QMainWindow Class

The QMainWindow class provides the main window of an application. More…

List of all members, including inherited members

Public Functions

Reimplemented Public Functions

Public Slots

Signals

Detailed Description

A main window has a menu bar at the top, tool bars under it and at the sides, dock widgets around a central widget, and a status bar at the bottom. All are optional except the central widget, which fills the space that is left:

QMainWindow window;
window.setCentralWidget(new QPlainTextEdit);
QMenu *file = window.menuBar()->addMenu("&File");
file->addAction("&Quit", [] { qApp->quit(); });
QToolBar *tools = window.addToolBar("Tools");
tools->addAction("Bold");
window.statusBar()->showMessage("Ready");
window.show();

menuBar() and statusBar() create the bars the first time they are called. Tool bars go in rows across the top and the bottom and in columns at the sides; addToolBarBreak() starts a new row. Dock widgets at the top and the bottom span the width of the window; the ones at the left and the right are between them, and several in one area share it.

createPopupMenu() returns a menu with the toggle view actions of the dock widgets and tool bars.

See also QMenuBar, QToolBar, QDockWidget and QStatusBar.

Differences from Qt

Member Function Documentation

[explicit] QMainWindow::QMainWindow(QWidget *parent = nullptr, Qt::WindowFlags flags = Qt::WindowFlags())

Constructs a main window with the given parent and window flags. A main window is always a window, even with a parent.

[override] QMainWindow::~QMainWindow()

Destroys the main window and its bars and widgets.

void QMainWindow::addDockWidget(Qt::DockWidgetArea area, QDockWidget *dockwidget)

Adds dockwidget to the area of the window, after the dock widgets there. A floating dock widget is docked, and one that is in the window already moves. Emits QDockWidget::dockLocationChanged().

See also removeDockWidget() and dockWidgetArea().

void QMainWindow::addDockWidget(Qt::DockWidgetArea area, QDockWidget *dockwidget, Qt::Orientation orientation)

This is an overloaded function.

Adds dockwidget to area; orientation is accepted for compatibility: the dock widgets of the left and right areas are always one above the other, and those of the top and bottom areas side by side.

void QMainWindow::addToolBar(Qt::ToolBarArea area, QToolBar *toolbar)

Adds toolbar to the area of the window, after the tool bars there. A tool bar that is in the window already moves.

See also removeToolBar() and toolBarArea().

void QMainWindow::addToolBar(QToolBar *toolbar)

This is an overloaded function.

Adds toolbar at the top of the window.

QToolBar * QMainWindow::addToolBar(const QString &title)

This is an overloaded function.

Creates a tool bar with the given window title, adds it at the top of the window and returns it.

void QMainWindow::addToolBarBreak(Qt::ToolBarArea area = Qt::TopToolBarArea)

Makes the next tool bar added to area start a new line.

See also insertToolBarBreak() and toolBarBreak().

QWidget * QMainWindow::centralWidget() const

Returns the central widget of the window, or nullptr.

See also setCentralWidget().

[virtual] QMenu * QMainWindow::createPopupMenu()

Returns a new menu with the toggle view actions of the dock widgets and, after a separator, of the tool bars of the window, or nullptr if it has neither. The caller owns the menu.

See also QToolBar::toggleViewAction() and QDockWidget::toggleViewAction().

Qt::DockWidgetArea QMainWindow::dockWidgetArea(QDockWidget *dockwidget) const

Returns the area that dockwidget is in, or Qt::NoDockWidgetArea if it is not in the window.

void QMainWindow::insertToolBar(QToolBar *before, QToolBar *toolbar)

Inserts toolbar before the tool bar before, in its area.

See also addToolBar().

void QMainWindow::insertToolBarBreak(QToolBar *before)

Makes the tool bar before start a new line of its area.

See also removeToolBarBreak().

QMenuBar * QMainWindow::menuBar() const

Returns the menu bar of the window, creating it the first time if the window has no menu widget.

See also setMenuBar() and menuWidget().

QWidget * QMainWindow::menuWidget() const

Returns the widget at the top of the window, usually the menu bar, or nullptr.

See also setMenuWidget().

[override] QSize QMainWindow::minimumSizeHint() const

Reimplements QWidget::minimumSizeHint().

void QMainWindow::removeDockWidget(QDockWidget *dockwidget)

Removes dockwidget from the window and hides it. The dock widget is not deleted.

See also addDockWidget().

void QMainWindow::removeToolBar(QToolBar *toolbar)

Removes toolbar from the window and hides it. The tool bar is not deleted.

See also addToolBar().

void QMainWindow::removeToolBarBreak(QToolBar *before)

Lets the tool bar before go on the line of the tool bar before it.

See also insertToolBarBreak().

bool QMainWindow::restoreDockWidget(QDockWidget *dockwidget)

Shows dockwidget again in its area if it is in the window, and returns whether it is.

void QMainWindow::setCentralWidget(QWidget *widget)

Makes widget the central widget, which fills the space that the bars and dock widgets leave. The window takes it as a child and deletes the central widget it had.

See also centralWidget() and takeCentralWidget().

void QMainWindow::setMenuBar(QMenuBar *menubar)

Makes menubar the menu bar of the window. The window takes it as a child and deletes the menu widget it had.

See also menuBar().

void QMainWindow::setMenuWidget(QWidget *menubar)

Makes menubar, which may be any widget, the widget at the top of the window. The window takes it as a child and deletes the one it had.

See also menuWidget() and setMenuBar().

void QMainWindow::setStatusBar(QStatusBar *statusbar)

Makes statusbar the status bar of the window, or removes the status bar with nullptr. The window takes it as a child and deletes the one it had.

See also statusBar().

[slot] void QMainWindow::setToolButtonStyle(Qt::ToolButtonStyle toolButtonStyle)

Sets the style of the tool buttons of the tool bars of the window to toolButtonStyle.

See also toolButtonStyle().

[override] QSize QMainWindow::sizeHint() const

Reimplements QWidget::sizeHint().

QStatusBar * QMainWindow::statusBar() const

Returns the status bar of the window, creating it the first time.

See also setStatusBar().

QWidget * QMainWindow::takeCentralWidget()

Removes the central widget from the window without deleting it and returns it; the widget no longer has a parent, and the caller owns it.

See also setCentralWidget().

Qt::ToolBarArea QMainWindow::toolBarArea(const QToolBar *toolbar) const

Returns the area that toolbar is in, or Qt::NoToolBarArea if it is not in the window.

bool QMainWindow::toolBarBreak(QToolBar *toolbar) const

Returns whether a new line of tool bars starts with toolbar.

See also insertToolBarBreak().

Qt::ToolButtonStyle QMainWindow::toolButtonStyle() const

Returns the style of the tool buttons of the tool bars of the window, Qt::ToolButtonIconOnly by default.

See also setToolButtonStyle().

[signal] void QMainWindow::toolButtonStyleChanged(Qt::ToolButtonStyle toolButtonStyle)

This signal is emitted when the style of the tool buttons changes to toolButtonStyle.