QQuickWindow

The QQuickWindow class provides the window for displaying a graphical QML scene. More…

Inheritance diagram of PySide2.QtQuick.QQuickWindow

Inherited by: QQuickView

Synopsis

Functions

Slots

Signals

Static functions

Detailed Description

QQuickWindow provides the graphical scene management needed to interact with and display a scene of QQuickItems.

A QQuickWindow always has a single invisible root item. To add items to this window, reparent the items to the root item or to an existing item in the scene.

For easily displaying a scene from a QML file, see QQuickView .

Rendering

QQuickWindow uses a scene graph to represent what needs to be rendered. This scene graph is disconnected from the QML scene and potentially lives in another thread, depending on the platform implementation. Since the rendering scene graph lives independently from the QML scene, it can also be completely released without affecting the state of the QML scene.

The sceneGraphInitialized() signal is emitted on the rendering thread before the QML scene is rendered to the screen for the first time. If the rendering scene graph has been released, the signal will be emitted again before the next frame is rendered.

Integration with OpenGL

When using the default OpenGL adaptation, it is possible to integrate OpenGL calls directly into the QQuickWindow using the same OpenGL context as the Qt Quick Scene Graph. This is done by connecting to the beforeRendering() or afterRendering() signal.

Note

When using beforeRendering() , make sure to disable clearing before rendering with setClearBeforeRendering() .

Exposure and Visibility

When a QQuickWindow instance is deliberately hidden with hide() or setVisible (false), it will stop rendering and its scene graph and graphics context might be released. The sceneGraphInvalidated() signal will be emitted when this happens.

Warning

It is crucial that graphics operations and interaction with the scene graph happens exclusively on the rendering thread, primarily during the updatePaintNode() phase.

Warning

As signals related to rendering might be emitted from the rendering thread, connections should be made using DirectConnection .

Resource Management

QML will try to cache images and scene graph nodes to improve performance, but in some low-memory scenarios it might be required to aggressively release these resources. The releaseResources() can be used to force the clean up of certain resources. Calling releaseResources() may result in the entire scene graph and in the case of the OpenGL adaptation the associated context will be deleted. The sceneGraphInvalidated() signal will be emitted when this happens.

Note

All classes with QSG prefix should be used solely on the scene graph’s rendering thread. See Scene Graph and Rendering for more information.

Context and Surface Formats

While it is possible to specify a QSurfaceFormat for every QQuickWindow by calling the member function setFormat() , windows may also be created from QML by using the Window and ApplicationWindow elements. In this case there is no C++ code involved in the creation of the window instance, yet applications may still wish to set certain surface format values, for example to request a given OpenGL version or profile. Such applications can call the static function setDefaultFormat() at startup. The specified format will be used for all Quick windows created afterwards.

See also

Scene Graph - OpenGL Under QML

class PySide2.QtQuick.QQuickWindow(renderControl)

PySide2.QtQuick.QQuickWindow([parent=None])

param parent:

PySide2.QtGui.QWindow

param renderControl:

PySide2.QtQuick.QQuickRenderControl

Constructs a window for displaying a QML scene with parent window parent .

PySide2.QtQuick.QQuickWindow.CreateTextureOption

The enums are used to customize a texture is wrapped.

Constant

Description

QQuickWindow.TextureHasAlphaChannel

The texture has an alpha channel and should be drawn using blending.

QQuickWindow.TextureHasMipmaps

The texture has mipmaps and can be drawn with mipmapping enabled.

QQuickWindow.TextureOwnsGLTexture

The texture object owns the texture id and will delete the OpenGL texture when the texture object is deleted.

QQuickWindow.TextureCanUseAtlas

The image can be uploaded into a texture atlas.

QQuickWindow.TextureIsOpaque

The texture will return false for hasAlphaChannel() and will not be blended. This flag was added in Qt 5.6.
PySide2.QtQuick.QQuickWindow.RenderStage

Constant

Description

QQuickWindow.BeforeSynchronizingStage

Before synchronization.

QQuickWindow.AfterSynchronizingStage

After synchronization.

QQuickWindow.BeforeRenderingStage

Before rendering.

QQuickWindow.AfterRenderingStage

After rendering.

QQuickWindow.AfterSwapStage

After the frame is swapped.

QQuickWindow.NoStage

As soon as possible. This value was added in Qt 5.6.

See also

Scene Graph and Rendering

PySide2.QtQuick.QQuickWindow.SceneGraphError

This enum describes the error in a sceneGraphError() signal.

Constant

Description

QQuickWindow.ContextNotAvailable

graphics context creation failed. This typically means that no suitable OpenGL implementation was found, for example because no graphics drivers are installed and so no OpenGL 2 support is present. On mobile and embedded boards that use OpenGL ES such an error is likely to indicate issues in the windowing system integration and possibly an incorrect configuration of Qt.
PySide2.QtQuick.QQuickWindow.TextRenderType

This enum describes the default render type of text-like elements in Qt Quick ( Text , TextInput , etc.).

Select if you prefer text to look native on the target platform and do not require advanced features such as transformation of the text. Using such features in combination with the render type will lend poor and sometimes pixelated results.

Constant

Description

QQuickWindow.QtTextRendering

Use Qt’s own rasterization algorithm.

QQuickWindow.NativeTextRendering

Use the operating system’s native rasterizer for text.

New in version 5.10.

PySide2.QtQuick.QQuickWindow.NativeObjectType

Specifies the type of the native object passed to functions such as createTextureFromNativeObject() .

Constant

Description

QQuickWindow.NativeObjectTexture

The native object is a 2D texture (OpenGL, Direct3D 11, Metal) or image (Vulkan).

New in version 5.14.

PySide2.QtQuick.QQuickWindow.activeFocusItem()
Return type:

PySide2.QtQuick.QQuickItem

This property holds The item which currently has active focus or null if there is no item with active focus..

See also

forceActiveFocus() Keyboard Focus in Qt Quick

PySide2.QtQuick.QQuickWindow.activeFocusItemChanged()
PySide2.QtQuick.QQuickWindow.afterAnimating()
PySide2.QtQuick.QQuickWindow.afterRenderPassRecording()
PySide2.QtQuick.QQuickWindow.afterRendering()
PySide2.QtQuick.QQuickWindow.afterSynchronizing()
PySide2.QtQuick.QQuickWindow.beforeRenderPassRecording()
PySide2.QtQuick.QQuickWindow.beforeRendering()
PySide2.QtQuick.QQuickWindow.beforeSynchronizing()
PySide2.QtQuick.QQuickWindow.beginExternalCommands()

When mixing raw graphics (OpenGL, Vulkan, Metal, etc.) commands with scene graph rendering, it is necessary to call this function before recording commands to the command buffer used by the scene graph to render its main render pass. This is to avoid clobbering state.

In practice this function is often called from a slot connected to the beforeRenderPassRecording() or afterRenderPassRecording() signals.

The function does not need to be called when recording commands to the application’s own command buffer (such as, a VkCommandBuffer or MTLCommandBuffer + MTLRenderCommandEncoder created and managed by the application, not retrieved from the scene graph). With graphics APIs where no native command buffer concept is exposed (OpenGL, Direct 3D 11), and endExternalCommands() together provide a replacement for resetOpenGLState() .

Calling this function and endExternalCommands() is not necessary within the render() implementation of a QSGRenderNode because the scene graph performs the necessary steps implicitly for render nodes.

Native graphics objects (such as, graphics device, command buffer or encoder) are accessible via getResource() .

Warning

Watch out for the fact that CommandListResource may return a different object between - endExternalCommands() . This can happen when the underlying implementation provides a dedicated secondary command buffer for recording external graphics commands within a render pass. Therefore, always query CommandListResource after calling this function. Do not attempt to reuse an object from an earlier query.

Note

This function has no effect when the scene graph is using OpenGL directly and the RHI graphics abstraction layer is not in use. Refer to resetOpenGLState() in that case.

Note

When the scenegraph is using the RHI graphics abstraction layer with the OpenGL backend underneath, pay attention to the fact that the OpenGL state in the context can have arbitrary settings, and this function does not perform any resetting of the state back to defaults. Call resetOpenGLState() if that is seen necessary.

See also

endExternalCommands() resetOpenGLState()

PySide2.QtQuick.QQuickWindow.clearBeforeRendering()
Return type:

bool

Returns whether clearing of the color buffer is done before rendering or not.

See also

setClearBeforeRendering()

PySide2.QtQuick.QQuickWindow.color()
Return type:

PySide2.QtGui.QColor

This property holds The color used to clear the OpenGL context..

Setting the clear color has no effect when clearing is disabled. By default, the clear color is white.

See also

setClearBeforeRendering() setDefaultAlphaBuffer()

PySide2.QtQuick.QQuickWindow.colorChanged(arg__1)
Parameters:

arg__1 – PySide2.QtGui.QColor

PySide2.QtQuick.QQuickWindow.contentItem()
Return type:

PySide2.QtQuick.QQuickItem

This property holds The invisible root item of the scene..

A QQuickWindow always has a single invisible root item containing all of its content. To add items to this window, reparent the items to the or to an existing item in the scene.

PySide2.QtQuick.QQuickWindow.createTextureFromId(id, size[, options=QQuickWindow.CreateTextureOption()])
Parameters:
Return type:

PySide2.QtQuick.QSGTexture

Note

This function is deprecated.

Creates a new QSGTexture object from an existing OpenGL texture id and size .

The caller of the function is responsible for deleting the returned texture.

The returned texture will be using GL_TEXTURE_2D as texture target and assumes that internal format is GL_RGBA . Reimplement QSGTexture to create textures with different parameters.

Use options to customize the texture attributes. The TextureUsesAtlas option is ignored.

Warning

This function will return null if the scenegraph has not yet been initialized or OpenGL is not in use.

Note

This function only has an effect when using the default OpenGL scene graph adaptation.

Note

This function has no effect when running on the RHI graphics abstraction. Use createTextureFromNativeObject() instead.

See also

sceneGraphInitialized() QSGTexture

PySide2.QtQuick.QQuickWindow.createTextureFromImage(image)
Parameters:

image – PySide2.QtGui.QImage

Return type:

PySide2.QtQuick.QSGTexture

This is an overloaded function.

PySide2.QtQuick.QQuickWindow.createTextureFromImage(image, options)
Parameters:
Return type:

PySide2.QtQuick.QSGTexture

Creates a new QSGTexture from the supplied image . If the image has an alpha channel, the corresponding texture will have an alpha channel.

The caller of the function is responsible for deleting the returned texture. For example whe using the OpenGL adaptation the actual OpenGL texture will be deleted when the texture object is deleted.

When options contains TextureCanUseAtlas , the engine may put the image into a texture atlas. Textures in an atlas need to rely on normalizedTextureSubRect() for their geometry and will not support Repeat . Other values from CreateTextureOption are ignored.

When options contains TextureIsOpaque , the engine will create an RGB texture which returns false for hasAlphaChannel() . Opaque textures will in most cases be faster to render. When this flag is not set, the texture will have an alpha channel based on the image’s format.

When options contains TextureHasMipmaps , the engine will create a texture which can use mipmap filtering. Mipmapped textures can not be in an atlas.

When using the OpenGL adaptation, the returned texture will be using GL_TEXTURE_2D as texture target and GL_RGBA as internal format. Reimplement QSGTexture to create textures with different parameters.

Warning

This function will return 0 if the scene graph has not yet been initialized.

Warning

The returned texture is not memory managed by the scene graph and must be explicitly deleted by the caller on the rendering thread. This is achieved by deleting the texture from a QSGNode destructor or by using deleteLater() in the case where the texture already has affinity to the rendering thread.

This function can be called from any thread.

See also

sceneGraphInitialized() QSGTexture

PySide2.QtQuick.QQuickWindow.createTextureFromNativeObject(type, nativeObjectPtr, nativeLayout, size[, options=QQuickWindow.CreateTextureOption()])
Parameters:
Return type:

PySide2.QtQuick.QSGTexture

Creates a new QSGTexture object from an existing native object.

The native object is wrapped, but not owned, by the resulting QSGTexture . The caller of the function is responsible for deleting the returned QSGTexture , but that will not destroy the underlying native object.

type specifies the type of the object. In practice the type is NativeObjectTexture , indicating that the native object is a texture or image of the underlying graphics API. Other types may be introduced in the future.

This function is currently suitable for 2D RGBA textures only.

Unlike createTextureFromId() , this function supports both direct OpenGL usage and the RHI abstracted rendering path.

Warning

This function will return null if the scenegraph has not yet been initialized.

Use options to customize the texture attributes. Only the TextureHasAlphaChannel and TextureHasMipmaps are taken into account here.

Warning

Unlike createTextureFromId() , this function never takes ownership of the native object, and the TextureOwnsGLTexture flag is ignored.

size specifies the size in pixels.

nativeObjectPtr is a pointer to the native object handle. With OpenGL, the native handle is a GLuint value, so nativeObjectPtr is then a pointer to a GLuint. With Vulkan, the native handle is a VkImage, so nativeObjectPtr is a pointer to a VkImage. With Direct3D 11 and Metal nativeObjectPtr is a pointer to a ID3D11Texture2D or MTLTexture pointer.

Note

Pay attention to the fact that nativeObjectPtr is always a pointer to the native texture handle type, even if the native type itself is a pointer.

nativeLayout is only used for APIs like Vulkan. When applicable, it must specify the current image layout, such as, a VkImageLayout value.

See also

sceneGraphInitialized() QSGTexture nativeTexture()

PySide2.QtQuick.QQuickWindow.effectiveDevicePixelRatio()
Return type:

float

Returns the device pixel ratio for this window.

This is different from devicePixelRatio() in that it supports redirected rendering via QQuickRenderControl . When using a QQuickRenderControl , the QQuickWindow is often not created, meaning it is never shown and there is no underlying native window created in the windowing system. As a result, querying properties like the device pixel ratio cannot give correct results. Use this function instead.

See also

devicePixelRatio()

PySide2.QtQuick.QQuickWindow.endExternalCommands()

When mixing raw graphics (OpenGL, Vulkan, Metal, etc.) commands with scene graph rendering, it is necessary to call this function after recording commands to the command buffer used by the scene graph to render its main render pass. This is to avoid clobbering state.

In practice this function is often called from a slot connected to the beforeRenderPassRecording() or afterRenderPassRecording() signals.

The function does not need to be called when recording commands to the application’s own command buffer (such as, a VkCommandBuffer or MTLCommandBuffer + MTLRenderCommandEncoder created and managed by the application, not retrieved from the scene graph). With graphics APIs where no native command buffer concept is exposed (OpenGL, Direct 3D 11), beginExternalCommands() and together provide a replacement for resetOpenGLState() .

Calling this function and beginExternalCommands() is not necessary within the render() implementation of a QSGRenderNode because the scene graph performs the necessary steps implicitly for render nodes.

Note

This function has no effect when the scene graph is using OpenGL directly and the RHI graphics abstraction layer is not in use. Refer to resetOpenGLState() in that case.

See also

beginExternalCommands()

PySide2.QtQuick.QQuickWindow.frameSwapped()
PySide2.QtQuick.QQuickWindow.grabWindow()
Return type:

PySide2.QtGui.QImage

Grabs the contents of the window and returns it as an image.

It is possible to call the function when the window is not visible. This requires that the window is created and has a valid size and that no other QQuickWindow instances are rendering in the same process.

Warning

Calling this function will cause performance problems.

Warning

This function can only be called from the GUI thread.

static PySide2.QtQuick.QQuickWindow.hasDefaultAlphaBuffer()
Return type:

bool

Returns whether to use alpha transparency on newly created windows.

See also

setDefaultAlphaBuffer()

PySide2.QtQuick.QQuickWindow.incubationController()
Return type:

PySide2.QtQml.QQmlIncubationController

Returns an incubation controller that splices incubation between frames for this window. QQuickView automatically installs this controller for you, otherwise you will need to install it yourself using setIncubationController() .

The controller is owned by the window and will be destroyed when the window is deleted.

PySide2.QtQuick.QQuickWindow.isPersistentOpenGLContext()
Return type:

bool

Returns whether the OpenGL context can be released during the lifetime of the QQuickWindow .

Note

This is a hint. When and how this happens is implementation specific. It also only has an effect when using the default OpenGL scene graph adaptation

PySide2.QtQuick.QQuickWindow.isPersistentSceneGraph()
Return type:

bool

Returns whether the scene graph nodes and resources can be released during the lifetime of this QQuickWindow .

Note

This is a hint. When and how this happens is implementation specific.

PySide2.QtQuick.QQuickWindow.isSceneGraphInitialized()
Return type:

bool

Returns true if the scene graph has been initialized; otherwise returns false.

PySide2.QtQuick.QQuickWindow.mouseGrabberItem()
Return type:

PySide2.QtQuick.QQuickItem

Returns the item which currently has the mouse grab.

PySide2.QtQuick.QQuickWindow.openglContext()
Return type:

PySide2.QtGui.QOpenGLContext

Returns the OpenGL context used for rendering.

Note

If the scene graph is not ready, or the scene graph is not using OpenGL (or RHI over OpenGL), this function will return null.

See also

sceneGraphInitialized() sceneGraphInvalidated()

PySide2.QtQuick.QQuickWindow.openglContextCreated(context)
Parameters:

context – PySide2.QtGui.QOpenGLContext

PySide2.QtQuick.QQuickWindow.releaseResources()

This function tries to release redundant resources currently held by the QML scene.

Calling this function might result in the scene graph and the OpenGL context used for rendering being released to release graphics memory. If this happens, the sceneGraphInvalidated() signal will be called, allowing users to clean up their own graphics resources. The setPersistentOpenGLContext() and setPersistentSceneGraph() functions can be used to prevent this from happening, if handling the cleanup is not feasible in the application, at the cost of higher memory usage.

See also

sceneGraphInvalidated() setPersistentOpenGLContext() setPersistentSceneGraph()

PySide2.QtQuick.QQuickWindow.renderTarget()
Return type:

PySide2.QtGui.QOpenGLFramebufferObject

Returns the render target for this window.

The default is to render to the surface of the window, in which case the render target is 0.

Note

This function will return nullptr when not using the OpenGL scene graph adaptation.

Note

This function has no effect and returns nullptr when running on the RHI graphics abstraction.

See also

setRenderTarget()

PySide2.QtQuick.QQuickWindow.renderTargetId()
Return type:

uint

Returns the FBO id of the render target when set; otherwise returns 0.

PySide2.QtQuick.QQuickWindow.renderTargetSize()
Return type:

PySide2.QtCore.QSize

Returns the size of the currently set render target; otherwise returns an empty size.

PySide2.QtQuick.QQuickWindow.rendererInterface()
Return type:

PySide2.QtQuick.QSGRendererInterface

Returns the current renderer interface. The value is always valid and is never null.

Note

This function can be called at any time after constructing the QQuickWindow , even while isSceneGraphInitialized() is still false. However, some renderer interface functions, in particular getResource() will not be functional until the scenegraph is up and running. Backend queries, like graphicsApi() or shaderType() , will always be functional on the other hand.

Note

The ownership of the returned pointer stays with Qt. The returned instance may or may not be shared between different QQuickWindow instances, depending on the scenegraph backend in use. Therefore applications are expected to query the interface object for each QQuickWindow instead of reusing the already queried pointer.

See also

QSGRenderNode QSGRendererInterface

PySide2.QtQuick.QQuickWindow.resetOpenGLState()

Call this function to reset the OpenGL context its default state.

The scene graph uses the OpenGL context and will both rely on and clobber its state. When mixing raw OpenGL commands with scene graph rendering, this function provides a convenient way of resetting the OpenGL context state back to its default values.

This function does not touch state in the fixed-function pipeline.

This function does not clear the color, depth and stencil buffers. Use setClearBeforeRendering to control clearing of the color buffer. The depth and stencil buffer might be clobbered by the scene graph renderer. Clear these manually on demand.

Note

This function only has an effect when using the default OpenGL scene graph adaptation.

Note

This function will only reset the OpenGL context in relation to what has been changed internally as part of the OpenGL scene graph. It does not reset anything that has been changed externally such as direct OpenGL calls done inside the application code if those same calls are not used internally.

Note

This function has no effect when running on the RHI graphics abstraction and the underlying RHI backend is not OpenGL.

See also

beforeRendering() beginExternalCommands() endExternalCommands()

PySide2.QtQuick.QQuickWindow.sceneGraphAboutToStop()
static PySide2.QtQuick.QQuickWindow.sceneGraphBackend()
Return type:

str

Returns the requested Qt Quick scenegraph backend.

Note

The return value of this function may still be outdated by subsequent calls to setSceneGraphBackend() until the first QQuickWindow in the application has been constructed.

See also

setSceneGraphBackend()

PySide2.QtQuick.QQuickWindow.sceneGraphError(error, message)
Parameters:
PySide2.QtQuick.QQuickWindow.sceneGraphInitialized()
PySide2.QtQuick.QQuickWindow.sceneGraphInvalidated()
PySide2.QtQuick.QQuickWindow.scheduleRenderJob(job, schedule)
Parameters:

Schedules job to run when the rendering of this window reaches the given stage .

This is a convenience to the equivalent signals in QQuickWindow for “one shot” tasks.

The window takes ownership over job and will delete it when the job is completed.

If rendering is shut down before job has a chance to run, the job will be run and then deleted as part of the scene graph cleanup. If the window is never shown and no rendering happens before the QQuickWindow is destroyed, all pending jobs will be destroyed without their run() method being called.

If the rendering is happening on a different thread, then the job will happen on the rendering thread.

If stage is NoStage , job will be run at the earliest opportunity whenever the render thread is not busy rendering a frame. If there is no OpenGL context available or the window is not exposed at the time the job is either posted or handled, it is deleted without executing the run() method. If a non-threaded renderer is in use, the run() method of the job is executed synchronously. The OpenGL context is changed to the renderer context before executing a NoStage job.

Note

This function does not trigger rendering; the jobs targeting any other stage than NoStage will be stored run until rendering is triggered elsewhere. To force the job to run earlier, call update() ;

See also

beforeRendering() afterRendering() beforeSynchronizing() afterSynchronizing() frameSwapped() sceneGraphInvalidated()

PySide2.QtQuick.QQuickWindow.sendEvent(arg__1, arg__2)
Parameters:
Return type:

bool

Note

This function is deprecated.

Propagates an event e to a QQuickItem item on the window.

Use sendEvent() directly instead.

The return value is currently not used.

PySide2.QtQuick.QQuickWindow.setClearBeforeRendering(enabled)
Parameters:

enabled – bool

Sets whether the scene graph rendering of QML should clear the color buffer before it starts rendering to enabled .

By disabling clearing of the color buffer, it is possible to render OpengGL content under the scene graph.

The color buffer is cleared by default.

Warning

This flag is ignored completely when running with the RHI graphics abstraction instead of using OpenGL directly. As explicit clear commands simply do not exist in some modern APIs, the scene graph cannot offer this flexibility anymore. The images associated with a render target will always get cleared when a render pass starts. As a solution, an alternative to disabling scene graph issued clears is provided in form of the beforeRenderPassRecording() signal.

See also

clearBeforeRendering() beforeRendering() beforeRenderPassRecording()

PySide2.QtQuick.QQuickWindow.setColor(color)
Parameters:

color – PySide2.QtGui.QColor

This property holds The color used to clear the OpenGL context..

Setting the clear color has no effect when clearing is disabled. By default, the clear color is white.

See also

setClearBeforeRendering() setDefaultAlphaBuffer()

static PySide2.QtQuick.QQuickWindow.setDefaultAlphaBuffer(useAlpha)
Parameters:

useAlpha – bool

useAlpha specifies whether to use alpha transparency on newly created windows.

In any application which expects to create translucent windows, it’s necessary to set this to true before creating the first QQuickWindow . The default value is false.

See also

hasDefaultAlphaBuffer()

PySide2.QtQuick.QQuickWindow.setPersistentOpenGLContext(persistent)
Parameters:

persistent – bool

Sets whether the OpenGL context should be preserved, and cannot be released until the last window is deleted, to persistent . The default value is true.

The OpenGL context can be released to free up graphics resources when the window is obscured, hidden or not rendering. When this happens is implementation specific.

The aboutToBeDestroyed() signal is emitted from the openglContext() when the OpenGL context is about to be released. The sceneGraphInitialized() signal is emitted when a new OpenGL context is created for this window. Make a DirectConnection to these signals to be notified.

The OpenGL context is still released when the last QQuickWindow is deleted.

Note

This only has an effect when using the default OpenGL scene graph adaptation.

See also

isPersistentOpenGLContext() setPersistentSceneGraph() aboutToBeDestroyed() sceneGraphInitialized()

PySide2.QtQuick.QQuickWindow.setPersistentSceneGraph(persistent)
Parameters:

persistent – bool

Sets whether the scene graph nodes and resources are persistent . Persistent means the nodes and resources cannot be released. The default value is true .

The scene graph nodes and resources can be released to free up graphics resources when the window is obscured, hidden or not rendering. When this happens is implementation specific.

The sceneGraphInvalidated() signal is emitted when cleanup occurs. The sceneGraphInitialized() signal is emitted when a new scene graph is recreated for this window. Make a DirectConnection to these signals to be notified.

The scene graph nodes and resources are still released when the last QQuickWindow is deleted.

See also

isPersistentSceneGraph() setPersistentOpenGLContext() sceneGraphInvalidated() sceneGraphInitialized()

PySide2.QtQuick.QQuickWindow.setRenderTarget(fboId, size)
Parameters:

This is an overloaded function.

Sets the render target for this window to be an FBO with fboId and size .

The specified FBO must be created in the context of the window or one that shares with it.

Note

fboId can also be set to 0. In this case rendering will target the default framebuffer of whichever surface is current when the scenegraph renders. size must still be valid, specifying the dimensions of the surface.

Note

This function only has an effect when using the default OpenGL scene graph adaptation.

Warning

This function can only be called from the thread doing the rendering.

PySide2.QtQuick.QQuickWindow.setRenderTarget(fbo)
Parameters:

fbo – PySide2.QtGui.QOpenGLFramebufferObject

Sets the render target for this window to be fbo .

The specified fbo must be created in the context of the window or one that shares with it.

Note

This function only has an effect when using the default OpenGL scene graph adaptation.

Note

This function has no effect when running on the RHI graphics abstraction.

Warning

This function can only be called from the thread doing the rendering.

See also

renderTarget()

static PySide2.QtQuick.QQuickWindow.setSceneGraphBackend(api)
Parameters:

api – GraphicsApi

Requests a Qt Quick scenegraph backend for the specified graphics api . Backends can either be built-in or be installed in form of dynamically loaded plugins.

Note

The call to the function must happen before constructing the first QQuickWindow in the application. It cannot be changed afterwards.

If the selected backend is invalid or an error occurs, the default backend (OpenGL or software, depending on the Qt configuration) is used.

See also

sceneGraphBackend()

static PySide2.QtQuick.QQuickWindow.setSceneGraphBackend(backend)
Parameters:

backend – str

static PySide2.QtQuick.QQuickWindow.setTextRenderType(renderType)
Parameters:

renderType – TextRenderType

Sets the default render type of text-like elements in Qt Quick to renderType .

Note

setting the render type will only affect elements created afterwards; the render type of existing elements will not be modified.

See also

textRenderType()

static PySide2.QtQuick.QQuickWindow.textRenderType()
Return type:

TextRenderType

Returns the render type of text-like elements in Qt Quick. The default is QtTextRendering .

See also

setTextRenderType()

PySide2.QtQuick.QQuickWindow.update()

Schedules the window to render another frame.

Calling differs from update() in that it always triggers a repaint, regardless of changes in the underlying scene graph or not.