QTextEdit and QTextBrowser classes have been renamed Q3TextEdit and Q3TextBrowser, and have been moved to Qt3Support. The new QTextEdit and QTextBrowser have a somewhat different API.

See Rich Text Processing for an overview of the Qt 4 rich text classes.

QTextOStreamIterator

The undocumented QTextOStreamIterator class has been removed from the Qt library. If you need it in your application, feel free to copy the source code from the Qt 3 <qtl.h> header file.

QTextStream

QTextStream has undergone a number of API and implementation enhancements, and some of the changes affect QTextStream's behavior:

QTextView

The QTextView class has been renamed Q3TextView and moved to the Qt3Support library.

QTimeEdit

The QTimeEdit class in Qt 4 is a convenience class based on QDateTimeEdit. The old class has been renamed Q3TimeEdit and moved to the Qt3Support library.

See Virtual Functions for a list of QTimeEdit virtual member functions in Qt 3 that are no longer virtual in Qt 4.

QToolBar

The old QToolBar class, which worked with the old QMainWindow and QDockArea classes and inherited from QDockWindow, has been renamed Q3ToolBar and moved to Qt3Support. Use the new QToolBar class in new applications.

QToolButton

See Properties for a list of QToolBar properties in Qt 3 that have changed in Qt 4.

QUriDrag

The QUriDrag class has been renamed Q3UriDrag and moved to the Qt3Support library. In Qt 4, use QMimeData instead and call QMimeData::setUrl() to set the URL.

QUrl

The QUrl class has been rewritten from scratch in Qt 4 to be more standard-compliant. The old QUrl class has been renamed Q3Url and moved to the Qt3Support library.

The new QUrl class provides an extensive list of compatibility functions to ease porting from Q3Url to QUrl. A few functions require you to change your code:

QUrlOperator

The QUrlOperator class is no longer part of the public Qt API. It has been renamed Q3UrlOperator and moved to Qt3Support.

In Qt 4 applications, you can use classes like QFtp and QHttp directly to perform file-related actions on a remote host.

QValueList<T>

The QValueList<T> class has been replaced by QList<T> and QLinkedList<T> in Qt 4. As a help when porting older Qt applications, the Qt3Support library contains a QValueList<T> class implemented in terms of the new QLinkedList<T>. Similarly, it contains QValueListIterator<T> and QValueListConstIterator<T> classes implemented in terms of QLinkedList<T>::iterator and QLinkedList<T>::const_iterator.

When porting to Qt 4, you have the choice of using QList<T> or QLinkedList<T> as alternatives to QValueList<T>. QList<T> has an index-based API and provides very fast random access (QList::operator[]), whereas QLinkedList<T> has an iterator-based API.

Here's a list of problem functions:

QValueVector<T>

The QValueVector<T> class has been replaced by QVector<T> in Qt 4. As a help when porting older Qt applications, the Qt3Support library contains a Q3ValueVector<T> class implemented in terms of the new QVector<T>.

When porting from QValueVector<T> to QVector<T>, you might run into the following incompatibilities:

See Generic Containers for an overview of the Qt 4 container classes.

QVariant

Some changes to the rest of the Qt library have implications on QVariant:

  1. The QVariant::ColorGroup enum value is defined only if QT3_SUPPORT is defined.
  2. The QVariant::IconSet enum value has been renamed QVariant::Icon.
  3. The QVariant::CString enum value is now a synonym for QVariant::ByteArray.

QVBox

The QVBox class is now only available as Q3VBox in Qt 4. You can achieve the same result as QVBox by creating a QWidget with a vertical layout:

For example, if you have code like

    QVBox *vbox = new QVBox;
    QPushButton *child1 = new QPushButton(vbox);
    QPushButton *child2 = new QPushButton(vbox);

you can rewrite it as

    QWidget *vbox = new QWidget;
    QPushButton *child1 = new QPushButton;
    QPushButton *child2 = new QPushButton;

    QVBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(child1);
    layout->addWidget(child2);
    vbox->setLayout(layout);

QWhatsThis

The QWhatsThis class has been redesigned in Qt 4. The old QWhatsThis class is available as Q3WhatsThis in Qt3Support.

QWidget

Widget background painting has been greatly improved, supporting flicker-free updates and making it possible to have semitransparent widgets. This renders the following background handling functions obsolete:

A widget now receives change events in its QWidget::changeEvent() handler. This makes the following virtual change handlers obsolete:

The following functions were slots, but are no more:

The following functions were incorrectly marked as virtual:

See Properties for a list of QWidget properties in Qt 3 that have changed in Qt 4.

QWidgetFactory

The QWidgetFactory class has been replaced by QFormBuilder in Qt 4.

QWidgetIntDict

The QWidgetIntDict class was a synonym for QIntDict<QWidget>. It is no longer available in Qt 4. If you link against Qt3Support, you can use QIntDict<QWidget> instead; otherwise, see the section on QDict<T>.

QWidgetList

In Qt 3, the QWidgetList class was a typedef for QPtrList<QWidget>. In Qt 4, it is a typedef for QList<QWidget *>. See the section on QPtrList<T>.

QWidgetStack

The QWidgetStack class is no longer part of the Qt public API. It has been renamed Q3WidgetStack and moved to Qt3Support. In Qt 4 applications, you can use QStackedWidget instead to obtain the same results.

QWizard

The QWizard class is no longer part of the Qt public API. It has been renamed Q3Wizard and moved to Qt3Support. In Qt 4 applications, you can easily obtain the same result by combining a QStackedBox with a QDialog and provide QPushButtons yourself.

The Simple Wizard and Complex Wizard examples show how to create wizards without using Q3Wizard.

QWorkspace

The QWorkspace in Qt 4 class requires explicit adding of MDI windows with QWorkspace::addWindow().

Virtual Functions

Virtual functions that changed their signature in Qt 4:

Qt 3 function signatureQt 4 function signature
int QAccessibleInterface::navigate(NavDirection, int) constint QAccessibleInterface::navigate(RelationFlag, int, QAccessibleInterface **) const
bool QApplication::winEventFilter(MSG *)bool QApplication::winEventFilter(MSG *, long *)
Function: Offset QIODevice::at() constFunction: Q_LONGLONG QIODevice::pos() const
bool QIODevice::at(Offset)bool QIODevice::seek(Q_LONGLONG)
bool QIODevice::open(int)bool QIODevice::open(OpenMode)
Q_LONG QIODevice::readBlock(char *, Q_ULONG)Q_LONGLONG QIODevice::readData(char *, Q_LONGLONG)
Q_LONG QIODevice::writeBlock(const char *, Q_ULONG)Q_LONGLONG QIODevice::writeData(const char *, Q_LONGLONG)
const char * QImageFormatType::formatName() constQByteArray QImageFormatType::formatName() const
QPopupMenu * QLineEdit::createPopupMenu()QMenu * QLineEdit::createPopupMenu()
bool QMacMime::canConvert(const char *, int)bool QMacMime::canConvert(const QString &, int)
QValueList<QByteArray> QMacMime::convertFromMime(QByteArray, const char *, int)QList<QByteArray> QMacMime::convertFromMime(QByteArray, const QString &, int)
QByteArray QMacMime::convertToMime(QValueList<QByteArray> data, const char *, int)QByteArray QMacMime::convertToMime(QList<QByteArray> data, const QString &, int)
const char * QMacMime::convertorName()QString QMacMime::convertorName()
int QMacMime::flavorFor(const char *)int QMacMime::flavorFor(const QString &)
const char * QMacMime::mimeFor(int)QString QMacMime::mimeFor(int)
QMetaObject * QObject::metaObject() constconst QMetaObject * QObject::metaObject() const
bool QScreen::onCard(unsigned char *) constbool QScreen::onCard(const unsigned char *) const
bool QScreen::onCard(unsigned char *, ulong &) constbool QScreen::onCard(const unsigned char *, ulong &) const
int QSpinBox::mapTextToValue(bool *)int QSpinBox::mapTextToValue(QString *, QValidator::State *) const
QString QSpinBox::mapValueToText(int)QString QSpinBox::mapValueToText(int) const
bool QSqlDriver::open(const QString &, const QString &, const QString &, const QString &, int)bool QSqlDriver::open(const QString &, const QString &, const QString &, const QString &, int, const QString &)
QStringList QSqlDriver::tables(const QString &) constQStringList QSqlDriver::tables(QSql::TableType) const
bool QSqlQuery::prev()bool QSqlQuery::previous()
QVariant QSqlResult::data(int)QVariant QSqlResult::data(int)
bool QSqlResult::fetchPrev()bool QSqlResult::fetchPrevious()
void QStyle::drawComplexControl(ComplexControl, QPainter *, const QWidget *, const QRect &, const QColorGroup &, SFlags, SCFlags, SCFlags, const QStyleOption &) constvoid QStyle::drawComplexControl(ComplexControl, const QStyleOptionComplex *, QPainter *, const QWidget *) const
void QStyle::drawComplexControlMask(ComplexControl, QPainter *, const QWidget *, const QRect &, const QStyleOption &) constvoid QStyle::drawComplexControlMask(ComplexControl, const QStyleOptionComplex *, QPainter *, const QWidget *) const
void QStyle::drawControl(ControlElement, QPainter *, const QWidget *, const QRect &, const QColorGroup &, SFlags, const QStyleOption &) constvoid QStyle::drawControl(ControlElement, const QStyleOption *, QPainter *, const QWidget *) const
void QStyle::drawControlMask(ControlElement, QPainter *, const QWidget *, const QRect &, const QStyleOption &) constvoid QStyle::drawControlMask(ControlElement, const QStyleOption *, QPainter *, const QWidget *) const
void QStyle::drawItem(QPainter *, const QRect &, int, const QColorGroup &, bool, const QPixmap *, const QString &, int, const QColor *) constvoid QStyle::drawItem(QPainter *, const QRect &, int, const QPalette &, bool, const QString &, int, const QColor *) const
void QStyle::drawPrimitive(PrimitiveElement, QPainter *, const QRect &, const QColorGroup &, SFlags, const QStyleOption &) constvoid QStyle::drawPrimitive(PrimitiveElement, const QStyleOption *, QPainter *, const QWidget *) const
QRect QStyle::itemRect(QPainter *, const QRect &, int, bool, const QPixmap *, const QString &, int) constQRect QStyle::itemRect(const QFontMetrics &, const QRect &, int, bool, const QString &, int) const
int QStyle::pixelMetric(PixelMetric, const QWidget *) constint QStyle::pixelMetric(PixelMetric, const QStyleOption *, const QWidget *) const
SubControl QStyle::querySubControl(ComplexControl, const QWidget *, const QPoint &, const QStyleOption &) constSubControl QStyle::hitTestComplexControl(ComplexControl, const QStyleOptionComplex *, const QPoint &, const QWidget *) const
QRect QStyle::querySubControlMetrics(ComplexControl, const QWidget *, SubControl, const QStyleOption &) constQRect QStyle::subControlRect(ComplexControl, const QStyleOptionComplex *, SubControl, const QWidget *) const
QSize QStyle::sizeFromContents(ContentsType, const QWidget *, const QSize &, const QStyleOption &) constQSize QStyle::sizeFromContents(ContentsType, const QStyleOption *, const QSize &, const QFontMetrics &, const QWidget *) const
int QStyle::styleHint(StyleHint, const QWidget *, const QStyleOption &, QStyleHintReturn *) constint QStyle::styleHint(StyleHint, const QStyleOption *, const QWidget *, QStyleHintReturn *) const
QPixmap QStyle::stylePixmap(StylePixmap, const QWidget *, const QStyleOption &) constQPixmap QStyle::standardPixmap(StandardPixmap, const QStyleOption *, const QWidget *) const
QRect QStyle::subRect(SubRect, const QWidget *) constQRect QStyle::subRect(SubRect, const QStyleOption *, const QFontMetrics &, const QWidget *) const
void QStyle::unPolish(QApplication *)void QStyle::unpolish(QApplication *)
void QStyle::unPolish(QWidget *)void QStyle::unpolish(QWidget *)
QCString QTextCodec::fromUnicode(const QString &, int &) constQByteArray QTextCodec::fromUnicode(const QString &, int &) const
QValueList<int> QTextCodecPlugin::mibEnums() constQList<int> QTextCodecPlugin::mibEnums() const
void QTextDrag::setSubtype(const QCString &)void QTextDrag::setSubtype(const QString &)
QCString QTextEncoder::fromUnicode(const QString &, int &)QByteArray QTextEncoder::fromUnicode(const QString &, int &)
void QUriDrag::setUris(QStrList)void QUriDrag::setUris(const QList<QByteArray> & list)
void QUrlInfo::setSize(uint)void QUrlInfo::setSize(Q_LONGLONG)
bool QWindowsMime::canConvert(const char *, int)bool QWindowsMime::canConvert(const QString &, int)
int QWindowsMime::cfFor(const char *)int QWindowsMime::cfFor(const QString &)
QByteArray QWindowsMime::convertFromMime(QByteArray, const char *, int)QByteArray QWindowsMime::convertFromMime(const QByteArray &, const QString &, int)
QByteArray QWindowsMime::convertToMime(QByteArray, const char *, int)QByteArray QWindowsMime::convertToMime(const QByteArray &, const QString &, int)
const char * QWindowsMime::convertorName()QString QWindowsMime::convertorName()
void QWSMouseHandler::calibrate(QWSPointerCalibrationData *)void QWSMouseHandler::calibrate(const QWSPointerCalibrationData *)
bool QWidget::macEvent(MSG *)bool QWidget::macEvent(EventHandlerCallRef, EventRef)
bool QWidget::winEvent(MSG *)bool QWidget::winEvent(MSG *, long *)
QString QXmlContentHandler::errorString()QString QXmlContentHandler::errorString() const
QString QXmlDTDHandler::errorString()QString QXmlDTDHandler::errorString() const
QString QXmlDeclHandler::errorString()QString QXmlDeclHandler::errorString() const
QString QXmlEntityResolver::errorString()QString QXmlEntityResolver::errorString() const
QString QXmlErrorHandler::errorString()QString QXmlErrorHandler::errorString() const
QString QXmlInputSource::data()QString QXmlInputSource::data() const
QString QXmlLexicalHandler::errorString()QString QXmlLexicalHandler::errorString() const
int QXmlLocator::columnNumber()int QXmlLocator::columnNumber() const
int QXmlLocator::lineNumber()int QXmlLocator::lineNumber() const

Virtual functions that are not virtual in Qt 4:

Qt 3 functionComment
void QAccessibleInterface::clearSelection()Port to the new QAccessibleInterface API.
int QAccessibleInterface::controlAt(int, int) constPort to the new QAccessibleInterface API.
bool QAccessibleInterface::doDefaultAction(int)Port to the new QAccessibleInterface API.
QMemArray<int> QAccessibleInterface::selection() constPort to the new QAccessibleInterface API.
bool QAccessibleInterface::setFocus(int)Port to the new QAccessibleInterface API.
bool QAccessibleInterface::setSelected(int, bool, bool)Port to the new QAccessibleInterface API.
bool QAction::addTo(QWidget *)Use Q3Action instead or port to the new QAction API.
void QAction::addedTo(QWidget *, QWidget *)Use Q3Action instead or port to the new QAction API.
void QAction::addedTo(int, QPopupMenu *)Use Q3Action instead or port to the new QAction API.
bool QAction::removeFrom(QWidget *)Use Q3Action instead or port to the new QAction API.
void QAction::setAccel(const QKeySequence &)Use Q3Action instead or port to the new QAction API.
void QAction::setEnabled(bool)Use Q3Action instead or port to the new QAction API.
void QAction::setIconSet(const QIcon &)Use Q3Action instead or port to the new QAction API.
void QAction::setMenuText(const QString &)Use Q3Action instead or port to the new QAction API.
void QAction::setOn(bool)Use Q3Action instead or port to the new QAction API.
void QAction::setStatusTip(const QString &)Use Q3Action instead or port to the new QAction API.
void QAction::setText(const QString &)Use Q3Action instead or port to the new QAction API.
void QAction::setToggleAction(bool)Use Q3Action instead or port to the new QAction API.
void QAction::setToolTip(const QString &)Use Q3Action instead or port to the new QAction API.
void QAction::setWhatsThis(const QString &)Use Q3Action instead or port to the new QAction API.
void QButton::drawButton(QPainter *)Use Q3Button instead or reimplement QButton::paintEvent().
void QButton::drawButtonLabel(QPainter *)Use Q3Button instead or reimplement QButton::paintEvent().
void QButton::setAccel(const QKeySequence &)Setter.
void QButton::setAutoRepeat(bool)Setter.
void QButton::setDown(bool)Setter.
void QButton::setPixmap(const QPixmap &)Setter.
void QButton::setState(ToggleState)Setter.
void QButton::setText(const QString &)Use the QAbstractButton::setText() setter function.
void QButton::setToggleType(ToggleType)Setter.
void QButtonGroup::moveFocus(int)Use the QWidget::setFocus() setter function.
void QButtonGroup::setButton(int)Setter.
void QButtonGroup::setExclusive(bool)Setter.
void QButtonGroup::setRadioButtonExclusive(bool)Setter.
void QComboBox::setAutoCompletion(bool)Setter.
void QComboBox::setAutoResize(bool)Setter.
void QComboBox::setCurrentItem(int)Setter.
void QComboBox::setCurrentText(const QString &)Setter.
void QComboBox::setFont(const QFont &)Setter.
void QComboBox::setInsertionPolicy(Policy)Setter.
void QComboBox::setLineEdit(QLineEdit *)Setter.
void QComboBox::setListBox(QListBox *)Setter.
void QComboBox::setMaxCount(int)Setter.
void QComboBox::setPalette(const QPalette &)Setter.
void QComboBox::setSizeLimit(int)Setter.
void QComboBox::setValidator(const QValidator *)Setter.
void QDateEdit::fix()Port to the new QDateTimeEdit API.
QString QDateEdit::sectionFormattedText(int)Port to the new QDateTimeEdit API.
void QDateEdit::setAutoAdvance(bool)Port to the new QDateTimeEdit API.
void QDateEdit::setDate(const QDate &)Port to the new QDateTimeEdit API.
void QDateEdit::setDay(int)Port to the new QDateTimeEdit API.
void QDateEdit::setMaxValue(const QDate &)Port to the new QDateTimeEdit API.
void QDateEdit::setMinValue(const QDate &)Port to the new QDateTimeEdit API.
void QDateEdit::setMonth(int)Port to the new QDateTimeEdit API.
void QDateEdit::setOrder(Order)Port to the new QDateTimeEdit API.
void QDateEdit::setRange(const QDate &, const QDate &)Port to the new QDateTimeEdit API.
void QDateEdit::setSeparator(const QString &)Port to the new QDateTimeEdit API.
void QDateEdit::setYear(int)Port to the new QDateTimeEdit API.
void QDateTimeEdit::setAutoAdvance(bool)Port to the new QDateTimeEdit API.
void QDateTimeEdit::setDateTime(const QDateTime &)Port to the new QDateTimeEdit API.
void QDial::rangeChange()Reimplement QDial::sliderChange() instead.
void QDial::repaintScreen(const QRect *)Reimplement QDial::paintEvent() instead.
void QDial::setNotchTarget(double)Setter.
void QDial::setNotchesVisible(bool)Setter.
void QDial::setTracking(bool)Setter.
void QDial::setValue(int)Use QDial::sliderChange() instead.
void QDial::setWrapping(bool)Setter.
void QDial::valueChange()Use QDial::sliderChange() instead.
QString QDir::absFilePath(const QString &, bool) constValue type.
QString QDir::absPath() constValue type.
QString QDir::canonicalPath() constValue type.
bool QDir::cd(const QString &, bool)Value type.
bool QDir::cdUp()Value type.
void QDir::convertToAbs()Value type.
QString QDir::dirName() constValue type.
QStrList QDir::encodedEntryList(int, int) constValue type.
QStrList QDir::encodedEntryList(const QString &, int, int) constValue type.
const QFileInfoList * QDir::entryInfoList(int, int) constValue type.
const QFileInfoList * QDir::entryInfoList(const QString &, int, int) constValue type.
QStringList QDir::entryList(const QString &, int, int) constValue type.
QStringList QDir::entryList(int, int) constValue type.
bool QDir::exists() constValue type.
bool QDir::exists(const QString &, bool)Value type.
QString QDir::filePath(const QString &, bool) constValue type.
bool QDir::isReadable() constValue type.
bool QDir::isRelative() constValue type.
bool QDir::isRoot() constValue type.
bool QDir::mkdir(const QString &, bool) constValue type.
bool QDir::operator!=() constValue type.
bool QDir::operator==() constValue type.
QString QDir::path() constValue type.
bool QDir::remove(const QString &, bool)Value type.
bool QDir::rename(const QString &, const QString &, bool)Value type.
bool QDir::rmdir(const QString &, bool) constValue type.
void QDir::setFilter(int)Value type.
void QDir::setMatchAllDirs(bool)Value type.
void QDir::setNameFilter(const QString &)Value type.
void QDir::setPath(const QString &)Value type.
void QDir::setSorting(int)Value type.
void QDns::setLabel(const QString &)Use Q3Dns instead.
void QDns::setLabel(const QHostAddress &)Use Q3Dns instead.
void QDns::setRecordType(RecordType)Use Q3Dns instead.
void QDockWindow::dock()Use Q3DockWindow instead or port to the new QDockWidget API.
void QDockWindow::setCloseMode(int)Use Q3DockWindow instead or port to the new QDockWidget API.
void QDockWindow::setFixedExtentHeight(int)Use Q3DockWindow instead or port to the new QDockWidget API.
void QDockWindow::setFixedExtentWidth(int)Use Q3DockWindow instead or port to the new QDockWidget API.
void QDockWindow::setHorizontallyStretchable(bool)Use Q3DockWindow instead or port to the new QDockWidget API.
void QDockWindow::setMovingEnabled(bool)Use Q3DockWindow instead or port to the new QDockWidget API.
void QDockWindow::setNewLine(bool)Use Q3DockWindow instead or port to the new QDockWidget API.
void QDockWindow::setOffset(int)Use Q3DockWindow instead or port to the new QDockWidget API.
void QDockWindow::setOpaqueMoving(bool)Use Q3DockWindow instead or port to the new QDockWidget API.
void QDockWindow::setOrientation(Orientation)Use Q3DockWindow instead or port to the new QDockWidget API.
void QDockWindow::setResizeEnabled(bool)Use Q3DockWindow instead or port to the new QDockWidget API.
void QDockWindow::setVerticallyStretchable(bool)Use Q3DockWindow instead or port to the new QDockWidget API.
void QDockWindow::setWidget(QWidget *)Use Q3DockWindow instead or port to the new QDockWidget API.
void QDockWindow::undock()Use Q3DockWindow instead or port to the new QDockWidget API.
QString QDomAttr::name() constValue type.
QDomElement QDomAttr::ownerElement() constValue type.
void QDomAttr::setValue(const QString &)Value type.
bool QDomAttr::specified() constValue type.
QString QDomAttr::value() constValue type.
void QDomCharacterData::appendData(const QString &)Value type.
QString QDomCharacterData::data() constValue type.
void QDomCharacterData::deleteData(unsigned, unsigned)Value type.
void QDomCharacterData::insertData(unsigned, const QString &)Value type.
uint QDomCharacterData::length() constValue type.
void QDomCharacterData::replaceData(unsigned, unsigned, const QString &)Value type.
void QDomCharacterData::setData(const QString &)Value type.
QString QDomCharacterData::substringData(unsigned, unsigned)Value type.
QDomNamedNodeMap QDomDocumentType::entities() constValue type.
QString QDomDocumentType::internalSubset() constValue type.
QString QDomDocumentType::name() constValue type.
QDomNamedNodeMap QDomDocumentType::notations() constValue type.
QString QDomDocumentType::publicId() constValue type.
QString QDomDocumentType::systemId() constValue type.
QDomNamedNodeMap QDomElement::attributes() constValue type.
QDomNodeList QDomElement::elementsByTagName(const QString &) constValue type.
QDomNodeList QDomElement::elementsByTagNameNS(const QString &, const QString &) constValue type.
QString QDomEntity::notationName() constValue type.
QString QDomEntity::publicId() constValue type.
QString QDomEntity::systemId() constValue type.
QDomDocument QDomImplementation::createDocument(const QString &, const QString &, const QDomDocumentType &)Value type.
QDomDocumentType QDomImplementation::createDocumentType(const QString &, const QString &, const QString &)Value type.
bool QDomImplementation::hasFeature(const QString &, const QString &)Value type.
QDomImplementation::~QDomImplementation()Value type.
QDomNode QDomNode::appendChild(const QDomNode &)Value type.
QDomNamedNodeMap QDomNode::attributes() constValue type.
QDomNodeList QDomNode::childNodes() constValue type.
QDomNode QDomNode::cloneNode(bool) constValue type.
QDomNode QDomNode::firstChild() constValue type.
bool QDomNode::hasAttributes() constValue type.
bool QDomNode::hasChildNodes() constValue type.
QDomNode QDomNode::insertAfter(const QDomNode &, const QDomNode &)Value type.
QDomNode QDomNode::insertBefore(const QDomNode &, const QDomNode &)Value type.
bool QDomNode::isAttr() constValue type.
bool QDomNode::isCDATASection() constValue type.
bool QDomNode::isCharacterData() constValue type.
bool QDomNode::isComment() constValue type.
bool QDomNode::isDocument() constValue type.
bool QDomNode::isDocumentFragment() constValue type.
bool QDomNode::isDocumentType() constValue type.
bool QDomNode::isElement() constValue type.
bool QDomNode::isEntity() constValue type.
bool QDomNode::isEntityReference() constValue type.
bool QDomNode::isNotation() constValue type.
bool QDomNode::isProcessingInstruction() constValue type.
bool QDomNode::isSupported(const QString &, const QString &) constValue type.
bool QDomNode::isText() constValue type.
QDomNode QDomNode::lastChild() constValue type.
QString QDomNode::localName() constValue type.
QString QDomNode::namespaceURI() constValue type.
QDomNode QDomNode::nextSibling() constValue type.
QString QDomNode::nodeName() constValue type.
QDomNode::NodeType QDomNode::nodeType() constValue type.
QString QDomNode::nodeValue() constValue type.
void QDomNode::normalize()Value type.
QDomDocument QDomNode::ownerDocument() constValue type.
QDomNode QDomNode::parentNode() constValue type.
QString QDomNode::prefix() constValue type.
QDomNode QDomNode::previousSibling() constValue type.
QDomNode QDomNode::removeChild(const QDomNode &)Value type.
QDomNode QDomNode::replaceChild(const QDomNode &, const QDomNode &)Value type.
void QDomNode::setNodeValue(const QString &)Value type.
void QDomNode::setPrefix(const QString &)Value type.
QDomNode::~QDomNode()Value type.
QDomNode QDomNodeList::item(int) constValue type.
uint QDomNodeList::length() constValue type.
QDomNodeList::~QDomNodeList()Value type.
QString QDomProcessingInstruction::data() constValue type.
void QDomProcessingInstruction::setData(const QString &)Value type.
QString QDomProcessingInstruction::target() constValue type.
int QEventLoop::enterLoop()Port to the new QAbstractEventDispatcher API.
int QEventLoop::exec()Port to the new QAbstractEventDispatcher API.
void QEventLoop::exit(int)Port to the new QAbstractEventDispatcher API.
void QEventLoop::exitLoop()Port to the new QAbstractEventDispatcher API.
bool QEventLoop::hasPendingEvents() constPort to the new QAbstractEventDispatcher API.
int QEventLoop::loopLevel() constPort to the new QAbstractEventDispatcher API.
bool QEventLoop::processEvents(ProcessEventsFlags)Port to the new QAbstractEventDispatcher API.
void QEventLoop::registerSocketNotifier(QSocketNotifier *)Port to the new QAbstractEventDispatcher API.
void QEventLoop::unregisterSocketNotifier(QSocketNotifier *)Port to the new QAbstractEventDispatcher API.
void QEventLoop::wakeUp()Port to the new QAbstractEventDispatcher API.
void QFrame::drawContents(QPainter *)Use Q3Frame or reimplement QFrame::paintEvent() instead.
void QFrame::drawFrame(QPainter *)Use Q3Frame or reimplement QFrame::paintEvent() instead.
void QFrame::frameChanged()Use Q3Frame or reimplement QFrame::resizeEvent() instead.
void QFrame::setFrameRect(const QRect &)Setter.
void QFrame::setFrameStyle(int)Setter.
void QFrame::setLineWidth(int)Setter.
void QFrame::setMargin(int)Setter.
void QFrame::setMidLineWidth(int)Setter.
void QGridLayout::setColStretch(int, int)Setter.
void QGridLayout::setRowStretch(int, int)Setter.
void QGroupBox::setAlignment(int)Setter.
void QGroupBox::setColumnLayout(int, Orientation)Setter.
void QGroupBox::setTitle(const QString &)Setter.
QHostAddress::~QHostAddress()Value type.
int QIODevice::getch()Port to the new QIODevice API.
int QIODevice::putch(int)Port to the new QIODevice API.
QByteArray QIODevice::readAll()Port to the new QIODevice API.
Q_LONG QIODevice::readLine(char *, Q_ULONG)Port to the new QIODevice API.
int QIODevice::ungetch(int)Port to the new QIODevice API.
void QIcon::setPixmap(const QString &, Size, Mode, State)Value type.
void QIcon::setPixmap(const QPixmap &, Size, Mode, State)Value type.
QIcon::~QIcon()Value type.
void QLabel::setAlignment(int)Setter.
void QLabel::setAutoResize(bool)Setter.
void QLabel::setBuddy(QWidget *)Setter.
void QLabel::setMovie(const QMovie &)Setter.
void QLabel::setNum(int)Setter.
void QLabel::setNum(double)Setter.
void QLabel::setPicture(const QPicture &)Setter.
void QLabel::setPixmap(const QPixmap &)Setter.
void QLabel::setText(const QString &)Setter.
QLayoutIterator QLayout::iterator()Port to the new QLayout API.
void QLayout::setAutoAdd(bool)Setter.
void QLayout::setMargin(int)Setter.
void QLayout::setMenuBar(QMenuBar *)Setter.
void QLayout::setSpacing(int)Setter.
QLayoutIterator QLayoutItem::iterator()Port to the new QLayoutItem API.
void QLayoutItem::setAlignment(int)Setter.
bool QLibrary::unload()Never used polymorphically in Qt.
void QLineEdit::clear()Connect to QLineEdit::textChanged() instead.
void QLineEdit::clearValidator()Never used polymorphically in Qt.
void QLineEdit::copy() constNever used polymorphically in Qt.
void QLineEdit::cut()Never used polymorphically in Qt.
void QLineEdit::deselect()Connect to QLineEdit::selectionChanged() instead.
void QLineEdit::insert(const QString &)Connect to QLineEdit::textChanged() instead.
void QLineEdit::paste()Connect to QLineEdit::textChanged() instead.
void QLineEdit::redo()Never used polymorphically in Qt.
void QLineEdit::selectAll()Connect to QLineEdit::selectionChanged() instead.
void QLineEdit::setAlignment(int)Setter.
void QLineEdit::setCursorPosition(int)Connect to QLineEdit::cursorPositionChanged() instead.
void QLineEdit::setDragEnabled(bool)Setter.
void QLineEdit::setEchoMode(EchoMode)Setter.
void QLineEdit::setFrame(bool)Setter.
void QLineEdit::setMaxLength(int)Setter.
void QLineEdit::setReadOnly(bool)Setter.
void QLineEdit::setSelection(int, int)Connect to QLineEdit::selectionChanged() instead.
void QLineEdit::setText(const QString &)Connect to QLineEdit::textChanged() instead.
void QLineEdit::setValidator(const QValidator *)Setter.
void QLineEdit::undo()Never used in a polymorphic way by Qt.
void QMainWindow::addDockWindow(QDockWindow *, Dock, bool)Port to the new QMainWindow API.
void QMainWindow::addDockWindow(QDockWindow *, const QString &, Dock, bool)Port to the new QMainWindow API.
void QMainWindow::customize()Port to the new QMainWindow API.
bool QMainWindow::isCustomizable() constPort to the new QMainWindow API.
void QMainWindow::moveDockWindow(QDockWindow *, Dock)Port to the new QMainWindow API.
void QMainWindow::moveDockWindow(QDockWindow *, Dock, bool, int, int)Port to the new QMainWindow API.
void QMainWindow::removeDockWindow(QDockWindow *)Port to the new QMainWindow API.
void QMainWindow::setAppropriate(QDockWindow *, bool)Port to the new QMainWindow API.
void QMainWindow::setCentralWidget(QWidget *)Setter.
void QMainWindow::setDockEnabled(QDockWindow *, Dock, bool)Port to the new QMainWindow API.
void QMainWindow::setDockEnabled(Dock, bool)Port to the new QMainWindow API.
void QMainWindow::setDockMenuEnabled(bool)Port to the new QMainWindow API.
void QMainWindow::setDockWindowsMovable(bool)Port to the new QMainWindow API.
void QMainWindow::setOpaqueMoving(bool)Port to the new QMainWindow API.
void QMainWindow::setRightJustification(bool)Port to the new QMainWindow API.
void QMainWindow::setUpLayout()Port to the new QMainWindow API.
void QMainWindow::setUsesBigPixmaps(bool)Port to the new QMainWindow API.
void QMainWindow::setUsesTextLabel(bool)Port to the new QMainWindow API.
bool QMainWindow::showDockMenu(const QPoint &)Port to the new QMainWindow API.
void QMenuBar::activateItemAt(int)Port to the new QMenuBar API.
void QMenuBar::menuContentsChanged()Port to the new QMenuBar API.
void QMenuBar::menuDelPopup(QPopupMenu *)Port to the new QMenuBar API.
void QMenuBar::menuInsPopup(QPopupMenu *)Port to the new QMenuBar API.
void QMenuBar::menuStateChanged()Port to the new QMenuBar API.
void QMenuBar::setId(int, int)Port to the new QMenuBar API.
void QMenuBar::setSeparator(Separator)Port to the new QMenuBar API.
void QMenuBar::updateItem(int)Port to the new QMenuBar API.
QMutex::~QMutex()Value type.
bool QObject::checkConnectArgs(const char *, const QObject *, const char *)Reimplementing this function is no longer possible.
const char * QObject::className() constReimplementing this function is no longer supported.
void QObject::insertChild(QObject *)Reimplement QObject::childEvent() instead and handle QEvent:ChildAdded events.
QVariant QObject::property(const char *) constReimplementing this function is no longer supported.
void QObject::removeChild(QObject *)Reimplement QObject::childEvent() instead and handle QEvent:ChildRemoved events.
void QObject::setName(const char *)Setter.
bool QObject::setProperty(const char *, const QVariant &)Setter.
bool QPaintDevice::cmd(int , QPainter * , QPDevCmdParam *)Port to the new QPaintEngine API.
Qt::HANDLE QPaintDevice::handle() constPort to the new QPaintDevice API.
HDC QPaintDevice::handle() constPort to the new QPaintDevice API.
void QPopupMenu::activateItemAt(int)Port to the new QMenu API.
void QPopupMenu::menuContentsChanged()Port to the new QMenu API.
void QPopupMenu::menuDelPopup(QPopupMenu *)Port to the new QMenu API.
void QPopupMenu::menuInsPopup(QPopupMenu *)Port to the new QMenu API.
void QPopupMenu::menuStateChanged()Port to the new QMenu API.
void QPopupMenu::setActiveItem(int)Port to the new QMenu API.
void QPopupMenu::setCheckable(bool)Port to the new QMenu API.
void QPopupMenu::setId(int, int)Port to the new QMenu API.
void QPopupMenu::updateItem(int)Port to the new QMenu API.
int QPrinter::resolution() constCall QPrinter::setResolution() to change the resolution.
void QPrinter::setColorMode(ColorMode)Subclass QPrintEngine instead.
void QPrinter::setCreator(const QString &)Subclass QPrintEngine instead.
void QPrinter::setDocName(const QString &)Subclass QPrintEngine instead.
void QPrinter::setFromTo(int, int)Subclass QPrintEngine instead.
void QPrinter::setFullPage(bool)Subclass QPrintEngine instead.
void QPrinter::setMinMax(int, int)Subclass QPrintEngine instead.
void QPrinter::setNumCopies(int)Subclass QPrintEngine instead.
void QPrinter::setOrientation(Orientation)Subclass QPrintEngine instead.
void QPrinter::setOutputFileName(const QString &)Subclass QPrintEngine instead.
void QPrinter::setOutputToFile(bool)Subclass QPrintEngine instead.
void QPrinter::setPageOrder(PageOrder)Subclass QPrintEngine instead.
void QPrinter::setPageSize(PageSize)Subclass QPrintEngine instead.
void QPrinter::setPaperSource(PaperSource)Subclass QPrintEngine instead.
void QPrinter::setPrintProgram(const QString &)Subclass QPrintEngine instead.
void QPrinter::setPrinterName(const QString &)Subclass QPrintEngine instead.
void QPrinter::setPrinterSelectionOption(const QString &)Subclass QPrintEngine instead.
void QPrinter::setResolution(int)Subclass QPrintEngine instead.
void QProcess::addArgument(const QString &)Not used polymorphically in Qt.
void QProcess::closeStdin()Not used polymorphically in Qt.
bool QProcess::launch(const QByteArray & buf, QStringList *)Not used polymorphically in Qt.
bool QProcess::launch(const QString & buf, QStringList *)Not used polymorphically in Qt.
QString QProcess::readLineStderr()Not used polymorphically in Qt.
QString QProcess::readLineStdout()Not used polymorphically in Qt.
QByteArray QProcess::readStderr()Not used polymorphically in Qt.
QByteArray QProcess::readStdout()Not used polymorphically in Qt.
void QProcess::setArguments(const QStringList &)Not used polymorphically in Qt.
void QProcess::setWorkingDirectory(const QDir &)Not used polymorphically in Qt.
bool QProcess::start(QStringList *)Not used polymorphically in Qt.
void QProcess::writeToStdin(const QByteArray &)Not used polymorphically in Qt.
bool QProgressBar::setIndicator(QString &, int, int)Not used polymorphically in Qt.
void QProgressBar::setProgress(int)Not used polymorphically in Qt.
void QProgressBar::setTotalSteps(int)Not used polymorphically in Qt.
void QPushButton::setAutoDefault(bool)Not used polymorphically in Qt.
void QPushButton::setDefault(bool)Not used polymorphically in Qt.
void QPushButton::setIsMenuButton(bool)Not used polymorphically in Qt.
void QPushButton::setOn(bool)Connect to QPushButton::toggled(bool) instead.
void QRadioButton::setChecked(bool)Connect to QRadioButton::toggled(bool) instead.
uchar * QScreen::cache(int , int)Port to the new QScreen API.
void QScreen::set(unsigned int , unsigned int , unsigned int , unsigned)Port to the new QScreen API.
void QScreen::uncache(uchar *)Port to the new QScreen API.
void QScrollBar::setOrientation(Orientation)Setter.
void QScrollBar::setTracking(bool)Setter.
void QSignalMapper::setMapping(const QObject *, const QString &)Setter.
void QSignalMapper::setMapping(const QObject *, int)Setter.
void QSlider::rangeChange()Reimplement QSlider::sliderChange() instead.
void QSlider::setOrientation(Orientation)Setter.
void QSlider::setPalette(const QPalette &)Setter.
void QSlider::setTickInterval(int)Setter.
void QSlider::setTickmarks(TickSetting)Setter.
void QSlider::setTracking(bool)Setter.
void QSlider::setValue(int)Reimplement QSlider::sliderChange() instead.
void QSlider::valueChange()Reimplement QSlider::sliderChange() instead.
QString QSpinBox::cleanText() constPort to the new QSpinBox API.
void QSpinBox::interpretText()Port to the new QSpinBox API.
QString QSpinBox::prefix() constPort to the new QSpinBox API.
void QSpinBox::rangeChange()Reimplement QSpinBox::sliderChange() instead.
void QSpinBox::selectAll()Port to the new QSpinBox API.
void QSpinBox::setButtonSymbols(ButtonSymbols)Setter.
void QSpinBox::setPrefix(const QString &)Setter.
void QSpinBox::setSpecialValueText(const QString &)Setter.
void QSpinBox::setSuffix(const QString &)Setter.
void QSpinBox::setValidator(const QValidator *)Setter.
void QSpinBox::setValue(int)Connect to QSpinBox::valueChanged().
void QSpinBox::setWrapping(bool)Setter.
void QSpinBox::stepDown()Reimplement QSpinBox::stepBy() instead.
void QSpinBox::stepUp()Reimplement QSpinBox::stepBy() instead.
QString QSpinBox::suffix() constPort to the new QSpinBox API.
void QSpinBox::updateDisplay()Port to the new QSpinBox API.
void QSpinBox::valueChange()Reimplement QSpinBox::sliderChange() instead.
void QSplitter::drawSplitter(QPainter *, QCOORD, QCOORD, QCOORD, QCOORD)Reimplement QStyle::drawPrimitive() instead and handle QStyle::PE_Splitter.
void QSplitter::setOpaqueResize(bool)Setter.
void QSplitter::setOrientation(Orientation)Setter.
void QSplitter::setResizeMode(QWidget *, ResizeMode)Setter.
void QSqlDatabase::setDatabaseName(const QString &)Setter.
void QSqlDatabase::setHostName(const QString &)Setter.
void QSqlDatabase::setPassword(const QString &)Setter.
void QSqlDatabase::setPort(int)Setter.
void QSqlDatabase::setUserName(const QString &)Setter.
QSqlQuery QSqlDriver::createQuery() constPort to the new QSqlDriver API.
QString QSqlDriver::nullText() constPort to the new QSqlDriver API.
QSqlRecord QSqlDriver::record(const QSqlQuery &) constPort to the new QSqlDriver API.
QSqlRecordInfo QSqlDriver::recordInfo(const QSqlQuery &) constPort to the new QSqlDriver API.
QSqlRecordInfo QSqlDriver::recordInfo(const QString &) constPort to the new QSqlDriver API.
void QSqlError::setDatabaseText(const QString &)Value type.
void QSqlError::setDriverText(const QString &)Value type.
void QSqlError::setNumber(int)Value type.
void QSqlError::setType(int)Value type.
QSqlError::~QSqlError()Value type.
void QSqlField::setName(const QString &)Value type.
void QSqlField::setNull()Value type.
void QSqlField::setReadOnly(bool)Value type.
void QSqlField::setValue(const QVariant &)Value type.
QVariant QSqlField::value() constValue type.
QSqlField::~QSqlField()Value type.
void QSqlFieldInfo::setCalculated(bool)Value type.
void QSqlFieldInfo::setGenerated(bool)Value type.
void QSqlFieldInfo::setTrim(bool)Value type.
QSqlFieldInfo::~QSqlFieldInfo()Value type.
void QSqlIndex::append(const QSqlField &)Value type.
void QSqlIndex::append(const QSqlField &, bool)Value type.
void QSqlIndex::setCursorName(const QString &)Value type.
void QSqlIndex::setDescending(int, bool)Value type.
void QSqlIndex::setName(const QString &)Value type.
QVariant QSqlQuery::value(int) constExists as a non-virtual function.
void QSqlRecord::append(const QSqlField &)Value type.
void QSqlRecord::clear()Value type.
void QSqlRecord::clearValues(bool)Value type.
void QSqlRecord::insert(int, const QSqlField &)Value type.
void QSqlRecord::remove(int)Value type.
void QSqlRecord::setGenerated(const QString &, bool)Value type.
void QSqlRecord::setGenerated(int, bool)Value type.
void QSqlRecord::setNull(int)Value type.
void QSqlRecord::setNull(const QString &)Value type.
void QSqlRecord::setValue(const QString &, const QVariant &)Value type.
void QSqlRecord::setValue(int, const QVariant &)Value type.
QString QSqlRecord::toString(const QString &, const QString &) constValue type.
QStringList QSqlRecord::toStringList(const QString &) constValue type.
QVariant QSqlRecord::value(int) constValue type.
QVariant QSqlRecord::value(const QString &) constValue type.
QSqlRecord::~QSqlRecord()Value type.
void QStyle::polishPopupMenu(QPopupMenu *)Reimplement QStyle::polish(QWidget *) instead.
int QTabBar::addTab(QTab *)Reimplement QTabBar::tabInserted() instead.
int QTabBar::insertTab(QTab *, int)Reimplement QTabBar::tabInserted() instead.
void QTabBar::layoutTabs()Reimplement QTabBar::tabLayoutChange() instead.
void QTabBar::paint(QPainter *, QTab *, bool) constReimplement QTabBar::paintEvent() instead.
void QTabBar::paintLabel(QPainter *, const QRect &, QTab *, bool) constReimplement QTabBar::paintEvent() instead.
void QTabBar::removeTab(QTab *)Reimplement QTabBar::tabRemoved() instead.
QTab * QTabBar::selectTab(const QPoint &) constReimplement QTabBar::mousePressEvent() instead.
void QTabBar::setCurrentTab(int)Connect to the QTabBar::currentChanged() signal.
void QTabBar::setCurrentTab(QTab *)Connect to the QTabBar::currentChanged() signal.
void QTabBar::setShape(Shape)Setter.
void QTabBar::setTabEnabled(int, bool)Setter.
void QTabWidget::addTab(QWidget *, const QString &)Reimplement QTabWidget::tabInserted() instead.
void QTabWidget::addTab(QWidget *, const QIcon &, const QString &)Reimplement QTabWidget::tabInserted() instead.
void QTabWidget::addTab(QWidget *, QTab *)Reimplement QTabWidget::tabInserted() instead.
void QTabWidget::insertTab(QWidget *, const QIcon &, const QString &, int)Reimplement QTabWidget::tabInserted() instead.
void QTabWidget::insertTab(QWidget *, const QString &, int)Reimplement QTabWidget::tabInserted() instead.
void QTabWidget::insertTab(QWidget *, QTab *, int)Reimplement QTabWidget::tabInserted() instead.
void QTabWidget::removePage(QWidget *)Reimplement QTabWidget::tabRemoved() instead.
void QTabWidget::showPage(QWidget *)Connect to QTabWidget::currentChanged() instead.
void QTextEdit::append(const QString &)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::clear()Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::clearParagraphBackground(int)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::copy()Use Q3TextEdit or port to the new QTextEdit API.
QPopupMenu * QTextEdit::createPopupMenu(const QPoint &)Use Q3TextEdit or port to the new QTextEdit API.
QPopupMenu * QTextEdit::createPopupMenu()Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::cut()Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::del()Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::doKeyboardAction(KeyboardAction)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::ensureCursorVisible()Use Q3TextEdit or port to the new QTextEdit API.
bool QTextEdit::find(const QString &, bool, bool, bool, int *, int *)Use Q3TextEdit or port to the new QTextEdit API.
bool QTextEdit::focusNextPrevChild(bool)Use Q3TextEdit or port to the new QTextEdit API.
int QTextEdit::heightForWidth(int) constUse Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::insert(const QString &, bool, bool, bool)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::insertAt(const QString &, int, int)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::insertParagraph(const QString &, int)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::moveCursor(CursorAction, bool)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::paste()Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::pasteSubType(const QCString &)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::placeCursor(const QPoint &, QTextCursor *)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::redo()Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::removeParagraph(int)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::removeSelectedText(int)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::removeSelection(int)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::scrollToAnchor(const QString &)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::scrollToBottom()Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::selectAll(bool)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setAlignment(int)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setBold(bool)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setColor(const QColor &)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setCurrentFont(const QFont &)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setCursorPosition(int, int)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setFamily(const QString &)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setItalic(bool)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setLinkUnderline(bool)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setMimeSourceFactory(QMimeSourceFactory *)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setModified(bool)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setOverwriteMode(bool)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setPaper(const QBrush &)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setParagraphBackgroundColor(int, const QColor &)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setPointSize(int)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setReadOnly(bool)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setSelection(int, int, int, int, int)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setSelectionAttributes(int, const QColor &, bool)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setStyleSheet(QStyleSheet *)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setTabStopWidth(int)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setText(const QString &, const QString &)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setTextFormat(TextFormat)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setUnderline(bool)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setUndoDepth(int)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setUndoRedoEnabled(bool)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setVerticalAlignment(VerticalAlignment)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setWordWrap(WordWrap)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setWrapColumnOrWidth(int)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::setWrapPolicy(WrapPolicy)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::sync()Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::undo()Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::zoomIn()Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::zoomIn(int)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::zoomOut(int)Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::zoomOut()Use Q3TextEdit or port to the new QTextEdit API.
void QTextEdit::zoomTo(int)Use Q3TextEdit or port to the new QTextEdit API.
QString QTimeEdit::sectionFormattedText(int)Port to the new QDateTimeEdit API.
void QTimeEdit::setAutoAdvance(bool)Port to the new QDateTimeEdit API.
void QTimeEdit::setHour(int)Port to the new QDateTimeEdit API.
void QTimeEdit::setMaxValue(const QTime &)Port to the new QDateTimeEdit API.
void QTimeEdit::setMinValue(const QTime &)Port to the new QDateTimeEdit API.
void QTimeEdit::setMinute(int)Port to the new QDateTimeEdit API.
void QTimeEdit::setRange(const QTime &, const QTime &)Port to the new QDateTimeEdit API.
void QTimeEdit::setSecond(int)Port to the new QDateTimeEdit API.
void QTimeEdit::setSeparator(const QString &)Port to the new QDateTimeEdit API.
void QTimeEdit::setTime(const QTime &)Port to the new QDateTimeEdit API.
void QToolBar::clear()Setter.
void QToolBar::setLabel(const QString &)Setter.
void QToolBar::setStretchableWidget(QWidget *)Setter.
void QToolButton::setIconSet(const QIcon &)Setter.
void QToolButton::setOn(bool)Connect to QToolButton::toggled(bool) instead.
void QToolButton::setTextLabel(const QString &, bool)Setter.
void QToolButton::setToggleButton(bool)Setter.
void QToolButton::setUsesBigPixmap(bool)Setter.
void QToolButton::setUsesTextLabel(bool)Setter.
void QToolTip::maybeTip(const QPoint &)Port to the new QToolTip API.
void QUrl::addPath(const QString &)Value type.
bool QUrl::cdUp()Value type.
bool QUrl::parse(const QString &)Value type.
void QUrl::reset()Value type.
void QUrl::setEncodedPathAndQuery(const QString &)Value type.
void QUrl::setFileName(const QString &)Value type.
void QUrl::setHost(const QString &)Value type.
void QUrl::setPassword(const QString &)Value type.
void QUrl::setPath(const QString &)Value type.
void QUrl::setPort(int)Value type.
void QUrl::setProtocol(const QString &)Value type.
void QUrl::setQuery(const QString &)Value type.
void QUrl::setRef(const QString &)Value type.
void QUrl::setUser(const QString &)Value type.
QString QUrl::toString(bool, bool) constValue type.
QUrl::~QUrl()Value type.
QWaitCondition::~QWaitCondition()Value type.
bool QWhatsThis::clicked(const QString &)Port to the new QWhatsThis API.
QString QWhatsThis::text(const QPoint &)Port to the new QWhatsThis API.
QWhatsThis::~QWhatsThis()Port to the new QSpinBox API.
void QWidget::adjustSize()Reimplement QWidget::sizeHint() instead.
bool QWidget::close(bool)Reimplement QWidget::closeEvent().
void QWidget::create(WId, bool, bool)Not supported in Qt 4.
bool QWidget::customWhatsThis() constNot supported in Qt 4.
void QWidget::destroy(bool, bool)Not supported in Qt 4.
void QWidget::enabledChange(bool)Reimplement QWidget::changeEvent() and handle QEvent::EnabledChange.
void QWidget::fontChange(const QFont &)Reimplement QWidget::changeEvent() and handle QEvent::FontChange.
void QWidget::imComposeEvent(QIMEvent *)Reimplement QWidget::inputMethodEvent() instead.
void QWidget::imEndEvent(QIMEvent *)Reimplement QWidget::inputMethodEvent() instead.
void QWidget::imStartEvent(QIMEvent *)Reimplement QWidget::inputMethodEvent() instead.
void QWidget::move(int, int)Setter.
void QWidget::paletteChange(const QPalette &)Reimplement QWidget::changeEvent() and handle QEvent::PaletteChange and/or QEvent::ApplicationPaletteChange.
void QWidget::polish()Reimplement QWidget::polishEvent() instead.
void QWidget::reparent(QWidget *, WFlags, const QPoint &, bool)Reimplement QWidget::event() and handle QEvent::Reparent.
void QWidget::resize(int, int)Reimplement QWidget::resizeEvent() instead.
void QWidget::setAcceptDrops(bool)Setter.
void QWidget::setActiveWindow()Reimplement QWidget::changeEvent() and handle QEvent::ActivationChange.
void QWidget::setAutoMask(bool)Setter.
void QWidget::setBackgroundColor(const QColor &)Setter.
void QWidget::setBackgroundMode(BackgroundMode)Setter.
void QWidget::setBackgroundOrigin(BackgroundOrigin)Setter.
void QWidget::setBackgroundPixmap(const QPixmap &)Setter.
void QWidget::setCaption(const QString &)Reimplement QWidget::changeEvent() and handle QEvent::WindowTitleChange.
void QWidget::setCursor(const QCursor &)Setter.
void QWidget::setEnabled(bool)Reimplement QWidget::changeEvent() and handle QEvent::EnabledChange.
void QWidget::setEraseColor(const QColor &)Setter.
void QWidget::setErasePixmap(const QPixmap &)Setter.
void QWidget::setFocus()Reimplement QWidget::focusInEvent() or QWidget::focusOutEvent().
void QWidget::setFocusPolicy(FocusPolicy)Setter.
void QWidget::setFocusProxy(QWidget *)Setter.
void QWidget::setFont(const QFont &)Reimplement QWidget::changeEvent() and handle QEvent::FontChange and/or QEvent::ApplicationFontChange.
void QWidget::setGeometry(int, int, int, int)Setter.
void QWidget::setGeometry(const QRect &)Setter.
void QWidget::setIcon(const QPixmap &)Reimplement QWidget::changeEvent() and handle QEvent::WindowIconChange.
void QWidget::setIconText(const QString &)Reimplement QWidget::changeEvent() and handle QEvent::IconTextChange.
void QWidget::setKeyCompression(bool)Setter.
void QWidget::setMask(const QRegion &)Setter.
void QWidget::setMask(const QBitmap &)Setter.
void QWidget::setMaximumSize(int, int)Setter.
void QWidget::setMicroFocusHint(int, int, int, int, bool, QFont *)Setter.
void QWidget::setMinimumSize(int, int)Setter.
void QWidget::setMouseTracking(bool)Reimplement QWidget::changeEvent() and handle QEvent::MouseTrackingChange.
void QWidget::setPalette(const QPalette &)Reimplement QWidget::changeEvent() and handle QEvent::PaletteChange and/or QEvent::ApplicationPaletteChange.
void QWidget::setPaletteBackgroundColor(const QColor &)Setter.
void QWidget::setPaletteBackgroundPixmap(const QPixmap &)Setter.
void QWidget::setSizeIncrement(int, int)Setter.
void QWidget::setSizePolicy(QSizePolicy)Setter.
void QWidget::setUpdatesEnabled(bool)Setter.
void QWidget::setWFlags(WFlags)Setter.
void QWidget::showMaximized()Reimplement QWidget::changeEvent() and handle QEvent::WindowStateChange.
void QWidget::showMinimized()Reimplement QWidget::changeEvent() and handle QEvent::WindowStateChange.
void QWidget::showNormal()Reimplement QWidget::changeEvent() and handle QEvent::WindowStateChange.
void QWidget::styleChange(QStyle &)Reimplement QWidget::changeEvent() and handle QEvent::StyleChange.
void QWidget::unsetCursor()Setter.
void QWidget::windowActivationChange(bool)Reimplement QWidget::changeEvent() and handle QEvent::ActivationChange.


Copyright © 2005 Trolltech Trademarks
Qt 4.0.1