QMdiSubWindow Class

The QMdiSubWindow class provides a subwindow class for QMdiArea. More...

Header:	#include <QMdiSubWindow>
qmake:	QT += widgets
Since:	Qt 4.3
Inherits:	QWidget

This class was introduced in Qt 4.3.

List of all members, including inherited members

Public Types

enum	SubWindowOption { RubberBandResize, RubberBandMove }

Properties

keyboardPageStep : int
keyboardSingleStep : int

Public Functions

int	keyboardPageStep() const
int	keyboardSingleStep() const
void	setKeyboardPageStep(int step)
void	setKeyboardSingleStep(int step)

Detailed Description

QMdiSubWindow represents a top-level window in a QMdiArea, and consists of a title bar with window decorations, an internal widget, and (depending on the current style) a window frame and a size grip. QMdiSubWindow has its own layout, which consists of the title bar and a center area for the internal widget.

The most common way to construct a QMdiSubWindow is to call QMdiArea::addSubWindow() with the internal widget as the argument. You can also create a subwindow yourself, and set an internal widget by calling setWidget().

You use the same API when programming with subwindows as with regular top-level windows (e.g., you can call functions such as show(), hide(), showMaximized(), and setWindowTitle()).

Subwindow Handling

QMdiSubWindow also supports behavior specific to subwindows in an MDI area.

By default, each QMdiSubWindow is visible inside the MDI area viewport when moved around, but it is also possible to specify transparent window movement and resizing behavior, where only the outline of a subwindow is updated during these operations. The setOption() function is used to enable this behavior.

The isShaded() function detects whether the subwindow is currently shaded (i.e., the window is collapsed so that only the title bar is visible). To enter shaded mode, call showShaded(). QMdiSubWindow emits the windowStateChanged() signal whenever the window state has changed (e.g., when the window becomes minimized, or is restored). It also emits aboutToActivate() before it is activated.

In keyboard-interactive mode, the windows are moved and resized with the keyboard. You can enter this mode through the system menu of the window. The keyboardSingleStep and keyboardPageStep properties control the distance the widget is moved or resized for each keypress event. When shift is pressed down page step is used; otherwise single step is used.

You can also change the active window with the keyboard. By pressing the control and tab keys at the same time, the next (using the current WindowOrder) subwindow will be activated. By pressing control, shift, and tab, you will activate the previous window. This is equivalent to calling activateNextSubWindow() and activatePreviousSubWindow(). Note that these shortcuts overrides global shortcuts, but not the QMdiAreas shortcuts.

See also QMdiArea.

Member Type Documentation

enum QMdiSubWindow::SubWindowOption

This enum describes options that customize the behavior of QMdiSubWindow.

Constant	Value	Description
`QMdiSubWindow::RubberBandResize`	`0x4`	If you enable this option, a rubber band control is used to represent the subwindow's outline, and the user resizes this instead of the subwindow itself. As a result, the subwindow maintains its original position and size until the resize operation has been completed, at which time it will receive a single QResizeEvent. By default, this option is disabled.
`QMdiSubWindow::RubberBandMove`	`0x8`	If you enable this option, a rubber band control is used to represent the subwindow's outline, and the user moves this instead of the subwindow itself. As a result, the subwindow remains in its original position until the move operation has completed, at which time a QMoveEvent is sent to the window. By default, this option is disabled.

Property Documentation

keyboardPageStep : int

sets how far a widget should move or resize when using the keyboard page keys.

When in keyboard-interactive mode, you can use the arrow and page keys to either move or resize the window. This property controls the page keys. The common way to enter keyboard interactive mode is to enter the subwindow menu, and select either "resize" or "move".

The default keyboard page step value is 20 pixels.

Access functions:

int	keyboardPageStep() const
void	setKeyboardPageStep(int step)

See also keyboardSingleStep.

keyboardSingleStep : int

sets how far a widget should move or resize when using the keyboard arrow keys.

When in keyboard-interactive mode, you can use the arrow and page keys to either move or resize the window. This property controls the arrow keys. The common way to enter keyboard interactive mode is to enter the subwindow menu, and select either "resize" or "move".

The default keyboard single step value is 5 pixels.