class QQuickItem

The QQuickItem class provides the most basic of all visual items in Qt Quick . More…

Inheritance diagram of PySide6.QtQuick.QQuickItem

Inherited by: QQuickRhiItem, QQuickPaintedItem, QQuickFramebufferObject

Synopsis

Properties

Methods

Virtual methods

Slots

Signals

Note

This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE

Detailed Description

All visual items in Qt Quick inherit from QQuickItem . Although a QQuickItem instance has no visual appearance, it defines all the attributes that are common across visual items, such as x and y position, width and height, anchoring and key handling support.

You can subclass QQuickItem to provide your own custom visual item that inherits these features.

Custom Scene Graph Items

All visual QML items are rendered using the scene graph, the default implementation of which is a low-level, high-performance rendering stack, closely tied to accelerated graphics APIs, such as OpenGL, Vulkan, Metal, or Direct 3D. It is possible for subclasses of QQuickItem to add their own custom content into the scene graph by setting the ItemHasContents flag and reimplementing the updatePaintNode() function.

Warning

It is crucial that graphics operations and interaction with the scene graph happens exclusively on the rendering thread, primarily during the updatePaintNode() call. The best rule of thumb is to only use classes with the “QSG” prefix inside the updatePaintNode() function.

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.

Graphics Resource Handling

The preferred way to handle cleanup of graphics resources used in the scene graph, is to rely on the automatic cleanup of nodes. A QSGNode returned from updatePaintNode() is automatically deleted on the right thread at the right time. Trees of QSGNode instances are managed through the use of OwnedByParent , which is set by default. So, for the majority of custom scene graph items, no extra work will be required.

Implementations that store graphics resources outside the node tree, such as an item implementing textureProvider() , will need to take care in cleaning it up correctly depending on how the item is used in QML. The situations to handle are:

  • The scene graph is invalidated; This can happen, depending on the platform and QQuickWindow configuration, when the window is hidden using QQuickWindow::hide(), or when it is closed. If the item class implements a slot named invalidateSceneGraph(), this slot will be called on the rendering thread while the GUI thread is blocked. This is equivalent to connecting to sceneGraphInvalidated() . When rendering through OpenGL, the OpenGL context of this item’s window will be bound when this slot is called. The only exception is if the native OpenGL has been destroyed outside Qt’s control, for instance through EGL_CONTEXT_LOST.

  • The item is removed from the scene; If an item is taken out of the scene, for instance because it’s parent was set to null or an item in another window, the releaseResources() will be called on the GUI thread. scheduleRenderJob() should be used to schedule cleanup of rendering resources.

  • The item is deleted; When the destructor if an item runs, it should delete any graphics resources it has. If neither of the two conditions above were already met, the item will be part of a window and it is possible to use scheduleRenderJob() to have them cleaned up. If an implementation ignores the call to releaseResources() , the item will in many cases no longer have access to a QQuickWindow and thus no means of scheduling cleanup.

When scheduling cleanup of graphics resources using scheduleRenderJob() , one should use either BeforeSynchronizingStage or AfterSynchronizingStage . The synchronization stage is where the scene graph is changed as a result of changes to the QML tree. If cleanup is scheduled at any other time, it may result in other parts of the scene graph referencing the newly deleted objects as these parts have not been updated.

Note

Use of QObject::deleteLater() to clean up graphics resources is strongly discouraged as this will make the delete operation run at an arbitrary time and it is unknown if there will be an OpenGL context bound when the deletion takes place.

Custom QPainter Items

The QQuickItem provides a subclass, QQuickPaintedItem , which allows the users to render content using QPainter.

Warning

Using QQuickPaintedItem uses an indirect 2D surface to render its content, using software rasterization, so the rendering is a two-step operation. First rasterize the surface, then draw the surface. Using scene graph API directly is always significantly faster.

Behavior Animations

If your Item uses the Behavior type to define animations for property changes, you should always use either QObject::setProperty(), QQmlProperty(), or QMetaProperty::write() when you need to modify those properties from C++. This ensures that the QML engine knows about the property change. Otherwise, the engine won’t be able to carry out your requested animation. Note that these functions incur a slight performance penalty. For more details, see Accessing Members of a QML Object Type from C++.

class Flag

(inherits enum.Flag) This enum type is used to specify various item properties.

Constant

Description

QQuickItem.ItemClipsChildrenToShape

Indicates this item should visually clip its children so that they are rendered only within the boundaries of this item.

QQuickItem.ItemAcceptsInputMethod

Indicates the item supports text input methods.

QQuickItem.ItemIsFocusScope

Indicates the item is a focus scope. See Keyboard Focus in Qt Quick for more information.

QQuickItem.ItemHasContents

Indicates the item has visual content and should be rendered by the scene graph.

QQuickItem.ItemAcceptsDrops

Indicates the item accepts drag and drop events.

QQuickItem.ItemIsViewport

Indicates that the item defines a viewport for its children.

QQuickItem.ItemObservesViewport

Indicates that the item wishes to know the viewport bounds when any ancestor has the ItemIsViewport flag set.

See also

setFlag() setFlags() flags()

class ItemChange

Used in conjunction with itemChange() to notify the item about certain types of changes.

Constant

Description

QQuickItem.ItemChildAddedChange

A child was added. ItemChangeData::item contains the added child.

QQuickItem.ItemChildRemovedChange

A child was removed. ItemChangeData::item contains the removed child.

QQuickItem.ItemSceneChange

The item was added to or removed from a scene. The QQuickWindow rendering the scene is specified in using ItemChangeData::window . The window parameter is null when the item is removed from a scene.

QQuickItem.ItemVisibleHasChanged

The item’s visibility has changed. ItemChangeData::boolValue contains the new visibility.

QQuickItem.ItemParentHasChanged

The item’s parent has changed. ItemChangeData::item contains the new parent.

QQuickItem.ItemOpacityHasChanged

The item’s opacity has changed. ItemChangeData::realValue contains the new opacity.

QQuickItem.ItemActiveFocusHasChanged

The item’s focus has changed. ItemChangeData::boolValue contains whether the item has focus or not.

QQuickItem.ItemRotationHasChanged

The item’s rotation has changed. ItemChangeData::realValue contains the new rotation.

QQuickItem.ItemDevicePixelRatioHasChanged

The device pixel ratio of the screen the item is on has changed. ItemChangedData::realValue contains the new device pixel ratio.

QQuickItem.ItemAntialiasingHasChanged

The antialiasing has changed. The current (boolean) value can be found in antialiasing .

QQuickItem.ItemEnabledHasChanged

The item’s enabled state has changed. ItemChangeData::boolValue contains the new enabled state. (since Qt 5.10)
class TransformOrigin

Controls the point about which simple transforms like scale apply.

Constant

Description

QQuickItem.TopLeft

The top-left corner of the item.

QQuickItem.Top

The center point of the top of the item.

QQuickItem.TopRight

The top-right corner of the item.

QQuickItem.Left

The left most point of the vertical middle.

QQuickItem.Center

The center of the item.

QQuickItem.Right

The right most point of the vertical middle.

QQuickItem.BottomLeft

The bottom-left corner of the item.

QQuickItem.Bottom

The center point of the bottom of the item.

QQuickItem.BottomRight

The bottom-right corner of the item.

See also

transformOrigin() setTransformOrigin()

Note

Properties can be used directly when from __feature__ import true_property is used or via accessor functions otherwise.

property activeFocusᅟ: bool

This read-only property indicates whether the item has active focus.

If activeFocus is true, either this item is the one that currently receives keyboard input, or it is a FocusScope ancestor of the item that currently receives keyboard input.

Usually, activeFocus is gained by setting focus on an item and its enclosing FocusScope objects. In the following example, the input and focusScope objects will have active focus, while the root rectangle object will not.

Access functions:
property activeFocusOnTabᅟ: bool

This property holds whether the item wants to be in the tab focus chain. By default, this is set to false.

Access functions:
property antialiasingᅟ: bool

This property Specifies whether the item is antialiased or not.

Used by visual elements to decide if the item should use antialiasing or not. In some cases items with antialiasing require more memory and are potentially slower to render (see Antialiasing for more details).

The default is false, but may be overridden by derived elements.

Access functions:
property baselineOffsetᅟ: float

Specifies the position of the item’s baseline in local coordinates.

The baseline of a Text item is the imaginary line on which the text sits. Controls containing text usually set their baseline to the baseline of their text.

For non-text items, a default baseline offset of 0 is used.

Access functions:
property childrenRectᅟ: QRectF

This property holds the collective position and size of the item’s children.

This property is useful if you need to access the collective geometry of an item’s children in order to correctly size the item.

The geometry that is returned is local to the item. For example:

Item {
    x: 50
    y: 100

    // prints: QRectF(-10, -20, 30, 40)
    Component.onCompleted: print(childrenRect)

    Item {
        x: -10
        y: -20
        width: 30
        height: 40
    }
}
Access functions:
property clipᅟ: bool

This property holds whether clipping is enabled. The default clip value is false.

If clipping is enabled, an item will clip its own painting, as well as the painting of its children, to its bounding rectangle. If you set clipping during an item’s paint operation, remember to re-set it to prevent clipping the rest of your scene.

Note

Clipping can affect rendering performance. See Clipping for more information.

Note

For the sake of QML, setting clip to true also sets the ItemIsViewport flag, which sometimes acts as an optimization: child items that have the ItemObservesViewport flag may forego creating scene graph nodes that fall outside the viewport. But the ItemIsViewport flag can also be set independently.

Access functions:
property containmentMaskᅟ: QObject

This property holds an optional mask to be used in the contains() method, which is mainly used for hit-testing each QPointerEvent.

By default, contains() will return true for any point within the Item’s bounding box. But any QQuickItem , or any QObject that implements a function of the form

Q_INVOKABLE bool contains(const QPointF &point) const;

can be used as a mask, to defer hit-testing to that object.

Note

contains() is called frequently during event delivery. Deferring hit-testing to another object slows it down somewhat. containmentMask() can cause performance problems if that object’s contains() method is not efficient. If you implement a custom QQuickItem subclass, you can alternatively override contains() .

See also

contains()

Access functions:
property enabledᅟ: bool

This property holds whether the item receives mouse and keyboard events. By default this is true.

Setting this property directly affects the enabled value of child items. When set to false, the enabled values of all child items also become false. When set to true, the enabled values of child items are returned to true, unless they have explicitly been set to false.

Setting this property to false automatically causes activeFocus to be set to false, and this item will longer receive keyboard events.

Note

Hover events are enabled separately by setAcceptHoverEvents() . Thus, a disabled item can continue to receive hover events, even when this property is false. This makes it possible to show informational feedback (such as ToolTip) even when an interactive item is disabled. The same is also true for any HoverHandlers added as children of the item. A HoverHandler can, however, be disabled explicitly, or for example be bound to the enabled state of the item.

See also

visible

Access functions:
property focusᅟ: bool

This property holds whether the item has focus within the enclosing FocusScope . If true, this item will gain active focus when the enclosing FocusScope gains active focus.

In the following example, input will be given active focus when scope gains active focus:

For the purposes of this property, the scene as a whole is assumed to act like a focus scope. On a practical level, that means the following QML will give active focus to input on startup.

See also

activeFocus Keyboard Focus in Qt Quick

Access functions:
property focusPolicyᅟ: Qt.FocusPolicy

This property determines the way the item accepts focus.

Access functions:
property heightᅟ: float

This property holds the height of this item.

Access functions:
property implicitHeightᅟ: float
Access functions:
property implicitWidthᅟ: float
Access functions:
property opacityᅟ: float

This property holds the opacity of the item. Opacity is specified as a number between 0.0 (fully transparent) and 1.0 (fully opaque). The default value is 1.0.

When this property is set, the specified opacity is also applied individually to child items. This may have an unintended effect in some circumstances. For example in the second set of rectangles below, the red rectangle has specified an opacity of 0.5, which affects the opacity of its blue child rectangle even though the child has not specified an opacity.

Values outside the range of 0 to 1 will be clamped.

+—————————————————++ | .. image:: images/declarative-item_opacity1.png|| +—————————————————++ | .. image:: images/declarative-item_opacity2.png|| +—————————————————++

Changing an item’s opacity does not affect whether the item receives user input events. (In contrast, setting visible property to false stops mouse events, and setting the enabled property to false stops mouse and keyboard events, and also removes active focus from the item.)

See also

visible

Access functions:
property parentᅟ: QQuickItem

This property holds the visual parent of the item.

Note

The concept of the visual parent differs from that of the QObject parent. An item’s visual parent may not necessarily be the same as its object parent. See Concepts - Visual Parent in Qt Quick for more details.

Note

The notification signal for this property gets emitted during destruction of the visual parent. C++ signal handlers cannot assume that items in the visual parent hierarchy are still fully constructed. Use qobject_cast to verify that items in the parent hierarchy can be used safely as the expected type.

Access functions:
property rotationᅟ: float

This property holds the rotation of the item in degrees clockwise around its transformOrigin .

The default value is 0 degrees (that is, no rotation).

+———————————————-++ | .. image:: images/declarative-rotation.png|| +———————————————-++

See also

Transform Rotation

Access functions:
property scaleᅟ: float

This property holds the scale factor for this item.

A scale of less than 1.0 causes the item to be rendered at a smaller size, and a scale greater than 1.0 renders the item at a larger size. A negative scale causes the item to be mirrored when rendered.

The default value is 1.0.

Scaling is applied from the transformOrigin .

+——————————————-++ | .. image:: images/declarative-scale.png|| +——————————————-++

See also

Transform Scale

Access functions:
property smoothᅟ: bool

This property Specifies whether the item is smoothed or not.

Primarily used in image based items to decide if the item should use smooth sampling or not. Smooth sampling is performed using linear interpolation, while non-smooth is performed using nearest neighbor.

In Qt Quick 2.0, this property has minimal impact on performance.

By default, this property is set to true.

Access functions:
property stateᅟ: str

This property holds the name of the current state of the item.

If the item is in its default state, that is, no explicit state has been set, then this property holds an empty string. Likewise, you can return an item to its default state by setting this property to an empty string.

See also

Qt Quick States

Access functions:
property transformOriginᅟ: QQuickItem.TransformOrigin

This property holds the origin point around which scale and rotation transform.

Nine transform origins are available, as shown in the image below. The default transform origin is Item.Center.

../../_images/declarative-transformorigin.png
Access functions:
property transformOriginPointᅟ: QPointF
Access functions:
property visibleᅟ: bool

This property holds whether the item is visible. By default this is true.

Setting this property directly affects the visible value of child items. When set to false, the visible values of all child items also become false. When set to true, the visible values of child items are returned to true, unless they have explicitly been set to false.

(Because of this flow-on behavior, using the visible property may not have the intended effect if a property binding should only respond to explicit property changes. In such cases it may be better to use the opacity property instead.)

If this property is set to false, the item will no longer receive mouse events, but will continue to receive key events and will retain the keyboard focus if it has been set. (In contrast, setting the enabled property to false stops both mouse and keyboard events, and also removes focus from the item.)

Note

This property’s value is only affected by changes to this property or the parent’s visible property. It does not change, for example, if this item moves off-screen, or if the opacity changes to 0. However, for historical reasons, this property is true after the item’s construction, even if the item hasn’t been added to a scene yet. Changing or reading this property of an item that has not been added to a scene might not produce the expected results.

Note

The notification signal for this property gets emitted during destruction of the visual parent. C++ signal handlers cannot assume that items in the visual parent hierarchy are still fully constructed. Use qobject_cast to verify that items in the parent hierarchy can be used safely as the expected type.

See also

opacity enabled

Access functions:
property widthᅟ: float

This property holds the width of this item.

Access functions:
property xᅟ: float

Defines the item’s x position relative to its parent.

Access functions:
property yᅟ: float

Defines the item’s y position relative to its parent.

Access functions:
property zᅟ: float

Sets the stacking order of sibling items. By default the stacking order is 0.

Items with a higher stacking value are drawn on top of siblings with a lower stacking order. Items with the same stacking value are drawn bottom up in the order they appear. Items with a negative stacking value are drawn under their parent’s content.

The following example shows the various effects of stacking order.

../../_images/declarative-item_stacking1.png

Same z - later children above earlier children:
../../_images/declarative-item_stacking2.png

Higher z on top:
../../_images/declarative-item_stacking3.png

Same z - children above parents:
../../_images/declarative-item_stacking4.png

Lower z below:
Access functions:
__init__([parent=None])
Parameters:

parent – QQuickItem

Constructs a QQuickItem with the given parent.

The parent will be used as both the visual parent and the QObject parent.

acceptHoverEvents()
Return type:

bool

Returns whether hover events are accepted by this item.

The default value is false.

If this is false, then the item will not receive any hover events through the hoverEnterEvent() , hoverMoveEvent() and hoverLeaveEvent() functions.

acceptTouchEvents()
Return type:

bool

Returns whether touch events are accepted by this item.

The default value is false.

If this is false, then the item will not receive any touch events through the touchEvent() function.

acceptedMouseButtons()
Return type:

Combination of MouseButton

Returns the mouse buttons accepted by this item.

The default value is Qt::NoButton; that is, no mouse buttons are accepted.

If an item does not accept the mouse button for a particular mouse event, the mouse event will not be delivered to the item and will be delivered to the next item in the item hierarchy instead.

activeFocusChanged(arg__1)
Parameters:

arg__1 – bool

Notification signal of property activeFocusᅟ .

activeFocusOnTab()
Return type:

bool

See also

setActiveFocusOnTab()

Getter of property activeFocusOnTabᅟ .

activeFocusOnTabChanged(arg__1)
Parameters:

arg__1 – bool

Notification signal of property activeFocusOnTabᅟ .

antialiasing()
Return type:

bool

See also

setAntialiasing()

Getter of property antialiasingᅟ .

antialiasingChanged(arg__1)
Parameters:

arg__1 – bool

Notification signal of property antialiasingᅟ .

baselineOffset()
Return type:

float

See also

setBaselineOffset()

Getter of property baselineOffsetᅟ .

baselineOffsetChanged(arg__1)
Parameters:

arg__1 – float

Notification signal of property baselineOffsetᅟ .

boundingRect()
Return type:

QRectF

Returns the extents of the item in its own coordinate system: a rectangle from 0, 0 to width() and height() .

childAt(x, y)
Parameters:

  • x – float

  • y – float

Return type:

QQuickItem

Returns the first visible child item found at point (x, y) within the coordinate system of this item.

Returns None if there is no such item.

childItems()
Return type:

.list of QQuickItem

Returns the children of this item.

childMouseEventFilter(arg__1, arg__2)
Parameters:
Return type:

bool

Reimplement this method to filter the pointer events that are received by this item’s children.

This method will only be called if filtersChildMouseEvents() is true.

Return true if the specified event should not be passed on to the specified child item, and false otherwise. If you return true, you should also accept or ignore the event, to signal if event propagation should stop or continue. The event will, however, always be sent to all childMouseEventFilters up the parent chain.

Note

Despite the name, this function filters all QPointerEvent instances during delivery to all children (typically mouse, touch, and tablet events). When overriding this function in a subclass, we suggest writing generic event-handling code using only the accessors found in QPointerEvent. Alternatively you can switch on event->type() and/or event->device()->type() to handle different event types in different ways.

Note

Filtering is just one way to share responsibility in case of gestural ambiguity (for example on press, you don’t know whether the user will tap or drag). Another way is to call QPointerEvent::addPassiveGrabber() on press, so as to non-exclusively monitor the progress of the QEventPoint. In either case, the item or pointer handler that is monitoring can steal the exclusive grab later on, when it becomes clear that the gesture fits the pattern that it is expecting.

See also

setFiltersChildMouseEvents()

childrenChanged()
childrenRect()
Return type:

QRectF

Getter of property childrenRectᅟ .

childrenRectChanged(arg__1)
Parameters:

arg__1 – QRectF

Notification signal of property childrenRectᅟ .

clip()
Return type:

bool

See also

setClip()

Getter of property clipᅟ .

clipChanged(arg__1)
Parameters:

arg__1 – bool

Notification signal of property clipᅟ .

clipRect()
Return type:

QRectF

Returns the rectangular area within this item that is currently visible in viewportItem() , if there is a viewport and the ItemObservesViewport flag is set; otherwise, the extents of this item in its own coordinate system: a rectangle from 0, 0 to width() and height() . This is the region intended to remain visible if clip is true. It can also be used in updatePaintNode() to limit the graphics added to the scene graph.

For example, a large drawing or a large text document might be shown in a Flickable that occupies only part of the application’s Window: in that case, Flickable is the viewport item, and a custom content-rendering item may choose to omit scene graph nodes that fall outside the area that is currently visible. If the ItemObservesViewport flag is set, this area will change each time the user scrolls the content in the Flickable.

In case of nested viewport items, clipRect() is the intersection of the boundingRects of all ancestors that have the ItemIsViewport flag set, mapped to the coordinate system of this item.

See also

boundingRect()

containmentMask()
Return type:

QObject

See also

setContainmentMask()

Getter of property containmentMaskᅟ .

containmentMaskChanged()

Notification signal of property containmentMaskᅟ .

contains(point)
Parameters:

point – QPointF

Return type:

bool

Returns true if this item contains point, which is in local coordinates; returns false otherwise.

This function can be overridden in order to handle point collisions in items with custom shapes. The default implementation checks whether the point is inside containmentMask() if it is set, or inside the bounding box otherwise.

Note

This method is used for hit-testing each QEventPoint during event delivery, so the implementation should be kept as lightweight as possible.

cursor()
Return type:

QCursor

Returns the cursor shape for this item.

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

If no cursor shape has been set this returns a cursor with the Qt::ArrowCursor shape, however another cursor shape may be displayed if an overlapping item has a valid cursor.

dragEnterEvent(arg__1)
Parameters:

arg__1 – QDragEnterEvent

This event handler can be reimplemented in a subclass to receive drag-enter events for an item. The event information is provided by the event parameter.

Drag and drop events are only provided if the ItemAcceptsDrops flag has been set for this item.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

See also

Drag Drag and Drop

dragLeaveEvent(arg__1)
Parameters:

arg__1 – QDragLeaveEvent

This event handler can be reimplemented in a subclass to receive drag-leave events for an item. The event information is provided by the event parameter.

Drag and drop events are only provided if the ItemAcceptsDrops flag has been set for this item.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

See also

Drag Drag and Drop

dragMoveEvent(arg__1)
Parameters:

arg__1 – QDragMoveEvent

This event handler can be reimplemented in a subclass to receive drag-move events for an item. The event information is provided by the event parameter.

Drag and drop events are only provided if the ItemAcceptsDrops flag has been set for this item.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

See also

Drag Drag and Drop

dropEvent(arg__1)
Parameters:

arg__1 – QDropEvent

This event handler can be reimplemented in a subclass to receive drop events for an item. The event information is provided by the event parameter.

Drag and drop events are only provided if the ItemAcceptsDrops flag has been set for this item.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

See also

Drag Drag and Drop

dumpItemTree()

Dumps some details about the visual tree of Items starting with this item, recursively.

Note

QObject::dumpObjectTree() dumps a similar tree; but, as explained in Concepts - Visual Parent in Qt Quick , an item’s QObject::parent() sometimes differs from its parentItem() . You can dump both trees to see the difference.

Note

The exact output format may change in future versions of Qt.

See also

GammaRay’s Qt Quick Inspector

enabledChanged()

Notification signal of property enabledᅟ .

ensurePolished()

Calls updatePolish()

This can be useful for items such as Layouts (or Positioners) which delay calculation of their implicitWidth and implicitHeight until they receive a PolishEvent.

Normally, if e.g. a child item is added or removed to a Layout, the implicit size is not immediately calculated (this is an optimization). In some cases it might be desirable to query the implicit size of the layout right after a child item has been added. If this is the case, use this function right before querying the implicit size.

filtersChildMouseEvents()
Return type:

bool

Returns whether pointer events intended for this item’s children should be filtered through this item.

If both this item and a child item have acceptTouchEvents() true, then when a touch interaction occurs, this item will filter the touch event. But if either this item or the child cannot handle touch events, childMouseEventFilter() will be called with a synthesized mouse event.

flags()
Return type:

Combination of Flag

Returns the item flags for this item.

focusChanged(arg__1)
Parameters:

arg__1 – bool

Notification signal of property focusᅟ .

focusInEvent(arg__1)
Parameters:

arg__1 – QFocusEvent

This event handler can be reimplemented in a subclass to receive focus-in events for an item. The event information is provided by the event parameter.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

If you do reimplement this function, you should call the base class implementation.

focusOutEvent(arg__1)
Parameters:

arg__1 – QFocusEvent

This event handler can be reimplemented in a subclass to receive focus-out events for an item. The event information is provided by the event parameter.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

focusPolicy()
Return type:

FocusPolicy

See also

setFocusPolicy()

Getter of property focusPolicyᅟ .

focusPolicyChanged(arg__1)
Parameters:

arg__1 – FocusPolicy

Notification signal of property focusPolicyᅟ .

forceActiveFocus()

Forces active focus on the item.

This method sets focus on the item and ensures that all ancestor FocusScope objects in the object hierarchy are also given focus .

The reason for the focus change will be Qt::OtherFocusReason. Use the overloaded method to specify the focus reason to enable better handling of the focus change.

See also

activeFocus

forceActiveFocus(reason)
Parameters:

reason – FocusReason

This is an overloaded function.

Forces active focus on the item with the given reason.

This method sets focus on the item and ensures that all ancestor FocusScope objects in the object hierarchy are also given focus .

See also

activeFocus FocusReason

geometryChange(newGeometry, oldGeometry)
Parameters:

This function is called to handle this item’s changes in geometry from oldGeometry to newGeometry. If the two geometries are the same, it doesn’t do anything.

Derived classes must call the base class method within their implementation.

grabMouse()

Use QPointerEvent::setExclusiveGrabber().

Grabs the mouse input.

This item will receive all mouse events until ungrabMouse() is called. Usually this function should not be called, since accepting for example a mouse press event makes sure that the following events are delivered to the item. If an item wants to take over mouse events from the current receiver, it needs to call this function.

Warning

This function should be used with caution.

grabToImage([targetSize=QSize()])
Parameters:

targetSize – QSize

Return type:

QSharedPointer

Grabs the item into an in-memory image.

The grab happens asynchronously and the signal ready() is emitted when the grab has been completed.

Use targetSize to specify the size of the target image. By default, the result will have the same size as item.

If the grab could not be initiated, the function returns null.

Note

This function will render the item to an offscreen surface and copy that surface from the GPU’s memory into the CPU’s memory, which can be quite costly. For “live” preview, use layers or ShaderEffectSource .

See also

grabWindow()

grabToImage(callback[, targetSize=QSize()])
Parameters:
Return type:

bool

grabTouchPoints(ids)
Parameters:

ids – .list of int

Use QPointerEvent::setExclusiveGrabber(). Grabs the touch points specified by ids.

These touch points will be owned by the item until they are released. Alternatively, the grab can be stolen by a filtering item like Flickable. Use setKeepTouchGrab() to prevent the grab from being stolen.

hasActiveFocus()
Return type:

bool

Getter of property activeFocusᅟ .

hasFocus()
Return type:

bool

Getter of property focusᅟ .

height()
Return type:

float

See also

setHeight()

Getter of property heightᅟ .

heightChanged()

Notification signal of property heightᅟ .

heightValid()
Return type:

bool

Returns whether the height property has been set explicitly.

hoverEnterEvent(event)
Parameters:

event – QHoverEvent

This event handler can be reimplemented in a subclass to receive hover-enter events for an item. The event information is provided by the event parameter.

Hover events are only provided if acceptHoverEvents() is true.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

hoverLeaveEvent(event)
Parameters:

event – QHoverEvent

This event handler can be reimplemented in a subclass to receive hover-leave events for an item. The event information is provided by the event parameter.

Hover events are only provided if acceptHoverEvents() is true.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

hoverMoveEvent(event)
Parameters:

event – QHoverEvent

This event handler can be reimplemented in a subclass to receive hover-move events for an item. The event information is provided by the event parameter.

Hover events are only provided if acceptHoverEvents() is true.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

implicitHeight()
Return type:

float

See also

setImplicitHeight()

Getter of property implicitHeightᅟ .

implicitHeightChanged()

Notification signal of property implicitHeightᅟ .

implicitWidth()
Return type:

float

Returns the width of the item that is implied by other properties that determine the content.

Getter of property implicitWidthᅟ .

implicitWidthChanged()

Notification signal of property implicitWidthᅟ .

inputMethodEvent(arg__1)
Parameters:

arg__1 – QInputMethodEvent

This event handler can be reimplemented in a subclass to receive input method events for an item. The event information is provided by the event parameter.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

inputMethodQuery(query)
Parameters:

query – InputMethodQuery

Return type:

object

This method is only relevant for input items.

If this item is an input item, this method should be reimplemented to return the relevant input method flags for the given query.

isAncestorOf(child)
Parameters:

child – QQuickItem

Return type:

bool

Returns true if this item is an ancestor of child (i.e., if this item is child's parent, or one of child's parent’s ancestors).

See also

parentItem()

isComponentComplete()
Return type:

bool

Returns true if construction of the QML component is complete; otherwise returns false.

It is often desirable to delay some processing until the component is completed.

See also

componentComplete()

isEnabled()
Return type:

bool

Getter of property enabledᅟ .

isFocusScope()
Return type:

bool

Returns true if this item is a focus scope, and false otherwise.

isTextureProvider()
Return type:

bool

Returns true if this item is a texture provider. The default implementation returns false.

This function can be called from any thread.

isUnderMouse()
Return type:

bool

isVisible()
Return type:

bool

Getter of property visibleᅟ .

itemTransform(arg__1)
Parameters:

arg__1 – QQuickItem

Return type:

PyTuple

keepMouseGrab()
Return type:

bool

Returns whether mouse input should exclusively remain with this item.

keepTouchGrab()
Return type:

bool

Returns whether the touch points grabbed by this item should exclusively remain with this item.

keyPressEvent(event)
Parameters:

event – QKeyEvent

This event handler can be reimplemented in a subclass to receive key press events for an item. The event information is provided by the event parameter.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

keyReleaseEvent(event)
Parameters:

event – QKeyEvent

This event handler can be reimplemented in a subclass to receive key release events for an item. The event information is provided by the event parameter.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

mapFromGlobal(point)
Parameters:

point – QPointF

Return type:

QPointF

Maps the given point in the global screen coordinate system to the equivalent point within this item’s coordinate system, and returns the mapped coordinate.

The following properties of the item are used in the mapping: x , y , scale , rotation , transformOrigin , and transform .

If the items are part of different scenes, the mapping includes the relative position of the two scenes.

For example, this may be helpful to add a popup to a Qt Quick component.

Note

Window positioning is done by the window manager and this value is treated only as a hint. So, the resulting window position may differ from what is expected.

Note

If this item is in a subscene, e.g. mapped onto a 3D Model object, the UV mapping is incorporated into this transformation, so that it really goes from screen coordinates to this item’s coordinates, as long as point is actually within this item’s bounds. The other mapping functions do not yet work that way.

See also

Concepts - Visual Coordinates in Qt Quick

mapFromGlobal(x, y)
Parameters:

  • x – float

  • y – float

Return type:

QPointF

mapFromItem(item, point)
Parameters:
Return type:

QPointF

Maps the given point in item's coordinate system to the equivalent point within this item’s coordinate system, and returns the mapped coordinate.

The following properties of the item are used in the mapping: x , y , scale , rotation , transformOrigin , and transform .

If the items are part of different scenes, the mapping includes the relative position of the two scenes.

If item is None, this maps point from the coordinate system of the scene.

mapFromItem(item, rect)
Parameters:
Return type:

QRectF

Maps the given point in item's coordinate system to the equivalent point within this item’s coordinate system, and returns the mapped coordinate.

The following properties of the item are used in the mapping: x , y , scale , rotation , transformOrigin , and transform .

If the items are part of different scenes, the mapping includes the relative position of the two scenes.

If item is None, this maps point from the coordinate system of the scene.

mapFromItem(item, x, y)
Parameters:
Return type:

QPointF

mapFromItem(item, x, y, width, height)
Parameters:

  • item – QQuickItem

  • x – float

  • y – float

  • width – float

  • height – float

Return type:

QRectF

mapFromScene(point)
Parameters:

point – QPointF

Return type:

QPointF

Maps the given point in the scene’s coordinate system to the equivalent point within this item’s coordinate system, and returns the mapped coordinate.

The following properties of the item are used in the mapping: x , y , scale , rotation , transformOrigin , and transform .

If the items are part of different scenes, the mapping includes the relative position of the two scenes.

mapRectFromItem(item, rect)
Parameters:
Return type:

QRectF

Maps the given rect in item's coordinate system to the equivalent rectangular area within this item’s coordinate system, and returns the mapped rectangle value.

The following properties of the item are used in the mapping: x , y , scale , rotation , transformOrigin , and transform .

If the items are part of different scenes, the mapping includes the relative position of the two scenes.

If item is None, this maps rect from the coordinate system of the scene.

mapRectFromScene(rect)
Parameters:

rect – QRectF

Return type:

QRectF

Maps the given rect in the scene’s coordinate system to the equivalent rectangular area within this item’s coordinate system, and returns the mapped rectangle value.

The following properties of the item are used in the mapping: x , y , scale , rotation , transformOrigin , and transform .

If the items are part of different scenes, the mapping includes the relative position of the two scenes.

mapRectToItem(item, rect)
Parameters:
Return type:

QRectF

Maps the given rect in this item’s coordinate system to the equivalent rectangular area within item's coordinate system, and returns the mapped rectangle value.

The following properties of the item are used in the mapping: x , y , scale , rotation , transformOrigin , and transform .

If the items are part of different scenes, the mapping includes the relative position of the two scenes.

If item is None, this maps rect to the coordinate system of the scene.

mapRectToScene(rect)
Parameters:

rect – QRectF

Return type:

QRectF

Maps the given rect in this item’s coordinate system to the equivalent rectangular area within the scene’s coordinate system, and returns the mapped rectangle value.

The following properties of the item are used in the mapping: x , y , scale , rotation , transformOrigin , and transform .

If the items are part of different scenes, the mapping includes the relative position of the two scenes.

mapToGlobal(point)
Parameters:

point – QPointF

Return type:

QPointF

Maps the given point in this item’s coordinate system to the equivalent point within global screen coordinate system, and returns the mapped coordinate.

The following properties of the item are used in the mapping: x , y , scale , rotation , transformOrigin , and transform .

If the items are part of different scenes, the mapping includes the relative position of the two scenes.

For example, this may be helpful to add a popup to a Qt Quick component.

Note

Window positioning is done by the window manager and this value is treated only as a hint. So, the resulting window position may differ from what is expected.

See also

Concepts - Visual Coordinates in Qt Quick

mapToGlobal(x, y)
Parameters:

  • x – float

  • y – float

Return type:

QPointF

mapToItem(item, point)
Parameters:
Return type:

QPointF

Maps the given point in this item’s coordinate system to the equivalent point within item's coordinate system, and returns the mapped coordinate.

The following properties of the item are used in the mapping: x , y , scale , rotation , transformOrigin , and transform .

If the items are part of different scenes, the mapping includes the relative position of the two scenes.

If item is None, this maps point to the coordinate system of the scene.

mapToItem(item, rect)
Parameters:
Return type:

QRectF

Maps the given point in this item’s coordinate system to the equivalent point within item's coordinate system, and returns the mapped coordinate.

The following properties of the item are used in the mapping: x , y , scale , rotation , transformOrigin , and transform .

If the items are part of different scenes, the mapping includes the relative position of the two scenes.

If item is None, this maps point to the coordinate system of the scene.

mapToItem(item, x, y)
Parameters:
Return type:

QPointF

mapToItem(item, x, y, width, height)
Parameters:

  • item – QQuickItem

  • x – float

  • y – float

  • width – float

  • height – float

Return type:

QRectF

mapToScene(point)
Parameters:

point – QPointF

Return type:

QPointF

Maps the given point in this item’s coordinate system to the equivalent point within the scene’s coordinate system, and returns the mapped coordinate.

The following properties of the item are used in the mapping: x , y , scale , rotation , transformOrigin , and transform .

If the items are part of different scenes, the mapping includes the relative position of the two scenes.

mouseDoubleClickEvent(event)
Parameters:

event – QMouseEvent

This event handler can be reimplemented in a subclass to receive mouse double-click events for an item. The event information is provided by the event parameter.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

mouseMoveEvent(event)
Parameters:

event – QMouseEvent

This event handler can be reimplemented in a subclass to receive mouse move events for an item. The event information is provided by the event parameter.

In order to receive mouse movement events, the preceding mouse press event must be accepted (by overriding mousePressEvent() , for example) and acceptedMouseButtons() must return the relevant mouse button.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

mousePressEvent(event)
Parameters:

event – QMouseEvent

This event handler can be reimplemented in a subclass to receive mouse press events for an item. The event information is provided by the event parameter.

In order to receive mouse press events, acceptedMouseButtons() must return the relevant mouse button.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

mouseReleaseEvent(event)
Parameters:

event – QMouseEvent

This event handler can be reimplemented in a subclass to receive mouse release events for an item. The event information is provided by the event parameter.

In order to receive mouse release events, the preceding mouse press event must be accepted (by overriding mousePressEvent() , for example) and acceptedMouseButtons() must return the relevant mouse button.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

mouseUngrabEvent()

This event handler can be reimplemented in a subclass to be notified when a mouse ungrab event has occurred on this item.

nextItemInFocusChain([forward=true])
Parameters:

forward – bool

Return type:

QQuickItem

Returns the item in the focus chain which is next to this item. If forward is true, or not supplied, it is the next item in the forwards direction. If forward is false, it is the next item in the backwards direction.

opacity()
Return type:

float

See also

setOpacity()

Getter of property opacityᅟ .

opacityChanged()

Notification signal of property opacityᅟ .

paletteChanged()
paletteCreated()
parentChanged(arg__1)
Parameters:

arg__1 – QQuickItem

Notification signal of property parentᅟ .

parentItem()
Return type:

QQuickItem

See also

setParentItem()

Getter of property parentᅟ .

polish()

Schedules a polish event for this item.

When the scene graph processes the request, it will call updatePolish() on this item.

position()
Return type:

QPointF

releaseResources()

This function is called when an item should release graphics resources which are not already managed by the nodes returned from updatePaintNode() .

This happens when the item is about to be removed from the window it was previously rendering to. The item is guaranteed to have a window when the function is called.

The function is called on the GUI thread and the state of the rendering thread, when it is used, is unknown. Objects should not be deleted directly, but instead scheduled for cleanup using scheduleRenderJob() .

See also

Graphics Resource Handling

resetAntialiasing()

Reset function of property antialiasingᅟ .

resetHeight()

Reset function of property heightᅟ .

resetWidth()

Reset function of property widthᅟ .

rotation()
Return type:

float

See also

setRotation()

Getter of property rotationᅟ .

rotationChanged()

Notification signal of property rotationᅟ .

scale()
Return type:

float

See also

setScale()

Getter of property scaleᅟ .

scaleChanged()

Notification signal of property scaleᅟ .

scopedFocusItem()
Return type:

QQuickItem

If this item is a focus scope, this returns the item in its focus chain that currently has focus.

Returns None if this item is not a focus scope.

setAcceptHoverEvents(enabled)
Parameters:

enabled – bool

If enabled is true, this sets the item to accept hover events; otherwise, hover events are not accepted by this item.

setAcceptTouchEvents(accept)
Parameters:

accept – bool

If enabled is true, this sets the item to accept touch events; otherwise, touch events are not accepted by this item.

setAcceptedMouseButtons(buttons)
Parameters:

buttons – Combination of MouseButton

Sets the mouse buttons accepted by this item to buttons.

Note

In Qt 5, calling setAcceptedMouseButtons() implicitly caused an item to receive touch events as well as mouse events; but it was recommended to call setAcceptTouchEvents() to subscribe for them. In Qt 6, it is necessary to call setAcceptTouchEvents() to continue to receive them.

See also

acceptedMouseButtons()

setActiveFocusOnTab(arg__1)
Parameters:

arg__1 – bool

See also

activeFocusOnTab()

Setter of property activeFocusOnTabᅟ .

setAntialiasing(arg__1)
Parameters:

arg__1 – bool

See also

antialiasing()

Setter of property antialiasingᅟ .

setBaselineOffset(arg__1)
Parameters:

arg__1 – float

See also

baselineOffset()

Setter of property baselineOffsetᅟ .

setClip(arg__1)
Parameters:

arg__1 – bool

See also

clip()

Setter of property clipᅟ .

setContainmentMask(mask)
Parameters:

mask – QObject

See also

containmentMask()

Setter of property containmentMaskᅟ .

setCursor(cursor)
Parameters:

cursor – QCursor

Sets the cursor shape for this item.

setEnabled(arg__1)
Parameters:

arg__1 – bool

See also

isEnabled()

Setter of property enabledᅟ .

setFiltersChildMouseEvents(filter)
Parameters:

filter – bool

Sets whether pointer events intended for this item’s children should be filtered through this item.

If filter is true, childMouseEventFilter() will be called when a pointer event is triggered for a child item.

setFlag(flag[, enabled=true])
Parameters:

  • flag – Flag

  • enabled – bool

Enables the specified flag for this item if enabled is true; if enabled is false, the flag is disabled.

These provide various hints for the item; for example, the ItemClipsChildrenToShape flag indicates that all children of this item should be clipped to fit within the item area.

setFlags(flags)
Parameters:

flags – Combination of Flag

Enables the specified flags for this item.

See also

flags() setFlag()

setFocus(arg__1)
Parameters:

arg__1 – bool

See also

hasFocus()

Setter of property focusᅟ .

setFocus(focus, reason)
Parameters:
setFocusPolicy(policy)
Parameters:

policy – FocusPolicy

Sets the focus policy of this item to policy.

See also

focusPolicy()

Setter of property focusPolicyᅟ .

setHeight(arg__1)
Parameters:

arg__1 – float

See also

height()

Setter of property heightᅟ .

setImplicitHeight(arg__1)
Parameters:

arg__1 – float

See also

implicitHeight()

Setter of property implicitHeightᅟ .

setImplicitSize(arg__1, arg__2)
Parameters:

  • arg__1 – float

  • arg__2 – float

setImplicitWidth(arg__1)
Parameters:

arg__1 – float

See also

implicitWidth()

Setter of property implicitWidthᅟ .

setKeepMouseGrab(arg__1)
Parameters:

arg__1 – bool

Sets whether the mouse input should remain exclusively with this item.

This is useful for items that wish to grab and keep mouse interaction following a predefined gesture. For example, an item that is interested in horizontal mouse movement may set keepMouseGrab to true once a threshold has been exceeded. Once keepMouseGrab has been set to true, filtering items will not react to mouse events.

If keep is false, a filtering item may steal the grab. For example, Flickable may attempt to steal a mouse grab if it detects that the user has begun to move the viewport.

See also

keepMouseGrab()

setKeepTouchGrab(arg__1)
Parameters:

arg__1 – bool

Sets whether the touch points grabbed by this item should remain exclusively with this item.

This is useful for items that wish to grab and keep specific touch points following a predefined gesture. For example, an item that is interested in horizontal touch point movement may set setKeepTouchGrab to true once a threshold has been exceeded. Once setKeepTouchGrab has been set to true, filtering items will not react to the relevant touch points.

If keep is false, a filtering item may steal the grab. For example, Flickable may attempt to steal a touch point grab if it detects that the user has begun to move the viewport.

setOpacity(arg__1)
Parameters:

arg__1 – float

See also

opacity()

Setter of property opacityᅟ .

setParentItem(parent)
Parameters:

parent – QQuickItem

See also

parentItem()

Setter of property parentᅟ .

setPosition(arg__1)
Parameters:

arg__1 – QPointF

setRotation(arg__1)
Parameters:

arg__1 – float

See also

rotation()

Setter of property rotationᅟ .

setScale(arg__1)
Parameters:

arg__1 – float

See also

scale()

Setter of property scaleᅟ .

setSize(size)
Parameters:

size – QSizeF

Sets the size of the item to size. This methods preserves any existing binding on width and height; thus any change that triggers the binding to execute again will override the set values.

setSmooth(arg__1)
Parameters:

arg__1 – bool

See also

smooth()

Setter of property smoothᅟ .

setState(arg__1)
Parameters:

arg__1 – str

See also

state()

Setter of property stateᅟ .

setTransformOrigin(arg__1)
Parameters:

arg__1 – TransformOrigin

See also

transformOrigin()

Setter of property transformOriginᅟ .

setTransformOriginPoint(arg__1)
Parameters:

arg__1 – QPointF

setVisible(arg__1)
Parameters:

arg__1 – bool

See also

isVisible()

Setter of property visibleᅟ .

setWidth(arg__1)
Parameters:

arg__1 – float

See also

width()

Setter of property widthᅟ .

setX(arg__1)
Parameters:

arg__1 – float

See also

x()

Setter of property xᅟ .

setY(arg__1)
Parameters:

arg__1 – float

See also

y()

Setter of property yᅟ .

setZ(arg__1)
Parameters:

arg__1 – float

See also

z()

Setter of property zᅟ .

size()
Return type:

QSizeF

Returns the size of the item.

See also

setSize width height

smooth()
Return type:

bool

See also

setSmooth()

Getter of property smoothᅟ .

smoothChanged(arg__1)
Parameters:

arg__1 – bool

Notification signal of property smoothᅟ .

stackAfter(arg__1)
Parameters:

arg__1 – QQuickItem

Moves the specified sibling item to the index after this item within the list of children. The order of children affects both the visual stacking order and tab focus navigation order.

Assuming the z values of both items are the same, this will cause sibling to be rendered below this item.

If both items have activeFocusOnTab set to true, this will also cause the tab focus order to change, with sibling receiving focus before this item.

The given sibling must be a sibling of this item; that is, they must have the same immediate parent .

stackBefore(arg__1)
Parameters:

arg__1 – QQuickItem

Moves the specified sibling item to the index before this item within the list of children. The order of children affects both the visual stacking order and tab focus navigation order.

Assuming the z values of both items are the same, this will cause sibling to be rendered above this item.

If both items have activeFocusOnTab set to true, this will also cause the tab focus order to change, with sibling receiving focus after this item.

The given sibling must be a sibling of this item; that is, they must have the same immediate parent .

state()
Return type:

str

See also

setState()

Getter of property stateᅟ .

stateChanged(arg__1)
Parameters:

arg__1 – str

Notification signal of property stateᅟ .

textureProvider()
Return type:

QSGTextureProvider

Returns the texture provider for an item. The default implementation returns None.

This function may only be called on the rendering thread.

touchEvent(event)
Parameters:

event – QTouchEvent

This event handler can be reimplemented in a subclass to receive touch events for an item. The event information is provided by the event parameter.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

touchUngrabEvent()

This event handler can be reimplemented in a subclass to be notified when a touch ungrab event has occurred on this item.

transformOrigin()
Return type:

TransformOrigin

See also

setTransformOrigin()

Getter of property transformOriginᅟ .

transformOriginChanged(arg__1)
Parameters:

arg__1 – TransformOrigin

Notification signal of property transformOriginᅟ .

transformOriginPoint()
Return type:

QPointF

Getter of property transformOriginPointᅟ .

ungrabMouse()

Use QPointerEvent::setExclusiveGrabber().

Releases the mouse grab following a call to grabMouse() .

Note that this function should only be called when the item wants to stop handling further events. There is no need to call this function after a release or cancel event since no future events will be received in any case. No move or release events will be delivered after this function was called.

ungrabTouchPoints()

Use QEventPoint::setExclusiveGrabber() instead. Ungrabs the touch points owned by this item.

unsetCursor()

Clears the cursor shape for this item.

update()

Schedules a call to updatePaintNode() for this item.

The call to updatePaintNode() will always happen if the item is showing in a QQuickWindow .

Only items which specify ItemHasContents are allowed to call QQuickItem::update().

updateInputMethod([queries=Qt.ImQueryInput])
Parameters:

queries – Combination of InputMethodQuery

Notify input method on updated query values if needed. queries indicates the changed attributes.

updatePaintNode(arg__1, arg__2)
Parameters:

  • arg__1 – QSGNode

  • arg__2 – UpdatePaintNodeData

Return type:

QSGNode

Called on the render thread when it is time to sync the state of the item with the scene graph.

The function is called as a result of update() , if the user has set the ItemHasContents flag on the item.

The function should return the root of the scene graph subtree for this item. Most implementations will return a single QSGGeometryNode containing the visual representation of this item. oldNode is the node that was returned the last time the function was called. updatePaintNodeData provides a pointer to the QSGTransformNode associated with this QQuickItem .

QSGNode *MyItem::updatePaintNode(QSGNode *node, UpdatePaintNodeData *)
{
    QSGSimpleRectNode *n = static_cast<QSGSimpleRectNode *>(node);
    if (!n) {
        n = new QSGSimpleRectNode();
        n->setColor(Qt::red);
    }
    n->setRect(boundingRect());
    return n;
}

The main thread is blocked while this function is executed so it is safe to read values from the QQuickItem instance and other objects in the main thread.

If no call to QQuickItem::updatePaintNode() result in actual scene graph changes, like markDirty() or adding and removing nodes, then the underlying implementation may decide to not render the scene again as the visual outcome is identical.

Warning

It is crucial that graphics operations and interaction with the scene graph happens exclusively on the render thread, primarily during the QQuickItem::updatePaintNode() call. The best rule of thumb is to only use classes with the “QSG” prefix inside the QQuickItem::updatePaintNode() function.

Warning

This function is called on the render thread. This means any QObjects or thread local storage that is created will have affinity to the render thread, so apply caution when doing anything other than rendering in this function. Similarly for signals, these will be emitted on the render thread and will thus often be delivered via queued connections.

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.

See also

QSGMaterial QSGGeometryNode QSGGeometry QSGFlatColorMaterial QSGTextureMaterial markDirty() Graphics Resource Handling

updatePolish()

This function should perform any layout as required for this item.

When polish() is called, the scene graph schedules a polish event for this item. When the scene graph is ready to render this item, it calls updatePolish() to do any item layout as required before it renders the next frame.

See also

ensurePolished()

viewportItem()
Return type:

QQuickItem

If the ItemObservesViewport flag is set, returns the nearest parent with the ItemIsViewport flag. Returns the window’s contentItem if the flag is not set, or if no other viewport item is found.

Returns None only if there is no viewport item and this item is not shown in a window.

See also

clipRect()

visibleChanged()

Notification signal of property visibleᅟ .

visibleChildrenChanged()
wheelEvent(event)
Parameters:

event – QWheelEvent

This event handler can be reimplemented in a subclass to receive wheel events for an item. The event information is provided by the event parameter.

The event is accepted by default, so it is not necessary to explicitly accept the event if you reimplement this function. If you don’t accept the event, call event->ignore().

width()
Return type:

float

See also

setWidth()

Getter of property widthᅟ .

widthChanged()

Notification signal of property widthᅟ .

widthValid()
Return type:

bool

Returns whether the width property has been set explicitly.

window()
Return type:

QQuickWindow

Returns the window in which this item is rendered.

The item does not have a window until it has been assigned into a scene. The windowChanged() signal provides a notification both when the item is entered into a scene and when it is removed from a scene.

windowChanged(window)
Parameters:

window – QQuickWindow

This signal is emitted when the item’s window changes.

x()
Return type:

float

See also

setX()

Getter of property xᅟ .

xChanged()

Notification signal of property xᅟ .

y()
Return type:

float

See also

setY()

Getter of property yᅟ .

yChanged()

Notification signal of property yᅟ .

z()
Return type:

float

See also

setZ()

Getter of property zᅟ .

zChanged()

Notification signal of property zᅟ .