QWindow Class

The QWindow class represents a window in the underlying windowing system. More...

Header: #include <QWindow>
qmake: QT += gui
Since: Qt 5.0
Inherits: QObject and QSurface
Inherited By:

QAbstract3DGraph, QPaintDeviceWindow, and QQuickWindow

Public Types

enum AncestorMode { ExcludeTransients, IncludeTransients }
enum Visibility { Windowed, Minimized, Maximized, FullScreen, AutomaticVisibility, Hidden }


  • 1 property inherited from QObject

Public Functions

QWindow(QScreen *targetScreen = Q_NULLPTR)
QWindow(QWindow *parent)
virtual ~QWindow()
QSize baseSize() const
Qt::ScreenOrientation contentOrientation() const
void create()
QCursor cursor() const
void destroy()
qreal devicePixelRatio() const
QString filePath() const
Qt::WindowFlags flags() const
virtual QObject *focusObject() const
QRect frameGeometry() const
QMargins frameMargins() const
QPoint framePosition() const
QRect geometry() const
int height() const
QIcon icon() const
bool isActive() const
bool isAncestorOf(const QWindow *child, AncestorMode mode = IncludeTransients) const
bool isExposed() const
bool isModal() const
bool isTopLevel() const
bool isVisible() const
QPoint mapFromGlobal(const QPoint &pos) const
QPoint mapToGlobal(const QPoint &pos) const
QRegion mask() const
int maximumHeight() const
QSize maximumSize() const
int maximumWidth() const
int minimumHeight() const
QSize minimumSize() const
int minimumWidth() const
Qt::WindowModality modality() const
qreal opacity() const
QWindow *parent() const
QPoint position() const
void reportContentOrientationChange(Qt::ScreenOrientation orientation)
QSurfaceFormat requestedFormat() const
void resize(const QSize &newSize)
void resize(int w, int h)
QScreen *screen() const
void setBaseSize(const QSize &size)
void setCursor(const QCursor &cursor)
void setFilePath(const QString &filePath)
void setFlags(Qt::WindowFlags flags)
void setFormat(const QSurfaceFormat &format)
void setFramePosition(const QPoint &point)
void setGeometry(int posx, int posy, int w, int h)
void setGeometry(const QRect &rect)
void setIcon(const QIcon &icon)
bool setKeyboardGrabEnabled(bool grab)
void setMask(const QRegion &region)
void setMaximumSize(const QSize &size)
void setMinimumSize(const QSize &size)
void setModality(Qt::WindowModality modality)
bool setMouseGrabEnabled(bool grab)
void setOpacity(qreal level)
void setParent(QWindow *parent)
void setPosition(const QPoint &pt)
void setPosition(int posx, int posy)
void setScreen(QScreen *newScreen)
void setSizeIncrement(const QSize &size)
void setSurfaceType(SurfaceType surfaceType)
void setTransientParent(QWindow *parent)
void setVisibility(Visibility v)
void setWindowState(Qt::WindowState state)
QSize sizeIncrement() const
QString title() const
QWindow *transientParent() const
Qt::WindowType type() const
void unsetCursor()
Visibility visibility() const
int width() const
WId winId() const
Qt::WindowState windowState() const
int x() const
int y() const

Reimplemented Public Functions

virtual QSurfaceFormat format() const
virtual QSize size() const
virtual SurfaceType surfaceType() const
  • 31 public functions inherited from QObject
  • 6 public functions inherited from QSurface

Public Slots

void alert(int msec)
bool close()
void hide()
void lower()
void raise()
void requestActivate()
void requestUpdate()
void setHeight(int arg)
void setMaximumHeight(int h)
void setMaximumWidth(int w)
void setMinimumHeight(int h)
void setMinimumWidth(int w)
void setTitle(const QString &)
void setVisible(bool visible)
void setWidth(int arg)
void setX(int arg)
void setY(int arg)
void show()
void showFullScreen()
void showMaximized()
void showMinimized()
void showNormal()
  • 1 public slot inherited from QObject


void activeChanged()
void contentOrientationChanged(Qt::ScreenOrientation orientation)
void focusObjectChanged(QObject *object)
void heightChanged(int arg)
void maximumHeightChanged(int arg)
void maximumWidthChanged(int arg)
void minimumHeightChanged(int arg)
void minimumWidthChanged(int arg)
void modalityChanged(Qt::WindowModality modality)
void opacityChanged(qreal opacity)
void screenChanged(QScreen *screen)
void visibilityChanged(QWindow::Visibility visibility)
void visibleChanged(bool arg)
void widthChanged(int arg)
void windowStateChanged(Qt::WindowState windowState)
void windowTitleChanged(const QString &title)
void xChanged(int arg)
void yChanged(int arg)

Static Public Members

QWindow *fromWinId(WId id)
  • 11 static public members inherited from QObject

Protected Functions

virtual void exposeEvent(QExposeEvent *ev)
virtual void focusInEvent(QFocusEvent *ev)
virtual void focusOutEvent(QFocusEvent *ev)
virtual void hideEvent(QHideEvent *ev)
virtual void keyPressEvent(QKeyEvent *ev)
virtual void keyReleaseEvent(QKeyEvent *ev)
virtual void mouseDoubleClickEvent(QMouseEvent *ev)
virtual void mouseMoveEvent(QMouseEvent *ev)
virtual void mousePressEvent(QMouseEvent *ev)
virtual void mouseReleaseEvent(QMouseEvent *ev)
virtual void moveEvent(QMoveEvent *ev)
virtual bool nativeEvent(const QByteArray &eventType, void *message, long *result)
virtual void resizeEvent(QResizeEvent *ev)
virtual void showEvent(QShowEvent *ev)
virtual void tabletEvent(QTabletEvent *ev)
virtual void touchEvent(QTouchEvent *ev)
virtual void wheelEvent(QWheelEvent *ev)

Reimplemented Protected Functions

virtual bool event(QEvent *ev)
  • 9 protected functions inherited from QObject

Detailed Description

The QWindow class represents a window in the underlying windowing system.

A window that is supplied a parent becomes a native child window of their parent window.

An application will typically use QWidget or QQuickView for its UI, and not QWindow directly. Still, it is possible to render directly to a QWindow with QBackingStore or QOpenGLContext, when wanting to keep dependencies to a minimum or when wanting to use OpenGL directly. The Raster Window Example and OpenGL Window Example are useful reference examples for how to render to a QWindow using either approach.

Resource Management

Windows can potentially use a lot of memory. A usual measurement is width times height times color depth. A window might also include multiple buffers to support double and triple buffering, as well as depth and stencil buffers. To release a window's memory resources, call the destroy() function.

Content Orientation

QWindow has reportContentOrientationChange() that can be used to specify the layout of the window contents in relation to the screen. The content orientation is simply a hint to the windowing system about which orientation the window contents are in. It's useful when you wish to keep the same window size, but rotate the contents instead, especially when doing rotation animations between different orientations. The windowing system might use this value to determine the layout of system popups or dialogs.

Visibility and Windowing System Exposure

By default, the window is not visible, and you must call setVisible(true), or show() or similar to make it visible. To make a window hidden again, call setVisible(false) or hide(). The visible property describes the state the application wants the window to be in. Depending on the underlying system, a visible window might still not be shown on the screen. It could, for instance, be covered by other opaque windows or moved outside the physical area of the screen. On windowing systems that have exposure notifications, the isExposed() accessor describes whether the window should be treated as directly visible on screen. The exposeEvent() function is called whenever the windows exposure in the windowing system changes. On windowing systems that do not make this information visible to the application, isExposed() will simply return the same value as isVisible().

QWindow::Visibility queried through visibility() is a convenience API combining the functions of visible() and windowState().


There are two Qt APIs that can be used to render content into a window, QBackingStore for rendering with a QPainter and flushing the contents to a window with type QSurface::RasterSurface, and QOpenGLContext for rendering with OpenGL to a window with type QSurface::OpenGLSurface.

The application can start rendering as soon as isExposed() returns true, and can keep rendering until it isExposed() returns false. To find out when isExposed() changes, reimplement exposeEvent(). The window will always get a resize event before the first expose event.

Initial Geometry

If the window's width and height are left uninitialized, the window will get a reasonable default geometry from the platform window. If the position is left uninitialized, then the platform window will allow the windowing system to position the window. For example on X11, the window manager usually does some kind of smart positioning to try to avoid having new windows completely obscure existing windows. However setGeometry() initializes both the position and the size, so if you want a fixed size but an automatic position, you should call resize() or setWidth() and setHeight() instead.

Member Type Documentation

enum QWindow::AncestorMode

This enum is used to control whether or not transient parents should be considered ancestors.

QWindow::ExcludeTransients0Transient parents are not considered ancestors.
QWindow::IncludeTransients1Transient parents are considered ancestors.

enum QWindow::Visibility

This enum describes what part of the screen the window occupies or should occupy.

QWindow::Windowed2The window occupies part of the screen, but not necessarily the entire screen. This state will occur only on windowing systems which support showing multiple windows simultaneously. In this state it is possible for the user to move and resize the window manually, if WindowFlags permit it and if it is supported by the windowing system.
QWindow::Minimized3The window is reduced to an entry or icon on the task bar, dock, task list or desktop, depending on how the windowing system handles minimized windows.
QWindow::Maximized4The window occupies one entire screen, and the titlebar is still visible. On most windowing systems this is the state achieved by clicking the maximize button on the toolbar.
QWindow::FullScreen5The window occupies one entire screen, is not resizable, and there is no titlebar. On some platforms which do not support showing multiple simultaneous windows, this can be the usual visibility when the window is not hidden.
QWindow::AutomaticVisibility1This means to give the window a default visible state, which might be fullscreen or windowed depending on the platform. It can be given as a parameter to setVisibility but will never be read back from the visibility accessor.
QWindow::Hidden0The window is not visible in any way, however it may remember a latent visibility which can be restored by setting AutomaticVisibility.

This enum was introduced or modified in Qt 5.1.

Property Documentation

active : const bool

This property holds the active status of the window.

This property was introduced in Qt 5.1.

Access functions:

bool isActive() const

Notifier signal:

void activeChanged()

See also requestActivate().

contentOrientation : Qt::ScreenOrientation

This property holds the orientation of the window's contents.

This is a hint to the window manager in case it needs to display additional content like popups, dialogs, status bars, or similar in relation to the window.

The recommended orientation is QScreen::orientation() but an application doesn't have to support all possible orientations, and thus can opt to ignore the current screen orientation.

The difference between the window and the content orientation determines how much to rotate the content by. QScreen::angleBetween(), QScreen::transformBetween(), and QScreen::mapBetween() can be used to compute the necessary transform.

The default value is Qt::PrimaryOrientation

Access functions:

Qt::ScreenOrientation contentOrientation() const
void reportContentOrientationChange(Qt::ScreenOrientation orientation)

Notifier signal:

void contentOrientationChanged(Qt::ScreenOrientation orientation)

flags : Qt::WindowFlags

This property holds the window flags of the window.

The window flags control the window's appearance in the windowing system, whether it's a dialog, popup, or a regular window, and whether it should have a title bar, etc.

The actual window flags might differ from the flags set with setFlags() if the requested flags could not be fulfilled.

Access functions:

Qt::WindowFlags flags() const
void setFlags(Qt::WindowFlags flags)

height : int

This property holds the height of the window's geometry.

Access functions:

int height() const
void setHeight(int arg)

Notifier signal:

void heightChanged(int arg)

maximumHeight : int

This property holds the maximum height of the window's geometry.

Access functions:

int maximumHeight() const
void setMaximumHeight(int h)

Notifier signal:

void maximumHeightChanged(int arg)

maximumWidth : int

This property holds the maximum width of the window's geometry.

Access functions:

int maximumWidth() const
void setMaximumWidth(int w)

Notifier signal:

void maximumWidthChanged(int arg)

minimumHeight : int

This property holds the minimum height of the window's geometry.

Access functions:

int minimumHeight() const
void setMinimumHeight(int h)

Notifier signal:

void minimumHeightChanged(int arg)

minimumWidth : int

This property holds the minimum width of the window's geometry.

Access functions:

int minimumWidth() const
void setMinimumWidth(int w)

Notifier signal:

void minimumWidthChanged(int arg)

modality : Qt::WindowModality

This property holds the modality of the window.

A modal window prevents other windows from receiving input events. Qt supports two types of modality: Qt::WindowModal and Qt::ApplicationModal.

By default, this property is Qt::NonModal

Access functions:

Qt::WindowModality modality() const
void setModality(Qt::WindowModality modality)

Notifier signal:

void modalityChanged(Qt::WindowModality modality)

See also Qt::WindowModality.

opacity : qreal

This property holds the opacity of the window in the windowing system.

If the windowing system supports window opacity, this can be used to fade the window in and out, or to make it semitransparent.

A value of 1.0 or above is treated as fully opaque, whereas a value of 0.0 or below is treated as fully transparent. Values inbetween represent varying levels of translucency between the two extremes.

The default value is 1.0.

This property was introduced in Qt 5.1.

Access functions:

qreal opacity() const
void setOpacity(qreal level)

Notifier signal:

void opacityChanged(qreal opacity)

title : QString

This property holds the window's title in the windowing system.

The window title might appear in the title area of the window decorations, depending on the windowing system and the window flags. It might also be used by the windowing system to identify the window in other contexts, such as in the task switcher.

Access functions:

QString title() const
void setTitle(const QString &)

Notifier signal:

void windowTitleChanged(const QString &title)

See also flags().

visibility : Visibility

This property holds the screen-occupation state of the window.

Visibility is whether the window should appear in the windowing system as normal, minimized, maximized, fullscreen or hidden.

To set the visibility to AutomaticVisibility means to give the window a default visible state, which might be fullscreen or windowed depending on the platform. When reading the visibility property you will always get the actual state, never AutomaticVisibility.

This property was introduced in Qt 5.1.

Access functions:

Visibility visibility() const
void setVisibility(Visibility v)

Notifier signal:

void visibilityChanged(QWindow::Visibility visibility)

visible : bool

This property holds whether the window is visible or not.

This property controls the visibility of the window in the windowing system.

By default, the window is not visible, you must call setVisible(true), or show() or similar to make it visible.

Access functions:

bool isVisible() const
void setVisible(bool visible)

Notifier signal:

void visibleChanged(bool arg)

See also show().

width : int

This property holds the width of the window's geometry.

Access functions:

int width() const
void setWidth(int arg)

Notifier signal:

void widthChanged(int arg)

x : int

This property holds the x position of the window's geometry.

Access functions:

int x() const
void setX(int arg)

Notifier signal:

void xChanged(int arg)

y : int

This property holds the y position of the window's geometry.

Access functions:

int y() const
void setY(int arg)

Notifier signal:

void yChanged(int arg)

Member Function Documentation

QWindow::QWindow(QScreen *targetScreen = Q_NULLPTR)

Creates a window as a top level on the targetScreen.

The window is not shown until setVisible(true), show(), or similar is called.

See also setScreen().

QWindow::QWindow(QWindow *parent)

Creates a window as a child of the given parent window.

The window will be embedded inside the parent window, its coordinates relative to the parent.

The screen is inherited from the parent.

See also setParent().

[virtual] QWindow::~QWindow()

Destroys the window.

[slot] void QWindow::alert(int msec)

Causes an alert to be shown for msec miliseconds. If msec is 0 (the default), then the alert is shown indefinitely until the window becomes active again. This function has no effect on an active window.

In alert state, the window indicates that it demands attention, for example by flashing or bouncing the taskbar entry.

This function was introduced in Qt 5.1.

QSize QWindow::baseSize() const

Returns the base size of the window.

See also setBaseSize().

[slot] bool QWindow::close()

Close the window.

This closes the window, effectively calling destroy(), and potentially quitting the application. Returns true on success, false if it has a parent window (in which case the top level window should be closed instead).

See also destroy() and QGuiApplication::quitOnLastWindowClosed().

void QWindow::create()

Allocates the platform resources associated with the window.

It is at this point that the surface format set using setFormat() gets resolved into an actual native surface. However, the window remains hidden until setVisible() is called.

Note that it is not usually necessary to call this function directly, as it will be implicitly called by show(), setVisible(), and other functions that require access to the platform resources.

Call destroy() to free the platform resources if necessary.

See also destroy().

QCursor QWindow::cursor() const

the cursor shape for this window

See also setCursor() and unsetCursor().

void QWindow::destroy()

Releases the native platform resources associated with this window.

See also create().

qreal QWindow::devicePixelRatio() const

Returns the ratio between physical pixels and device-independent pixels for the window. This value is dependent on the screen the window is on, and may change when the window is moved.

Common values are 1.0 on normal displays and 2.0 on Apple "retina" displays.

Note: For windows not backed by a platform window, meaning that create() was not called, the function will fall back to QGuiApplication::devicePixelRatio() which in turn returns the highest screen device pixel ratio found on the system.

See also QScreen::devicePixelRatio() and QGuiApplication::devicePixelRatio().

[virtual protected] bool QWindow::event(QEvent *ev)

Reimplemented from QObject::event().

Override this to handle any event (ev) sent to the window. Return true if the event was recognized and processed.

Remember to call the base class version if you wish for mouse events, key events, resize events, etc to be dispatched as usual.

[virtual protected] void QWindow::exposeEvent(QExposeEvent *ev)

The expose event (ev) is sent by the window system whenever the window's exposure on screen changes.

The application can start rendering into the window with QBackingStore and QOpenGLContext as soon as it gets an exposeEvent() such that isExposed() is true.

If the window is moved off screen, is made totally obscured by another window, iconified or similar, this function might be called and the value of isExposed() might change to false. When this happens, an application should stop its rendering as it is no longer visible to the user.

A resize event will always be sent before the expose event the first time a window is shown.

See also isExposed().

QString QWindow::filePath() const

the file name this window is representing.

See also setFilePath().

[virtual protected] void QWindow::focusInEvent(QFocusEvent *ev)

Override this to handle focus in events (ev).

Focus in events are sent when the window receives keyboard focus.

See also focusOutEvent().

[virtual] QObject *QWindow::focusObject() const

Returns the QObject that will be the final receiver of events tied focus, such as key events.

[signal] void QWindow::focusObjectChanged(QObject *object)

This signal is emitted when the final receiver of events tied to focus is changed to object.

See also focusObject().

[virtual protected] void QWindow::focusOutEvent(QFocusEvent *ev)

Override this to handle focus out events (ev).

Focus out events are sent when the window loses keyboard focus.

See also focusInEvent().

[virtual] QSurfaceFormat QWindow::format() const

Reimplemented from QSurface::format().

Returns the actual format of this window.

After the window has been created, this function will return the actual surface format of the window. It might differ from the requested format if the requested format could not be fulfilled by the platform. It might also be a superset, for example certain buffer sizes may be larger than requested.

Note: Depending on the platform, certain values in this surface format may still contain the requested values, that is, the values that have been passed to setFormat(). Typical examples are the OpenGL version, profile and options. These may not get updated during create() since these are context specific and a single window may be used together with multiple contexts over its lifetime. Use the QOpenGLContext's format() instead to query such values.

See also setFormat(), create(), requestedFormat(), and QOpenGLContext::format().

QRect QWindow::frameGeometry() const

Returns the geometry of the window, including its window frame.

See also geometry() and frameMargins().

QMargins QWindow::frameMargins() const

Returns the window frame margins surrounding the window.

See also geometry() and frameGeometry().

QPoint QWindow::framePosition() const

Returns the top left position of the window, including its window frame.

This returns the same value as frameGeometry().topLeft().

See also setFramePosition(), geometry(), and frameGeometry().

[static] QWindow *QWindow::fromWinId(WId id)

Creates a local representation of a window created by another process or by using native libraries below Qt.

Given the handle id to a native window, this method creates a QWindow object which can be used to represent the window when invoking methods like setParent() and setTransientParent().

This can be used, on platforms which support it, to embed a QWindow inside a native window, or to embed a native window inside a QWindow.

If foreign windows are not supported or embedding the native window failed in the platform plugin, this function returns 0.

Note: The resulting QWindow should not be used to manipulate the underlying native window (besides re-parenting), or to observe state changes of the native window. Any support for these kind of operations is incidental, highly platform dependent and untested.

See also setParent() and setTransientParent().

QRect QWindow::geometry() const

Returns the geometry of the window, excluding its window frame.

See also setGeometry(), frameMargins(), and frameGeometry().

[slot] void QWindow::hide()

Hides the window.

Equivalent to calling setVisible(false).

See also show() and setVisible().

[virtual protected] void QWindow::hideEvent(QHideEvent *ev)

Override this to handle hide events (ev).

The function is called when the window has requested being hidden in the windowing system.

QIcon QWindow::icon() const

Sets the window's icon in the windowing system

See also setIcon().

bool QWindow::isActive() const

Returns true if the window should appear active from a style perspective.

This is the case for the window that has input focus as well as windows that are in the same parent / transient parent chain as the focus window.

To get the window that currently has focus, use QGuiApplication::focusWindow().

Note: Getter function for property active.

bool QWindow::isAncestorOf(const QWindow *child, AncestorMode mode = IncludeTransients) const

Returns true if the window is an ancestor of the given child. If mode is IncludeTransients, then transient parents are also considered ancestors.

bool QWindow::isExposed() const

Returns if this window is exposed in the windowing system.

When the window is not exposed, it is shown by the application but it is still not showing in the windowing system, so the application should minimize rendering and other graphical activities.

An exposeEvent() is sent every time this value changes.

See also exposeEvent().

bool QWindow::isModal() const

Returns whether the window is modal.

A modal window prevents other windows from getting any input.

See also QWindow::modality.

bool QWindow::isTopLevel() const

Returns whether the window is top level, i.e. has no parent window.

[virtual protected] void QWindow::keyPressEvent(QKeyEvent *ev)

Override this to handle key press events (ev).

See also keyReleaseEvent().

[virtual protected] void QWindow::keyReleaseEvent(QKeyEvent *ev)

Override this to handle key release events (ev).

See also keyPressEvent().

[slot] void QWindow::lower()

Lower the window in the windowing system.

Requests that the window be lowered to appear below other windows.

QPoint QWindow::mapFromGlobal(const QPoint &pos) const

Translates the global screen coordinate pos to window coordinates.

See also mapToGlobal().

QPoint QWindow::mapToGlobal(const QPoint &pos) const

Translates the window coordinate pos to global screen coordinates. For example, mapToGlobal(QPoint(0,0)) would give the global coordinates of the top-left pixel of the window.

See also mapFromGlobal().

QRegion QWindow::mask() const

Returns the mask set on the window.

The mask is a hint to the windowing system that the application does not want to receive mouse or touch input outside the given region.

See also setMask().

QSize QWindow::maximumSize() const

Returns the maximum size of the window.

See also setMaximumSize().

QSize QWindow::minimumSize() const

Returns the minimum size of the window.

See also setMinimumSize().

[signal] void QWindow::modalityChanged(Qt::WindowModality modality)

This signal is emitted when the Qwindow::modality property changes to modality.

Note: Notifier signal for property modality.

[virtual protected] void QWindow::mouseDoubleClickEvent(QMouseEvent *ev)

Override this to handle mouse double click events (ev).

See also mousePressEvent() and QStyleHints::mouseDoubleClickInterval().

[virtual protected] void QWindow::mouseMoveEvent(QMouseEvent *ev)

Override this to handle mouse move events (ev).

[virtual protected] void QWindow::mousePressEvent(QMouseEvent *ev)

Override this to handle mouse press events (ev).

See also mouseReleaseEvent().

[virtual protected] void QWindow::mouseReleaseEvent(QMouseEvent *ev)

Override this to handle mouse release events (ev).

See also mousePressEvent().

[virtual protected] void QWindow::moveEvent(QMoveEvent *ev)

Override this to handle window move events (ev).

[virtual protected] bool QWindow::nativeEvent(const QByteArray &eventType, void *message, long *result)

Override this to handle platform dependent events. Will be given eventType, message and result.

This might make your application non-portable.

Should return true only if the event was handled.

QWindow *QWindow::parent() const

Returns the parent window, if any.

A window without a parent is known as a top level window.

See also setParent().

QPoint QWindow::position() const

Returns the position of the window on the desktop excluding any window frame

See also setPosition().

[slot] void QWindow::raise()

Raise the window in the windowing system.

Requests that the window be raised to appear above other windows.

[slot] void QWindow::requestActivate()

Requests the window to be activated, i.e. receive keyboard focus.

See also isActive(), QGuiApplication::focusWindow(), and QWindowsWindowFunctions::setWindowActivationBehavior().

[slot] void QWindow::requestUpdate()

Schedules a QEvent::UpdateRequest event to be delivered to this window.

The event is delivered in sync with the display vsync on platforms where this is possible. Otherwise, the event is delivered after a delay of 5 ms. The additional time is there to give the event loop a bit of idle time to gather system events, and can be overridden using the QT_QPA_UPDATE_IDLE_TIME environment variable.

When driving animations, this function should be called once after drawing has completed. Calling this function multiple times will result in a single event being delivered to the window.

Subclasses of QWindow should reimplement event(), intercept the event and call the application's rendering code, then call the base class implementation.

Note: The subclass' reimplementation of event() must invoke the base class implementation, unless it is absolutely sure that the event does not need to be handled by the base class. For example, the default implementation of this function relies on QEvent::Timer events. Filtering them away would therefore break the delivery of the update events.

This function was introduced in Qt 5.5.

QSurfaceFormat QWindow::requestedFormat() const

Returns the requested surface format of this window.

If the requested format was not supported by the platform implementation, the requestedFormat will differ from the actual window format.

This is the value set with setFormat().

See also setFormat() and format().

void QWindow::resize(const QSize &newSize)

set the size of the window, excluding any window frame, to newSize

See also size() and geometry().

void QWindow::resize(int w, int h)

set the size of the window, excluding any window frame, to a QSize constructed from width w and height h

See also size() and geometry().

[virtual protected] void QWindow::resizeEvent(QResizeEvent *ev)

Override this to handle resize events (ev).

The resize event is called whenever the window is resized in the windowing system, either directly through the windowing system acknowledging a setGeometry() or resize() request, or indirectly through the user resizing the window manually.

QScreen *QWindow::screen() const

Returns the screen on which the window is shown, or null if there is none.

For child windows, this returns the screen of the corresponding top level window.

See also setScreen() and QScreen::virtualSiblings().

[signal] void QWindow::screenChanged(QScreen *screen)

This signal is emitted when a window's screen changes, either by being set explicitly with setScreen(), or automatically when the window's screen is removed.

void QWindow::setBaseSize(const QSize &size)

Sets the base size of the window.

The base size is used to calculate a proper window size if the window defines sizeIncrement().

See also setMinimumSize(), setMaximumSize(), setSizeIncrement(), and baseSize().

void QWindow::setCursor(const QCursor &cursor)

set the cursor shape for this window

The mouse cursor will assume this shape when it is over this window, unless an override cursor is set. See the list of predefined cursor objects for a range of useful shapes.

If no cursor has been set, or after a call to unsetCursor(), the parent window's cursor is used.

By default, the cursor has the Qt::ArrowCursor shape.

Some underlying window implementations will reset the cursor if it leaves a window even if the mouse is grabbed. If you want to have a cursor set for all windows, even when outside the window, consider QGuiApplication::setOverrideCursor().

See also cursor() and QGuiApplication::setOverrideCursor().

void QWindow::setFilePath(const QString &filePath)

set the file name this window is representing.

The windowing system might use filePath to display the path of the document this window is representing in the tile bar.

See also filePath().

void QWindow::setFormat(const QSurfaceFormat &format)

Sets the window's surface format.

The format determines properties such as color depth, alpha, depth and stencil buffer size, etc. For example, to give a window a transparent background (provided that the window system supports compositing, and provided that other content in the window does not make it opaque again):

QSurfaceFormat format;

The surface format will be resolved in the create() function. Calling this function after create() has been called will not re-resolve the surface format of the native surface.

When the format is not explicitly set via this function, the format returned by QSurfaceFormat::defaultFormat() will be used. This means that when having multiple windows, individual calls to this function can be replaced by one single call to QSurfaceFormat::setDefaultFormat() before creating the first window.

See also format(), create(), destroy(), and QSurfaceFormat::setDefaultFormat().

void QWindow::setFramePosition(const QPoint &point)

Sets the upper left position of the window (point) including its window frame.

See also framePosition(), setGeometry(), and frameGeometry().

void QWindow::setGeometry(int posx, int posy, int w, int h)

Sets the geometry of the window, excluding its window frame, to a rectangle constructed from posx, posy, w and h.

See also geometry().

void QWindow::setGeometry(const QRect &rect)

Sets the geometry of the window, excluding its window frame, to rect.

See also geometry().

void QWindow::setIcon(const QIcon &icon)

Sets the window's icon in the windowing system

The window icon might be used by the windowing system for example to decorate the window, and/or in the task switcher.

See also icon().

bool QWindow::setKeyboardGrabEnabled(bool grab)

Sets whether keyboard grab should be enabled or not (grab).

If the return value is true, the window receives all key events until setKeyboardGrabEnabled(false) is called; other windows get no key events at all. Mouse events are not affected. Use setMouseGrabEnabled() if you want to grab that.

See also setMouseGrabEnabled().

void QWindow::setMask(const QRegion &region)

Sets the mask of the window.

The mask is a hint to the windowing system that the application does not want to receive mouse or touch input outside the given region.

The window manager may or may not choose to display any areas of the window not included in the mask, thus it is the application's responsibility to clear to transparent the areas that are not part of the mask.

Setting the mask before the window has been created has no effect.

See also mask().

void QWindow::setMaximumSize(const QSize &size)

Sets the maximum size of the window.

This is a hint to the window manager to prevent resizing above the specified size.

See also setMinimumSize() and maximumSize().

void QWindow::setMinimumSize(const QSize &size)

Sets the minimum size of the window.

This is a hint to the window manager to prevent resizing below the specified size.

See also setMaximumSize() and minimumSize().

bool QWindow::setMouseGrabEnabled(bool grab)

Sets whether mouse grab should be enabled or not (grab).

If the return value is true, the window receives all mouse events until setMouseGrabEnabled(false) is called; other windows get no mouse events at all. Keyboard events are not affected. Use setKeyboardGrabEnabled() if you want to grab that.

See also setKeyboardGrabEnabled().

void QWindow::setParent(QWindow *parent)

Sets the parent Window. This will lead to the windowing system managing the clip of the window, so it will be clipped to the parent window.

Setting parent to be 0 will make the window become a top level window.

If parent is a window created by fromWinId(), then the current window will be embedded inside parent, if the platform supports it.

See also parent().

void QWindow::setPosition(const QPoint &pt)

set the position of the window on the desktop to pt

See also position().

void QWindow::setPosition(int posx, int posy)

set the position of the window on the desktop to posx, posy

See also position().

void QWindow::setScreen(QScreen *newScreen)

Sets the screen on which the window should be shown.

If the window has been created, it will be recreated on the newScreen.

Note that if the screen is part of a virtual desktop of multiple screens, the window can appear on any of the screens returned by QScreen::virtualSiblings().

This function only works for top level windows.

See also screen() and QScreen::virtualSiblings().

void QWindow::setSizeIncrement(const QSize &size)

Sets the size increment (size) of the window.

When the user resizes the window, the size will move in steps of sizeIncrement().width() pixels horizontally and sizeIncrement().height() pixels vertically, with baseSize() as the basis.

By default, this property contains a size with zero width and height.

The windowing system might not support size increments.

See also sizeIncrement(), setBaseSize(), setMinimumSize(), and setMaximumSize().

void QWindow::setSurfaceType(SurfaceType surfaceType)

Sets the surfaceType of the window.

Specifies whether the window is meant for raster rendering with QBackingStore, or OpenGL rendering with QOpenGLContext.

The surfaceType will be used when the native surface is created in the create() function. Calling this function after the native surface has been created requires calling destroy() and create() to release the old native surface and create a new one.

See also surfaceType(), QBackingStore, QOpenGLContext, create(), and destroy().

void QWindow::setTransientParent(QWindow *parent)

Sets the transient parent

This is a hint to the window manager that this window is a dialog or pop-up on behalf of the given window.

In order to cause the window to be centered above its transient parent by default, depending on the window manager, it may also be necessary to call setFlags() with a suitable Qt::WindowType (such as Qt::Dialog).

See also transientParent() and parent().

void QWindow::setWindowState(Qt::WindowState state)

set the screen-occupation state of the window

The window state represents whether the window appears in the windowing system as maximized, minimized, fullscreen, or normal.

The enum value Qt::WindowActive is not an accepted parameter.

See also windowState(), showNormal(), showFullScreen(), showMinimized(), and showMaximized().

[slot] void QWindow::show()

Shows the window.

This is equivalent to calling showFullScreen(), showMaximized(), or showNormal(), depending on the platform's default behavior for the window type and flags.

See also showFullScreen(), showMaximized(), showNormal(), hide(), QStyleHints::showIsFullScreen(), and flags().

[virtual protected] void QWindow::showEvent(QShowEvent *ev)

Override this to handle show events (ev).

The function is called when the window has requested becoming visible.

If the window is successfully shown by the windowing system, this will be followed by a resize and an expose event.

[slot] void QWindow::showFullScreen()

Shows the window as fullscreen.

Equivalent to calling setWindowState(Qt::WindowFullScreen) and then setVisible(true).

See also setWindowState() and setVisible().

[slot] void QWindow::showMaximized()

Shows the window as maximized.

Equivalent to calling setWindowState(Qt::WindowMaximized) and then setVisible(true).

See also setWindowState() and setVisible().

[slot] void QWindow::showMinimized()

Shows the window as minimized.

Equivalent to calling setWindowState(Qt::WindowMinimized) and then setVisible(true).

See also setWindowState() and setVisible().

[slot] void QWindow::showNormal()

Shows the window as normal, i.e. neither maximized, minimized, nor fullscreen.

Equivalent to calling setWindowState(Qt::WindowNoState) and then setVisible(true).

See also setWindowState() and setVisible().

[virtual] QSize QWindow::size() const

Reimplemented from QSurface::size().

Returns the size of the window excluding any window frame

See also resize().

QSize QWindow::sizeIncrement() const

Returns the size increment of the window.

See also setSizeIncrement().

[virtual] SurfaceType QWindow::surfaceType() const

Reimplemented from QSurface::surfaceType().

Returns the surface type of the window.

See also setSurfaceType().

[virtual protected] void QWindow::tabletEvent(QTabletEvent *ev)

Override this to handle tablet press, move, and release events (ev).

Proximity enter and leave events are not sent to windows, they are delivered to the application instance.

[virtual protected] void QWindow::touchEvent(QTouchEvent *ev)

Override this to handle touch events (ev).

QWindow *QWindow::transientParent() const

Returns the transient parent of the window.

See also setTransientParent() and parent().

Qt::WindowType QWindow::type() const

Returns the type of the window.

This returns the part of the window flags that represents whether the window is a dialog, tooltip, popup, regular window, etc.

See also flags() and setFlags().

void QWindow::unsetCursor()

Restores the default arrow cursor for this window.

[virtual protected] void QWindow::wheelEvent(QWheelEvent *ev)

Override this to handle mouse wheel or other wheel events (ev).

WId QWindow::winId() const

Returns the window's platform id.

For platforms where this id might be useful, the value returned will uniquely represent the window inside the corresponding screen.

See also screen().

Qt::WindowState QWindow::windowState() const

the screen-occupation state of the window

See also setWindowState().

[signal] void QWindow::windowStateChanged(Qt::WindowState windowState)

This signal is emitted when the windowState changes, either by being set explicitly with setWindowState(), or automatically when the user clicks one of the titlebar buttons or by other means.

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