QDockWidget Class

The QDockWidget class provides a widget that can be docked inside a QMainWindow or floated as a top-level window on the desktop. More...

Header: #include <QDockWidget>
qmake: QT += widgets
Inherits: QWidget.

Public Types

enum DockWidgetFeature { DockWidgetClosable, DockWidgetMovable, DockWidgetFloatable, DockWidgetVerticalTitleBar, AllDockWidgetFeatures, NoDockWidgetFeatures }
flags DockWidgetFeatures

Properties

  • 59 properties inherited from QWidget
  • 1 property inherited from QObject

Public Functions

QDockWidget(const QString & title, QWidget * parent = 0, Qt::WindowFlags flags = 0)
QDockWidget(QWidget * parent = 0, Qt::WindowFlags flags = 0)
~QDockWidget()
Qt::DockWidgetAreas allowedAreas() const
DockWidgetFeatures features() const
bool isAreaAllowed(Qt::DockWidgetArea area) const
bool isFloating() const
void setAllowedAreas(Qt::DockWidgetAreas areas)
void setFeatures(DockWidgetFeatures features)
void setFloating(bool floating)
void setTitleBarWidget(QWidget * widget)
void setWidget(QWidget * widget)
QWidget * titleBarWidget() const
QAction * toggleViewAction() const
QWidget * widget() const
  • 217 public functions inherited from QWidget
  • 31 public functions inherited from QObject
  • 13 public functions inherited from QPaintDevice

Signals

void allowedAreasChanged(Qt::DockWidgetAreas allowedAreas)
void dockLocationChanged(Qt::DockWidgetArea area)
void featuresChanged(QDockWidget::DockWidgetFeatures features)
void topLevelChanged(bool topLevel)
void visibilityChanged(bool visible)

Protected Functions

void initStyleOption(QStyleOptionDockWidget * option) const

Reimplemented Protected Functions

virtual void changeEvent(QEvent * event)
virtual void closeEvent(QCloseEvent * event)
virtual bool event(QEvent * event)
virtual void paintEvent(QPaintEvent * event)
  • 37 protected functions inherited from QWidget
  • 9 protected functions inherited from QObject
  • 1 protected function inherited from QPaintDevice

Additional Inherited Members

  • 19 public slots inherited from QWidget
  • 1 public slot inherited from QObject
  • 1 public variable inherited from QObject
  • 5 static public members inherited from QWidget
  • 10 static public members inherited from QObject
  • 1 protected slot inherited from QWidget
  • 2 protected variables inherited from QObject
  • 1 protected type inherited from QPaintDevice

Detailed Description

The QDockWidget class provides a widget that can be docked inside a QMainWindow or floated as a top-level window on the desktop.

QDockWidget provides the concept of dock widgets, also know as tool palettes or utility windows. Dock windows are secondary windows placed in the dock widget area around the central widget in a QMainWindow.

Dock windows can be moved inside their current area, moved into new areas and floated (e.g., undocked) by the end-user. The QDockWidget API allows the programmer to restrict the dock widgets ability to move, float and close, as well as the areas in which they can be placed.

Appearance

A QDockWidget consists of a title bar and the content area. The title bar displays the dock widgets window title, a float button and a close button. Depending on the state of the QDockWidget, the float and close buttons may be either disabled or not shown at all.

The visual appearance of the title bar and buttons is dependent on the style in use.

A QDockWidget acts as a wrapper for its child widget, set with setWidget(). Custom size hints, minimum and maximum sizes and size policies should be implemented in the child widget. QDockWidget will respect them, adjusting its own constraints to include the frame and title. Size constraints should not be set on the QDockWidget itself, because they change depending on whether it is docked; a docked QDockWidget has no frame and a smaller title bar.

See also QMainWindow and Dock Widgets Example.

Member Type Documentation

enum QDockWidget::DockWidgetFeature
flags QDockWidget::DockWidgetFeatures

ConstantValueDescription
QDockWidget::DockWidgetClosable0x01The dock widget can be closed. On some systems the dock widget always has a close button when it's floating (for example on MacOS 10.5).
QDockWidget::DockWidgetMovable0x02The dock widget can be moved between docks by the user.
QDockWidget::DockWidgetFloatable0x04The dock widget can be detached from the main window, and floated as an independent window.
QDockWidget::DockWidgetVerticalTitleBar0x08The dock widget displays a vertical title bar on its left side. This can be used to increase the amount of vertical space in a QMainWindow.
QDockWidget::AllDockWidgetFeaturesDockWidgetClosable | DockWidgetMovable | DockWidgetFloatable(Deprecated) The dock widget can be closed, moved, and floated. Since new features might be added in future releases, the look and behavior of dock widgets might change if you use this flag. Please specify individual flags instead.
QDockWidget::NoDockWidgetFeatures0x00The dock widget cannot be closed, moved, or floated.

The DockWidgetFeatures type is a typedef for QFlags<DockWidgetFeature>. It stores an OR combination of DockWidgetFeature values.

Property Documentation

allowedAreas : Qt::DockWidgetAreas

This property holds areas where the dock widget may be placed.

The default is Qt::AllDockWidgetAreas.

Access functions:

Qt::DockWidgetAreas allowedAreas() const
void setAllowedAreas(Qt::DockWidgetAreas areas)

Notifier signal:

void allowedAreasChanged(Qt::DockWidgetAreas allowedAreas)

See also Qt::DockWidgetArea.

features : DockWidgetFeatures

This property holds whether the dock widget is movable, closable, and floatable.

By default, this property is set to a combination of DockWidgetClosable, DockWidgetMovable and DockWidgetFloatable.

Access functions:

DockWidgetFeatures features() const
void setFeatures(DockWidgetFeatures features)

Notifier signal:

void featuresChanged(QDockWidget::DockWidgetFeatures features)

See also DockWidgetFeature.

floating : bool

This property holds whether the dock widget is floating.

A floating dock widget is presented to the user as an independent window "on top" of its parent QMainWindow, instead of being docked in the QMainWindow.

By default, this property is true.

Access functions:

bool isFloating() const
void setFloating(bool floating)

See also isWindow().

windowTitle : QString

This property holds the dock widget title (caption).

By default, this property contains an empty string.

Access functions:

QString windowTitle() const
void setWindowTitle(const QString &)

Notifier signal:

void windowTitleChanged(const QString & title)

Member Function Documentation

QDockWidget::QDockWidget(const QString & title, QWidget * parent = 0, Qt::WindowFlags flags = 0)

Constructs a QDockWidget with parent parent and window flags flags. The dock widget will be placed in the left dock widget area.

The window title is set to title. This title is used when the QDockWidget is docked and undocked. It is also used in the context menu provided by QMainWindow.

See also setWindowTitle().

QDockWidget::QDockWidget(QWidget * parent = 0, Qt::WindowFlags flags = 0)

Constructs a QDockWidget with parent parent and window flags flags. The dock widget will be placed in the left dock widget area.

QDockWidget::~QDockWidget()

Destroys the dock widget.

void QDockWidget::changeEvent(QEvent * event) [virtual protected]

Reimplemented from QWidget::changeEvent().

void QDockWidget::closeEvent(QCloseEvent * event) [virtual protected]

Reimplemented from QWidget::closeEvent().

void QDockWidget::dockLocationChanged(Qt::DockWidgetArea area) [signal]

This signal is emitted when the dock widget is moved to another dock area, or is moved to a different location in its current dock area. This happens when the dock widget is moved programmatically or is dragged to a new location by the user.

This function was introduced in Qt 4.3.

bool QDockWidget::event(QEvent * event) [virtual protected]

Reimplemented from QObject::event().

void QDockWidget::initStyleOption(QStyleOptionDockWidget * option) const [protected]

Initialize option with the values from this QDockWidget. This method is useful for subclasses when they need a QStyleOptionDockWidget, but don't want to fill in all the information themselves.

See also QStyleOption::initFrom().

bool QDockWidget::isAreaAllowed(Qt::DockWidgetArea area) const

Returns true if this dock widget can be placed in the given area; otherwise returns false.

void QDockWidget::paintEvent(QPaintEvent * event) [virtual protected]

Reimplemented from QWidget::paintEvent().

void QDockWidget::setTitleBarWidget(QWidget * widget)

Sets an arbitrary widget as the dock widget's title bar. If widget is 0, any custom title bar widget previously set on the dock widget is removed, but not deleted, and the default title bar will be used instead.

If a title bar widget is set, QDockWidget will not use native window decorations when it is floated.

Here are some tips for implementing custom title bars:

  • Mouse events that are not explicitly handled by the title bar widget must be ignored by calling QMouseEvent::ignore(). These events then propagate to the QDockWidget parent, which handles them in the usual manner, moving when the title bar is dragged, docking and undocking when it is double-clicked, etc.
  • When DockWidgetVerticalTitleBar is set on QDockWidget, the title bar widget is repositioned accordingly. In resizeEvent(), the title bar should check what orientation it should assume:
    QDockWidget *dockWidget = qobject_cast<QDockWidget*>(parentWidget());
    if (dockWidget->features() & QDockWidget::DockWidgetVerticalTitleBar) {
        // I need to be vertical
    } else {
        // I need to be horizontal
    }
  • The title bar widget must have a valid QWidget::sizeHint() and QWidget::minimumSizeHint(). These functions should take into account the current orientation of the title bar.
  • It is not possible to remove a title bar from a dock widget. However, a similar effect can be achieved by setting a default constructed QWidget as the title bar widget.

Using qobject_cast() as shown above, the title bar widget has full access to its parent QDockWidget. Hence it can perform such operations as docking and hiding in response to user actions.

This function was introduced in Qt 4.3.

See also titleBarWidget() and DockWidgetVerticalTitleBar.

void QDockWidget::setWidget(QWidget * widget)

Sets the widget for the dock widget to widget.

If the dock widget is visible when widget is added, you must show() it explicitly.

Note that you must add the layout of the widget before you call this function; if not, the widget will not be visible.

See also widget().

QWidget * QDockWidget::titleBarWidget() const

Returns the custom title bar widget set on the QDockWidget, or 0 if no custom title bar has been set.

This function was introduced in Qt 4.3.

See also setTitleBarWidget().

QAction * QDockWidget::toggleViewAction() const

Returns a checkable action that can be used to show or close this dock widget.

The action's text is set to the dock widget's window title.

See also QAction::text and QWidget::windowTitle.

void QDockWidget::topLevelChanged(bool topLevel) [signal]

This signal is emitted when the floating property changes. The topLevel parameter is true if the dock widget is now floating; otherwise it is false.

See also isWindow().

void QDockWidget::visibilityChanged(bool visible) [signal]

This signal is emitted when the dock widget becomes visible (or invisible). This happens when the widget is hidden or shown, as well as when it is docked in a tabbed dock area and its tab becomes selected or unselected.

This function was introduced in Qt 4.3.

QWidget * QDockWidget::widget() const

Returns the widget for the dock widget. This function returns zero if the widget has not been set.

See also setWidget().

Notes provided by the Qt Community

No notes