QQuickItem

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

Inherited by: QQuickFramebufferObject, QQuickPaintedItem

Synopsis

Functions

• def acceptHoverEvents ()

• def acceptTouchEvents ()

• def acceptedMouseButtons ()

• def activeFocusOnTab ()

• def antialiasing ()

• def baselineOffset ()

• def childAt (x, y)

• def childItems ()

• def childrenRect ()

• def clip ()

• def containmentMask ()

• def cursor ()

• def filtersChildMouseEvents ()

• def flags ()

• def forceActiveFocus ()

• def forceActiveFocus (reason)

• def grabMouse ()

• def grabToImage ([targetSize=QSize()])

• def grabToImage (callback[, targetSize=QSize()])

• def grabTouchPoints (ids)

• def hasActiveFocus ()

• def hasFocus ()

• def height ()

• def heightValid ()

• def implicitHeight ()

• def implicitWidth ()

• def isAncestorOf (child)

• def isComponentComplete ()

• def isEnabled ()

• def isFocusScope ()

• def isUnderMouse ()

• def isVisible ()

• def itemTransform (arg__1)

• def keepMouseGrab ()

• def keepTouchGrab ()

• def mapFromGlobal (point)

• def mapFromItem (item, point)

• def mapFromScene (point)

• def mapRectFromItem (item, rect)

• def mapRectFromScene (rect)

• def mapRectToItem (item, rect)

• def mapRectToScene (rect)

• def mapToGlobal (point)

• def mapToItem (item, point)

• def mapToScene (point)

• def nextItemInFocusChain ([forward=true])

• def opacity ()

• def parentItem ()

• def polish ()

• def position ()

• def resetAntialiasing ()

• def resetHeight ()

• def resetWidth ()

• def rotation ()

• def scale ()

• def scopedFocusItem ()

• def setAcceptHoverEvents (enabled)

• def setAcceptTouchEvents (accept)

• def setAcceptedMouseButtons (buttons)

• def setActiveFocusOnTab (arg__1)

• def setAntialiasing (arg__1)

• def setBaselineOffset (arg__1)

• def setClip (arg__1)

• def setContainmentMask (mask)

• def setCursor (cursor)

• def setEnabled (arg__1)

• def setFiltersChildMouseEvents (filter)

• def setFlag (flag[, enabled=true])

• def setFlags (flags)

• def setFocus (arg__1)

• def setFocus (focus, reason)

• def setHeight (arg__1)

• def setImplicitHeight (arg__1)

• def setImplicitSize (arg__1, arg__2)

• def setImplicitWidth (arg__1)

• def setKeepMouseGrab (arg__1)

• def setKeepTouchGrab (arg__1)

• def setOpacity (arg__1)

• def setParentItem (parent)

• def setPosition (arg__1)

• def setRotation (arg__1)

• def setScale (arg__1)

• def setSize (size)

• def setSmooth (arg__1)

• def setState (arg__1)

• def setTransformOrigin (arg__1)

• def setTransformOriginPoint (arg__1)

• def setVisible (arg__1)

• def setWidth (arg__1)

• def setX (arg__1)

• def setY (arg__1)

• def setZ (arg__1)

• def size ()

• def smooth ()

• def stackAfter (arg__1)

• def stackBefore (arg__1)

• def state ()

• def transformOrigin ()

• def transformOriginPoint ()

• def ungrabMouse ()

• def ungrabTouchPoints ()

• def unsetCursor ()

• def updateInputMethod ([queries=Qt.ImQueryInput])

• def width ()

• def widthValid ()

• def window ()

• def x ()

• def y ()

• def z ()

Virtual functions

• def boundingRect ()

• def childMouseEventFilter (arg__1, arg__2)

• def clipRect ()

• def contains (point)

• def dragEnterEvent (arg__1)

• def dragLeaveEvent (arg__1)

• def dragMoveEvent (arg__1)

• def dropEvent (arg__1)

• def focusInEvent (arg__1)

• def focusOutEvent (arg__1)

• def geometryChanged (newGeometry, oldGeometry)

• def hoverEnterEvent (event)

• def hoverLeaveEvent (event)

• def hoverMoveEvent (event)

• def inputMethodEvent (arg__1)

• def inputMethodQuery (query)

• def isTextureProvider ()

• def keyPressEvent (event)

• def keyReleaseEvent (event)

• def mouseDoubleClickEvent (event)

• def mouseMoveEvent (event)

• def mousePressEvent (event)

• def mouseReleaseEvent (event)

• def mouseUngrabEvent ()

• def releaseResources ()

• def textureProvider ()

• def touchEvent (event)

• def touchUngrabEvent ()

• def updatePaintNode (arg__1, arg__2)

• def updatePolish ()

• def wheelEvent (event)

• def windowDeactivateEvent ()

Slots

• def update ()

Signals

• def activeFocusChanged (arg__1)

• def activeFocusOnTabChanged (arg__1)

• def antialiasingChanged (arg__1)

• def baselineOffsetChanged (arg__1)

• def childrenChanged ()

• def childrenRectChanged (arg__1)

• def clipChanged (arg__1)

• def containmentMaskChanged ()

• def enabledChanged ()

• def focusChanged (arg__1)

• def heightChanged ()

• def implicitHeightChanged ()

• def implicitWidthChanged ()

• def opacityChanged ()

• def parentChanged (arg__1)

• def rotationChanged ()

• def scaleChanged ()

• def smoothChanged (arg__1)

• def stateChanged (arg__1)

• def transformOriginChanged (arg__1)

• def visibleChanged ()

• def visibleChildrenChanged ()

• def widthChanged ()

• def windowChanged (window)

• def xChanged ()

• def yChanged ()

• def zChanged ()

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 OpenGL. 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 OpenGL 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, for instance, if the window is hidden using hide() . 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() . 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 deleteLater() to clean up graphics resources is not recommended as this will 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, either using software rasterization or using an OpenGL framebuffer object (FBO), 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 setProperty() , QQmlProperty(), or 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++ .

See also

QQuickWindow QQuickPaintedItem

class PySide2.QtQuick.QQuickItem([parent=None])

param parent:

PySide2.QtQuick.QQuickItem

Constructs a QQuickItem with the given parent .

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

PySide2.QtQuick.QQuickItem.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.

See also

setFlag() setFlags() flags()

PySide2.QtQuick.QQuickItem.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)

PySide2.QtQuick.QQuickItem.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()

PySide2.QtQuick.QQuickItem.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.

See also

setAcceptHoverEvents()

PySide2.QtQuick.QQuickItem.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.

See also

setAcceptTouchEvents()

PySide2.QtQuick.QQuickItem.acceptedMouseButtons()

Return type:

MouseButtons

Returns the mouse buttons accepted by this item.

The default value is 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.

See also

setAcceptedMouseButtons() acceptTouchEvents()

PySide2.QtQuick.QQuickItem.activeFocusChanged(arg__1)

Parameters:

arg__1 – bool

PySide2.QtQuick.QQuickItem.activeFocusOnTab()

Return type:

bool

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

PySide2.QtQuick.QQuickItem.activeFocusOnTabChanged(arg__1)

Parameters:

arg__1 – bool

PySide2.QtQuick.QQuickItem.antialiasing()

Return type:

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.

PySide2.QtQuick.QQuickItem.antialiasingChanged(arg__1)

Parameters:

arg__1 – bool

PySide2.QtQuick.QQuickItem.baselineOffset()

Return type:

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.

PySide2.QtQuick.QQuickItem.baselineOffsetChanged(arg__1)

Parameters:

arg__1 – float

PySide2.QtQuick.QQuickItem.boundingRect()

Return type:

PySide2.QtCore.QRectF

PySide2.QtQuick.QQuickItem.childAt(x, y)

Parameters:

• x – float

• y – float

Return type:

PySide2.QtQuick.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.

PySide2.QtQuick.QQuickItem.childItems()

Return type:

Returns the children of this item.

PySide2.QtQuick.QQuickItem.childMouseEventFilter(arg__1, arg__2)

Parameters:

• arg__1 – PySide2.QtQuick.QQuickItem

• arg__2 – PySide2.QtCore.QEvent

Return type:

bool

Reimplement this method to filter the mouse 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 onto the specified child item , and false otherwise.

See also

setFiltersChildMouseEvents()

PySide2.QtQuick.QQuickItem.childrenChanged()

PySide2.QtQuick.QQuickItem.childrenRect()

Return type:

PySide2.QtCore.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
    }
}

PySide2.QtQuick.QQuickItem.childrenRectChanged(arg__1)

Parameters:

arg__1 – PySide2.QtCore.QRectF

PySide2.QtQuick.QQuickItem.clip()

Return type:

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.

PySide2.QtQuick.QQuickItem.clipChanged(arg__1)

Parameters:

arg__1 – bool

PySide2.QtQuick.QQuickItem.clipRect()

Return type:

PySide2.QtCore.QRectF

PySide2.QtQuick.QQuickItem.containmentMask()

Return type:

PySide2.QtCore.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. 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()

PySide2.QtQuick.QQuickItem.containmentMaskChanged()

PySide2.QtQuick.QQuickItem.contains(point)

Parameters:

point – PySide2.QtCore.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.

PySide2.QtQuick.QQuickItem.cursor()

Return type:

PySide2.QtGui.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 ArrowCursor shape, however another cursor shape may be displayed if an overlapping item has a valid cursor.

See also

setCursor() unsetCursor()

PySide2.QtQuick.QQuickItem.dragEnterEvent(arg__1)

Parameters:

arg__1 – PySide2.QtGui.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

PySide2.QtQuick.QQuickItem.dragLeaveEvent(arg__1)

Parameters:

arg__1 – PySide2.QtGui.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

PySide2.QtQuick.QQuickItem.dragMoveEvent(arg__1)

Parameters:

arg__1 – PySide2.QtGui.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

PySide2.QtQuick.QQuickItem.dropEvent(arg__1)

Parameters:

arg__1 – PySide2.QtGui.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

PySide2.QtQuick.QQuickItem.enabledChanged()

PySide2.QtQuick.QQuickItem.filtersChildMouseEvents()

Return type:

bool

Returns whether mouse and touch events of this item’s children should be filtered through this item.

See also

setFiltersChildMouseEvents() childMouseEventFilter()

PySide2.QtQuick.QQuickItem.flags()

Return type:

Flags

Returns the item flags for this item.

See also

setFlags() setFlag()

PySide2.QtQuick.QQuickItem.focusChanged(arg__1)

Parameters:

arg__1 – bool

PySide2.QtQuick.QQuickItem.focusInEvent(arg__1)

Parameters:

arg__1 – PySide2.QtGui.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.

PySide2.QtQuick.QQuickItem.focusOutEvent(arg__1)

Parameters:

arg__1 – PySide2.QtGui.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() .

PySide2.QtQuick.QQuickItem.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 OtherFocusReason . Use the overloaded method to specify the focus reason to enable better handling of the focus change.

See also

activeFocus

PySide2.QtQuick.QQuickItem.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

PySide2.QtQuick.QQuickItem.geometryChanged(newGeometry, oldGeometry)

Parameters:

• newGeometry – PySide2.QtCore.QRectF

• oldGeometry – PySide2.QtCore.QRectF

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.

PySide2.QtQuick.QQuickItem.grabMouse()

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.

PySide2.QtQuick.QQuickItem.grabToImage(callback[, targetSize=QSize()])

Parameters:

• callback – PySide2.QtQml.QJSValue

• targetSize – PySide2.QtCore.QSize

Return type:

bool

Only visible from QML.

PySide2.QtQuick.QQuickItem.grabToImage([targetSize=QSize()])

Parameters:

targetSize – PySide2.QtCore.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()

PySide2.QtQuick.QQuickItem.grabTouchPoints(ids)

Parameters:

ids –

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.

See also

ungrabTouchPoints() setKeepTouchGrab()

PySide2.QtQuick.QQuickItem.hasActiveFocus()

Return type:

bool

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

If 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, 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.

See also

focus Keyboard Focus in Qt Quick

PySide2.QtQuick.QQuickItem.hasFocus()

Return type:

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

PySide2.QtQuick.QQuickItem.height()

Return type:

float

This property holds the height of this item.

PySide2.QtQuick.QQuickItem.heightChanged()

PySide2.QtQuick.QQuickItem.heightValid()

Return type:

bool

Returns whether the height property has been set explicitly.

PySide2.QtQuick.QQuickItem.hoverEnterEvent(event)

Parameters:

event – PySide2.QtGui.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() .

PySide2.QtQuick.QQuickItem.hoverLeaveEvent(event)

Parameters:

event – PySide2.QtGui.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() .

PySide2.QtQuick.QQuickItem.hoverMoveEvent(event)

Parameters:

event – PySide2.QtGui.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() .

PySide2.QtQuick.QQuickItem.implicitHeight()

Return type:

float

PySide2.QtQuick.QQuickItem.implicitHeightChanged()

PySide2.QtQuick.QQuickItem.implicitWidth()

Return type:

float

PySide2.QtQuick.QQuickItem.implicitWidthChanged()

PySide2.QtQuick.QQuickItem.inputMethodEvent(arg__1)

Parameters:

arg__1 – PySide2.QtGui.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() .

PySide2.QtQuick.QQuickItem.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 .

See also

inputMethodQuery()

PySide2.QtQuick.QQuickItem.isAncestorOf(child)

Parameters:

child – PySide2.QtQuick.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()

PySide2.QtQuick.QQuickItem.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()

PySide2.QtQuick.QQuickItem.isEnabled()

Return type:

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.

See also

visible

PySide2.QtQuick.QQuickItem.isFocusScope()

Return type:

bool

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

PySide2.QtQuick.QQuickItem.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.

PySide2.QtQuick.QQuickItem.isUnderMouse()

Return type:

bool

PySide2.QtQuick.QQuickItem.isVisible()

Return type:

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.

See also

opacity enabled

PySide2.QtQuick.QQuickItem.itemTransform(arg__1)

Parameters:

arg__1 – PySide2.QtQuick.QQuickItem

Return type:

PyTuple

PySide2.QtQuick.QQuickItem.keepMouseGrab()

Return type:

bool

Returns whether mouse input should exclusively remain with this item.

See also

setKeepMouseGrab()

PySide2.QtQuick.QQuickItem.keepTouchGrab()

Return type:

bool

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

See also

setKeepTouchGrab() keepMouseGrab()

PySide2.QtQuick.QQuickItem.keyPressEvent(event)

Parameters:

event – PySide2.QtGui.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() .

PySide2.QtQuick.QQuickItem.keyReleaseEvent(event)

Parameters:

event – PySide2.QtGui.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() .

PySide2.QtQuick.QQuickItem.mapFromGlobal(point)

Parameters:

point – PySide2.QtCore.QPointF

Return type:

PySide2.QtCore.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 .

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

PySide2.QtQuick.QQuickItem.mapFromItem(item, point)

Parameters:

• item – PySide2.QtQuick.QQuickItem

• point – PySide2.QtCore.QPointF

Return type:

PySide2.QtCore.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 item is 0, this maps point from the coordinate system of the scene.

See also

Concepts - Visual Coordinates in Qt Quick

PySide2.QtQuick.QQuickItem.mapFromScene(point)

Parameters:

point – PySide2.QtCore.QPointF

Return type:

PySide2.QtCore.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 .

See also

Concepts - Visual Coordinates in Qt Quick

PySide2.QtQuick.QQuickItem.mapRectFromItem(item, rect)

Parameters:

• item – PySide2.QtQuick.QQuickItem

• rect – PySide2.QtCore.QRectF

Return type:

PySide2.QtCore.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 item is 0, this maps rect from the coordinate system of the scene.

See also

Concepts - Visual Coordinates in Qt Quick

PySide2.QtQuick.QQuickItem.mapRectFromScene(rect)

Parameters:

rect – PySide2.QtCore.QRectF

Return type:

PySide2.QtCore.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 .

See also

Concepts - Visual Coordinates in Qt Quick

PySide2.QtQuick.QQuickItem.mapRectToItem(item, rect)

Parameters:

• item – PySide2.QtQuick.QQuickItem

• rect – PySide2.QtCore.QRectF

Return type:

PySide2.QtCore.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 item is 0, this maps rect to the coordinate system of the scene.

See also

Concepts - Visual Coordinates in Qt Quick

PySide2.QtQuick.QQuickItem.mapRectToScene(rect)

Parameters:

rect – PySide2.QtCore.QRectF

Return type:

PySide2.QtCore.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 .

See also

Concepts - Visual Coordinates in Qt Quick

PySide2.QtQuick.QQuickItem.mapToGlobal(point)

Parameters:

point – PySide2.QtCore.QPointF

Return type:

PySide2.QtCore.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 .

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

PySide2.QtQuick.QQuickItem.mapToItem(item, point)

Parameters:

• item – PySide2.QtQuick.QQuickItem

• point – PySide2.QtCore.QPointF

Return type:

PySide2.QtCore.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 item is 0, this maps point to the coordinate system of the scene.

See also

Concepts - Visual Coordinates in Qt Quick

PySide2.QtQuick.QQuickItem.mapToScene(point)

Parameters:

point – PySide2.QtCore.QPointF

Return type:

PySide2.QtCore.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 .

See also

Concepts - Visual Coordinates in Qt Quick

PySide2.QtQuick.QQuickItem.mouseDoubleClickEvent(event)

Parameters:

event – PySide2.QtGui.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() .

PySide2.QtQuick.QQuickItem.mouseMoveEvent(event)

Parameters:

event – PySide2.QtGui.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() .

PySide2.QtQuick.QQuickItem.mousePressEvent(event)

Parameters:

event – PySide2.QtGui.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() .

PySide2.QtQuick.QQuickItem.mouseReleaseEvent(event)

Parameters:

event – PySide2.QtGui.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() .

PySide2.QtQuick.QQuickItem.mouseUngrabEvent()

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

PySide2.QtQuick.QQuickItem.nextItemInFocusChain([forward=true])

Parameters:

forward – bool

Return type:

PySide2.QtQuick.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.

PySide2.QtQuick.QQuickItem.opacity()

Return type:

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

PySide2.QtQuick.QQuickItem.opacityChanged()

PySide2.QtQuick.QQuickItem.parentChanged(arg__1)

Parameters:

arg__1 – PySide2.QtQuick.QQuickItem

PySide2.QtQuick.QQuickItem.parentItem()

Return type:

PySide2.QtQuick.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.

PySide2.QtQuick.QQuickItem.polish()

Schedules a polish event for this item.

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

See also

updatePolish() qIsPolishScheduled()

PySide2.QtQuick.QQuickItem.position()

Return type:

PySide2.QtCore.QPointF

PySide2.QtQuick.QQuickItem.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

PySide2.QtQuick.QQuickItem.resetAntialiasing()

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.

PySide2.QtQuick.QQuickItem.resetHeight()

This property holds the height of this item.

PySide2.QtQuick.QQuickItem.resetWidth()

This property holds the width of this item.

PySide2.QtQuick.QQuickItem.rotation()

Return type:

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

PySide2.QtQuick.QQuickItem.rotationChanged()

PySide2.QtQuick.QQuickItem.scale()

Return type:

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

PySide2.QtQuick.QQuickItem.scaleChanged()

PySide2.QtQuick.QQuickItem.scopedFocusItem()

Return type:

PySide2.QtQuick.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.

PySide2.QtQuick.QQuickItem.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.

See also

acceptHoverEvents()

PySide2.QtQuick.QQuickItem.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.

See also

acceptTouchEvents()

PySide2.QtQuick.QQuickItem.setAcceptedMouseButtons(buttons)

Parameters:

buttons – MouseButtons

Sets the mouse buttons accepted by this item to buttons .

Note

In Qt 5, calling 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()

PySide2.QtQuick.QQuickItem.setActiveFocusOnTab(arg__1)

Parameters:

arg__1 – bool

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

PySide2.QtQuick.QQuickItem.setAntialiasing(arg__1)

Parameters:

arg__1 – 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.

PySide2.QtQuick.QQuickItem.setBaselineOffset(arg__1)

Parameters:

arg__1 – 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.

PySide2.QtQuick.QQuickItem.setClip(arg__1)

Parameters:

arg__1 – 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.

PySide2.QtQuick.QQuickItem.setContainmentMask(mask)

Parameters:

mask – PySide2.QtCore.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. 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()

PySide2.QtQuick.QQuickItem.setCursor(cursor)

Parameters:

cursor – PySide2.QtGui.QCursor

Sets the cursor shape for this item.

See also

cursor() unsetCursor()

PySide2.QtQuick.QQuickItem.setEnabled(arg__1)

Parameters:

arg__1 – 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.

See also

visible

PySide2.QtQuick.QQuickItem.setFiltersChildMouseEvents(filter)

Parameters:

filter – bool

Sets whether mouse and touch events of this item’s children should be filtered through this item.

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

See also

filtersChildMouseEvents()

PySide2.QtQuick.QQuickItem.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.

PySide2.QtQuick.QQuickItem.setFlags(flags)

Parameters:

flags – Flags

Enables the specified flags for this item.

See also

flags() setFlag()

PySide2.QtQuick.QQuickItem.setFocus(arg__1)

Parameters:

arg__1 – 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

PySide2.QtQuick.QQuickItem.setFocus(focus, reason)

Parameters:

• focus – bool

• reason – FocusReason

PySide2.QtQuick.QQuickItem.setHeight(arg__1)

Parameters:

arg__1 – float

This property holds the height of this item.

PySide2.QtQuick.QQuickItem.setImplicitHeight(arg__1)

Parameters:

arg__1 – float

PySide2.QtQuick.QQuickItem.setImplicitSize(arg__1, arg__2)

Parameters:

• arg__1 – float

• arg__2 – float

PySide2.QtQuick.QQuickItem.setImplicitWidth(arg__1)

Parameters:

arg__1 – float

PySide2.QtQuick.QQuickItem.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()

PySide2.QtQuick.QQuickItem.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 to true once a threshold has been exceeded. Once 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.

See also

keepTouchGrab() setKeepMouseGrab()

PySide2.QtQuick.QQuickItem.setOpacity(arg__1)

Parameters:

arg__1 – 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

PySide2.QtQuick.QQuickItem.setParentItem(parent)

Parameters:

parent – PySide2.QtQuick.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.

PySide2.QtQuick.QQuickItem.setPosition(arg__1)

Parameters:

arg__1 – PySide2.QtCore.QPointF

PySide2.QtQuick.QQuickItem.setRotation(arg__1)

Parameters:

arg__1 – 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

PySide2.QtQuick.QQuickItem.setScale(arg__1)

Parameters:

arg__1 – 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

PySide2.QtQuick.QQuickItem.setSize(size)

Parameters:

size – PySide2.QtCore.QSizeF

Sets the size of the item to size .

See also

size setWidth setHeight

PySide2.QtQuick.QQuickItem.setSmooth(arg__1)

Parameters:

arg__1 – 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 .

PySide2.QtQuick.QQuickItem.setState(arg__1)

Parameters:

arg__1 – 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

PySide2.QtQuick.QQuickItem.setTransformOrigin(arg__1)

Parameters:

arg__1 – 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 .

PySide2.QtQuick.QQuickItem.setTransformOriginPoint(arg__1)

Parameters:

arg__1 – PySide2.QtCore.QPointF

PySide2.QtQuick.QQuickItem.setVisible(arg__1)

Parameters:

arg__1 – 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.

See also

opacity enabled

PySide2.QtQuick.QQuickItem.setWidth(arg__1)

Parameters:

arg__1 – float

This property holds the width of this item.

PySide2.QtQuick.QQuickItem.setX(arg__1)

Parameters:

arg__1 – float

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

PySide2.QtQuick.QQuickItem.setY(arg__1)

Parameters:

arg__1 – float

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

PySide2.QtQuick.QQuickItem.setZ(arg__1)

Parameters:

arg__1 – 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.

	Same z - later children above earlier children:
	Higher z on top:
	Same z - children above parents:
	Lower z below:

PySide2.QtQuick.QQuickItem.size()

Return type:

PySide2.QtCore.QSizeF

Returns the size of the item.

See also

setSize width height

PySide2.QtQuick.QQuickItem.smooth()

Return type:

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 .

PySide2.QtQuick.QQuickItem.smoothChanged(arg__1)

Parameters:

arg__1 – bool

PySide2.QtQuick.QQuickItem.stackAfter(arg__1)

Parameters:

arg__1 – PySide2.QtQuick.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 .

See also

Concepts - Visual Parent in Qt Quick

PySide2.QtQuick.QQuickItem.stackBefore(arg__1)

Parameters:

arg__1 – PySide2.QtQuick.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 .

See also

Concepts - Visual Parent in Qt Quick

PySide2.QtQuick.QQuickItem.state()

Return type:

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

PySide2.QtQuick.QQuickItem.stateChanged(arg__1)

Parameters:

arg__1 – str

PySide2.QtQuick.QQuickItem.textureProvider()

Return type:

PySide2.QtQuick.QSGTextureProvider

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

This function may only be called on the rendering thread.

PySide2.QtQuick.QQuickItem.touchEvent(event)

Parameters:

event – PySide2.QtGui.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() .

PySide2.QtQuick.QQuickItem.touchUngrabEvent()

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

PySide2.QtQuick.QQuickItem.transformOrigin()

Return type:

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 .

PySide2.QtQuick.QQuickItem.transformOriginChanged(arg__1)

Parameters:

arg__1 – TransformOrigin

PySide2.QtQuick.QQuickItem.transformOriginPoint()

Return type:

PySide2.QtCore.QPointF

PySide2.QtQuick.QQuickItem.ungrabMouse()

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.

PySide2.QtQuick.QQuickItem.ungrabTouchPoints()

Ungrabs the touch points owned by this item.

Note

there is hardly any reason to call this function. It should only be called when an item does not want to receive any further events, so no move or release events will be delivered after calling this function.

See also

grabTouchPoints()

PySide2.QtQuick.QQuickItem.unsetCursor()

Clears the cursor shape for this item.

See also

cursor() setCursor()

PySide2.QtQuick.QQuickItem.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 .

PySide2.QtQuick.QQuickItem.updateInputMethod([queries=Qt.ImQueryInput])

Parameters:

queries – InputMethodQueries

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

PySide2.QtQuick.QQuickItem.updatePaintNode(arg__1, arg__2)

Parameters:

• arg__1 – PySide2.QtQuick.QSGNode

• arg__2 – PySide2.QtQuick.QQuickItem.UpdatePaintNodeData

Return type:

PySide2.QtQuick.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 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 OpenGL operations and interaction with the scene graph happens exclusively on the render thread, primarily during the call. The best rule of thumb is to only use classes with the “QSG” prefix inside the 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 QSGSimpleMaterial QSGGeometryNode QSGGeometry QSGFlatColorMaterial QSGTextureMaterial markDirty() Graphics Resource Handling

PySide2.QtQuick.QQuickItem.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 to do any item layout as required before it renders the next frame.

PySide2.QtQuick.QQuickItem.visibleChanged()

PySide2.QtQuick.QQuickItem.visibleChildrenChanged()

PySide2.QtQuick.QQuickItem.wheelEvent(event)

Parameters:

event – PySide2.QtGui.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() .

PySide2.QtQuick.QQuickItem.width()

Return type:

float

This property holds the width of this item.

PySide2.QtQuick.QQuickItem.widthChanged()

PySide2.QtQuick.QQuickItem.widthValid()

Return type:

bool

Returns whether the width property has been set explicitly.

PySide2.QtQuick.QQuickItem.window()

Return type:

PySide2.QtQuick.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.

PySide2.QtQuick.QQuickItem.windowChanged(window)

Parameters:

window – PySide2.QtQuick.QQuickWindow

PySide2.QtQuick.QQuickItem.windowDeactivateEvent()

PySide2.QtQuick.QQuickItem.x()

Return type:

float

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

PySide2.QtQuick.QQuickItem.xChanged()

PySide2.QtQuick.QQuickItem.y()

Return type:

float

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

PySide2.QtQuick.QQuickItem.yChanged()

PySide2.QtQuick.QQuickItem.z()

Return type:

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.

	Same z - later children above earlier children:
	Higher z on top:
	Same z - children above parents:
	Lower z below:

PySide2.QtQuick.QQuickItem.zChanged()