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java.lang.Objectcom.trolltech.qt.QSignalEmitter
com.trolltech.qt.QtJambiObject
com.trolltech.qt.core.QObject
com.trolltech.qt.gui.QGraphicsWidget
public class QGraphicsWidget
The QGraphicsWidget
class is the base class for all widget items in a QGraphicsScene
. QGraphicsWidget
is an extended base item that provides extra functionality over QGraphicsItem
. It is similar to QWidget
in many ways:
palette
, a font
and a style()
.geometry()
.setLayout()
and layout()
.QGraphicsItem
, QGraphicsWidget
is not an abstract class; you can create instances of a QGraphicsWidget
without having to subclass it. This approach is useful for widgets that only serve the purpose of organizing child widgets into a layout. QGraphicsWidget
can be used as a base item for your own custom item if you require advanced input focus handling, e.g., tab focus and activation, or layouts.
Since QGraphicsWidget
resembles QWidget
and has similar API, it is easier to port a widget from QWidget
to QGraphicsWidget
, instead of QGraphicsItem
.
Note:QWidget
-based widgets can be directly embedded into a QGraphicsScene
using QGraphicsProxyWidget
.
Noticeable differences between QGraphicsWidget
and QWidget
are:
QGraphicsWidget | QWidget |
---|---|
Coordinates and geometry are defined with qreals (doubles or floats, depending on the platform). | QWidget uses integer geometry (QPoint , QRect ). |
The widget is already visible by default; you do not have to call show() to display the widget. | QWidget is hidden by default until you call show() . |
A subset of widget attributes are supported. | All widget attributes are supported. |
A top-level item's style defaults to QGraphicsScene::style | A top-level widget's style defaults to QApplication::style |
Graphics View provides a custom DnD framework, different from QWidget . | Standard DnD framework. |
Widget items do not support modality. | Full modality support. |
QGraphicsWidget
supports a subset of Qt's widget attributes, (Qt::WidgetAttribute
), as shown in the table below. Any attributes not listed in this table are unsupported, or otherwise unused. Widget Attribute | Usage |
---|---|
Qt::WA_SetLayoutDirection | Set by setLayoutDirection() , cleared by unsetLayoutDirection() . You can test this attribute to check if the widget has been explicitly assigned a layoutDirection . If the attribute is not set, the layoutDirection() is inherited. |
Qt::WA_RightToLeft | Toggled by setLayoutDirection() . Inherited from the parent/scene. If set, the widget's layout will order horizontally arranged widgets from right to left. |
Qt::WA_SetStyle | Set and cleared by setStyle() . If this attribute is set, the widget has been explicitly assigned a style. If it is unset, the widget will use the scene's or the application's style. |
Qt::WA_Resized | Set by setGeometry() and resize() . |
QGraphicsWidget
inherits from both QObject
and QGraphicsItem
, you should use the functions provided by QGraphicsItem
, notQObject
, to manage the relationships between parent and child items. These functions control the stacking order of items as well as their ownership. Note: The QObject::parent()
should always return 0 for QGraphicsWidgets
, but this policy is not strictly defined.
QGraphicsProxyWidget
, QGraphicsItem
, and Widgets and Layouts.
Nested Class Summary | |
---|---|
static class |
QGraphicsWidget.enum_1
|
Nested classes/interfaces inherited from class com.trolltech.qt.QtJambiObject |
---|
QtJambiObject.QPrivateConstructor |
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter |
---|
QSignalEmitter.AbstractSignal, QSignalEmitter.Signal0, QSignalEmitter.Signal1<A>, QSignalEmitter.Signal2<A,B>, QSignalEmitter.Signal3<A,B,C>, QSignalEmitter.Signal4<A,B,C,D>, QSignalEmitter.Signal5<A,B,C,D,E>, QSignalEmitter.Signal6<A,B,C,D,E,F>, QSignalEmitter.Signal7<A,B,C,D,E,F,G>, QSignalEmitter.Signal8<A,B,C,D,E,F,G,H>, QSignalEmitter.Signal9<A,B,C,D,E,F,G,H,I> |
Constructor Summary | |
---|---|
|
QGraphicsWidget()
Constructs a QGraphicsWidget instance. |
|
QGraphicsWidget(QGraphicsItemInterface parent)
Constructs a QGraphicsWidget instance. |
|
QGraphicsWidget(QGraphicsItemInterface parent,
Qt.WindowFlags wFlags)
Constructs a QGraphicsWidget instance. |
|
QGraphicsWidget(QGraphicsItemInterface parent,
Qt.WindowType... wFlags)
Constructs a QGraphicsWidget instance. |
protected |
QGraphicsWidget(QtJambiObject.QPrivateConstructor p)
This method is internal to Qt Jambi. |
Method Summary | |
---|---|
long |
__qt_cast_to_QGraphicsItem(long ptr)
This method is internal to Qt Jambi. |
long |
__qt_cast_to_QGraphicsLayoutItem(long ptr)
This method is internal to Qt Jambi. |
boolean |
acceptDrops()
Returns true if this item can accept drag and drop events; otherwise, returns false. |
Qt.MouseButtons |
acceptedMouseButtons()
Returns the mouse buttons that this item accepts mouse events for. |
boolean |
acceptHoverEvents()
Returns true if an item accepts hover events ( QGraphicsSceneHoverEvent ); otherwise, returns false. |
boolean |
acceptsHoverEvents()
Call acceptHoverEvents() instead. |
void |
addToIndex()
This method is internal to Qt Jambi. |
void |
adjustSize()
Adjusts the size of the widget to its effective minimum size hint. |
void |
advance(int phase)
This virtual function is called twice for all items by the QGraphicsScene::advance() slot. |
QRectF |
boundingRect()
This pure virtual function defines the outer bounds of the item as a rectangle; all painting must be restricted to inside an item's bounding rect. |
QRegion |
boundingRegion(QTransform itemToDeviceTransform)
Returns the bounding region for this item. |
double |
boundingRegionGranularity()
Returns the item's bounding region granularity; a value between and including 0 and 1. |
QGraphicsItem.CacheMode |
cacheMode()
Returns the cache mode for this item. |
protected void |
changeEvent(QEvent event)
This event handler can be reimplemented to handle state changes. |
java.util.List<QGraphicsItemInterface> |
childItems()
Returns a list of this item's children. |
QRectF |
childrenBoundingRect()
Returns the bounding rect of this item's descendents (i.e., its children, their children, etc.) in local coordinates. |
void |
clearFocus()
Takes keyboard input focus from the item. |
boolean |
close()
Call this function to close the widget. |
protected void |
closeEvent(QCloseEvent event)
This event handler, for event, can be reimplemented in a subclass to receive widget close events. |
boolean |
collidesWithItem(QGraphicsItemInterface other,
Qt.ItemSelectionMode mode)
Returns true if this item collides with other; otherwise returns false. |
boolean |
collidesWithPath(QPainterPath path,
Qt.ItemSelectionMode mode)
Returns true if this item collides with path. |
java.util.List<QGraphicsItemInterface> |
collidingItems(Qt.ItemSelectionMode mode)
Returns a list of all items that collide with this item. |
QGraphicsItemInterface |
commonAncestorItem(QGraphicsItemInterface other)
Returns the closest common ancestor item of this item and other, or 0 if either other is 0, or there is no common ancestor. |
boolean |
contains(QPointF point)
Returns true if this item contains point, which is in local coordinates; otherwise, false is returned. |
QRectF |
contentsRect()
Returns the contents rect in local coordinates. |
void |
contextMenuEvent(QGraphicsSceneContextMenuEvent event)
This event handler can be reimplemented in a subclass to process context menu events. |
QCursor |
cursor()
Returns the current cursor shape for the item. |
java.lang.Object |
data(int key)
Returns this item's custom data for the key key as a QVariant . |
QTransform |
deviceTransform(QTransform viewportTransform)
Returns this item's device transformation matrix, using viewportTransform to map from scene to device coordinates. |
void |
dragEnterEvent(QGraphicsSceneDragDropEvent event)
This event handler, for event event, can be reimplemented to receive drag enter events for this item. |
void |
dragLeaveEvent(QGraphicsSceneDragDropEvent event)
This event handler, for event event, can be reimplemented to receive drag leave events for this item. |
void |
dragMoveEvent(QGraphicsSceneDragDropEvent event)
This event handler, for event event, can be reimplemented to receive drag move events for this item. |
void |
dropEvent(QGraphicsSceneDragDropEvent event)
This event handler, for event event, can be reimplemented to receive drop events for this item. |
QSizeF |
effectiveSizeHint(Qt.SizeHint which,
QSizeF constraint)
Returns the effective size hint for this QGraphicsLayoutItem . |
void |
ensureVisible(double x,
double y,
double w,
double h,
int xmargin,
int ymargin)
This convenience function is equivalent to calling ensureVisible( QRectF (x, y, w, h), xmargin, ymargin): |
void |
ensureVisible(QRectF rect,
int xmargin,
int ymargin)
If this item is part of a scene that is viewed by a QGraphicsView , this convenience function will attempt to scroll the view to ensure that rect is visible inside the view's viewport. |
boolean |
event(QEvent event)
|
java.lang.Object |
extension(java.lang.Object variant)
This method is internal to Qt Jambi. |
QGraphicsItem.GraphicsItemFlags |
flags()
Returns this item's flags. |
void |
focusInEvent(QFocusEvent event)
This event handler, for event event, can be reimplemented to receive focus in events for this item. |
protected boolean |
focusNextPrevChild(boolean next)
Finds a new widget to give the keyboard focus to, as appropriate for Tab and Shift+Tab, and returns true if it can find a new widget; returns false otherwise. |
void |
focusOutEvent(QFocusEvent event)
This event handler, for event event, can be reimplemented to receive focus out events for this item. |
Qt.FocusPolicy |
focusPolicy()
This property holds the way the widget accepts keyboard focus. |
QGraphicsWidget |
focusWidget()
If this widget, a child or descendent of this widget currently has input focus, this function will return a pointer to that widget. |
QFont |
font()
This property holds the widgets' font. |
static QGraphicsWidget |
fromNativePointer(QNativePointer nativePointer)
|
QRectF |
geometry()
Returns the item's geometry (e.g., position and size) as a QRectF . |
QMarginsF |
getContentsMargins()
This virtual function provides the left, top, right and bottom contents margins for this QGraphicsLayoutItem . |
QMarginsF |
getWindowFrameMargins()
Gets the widget's window frame margins. |
void |
grabKeyboard()
Grabs the keyboard input. |
protected void |
grabKeyboardEvent(QEvent event)
This event handler, for event, can be reimplemented in a subclass to receive notifications for Qt::GrabKeyboard events. |
void |
grabMouse()
Grabs the mouse input. |
protected void |
grabMouseEvent(QEvent event)
This event handler, for event, can be reimplemented in a subclass to receive notifications for Qt::GrabMouse events. |
QGraphicsItemGroup |
group()
Returns a pointer to this item's item group, or 0 if this item is not member of a group. |
boolean |
handlesChildEvents()
Returns true if this item handles child events (i.e., all events intended for any of its children are instead sent to this item); otherwise, false is returned. |
boolean |
hasCursor()
Returns true if this item has a cursor set; otherwise, false is returned. |
boolean |
hasFocus()
Returns true if this item has keyboard input focus; otherwise, returns false. |
void |
hide()
Hides the item. |
protected void |
hideEvent(QHideEvent event)
This event handler, for Hide events, is delivered after the widget has been hidden, for example, setVisible (false) has been called for the widget or one of its ancestors when the widget was previously shown. |
void |
hoverEnterEvent(QGraphicsSceneHoverEvent event)
This event handler, for event event, can be reimplemented to receive hover enter events for this item. |
void |
hoverLeaveEvent(QGraphicsSceneHoverEvent event)
This event handler, for event event, can be reimplemented to receive hover leave events for this item. |
void |
hoverMoveEvent(QGraphicsSceneHoverEvent event)
This event handler, for event event, can be reimplemented to receive hover move events for this item. |
protected void |
initStyleOption(QStyleOption option)
Populates a style option object for this widget based on its current state, and stores the output in option. |
void |
inputMethodEvent(QInputMethodEvent event)
This event handler, for event event, can be reimplemented to receive input method events for this item. |
java.lang.Object |
inputMethodQuery(Qt.InputMethodQuery query)
This method is only relevant for input items. |
void |
installSceneEventFilter(QGraphicsItemInterface filterItem)
Installs an event filter for this item on filterItem, causing all events for this item to first pass through filterItem's sceneEventFilter() function. |
boolean |
isActiveWindow()
Returns true if this widget's window is in the active window, or if the widget does not have a window but is in an active scene (i.e., a scene that currently has focus). |
boolean |
isAncestorOf(QGraphicsItemInterface child)
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). |
boolean |
isEnabled()
Returns true if the item is enabled; otherwise, false is returned. |
boolean |
isLayout()
Returns true if this QGraphicsLayoutItem is a layout (e.g., is inherited by an object that arranges other QGraphicsLayoutItem objects); otherwise returns false. |
boolean |
isObscured()
Returns true if this item's bounding rect is completely obscured by the opaque shape of any of colliding items above it (i.e., with a higher Z value than this item). |
boolean |
isObscured(double x,
double y,
double w,
double h)
This convenience function is equivalent to calling isObscured( QRectF (x, y, w, h)). |
boolean |
isObscured(QRectF rect)
Returns true if rect is completely obscured by the opaque shape of any of colliding items above it (i.e., with a higher Z value than this item). |
boolean |
isObscuredBy(QGraphicsItemInterface item)
Returns true if this item's bounding rect is completely obscured by the opaque shape of item. |
boolean |
isSelected()
Returns true if this item is selected; otherwise, false is returned. |
boolean |
isUnderMouse()
Returns true if this item is currently under the mouse cursor in one of the views; otherwise, false is returned. |
boolean |
isVisible()
Returns true if the item is visible; otherwise, false is returned. |
boolean |
isVisibleTo(QGraphicsItemInterface parent)
Returns true if the item is visible to parent; otherwise, false is returned. |
boolean |
isWidget()
Returns true if this item is a widget (i.e., QGraphicsWidget ); otherwise, returns false. |
boolean |
isWindow()
Returns true if the item is a QGraphicsWidget window, otherwise returns false. |
java.lang.Object |
itemChange(QGraphicsItem.GraphicsItemChange change,
java.lang.Object value)
This virtual function is called by QGraphicsItem to notify custom items that some part of the item's state changes. |
void |
keyPressEvent(QKeyEvent event)
This event handler, for event event, can be reimplemented to receive key press events for this item. |
void |
keyReleaseEvent(QKeyEvent event)
This event handler, for event event, can be reimplemented to receive key release events for this item. |
QGraphicsLayout |
layout()
Returns this widget's layout, or 0 if no layout is currently managing this widget. |
Qt.LayoutDirection |
layoutDirection()
This property holds the layout direction for this widget.. |
QPointF |
mapFromItem(QGraphicsItemInterface item,
double x,
double y)
This convenience function is equivalent to calling mapFromItem(item, QPointF (x, y)). |
QPolygonF |
mapFromItem(QGraphicsItemInterface item,
double x,
double y,
double w,
double h)
This convenience function is equivalent to calling mapFromItem(item, QRectF (x, y, w, h)). |
QPainterPath |
mapFromItem(QGraphicsItemInterface item,
QPainterPath path)
Maps the path path, which is in item's coordinate system, to this item's coordinate system, and returns the mapped path. |
QPointF |
mapFromItem(QGraphicsItemInterface item,
QPointF point)
Maps the point point, which is in item's coordinate system, to this item's coordinate system, and returns the mapped coordinate. |
QPolygonF |
mapFromItem(QGraphicsItemInterface item,
QPolygonF polygon)
Maps the polygon polygon, which is in item's coordinate system, to this item's coordinate system, and returns the mapped polygon. |
QPolygonF |
mapFromItem(QGraphicsItemInterface item,
QRectF rect)
Maps the rectangle rect, which is in item's coordinate system, to this item's coordinate system, and returns the mapped rectangle as a polygon. |
QPointF |
mapFromParent(double x,
double y)
This convenience function is equivalent to calling mapFromParent( QPointF (x, y)). |
QPolygonF |
mapFromParent(double x,
double y,
double w,
double h)
This convenience function is equivalent to calling mapFromItem( QRectF (x, y, w, h)). |
QPainterPath |
mapFromParent(QPainterPath path)
Maps the path path, which is in this item's parent's coordinate system, to this item's coordinate system, and returns the mapped path. |
QPointF |
mapFromParent(QPointF point)
Maps the point point, which is in this item's parent's coordinate system, to this item's coordinate system, and returns the mapped coordinate. |
QPolygonF |
mapFromParent(QPolygonF polygon)
Maps the polygon polygon, which is in this item's parent's coordinate system, to this item's coordinate system, and returns the mapped polygon. |
QPolygonF |
mapFromParent(QRectF rect)
Maps the rectangle rect, which is in this item's parent's coordinate system, to this item's coordinate system, and returns the mapped rectangle as a polygon. |
QPointF |
mapFromScene(double x,
double y)
This convenience function is equivalent to calling mapFromScene( QPointF (x, y)). |
QPolygonF |
mapFromScene(double x,
double y,
double w,
double h)
This convenience function is equivalent to calling mapFromScene( QRectF (x, y, w, h)). |
QPainterPath |
mapFromScene(QPainterPath path)
Maps the path path, which is in this item's scene's coordinate system, to this item's coordinate system, and returns the mapped path. |
QPointF |
mapFromScene(QPointF point)
Maps the point point, which is in this item's scene's coordinate system, to this item's coordinate system, and returns the mapped coordinate. |
QPolygonF |
mapFromScene(QPolygonF polygon)
Maps the polygon polygon, which is in this item's scene's coordinate system, to this item's coordinate system, and returns the mapped polygon. |
QPolygonF |
mapFromScene(QRectF rect)
Maps the rectangle rect, which is in this item's scene's coordinate system, to this item's coordinate system, and returns the mapped rectangle as a polygon. |
QPointF |
mapToItem(QGraphicsItemInterface item,
double x,
double y)
This convenience function is equivalent to calling mapToItem(item, QPointF (x, y)). |
QPolygonF |
mapToItem(QGraphicsItemInterface item,
double x,
double y,
double w,
double h)
This convenience function is equivalent to calling mapToItem(item, QRectF (x, y, w, h)). |
QPainterPath |
mapToItem(QGraphicsItemInterface item,
QPainterPath path)
Maps the path path, which is in this item's coordinate system, to item's coordinate system, and returns the mapped path. |
QPointF |
mapToItem(QGraphicsItemInterface item,
QPointF point)
Maps the point point, which is in this item's coordinate system, to item's coordinate system, and returns the mapped coordinate. |
QPolygonF |
mapToItem(QGraphicsItemInterface item,
QPolygonF polygon)
Maps the polygon polygon, which is in this item's coordinate system, to item's coordinate system, and returns the mapped polygon. |
QPolygonF |
mapToItem(QGraphicsItemInterface item,
QRectF rect)
Maps the rectangle rect, which is in this item's coordinate system, to item's coordinate system, and returns the mapped rectangle as a polygon. |
QPointF |
mapToParent(double x,
double y)
This convenience function is equivalent to calling mapToParent( QPointF (x, y)). |
QPolygonF |
mapToParent(double x,
double y,
double w,
double h)
This convenience function is equivalent to calling mapToParent( QRectF (x, y, w, h)). |
QPainterPath |
mapToParent(QPainterPath path)
Maps the path path, which is in this item's coordinate system, to its parent's coordinate system, and returns the mapped path. |
QPointF |
mapToParent(QPointF point)
Maps the point point, which is in this item's coordinate system, to its parent's coordinate system, and returns the mapped coordinate. |
QPolygonF |
mapToParent(QPolygonF polygon)
Maps the polygon polygon, which is in this item's coordinate system, to its parent's coordinate system, and returns the mapped polygon. |
QPolygonF |
mapToParent(QRectF rect)
Maps the rectangle rect, which is in this item's coordinate system, to its parent's coordinate system, and returns the mapped rectangle as a polygon. |
QPointF |
mapToScene(double x,
double y)
This convenience function is equivalent to calling mapToScene( QPointF (x, y)). |
QPolygonF |
mapToScene(double x,
double y,
double w,
double h)
This convenience function is equivalent to calling mapToScene( QRectF (x, y, w, h)). |
QPainterPath |
mapToScene(QPainterPath path)
Maps the path path, which is in this item's coordinate system, to the scene's coordinate system, and returns the mapped path. |
QPointF |
mapToScene(QPointF point)
Maps the point point, which is in this item's coordinate system, to the scene's coordinate system, and returns the mapped coordinate. |
QPolygonF |
mapToScene(QPolygonF polygon)
Maps the polygon polygon, which is in this item's coordinate system, to the scene's coordinate system, and returns the mapped polygon. |
QPolygonF |
mapToScene(QRectF rect)
Maps the rectangle rect, which is in this item's coordinate system, to the scene's coordinate system, and returns the mapped rectangle as a polygon. |
double |
maximumHeight()
Returns the maximum height. |
QSizeF |
maximumSize()
Returns the maximum size. |
double |
maximumWidth()
Returns the maximum width. |
double |
minimumHeight()
Returns the minimum height. |
QSizeF |
minimumSize()
Returns the minimum size. |
double |
minimumWidth()
Returns the minimum width. |
void |
mouseDoubleClickEvent(QGraphicsSceneMouseEvent event)
This event handler, for event event, can be reimplemented to receive mouse doubleclick events for this item. |
void |
mouseMoveEvent(QGraphicsSceneMouseEvent event)
This event handler, for event event, can be reimplemented to receive mouse move events for this item. |
void |
mousePressEvent(QGraphicsSceneMouseEvent event)
This event handler, for event event, can be reimplemented to receive mouse press events for this item. |
void |
mouseReleaseEvent(QGraphicsSceneMouseEvent event)
This event handler, for event event, can be reimplemented to receive mouse release events for this item. |
void |
moveBy(double dx,
double dy)
Moves the item by dx points horizontally, and dy point vertically. |
protected void |
moveEvent(QGraphicsSceneMoveEvent event)
This event handler, for GraphicsSceneMove events, is delivered after the widget has moved (e.g., its local position has changed). |
QPainterPath |
opaqueArea()
This virtual function returns a shape representing the area where this item is opaque. |
void |
paint(QPainter painter,
QStyleOptionGraphicsItem option,
QWidget widget)
This function, which is usually called by QGraphicsView , paints the contents of an item in local coordinates. |
void |
paintWindowFrame(QPainter painter,
QStyleOptionGraphicsItem option)
This virtual function is called by QGraphicsScene to draw the window frame for windows using painter, option, and widget, in local coordinates. |
void |
paintWindowFrame(QPainter painter,
QStyleOptionGraphicsItem option,
QWidget widget)
This virtual function is called by QGraphicsScene to draw the window frame for windows using painter, option, and widget, in local coordinates. |
QPalette |
palette()
This property holds the widgets' palette. |
QGraphicsItemInterface |
parentItem()
Returns a pointer to this item's parent item. |
QGraphicsLayoutItemInterface |
parentLayoutItem()
Returns the parent of this QGraphicsLayoutItem , or 0 if there is no parent, or if the parent does not inherit from QGraphicsLayoutItem (QGraphicsLayoutItem is often used through multiple inheritance with QObject -derived classes). |
QGraphicsWidget |
parentWidget()
Returns a pointer to the item's parent widget. |
protected void |
polishEvent()
This event is delivered to the item by the scene at some point after it has been constructed, but before it is shown or otherwise accessed through the scene. |
QPointF |
pos()
Returns the position of the item in parent coordinates. |
double |
preferredHeight()
Returns the preferred height. |
QSizeF |
preferredSize()
Returns the preferred size. |
double |
preferredWidth()
Returns the preferred width. |
void |
prepareGeometryChange()
Prepares the item for a geometry change. |
protected java.lang.Object |
propertyChange(java.lang.String propertyName,
java.lang.Object value)
This method is internal to Qt Jambi. |
QRectF |
rect()
Returns the item's local rect as a QRectF . |
void |
removeFromIndex()
This method is internal to Qt Jambi. |
void |
removeSceneEventFilter(QGraphicsItemInterface filterItem)
Removes an event filter on this item from filterItem. |
void |
resetTransform()
Resets this item's transformation matrix to the identity matrix. |
void |
resize(double w,
double h)
This property holds the size of the widget. |
void |
resize(QSizeF size)
This property holds the size of the widget. |
protected void |
resizeEvent(QGraphicsSceneResizeEvent event)
This event handler, for GraphicsSceneResize events, is delivered after the widget has been resized (i.e., its local size has changed). |
void |
rotate(double angle)
Rotates the current item transformation angle degrees clockwise around its origin. |
void |
scale(double sx,
double sy)
Scales the current item transformation by (sx, sy) around its origin. |
QGraphicsScene |
scene()
Returns the current scene for the item, or 0 if the item is not stored in a scene. |
QRectF |
sceneBoundingRect()
Returns the bounding rect of this item in scene coordinates, by combining sceneTransform() with boundingRect() . |
boolean |
sceneEvent(QEvent event)
This virtual function receives events to this item. |
boolean |
sceneEventFilter(QGraphicsItemInterface watched,
QEvent event)
Filters events for the item watched. |
QPointF |
scenePos()
Returns the item's position in scene coordinates. |
QTransform |
sceneTransform()
Returns this item's scene transformation matrix. |
void |
scroll(double dx,
double dy,
QRectF rect)
Scrolls the contents of rect by dx, dy. |
void |
setAcceptDrops(boolean on)
If on is true, this item will accept drag and drop events; otherwise, it is transparent for drag and drop events. |
void |
setAcceptedMouseButtons(Qt.MouseButtons buttons)
Sets the mouse buttons that this item accepts mouse events for. |
void |
setAcceptHoverEvents(boolean enabled)
If enabled is true, this item will accept hover events; otherwise, it will ignore them. |
void |
setAcceptsHoverEvents(boolean enabled)
Use setAcceptHoverEvents(enabled) instead. |
void |
setAttribute(Qt.WidgetAttribute attribute)
If on is true, this function enables attribute; otherwise attribute is disabled. |
void |
setAttribute(Qt.WidgetAttribute attribute,
boolean on)
If on is true, this function enables attribute; otherwise attribute is disabled. |
void |
setBoundingRegionGranularity(double granularity)
Sets the bounding region granularity to granularity; a value between and including 0 and 1. |
void |
setCacheMode(QGraphicsItem.CacheMode mode,
QSize cacheSize)
Sets the item's cache mode to mode. |
void |
setContentsMargins(double left,
double top,
double right,
double bottom)
Sets the widget's contents margins to left, top, right and bottom. |
void |
setCursor(QCursor cursor)
Sets the current cursor shape for the item to cursor. |
void |
setData(int key,
java.lang.Object value)
Sets this item's custom data for the key key to value. |
void |
setEnabled(boolean enabled)
If enabled is true, the item is enabled; otherwise, it is disabled. |
void |
setExtension(QGraphicsItem.Extension extension,
java.lang.Object variant)
This method is internal to Qt Jambi. |
void |
setFlag(QGraphicsItem.GraphicsItemFlag flag,
boolean enabled)
If enabled is true, the item flag flag is enabled; otherwise, it is disabled. |
void |
setFlags(QGraphicsItem.GraphicsItemFlags flags)
Sets the item flags to flags. |
void |
setFocus(Qt.FocusReason focusReason)
Gives keyboard input focus to this item. |
void |
setFocusPolicy(Qt.FocusPolicy policy)
This property holds the way the widget accepts keyboard focus. |
void |
setFont(QFont font)
This property holds the widgets' font. |
void |
setGeometry(double x,
double y,
double w,
double h)
This convenience function is equivalent to calling setGeometry( QRectF ( x, y, w, h)). |
void |
setGeometry(QRectF rect)
This pure virtual function sets the geometry of the QGraphicsLayoutItem to rect, which is in parent coordinates (e.g., the top-left corner of rect is equivalent to the item's position in parent coordinates). |
void |
setGroup(QGraphicsItemGroup group)
Adds this item to the item group group. |
void |
setHandlesChildEvents(boolean enabled)
If enabled is true, this item is set to handle all events for all its children (i.e., all events intented for any of its children are instead sent to this item); otherwise, if enabled is false, this item will only handle its own events. |
void |
setLayout(QGraphicsLayout layout)
Sets the layout for this widget to layout. |
void |
setLayoutDirection(Qt.LayoutDirection direction)
This property holds the layout direction for this widget.. |
void |
setMaximumHeight(double height)
Sets the maximum height to height. |
void |
setMaximumSize(double w,
double h)
This convenience function is equivalent to calling setMaximumSize( QSizeF (w, h)). |
void |
setMaximumSize(QSizeF size)
Sets the maximum size to size. |
void |
setMaximumWidth(double width)
Sets the maximum width to width. |
void |
setMinimumHeight(double height)
Sets the minimum height to height. |
void |
setMinimumSize(double w,
double h)
This convenience function is equivalent to calling setMinimumSize( QSizeF (w, h)). |
void |
setMinimumSize(QSizeF size)
Sets the minimum size to size. |
void |
setMinimumWidth(double width)
Sets the minimum width to width. |
void |
setPalette(QPalette palette)
This property holds the widgets' palette. |
void |
setParentItem(QGraphicsItemInterface parent)
Sets this item's parent item to parent. |
void |
setParentLayoutItem(QGraphicsLayoutItemInterface parent)
Sets the parent of this QGraphicsLayoutItem to parent. |
void |
setPos(double x,
double y)
This convenience function is equivalent to calling setPos( QPointF (x, y)). |
void |
setPos(QPointF pos)
Sets the position of the item to pos, which is in parent coordinates. |
void |
setPreferredHeight(double height)
Sets the preferred height to height. |
void |
setPreferredSize(double w,
double h)
This convenience function is equivalent to calling setPreferredSize( QSizeF (w, h)). |
void |
setPreferredSize(QSizeF size)
Sets the preferred size to size. |
void |
setPreferredWidth(double width)
Sets the preferred width to width. |
void |
setSelected(boolean selected)
If selected is true and this item is selectable, this item is selected; otherwise, it is unselected. |
void |
setSizePolicy(QSizePolicy.Policy hPolicy,
QSizePolicy.Policy vPolicy,
QSizePolicy.ControlType controlType)
This function is equivalent to calling setSizePolicy( QSizePolicy (hPolicy, vPolicy, controlType)). |
void |
setSizePolicy(QSizePolicy policy)
Sets the size policy to policy. |
void |
setStyle(QStyle style)
Sets the widget's style to style. |
static void |
setTabOrder(QGraphicsWidget first,
QGraphicsWidget second)
Moves the second widget around the ring of focus widgets so that keyboard focus moves from the first widget to the second widget when the Tab key is pressed. |
void |
setToolTip(java.lang.String toolTip)
Sets the item's tool tip to toolTip. |
void |
setTransform(QTransform matrix,
boolean combine)
Sets the item's current transformation matrix to matrix. |
void |
setVisible(boolean visible)
If visible is true, the item is made visible. |
void |
setWindowFlags(Qt.WindowFlags wFlags)
This property holds This propery holds the widget's window flags.. |
void |
setWindowFlags(Qt.WindowType... wFlags)
This property holds This propery holds the widget's window flags.. |
void |
setWindowFrameMargins(double left,
double top,
double right,
double bottom)
Sets the widget's window frame margins to left, top, right and bottom. |
void |
setWindowTitle(java.lang.String title)
This property holds This property holds the window title (caption).. |
void |
setZValue(double z)
Sets the Z-value, or the elevation, of the item, to z. |
QPainterPath |
shape()
Returns the shape of this item as a QPainterPath in local coordinates. |
void |
shear(double sh,
double sv)
Shears the current item transformation by (sh, sv). |
void |
show()
Shows the item. |
protected void |
showEvent(QShowEvent event)
This event handler, for Show events, is delivered before the widget has been shown, for example, setVisible (true) has been called for the widget or one of its ancestors when the widget was previously hidden. |
QSizeF |
size()
This property holds the size of the widget. |
QSizeF |
sizeHint(Qt.SizeHint which,
QSizeF constraint)
This pure virtual function returns the size hint for which of the QGraphicsLayoutItem , using the width or height of constraint to constrain the output. |
QSizePolicy |
sizePolicy()
Returns the current size policy. |
QStyle |
style()
Returns a pointer to the widget's style. |
boolean |
supportsExtension(QGraphicsItem.Extension extension)
This method is internal to Qt Jambi. |
boolean |
testAttribute(Qt.WidgetAttribute attribute)
Returns true if attribute is enabled for this widget; otherwise, returns false. |
java.lang.String |
toolTip()
Returns the item's tool tip, or an empty QString if no tool tip has been set. |
QGraphicsItemInterface |
topLevelItem()
Returns this item's top-level item. |
QGraphicsWidget |
topLevelWidget()
Returns a pointer to the item's top level widget (i.e., the item's ancestor whose parent is 0, or whose parent is not a widget), or 0 if this item does not have a top level widget. |
QTransform |
transform()
Returns this item's transformation matrix. |
void |
translate(double dx,
double dy)
Translates the current item transformation by (dx, dy). |
int |
type()
Returns the type of an item as an int. |
void |
ungrabKeyboard()
Releases the keyboard grab. |
protected void |
ungrabKeyboardEvent(QEvent event)
This event handler, for event, can be reimplemented in a subclass to receive notifications for Qt::UngrabKeyboard events. |
void |
ungrabMouse()
Releases the mouse grab. |
protected void |
ungrabMouseEvent(QEvent event)
This event handler, for event, can be reimplemented in a subclass to receive notifications for Qt::UngrabMouse events. |
void |
unsetCursor()
Clears the cursor from this item. |
void |
unsetLayoutDirection()
This property holds the layout direction for this widget.. |
void |
unsetWindowFrameMargins()
Resets the window frame margins to the default value, provided by the style. |
void |
update(double x,
double y,
double width,
double height)
This convenience function is equivalent to calling update( QRectF (x, y, width, height)). |
void |
update(QRectF rect)
Schedules a redraw of the area covered by rect in this item. |
void |
updateGeometry()
This virtual function discards any cached size hint information. |
void |
wheelEvent(QGraphicsSceneWheelEvent event)
This event handler, for event event, can be reimplemented to receive wheel events for this item. |
QGraphicsWidget |
window()
Returns the item's window, or 0 if this item does not have a window. |
Qt.WindowFlags |
windowFlags()
This property holds This propery holds the widget's window flags.. |
protected boolean |
windowFrameEvent(QEvent e)
This event handler, for event, receives events for the window frame if this widget is a window. |
QRectF |
windowFrameGeometry()
Returns the widget's geometry in parent coordinates including any window frame. |
QRectF |
windowFrameRect()
Returns the widget's local rect including any window frame. |
protected Qt.WindowFrameSection |
windowFrameSectionAt(QPointF pos)
Returns the window frame section at position pos, or Qt::NoWindowFrameSection if there is no window frame section at this position. |
java.lang.String |
windowTitle()
This property holds This property holds the window title (caption).. |
Qt.WindowType |
windowType()
Returns the widgets window type. |
double |
x()
This convenience function is equivalent to calling pos() .x() . |
double |
y()
This convenience function is equivalent to calling pos() .y() . |
double |
zValue()
Returns the Z-value, or the elevation, of the item. |
Methods inherited from class com.trolltech.qt.core.QObject |
---|
blockSignals, childEvent, children, connectSlotsByName, customEvent, disposeLater, dumpObjectInfo, dumpObjectTree, dynamicPropertyNames, eventFilter, findChild, findChild, findChild, findChildren, findChildren, findChildren, findChildren, indexOfProperty, installEventFilter, isWidgetType, killTimer, moveToThread, objectName, parent, properties, property, removeEventFilter, setObjectName, setParent, setProperty, signalsBlocked, startTimer, thread, timerEvent, toString, userProperty |
Methods inherited from class com.trolltech.qt.QtJambiObject |
---|
disableGarbageCollection, dispose, disposed, equals, finalize, nativeId, nativePointer, reassignNativeResources, reenableGarbageCollection, setJavaOwnership, tr, tr, tr |
Methods inherited from class com.trolltech.qt.QSignalEmitter |
---|
__qt_signalInitialization, disconnect, disconnect, signalSender |
Methods inherited from class java.lang.Object |
---|
clone, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Methods inherited from interface com.trolltech.qt.QtJambiInterface |
---|
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership |
Constructor Detail |
---|
public QGraphicsWidget(QGraphicsItemInterface parent, Qt.WindowType... wFlags)
QGraphicsWidget
instance. The optional parent argument is passed to QGraphicsItem
's constructor. The optional wFlags argument specifies the widget's window flags (e.g., whether the widget should be a window, a tool, a popup, etc).
public QGraphicsWidget(QGraphicsItemInterface parent)
QGraphicsWidget
instance. The optional parent argument is passed to QGraphicsItem
's constructor. The optional wFlags argument specifies the widget's window flags (e.g., whether the widget should be a window, a tool, a popup, etc).
public QGraphicsWidget()
QGraphicsWidget
instance. The optional parent argument is passed to QGraphicsItem
's constructor. The optional wFlags argument specifies the widget's window flags (e.g., whether the widget should be a window, a tool, a popup, etc).
public QGraphicsWidget(QGraphicsItemInterface parent, Qt.WindowFlags wFlags)
QGraphicsWidget
instance. The optional parent argument is passed to QGraphicsItem
's constructor. The optional wFlags argument specifies the widget's window flags (e.g., whether the widget should be a window, a tool, a popup, etc).
protected QGraphicsWidget(QtJambiObject.QPrivateConstructor p)
Method Detail |
---|
public final boolean acceptDrops()
setAcceptDrops()
.
acceptDrops
in interface QGraphicsItemInterface
public final boolean acceptHoverEvents()
QGraphicsSceneHoverEvent
); otherwise, returns false. By default, items do not accept hover events. setAcceptHoverEvents()
, and setAcceptedMouseButtons()
.
acceptHoverEvents
in interface QGraphicsItemInterface
public final Qt.MouseButtons acceptedMouseButtons()
If an item accepts a mouse button, it will become the mouse grabber item when a mouse press event is delivered for that mouse button. However, if the item does not accept the button, QGraphicsScene
will forward the mouse events to the first item beneath it that does.
setAcceptedMouseButtons()
, and mousePressEvent()
.
acceptedMouseButtons
in interface QGraphicsItemInterface
public final boolean acceptsHoverEvents()
acceptHoverEvents()
instead.
acceptsHoverEvents
in interface QGraphicsItemInterface
public final void addToIndex()
addToIndex
in interface QGraphicsItemInterface
public final void adjustSize()
This function is called implicitly when the item is shown for the first time.
effectiveSizeHint()
, and Qt::MinimumSize
.
public final QRegion boundingRegion(QTransform itemToDeviceTransform)
QTransform
as a parameter, this function will return a local coordinate region. The bounding region describes a coarse outline of the item's visual contents. Although it's expensive to calculate, it's also more precise than boundingRect()
, and it can help to avoid unnecessary repainting when an item is updated. This is particularily efficient for thin items (e.g., lines or simple polygons). You can tune the granularity for the bounding region by calling setBoundingRegionGranularity()
. The default granularity is 0; in which the item's bounding region is the same as its bounding rect.
itemToDeviceTransform is the transformation from item coordinates to device coordinates. If you want this function to return a QRegion
in scene coordinates, you can pass sceneTransform()
as an argument.
boundingRegionGranularity()
.
boundingRegion
in interface QGraphicsItemInterface
public final double boundingRegionGranularity()
setBoundingRegionGranularity()
.
boundingRegionGranularity
in interface QGraphicsItemInterface
public final QGraphicsItem.CacheMode cacheMode()
NoCache
(i.e., cache is disabled and all painting is immediate). setCacheMode()
.
cacheMode
in interface QGraphicsItemInterface
public final java.util.List<QGraphicsItemInterface> childItems()
setParentItem()
.
childItems
in interface QGraphicsItemInterface
public final QRectF childrenBoundingRect()
QRectF
. This does not include this item's own bounding rect; it only returns its descendents' accumulated bounding rect. If you need to include this item's bounding rect, you can add boundingRect()
to childrenBoundingRect()
using QRectF::operator
|().
This function is linear in complexity; it determines the size of the returned bounding rect by iterating through all descendents.
boundingRect()
, and sceneBoundingRect()
.
childrenBoundingRect
in interface QGraphicsItemInterface
public final void clearFocus()
If it has focus, a focus out event is sent to this item to tell it that it is about to lose the focus.
Only items that set the ItemIsFocusable
flag, or widgets that set an appropriate focus policy, can accept keyboard focus.
setFocus()
, and QGraphicsWidget::focusPolicy
.
clearFocus
in interface QGraphicsItemInterface
public final boolean close()
Returns true if the widget was closed; otherwise returns false. This slot will first send a QCloseEvent
to the widget, which may or may not accept the event. If the event was ignored, nothing happens. If the event was accepted, it will hide()
the widget.
If the widget has the Qt::WA_DeleteOnClose
attribute set it will be deleted.
public final java.util.List<QGraphicsItemInterface> collidingItems(Qt.ItemSelectionMode mode)
The way collisions are detected is determined by mode. The default value for mode is Qt::IntersectsItemShape
; All items whose shape intersects or is contained by this item's shape are returned.
QGraphicsScene::collidingItems()
, and collidesWithItem()
.
collidingItems
in interface QGraphicsItemInterface
public final QGraphicsItemInterface commonAncestorItem(QGraphicsItemInterface other)
isAncestorOf()
.
commonAncestorItem
in interface QGraphicsItemInterface
public final QRectF contentsRect()
The contents rect defines the subrectangle used by an associated layout when arranging subitems. This function is a convenience function that adjusts the item's geometry()
by its contents margins. Note that getContentsMargins()
is a virtual function that you can reimplement to return the item's contents margins.
getContentsMargins()
, and geometry()
.
contentsRect
in interface QGraphicsLayoutItemInterface
public final QCursor cursor()
list of predefined cursor objects
for a range of useful shapes. An editor item might want to use an I-beam cursor:
The following code example is written in c++.
item->setCursor(Qt::IBeamCursor);If no cursor has been set, the parent's cursor is used.
setCursor()
, hasCursor()
, unsetCursor()
, QWidget::cursor
, and QApplication::overrideCursor()
.
cursor
in interface QGraphicsItemInterface
public final java.lang.Object data(int key)
QVariant
. Custom item data is useful for storing arbitrary properties in any item. Example:
The following code example is written in c++.
static const int ObjectName = 0; QGraphicsItem *item = scene.itemAt(100, 50); if (item->data(ObjectName).toString().isEmpty()) { if (qgraphicsitem_cast<ButtonItem *>(item)) item->setData(ObjectName, "Button"); }Qt does not use this feature for storing data; it is provided solely for the convenience of the user.
setData()
.
data
in interface QGraphicsItemInterface
public final QTransform deviceTransform(QTransform viewportTransform)
Example:
The following code example is written in c++.
QGraphicsRectItem rect; rect.setPos(100, 100); rect.deviceTransform(view->viewportTransform()).map(QPointF(0, 0)); // returns the item's (0, 0) point in view's viewport coordinates rect.deviceTransform(view->viewportTransform()).inverted().map(QPointF(100, 100)); // returns view's viewport's (100, 100) coordinate in item coordinatesThis function is the same as combining this item's scene transform with the view's viewport transform, but is also understands
ItemIgnoresTransformations
. transform()
, setTransform()
, scenePos()
, and The Graphics View Coordinate System.
deviceTransform
in interface QGraphicsItemInterface
public final QSizeF effectiveSizeHint(Qt.SizeHint which, QSizeF constraint)
QGraphicsLayoutItem
. which is the size hint in question. constraint is an optional argument that defines a special constrain when calculating the effective size hint. By default, constraint is QSizeF
(-1, -1), which means there is no constraint to the size hint.
If you want to specify the widget's size hint for a given width or height, you can provide the fixed dimension in constraint. This is useful for widgets that can grow only either vertically or horizontally, and need to set either their width or their height to a special value.
For example, a text paragraph item fit into a column width of 200 may grow vertically. You can pass QSizeF
(200, -1) as a constraint to get a suitable minimum, preferred and maximum height).
You can adjust the effective size hint by reimplementing sizeHint()
in a QGraphicsLayoutItem
subclass, or by calling one of the following functions: setMinimumSize()
, setPreferredSize
, or setMaximumSize()
(or a combination of both).
This function caches each of the size hints and guarantees that sizeHint()
will be called only once for each value of which - unless constraint is not specified and updateGeometry()
has been called.
sizeHint()
.
effectiveSizeHint
in interface QGraphicsLayoutItemInterface
public final void ensureVisible(QRectF rect, int xmargin, int ymargin)
QGraphicsView
, this convenience function will attempt to scroll the view to ensure that rect is visible inside the view's viewport. If rect is a null rect (the default), QGraphicsItem
will default to the item's bounding rect. xmargin and ymargin are the number of pixels the view should use for margins. If the specified rect cannot be reached, the contents are scrolled to the nearest valid position.
If this item is not viewed by a QGraphicsView
, this function does nothing.
QGraphicsView::ensureVisible()
.
ensureVisible
in interface QGraphicsItemInterface
public final void ensureVisible(double x, double y, double w, double h, int xmargin, int ymargin)
QRectF
(x, y, w, h), xmargin, ymargin):
ensureVisible
in interface QGraphicsItemInterface
public final QGraphicsItem.GraphicsItemFlags flags()
ItemIsFocusable
, the item can accept input focus. By default, no flags are enabled.
setFlags()
, and setFlag()
.
flags
in interface QGraphicsItemInterface
public final Qt.FocusPolicy focusPolicy()
Qt::TabFocus
if the widget accepts keyboard focus by tabbing, Qt::ClickFocus
if the widget accepts focus by clicking, Qt::StrongFocus
if it accepts both, and Qt::NoFocus
(the default) if it does not accept focus at all. You must enable keyboard focus for a widget if it processes keyboard events. This is normally done from the widget's constructor. For instance, the QLineEdit
constructor calls setFocusPolicy
(Qt::StrongFocus
).
If you enable a focus policy (i.e., not Qt::NoFocus
), QGraphicsWidget
will automatically enable the ItemIsFocusable
flag. Setting Qt::NoFocus
on a widget will clear the ItemIsFocusable
flag. If the widget currently has keyboard focus, the widget will automatically lose focus.
focusInEvent()
, focusOutEvent()
, keyPressEvent()
, keyReleaseEvent()
, and enabled.
public final QGraphicsWidget focusWidget()
QWidget::focusWidget()
.
public final QFont font()
QFont
consists of font properties that have been explicitly defined and properties implicitly inherited from the widget's parent. Hence, font()
can return a different font compared to the one set with setFont()
. This scheme allows you to define single entries in a font without affecting the font's inherited entries.
When a widget's font changes, it resolves its entries against its parent widget. If the widget does not have a parent widget, it resolves its entries against the scene. The widget then sends itself a FontChange
event and notifies all its descendants so that they can resolve their fonts as well.
QApplication::font()
, QGraphicsScene::font
, and QFont::resolve()
.
public final QRectF geometry()
QRectF
. This function is equivalent to QRectF
(pos()
, size()
). setGeometry()
.
geometry
in interface QGraphicsLayoutItemInterface
public final void grabKeyboard()
The item will receive all keyboard input to the scene until one of the following events occur:
ungrabKeyboard()
grabKeyboard()
; the item will regain the keyboard grab when the other item calls ungrabKeyboard()
.QEvent::GrabKeyboard
event. When it loses the keyboard grab, it receives a QEvent::UngrabKeyboard
event. These events can be used to detect when your item gains or loses the keyboard grab through other means than gaining input focus. It is almost never necessary to explicitly grab the keyboard in Qt, as Qt grabs and releases it sensibly. In particular, Qt grabs the keyboard when your item gains input focus, and releases it when your item loses input focus, or when the item is hidden.
Note that only visible items can grab keyboard input. Calling grabKeyboard()
on an invisible item has no effect.
Keyboard events are not affected.
ungrabKeyboard()
, grabMouse()
, and setFocus()
.
grabKeyboard
in interface QGraphicsItemInterface
public final void grabMouse()
This item will receive all mouse events for the scene until any of the following events occurs:
ungrabMouse()
grabMouse()
; the item will regain the mouse grab when the other item calls ungrabMouse()
.QEvent::GrabMouse
event. When it loses the mouse grab, it receives a QEvent::UngrabMouse
event. These events can be used to detect when your item gains or loses the mouse grab through other means than receiving mouse button events. It is almost never necessary to explicitly grab the mouse in Qt, as Qt grabs and releases it sensibly. In particular, Qt grabs the mouse when you press a mouse button, and keeps the mouse grabbed until you release the last mouse button. Also, Qt::Popup
widgets implicitly call grabMouse()
when shown, and ungrabMouse()
when hidden.
Note that only visible items can grab mouse input. Calling grabMouse()
on an invisible item has no effect.
Keyboard events are not affected.
QGraphicsScene::mouseGrabberItem()
, ungrabMouse()
, and grabKeyboard()
.
grabMouse
in interface QGraphicsItemInterface
public final QGraphicsItemGroup group()
setGroup()
, QGraphicsItemGroup
, and QGraphicsScene::createItemGroup()
.
group
in interface QGraphicsItemInterface
public final boolean handlesChildEvents()
This property is useful for item groups; it allows one item to handle events on behalf of its children, as opposed to its children handling their events individually.
The default is to return false; children handle their own events. The exception for this is if the item is a QGraphicsItemGroup
, then it defaults to return true.
setHandlesChildEvents()
.
handlesChildEvents
in interface QGraphicsItemInterface
public final boolean hasCursor()
By default, items don't have any cursor set. cursor()
will return a standard pointing arrow cursor.
unsetCursor()
.
hasCursor
in interface QGraphicsItemInterface
public final boolean hasFocus()
focusWidget()
, QGraphicsScene::focusItem()
, setFocus()
, and QGraphicsScene::setFocusItem()
.
hasFocus
in interface QGraphicsItemInterface
public final void hide()
This convenience function is equivalent to calling setVisible(false).
show()
, and setVisible()
.
hide
in interface QGraphicsItemInterface
public final void installSceneEventFilter(QGraphicsItemInterface filterItem)
sceneEventFilter()
function. To filter another item's events, install this item as an event filter for the other item. Example:
The following code example is written in c++.
QGraphicsScene scene; QGraphicsEllipseItem *ellipse = scene.addEllipse(QRectF(-10, -10, 20, 20)); QGraphicsLineItem *line = scene.addLine(QLineF(-10, -10, 20, 20)); line->installSceneEventFilter(ellipse); // line's events are filtered by ellipse's sceneEventFilter() function. ellipse->installSceneEventFilter(line); // ellipse's events are filtered by line's sceneEventFilter() function.An item can only filter events for other items in the same scene. Also, an item cannot filter its own events; instead, you can reimplement
sceneEvent()
directly. Items must belong to a scene for scene event filters to be installed and used.
removeSceneEventFilter()
, sceneEventFilter()
, and sceneEvent()
.
installSceneEventFilter
in interface QGraphicsItemInterface
public final boolean isActiveWindow()
The active window is the window that either contains a child widget that currently has input focus, or that itself has input focus.
QGraphicsScene::activeWindow()
, and QGraphicsScene::setActiveWindow()
.
public final boolean isAncestorOf(QGraphicsItemInterface child)
parentItem()
.
isAncestorOf
in interface QGraphicsItemInterface
public final boolean isEnabled()
setEnabled()
.
isEnabled
in interface QGraphicsItemInterface
public final boolean isLayout()
QGraphicsLayoutItem
is a layout (e.g., is inherited by an object that arranges other QGraphicsLayoutItem
objects); otherwise returns false. QGraphicsLayout
.
isLayout
in interface QGraphicsLayoutItemInterface
public final boolean isObscured()
Its implementation is based on calling isObscuredBy()
, which you can reimplement to provide a custom obscurity algorithm.
opaqueArea()
.
isObscured
in interface QGraphicsItemInterface
public final boolean isObscured(QRectF rect)
Unlike the default isObscured()
function, this function does not call isObscuredBy()
.
opaqueArea()
.
isObscured
in interface QGraphicsItemInterface
public final boolean isObscured(double x, double y, double w, double h)
QRectF
(x, y, w, h)).
isObscured
in interface QGraphicsItemInterface
public final boolean isSelected()
Items that are in a group inherit the group's selected state.
Items are not selected by default.
setSelected()
, and QGraphicsScene::setSelectionArea()
.
isSelected
in interface QGraphicsItemInterface
public final boolean isUnderMouse()
QGraphicsScene::views()
, and QCursor::pos()
.
isUnderMouse
in interface QGraphicsItemInterface
public final boolean isVisible()
Note that the item's general visibility is unrelated to whether or not it is actually being visualized by a QGraphicsView
.
setVisible()
.
isVisible
in interface QGraphicsItemInterface
public final boolean isVisibleTo(QGraphicsItemInterface parent)
An item may not be visible to its ancestors even if isVisible()
is true. If any ancestor is hidden, the item itself will be implicitly hidden, in which case this function will return false.
isVisible()
, and setVisible()
.
isVisibleTo
in interface QGraphicsItemInterface
public final boolean isWidget()
QGraphicsWidget
); otherwise, returns false.
isWidget
in interface QGraphicsItemInterface
public final boolean isWindow()
QGraphicsWidget
window, otherwise returns false. QGraphicsWidget::windowFlags()
.
isWindow
in interface QGraphicsItemInterface
public final QGraphicsLayout layout()
setLayout()
.
public final Qt.LayoutDirection layoutDirection()
Qt::WA_RightToLeft
attribute. It also sets this widget's Qt::WA_SetLayoutDirection
attribute. The widget's layout direction determines the order in which the layout manager horizontally arranges subwidgets of this widget. The default value depends on the language and locale of the application, and is typically in the same direction as words are read and written. With Qt::LeftToRight
, the layout starts placing subwidgets from the left side of this widget towards the right. Qt::RightToLeft
does the opposite - the layout will place widgets starting from the right edge moving towards the left.
Subwidgets inherit their layout direction from the parent. Top-level widget items inherit their layout direction from QGraphicsScene::layoutDirection
. If you change a widget's layout direction by calling setLayoutDirection()
, the widget will send itself a LayoutDirectionChange
event, and then propagate the new layout direction to all its descendants.
QWidget::layoutDirection
, and QApplication::layoutDirection
.
public final QPainterPath mapFromItem(QGraphicsItemInterface item, QPainterPath path)
If item is 0, this function returns the same as mapFromScene()
.
mapFromParent()
, mapFromScene()
, mapToItem()
, and The Graphics View Coordinate System.
mapFromItem
in interface QGraphicsItemInterface
public final QPointF mapFromItem(QGraphicsItemInterface item, QPointF point)
If item is 0, this function returns the same as mapFromScene()
.
mapFromParent()
, mapFromScene()
, transform()
, mapToItem()
, and The Graphics View Coordinate System.
mapFromItem
in interface QGraphicsItemInterface
public final QPolygonF mapFromItem(QGraphicsItemInterface item, QPolygonF polygon)
If item is 0, this function returns the same as mapFromScene()
.
mapToItem()
, mapFromParent()
, transform()
, and The Graphics View Coordinate System.
mapFromItem
in interface QGraphicsItemInterface
public final QPolygonF mapFromItem(QGraphicsItemInterface item, QRectF rect)
If item is 0, this function returns the same as mapFromScene()
mapToItem()
, mapFromParent()
, transform()
, and The Graphics View Coordinate System.
mapFromItem
in interface QGraphicsItemInterface
public final QPointF mapFromItem(QGraphicsItemInterface item, double x, double y)
QPointF
(x, y)).
mapFromItem
in interface QGraphicsItemInterface
public final QPolygonF mapFromItem(QGraphicsItemInterface item, double x, double y, double w, double h)
QRectF
(x, y, w, h)).
mapFromItem
in interface QGraphicsItemInterface
public final QPainterPath mapFromParent(QPainterPath path)
mapFromScene()
, mapFromItem()
, mapToParent()
, and The Graphics View Coordinate System.
mapFromParent
in interface QGraphicsItemInterface
public final QPointF mapFromParent(QPointF point)
mapFromItem()
, mapFromScene()
, transform()
, mapToParent()
, and The Graphics View Coordinate System.
mapFromParent
in interface QGraphicsItemInterface
public final QPolygonF mapFromParent(QPolygonF polygon)
mapToParent()
, mapToItem()
, transform()
, and The Graphics View Coordinate System.
mapFromParent
in interface QGraphicsItemInterface
public final QPolygonF mapFromParent(QRectF rect)
mapToParent()
, mapFromItem()
, transform()
, and The Graphics View Coordinate System.
mapFromParent
in interface QGraphicsItemInterface
public final QPointF mapFromParent(double x, double y)
QPointF
(x, y)).
mapFromParent
in interface QGraphicsItemInterface
public final QPolygonF mapFromParent(double x, double y, double w, double h)
QRectF
(x, y, w, h)).
mapFromParent
in interface QGraphicsItemInterface
public final QPainterPath mapFromScene(QPainterPath path)
mapFromParent()
, mapFromItem()
, mapToScene()
, and The Graphics View Coordinate System.
mapFromScene
in interface QGraphicsItemInterface
public final QPointF mapFromScene(QPointF point)
mapFromItem()
, mapFromParent()
, transform()
, mapToScene()
, and The Graphics View Coordinate System.
mapFromScene
in interface QGraphicsItemInterface
public final QPolygonF mapFromScene(QPolygonF polygon)
mapToScene()
, mapFromParent()
, transform()
, and The Graphics View Coordinate System.
mapFromScene
in interface QGraphicsItemInterface
public final QPolygonF mapFromScene(QRectF rect)
mapToScene()
, mapFromItem()
, transform()
, and The Graphics View Coordinate System.
mapFromScene
in interface QGraphicsItemInterface
public final QPointF mapFromScene(double x, double y)
QPointF
(x, y)).
mapFromScene
in interface QGraphicsItemInterface
public final QPolygonF mapFromScene(double x, double y, double w, double h)
QRectF
(x, y, w, h)).
mapFromScene
in interface QGraphicsItemInterface
public final QPainterPath mapToItem(QGraphicsItemInterface item, QPainterPath path)
If item is 0, this function returns the same as mapToScene()
.
mapToParent()
, mapToScene()
, mapFromItem()
, and The Graphics View Coordinate System.
mapToItem
in interface QGraphicsItemInterface
public final QPointF mapToItem(QGraphicsItemInterface item, QPointF point)
If item is 0, this function returns the same as mapToScene()
.
mapToParent()
, mapToScene()
, transform()
, mapFromItem()
, and The Graphics View Coordinate System.
mapToItem
in interface QGraphicsItemInterface
public final QPolygonF mapToItem(QGraphicsItemInterface item, QPolygonF polygon)
If item is 0, this function returns the same as mapToScene()
.
mapToParent()
, mapToScene()
, mapFromItem()
, and The Graphics View Coordinate System.
mapToItem
in interface QGraphicsItemInterface
public final QPolygonF mapToItem(QGraphicsItemInterface item, QRectF rect)
If item is 0, this function returns the same as mapToScene()
.
mapToParent()
, mapToScene()
, mapFromItem()
, and The Graphics View Coordinate System.
mapToItem
in interface QGraphicsItemInterface
public final QPointF mapToItem(QGraphicsItemInterface item, double x, double y)
QPointF
(x, y)).
mapToItem
in interface QGraphicsItemInterface
public final QPolygonF mapToItem(QGraphicsItemInterface item, double x, double y, double w, double h)
QRectF
(x, y, w, h)).
mapToItem
in interface QGraphicsItemInterface
public final QPainterPath mapToParent(QPainterPath path)
mapToScene()
, mapToItem()
, mapFromParent()
, and The Graphics View Coordinate System.
mapToParent
in interface QGraphicsItemInterface
public final QPointF mapToParent(QPointF point)
mapToItem()
, mapToScene()
, transform()
, mapFromParent()
, and The Graphics View Coordinate System.
mapToParent
in interface QGraphicsItemInterface
public final QPolygonF mapToParent(QPolygonF polygon)
mapToScene()
, mapToItem()
, mapFromParent()
, and The Graphics View Coordinate System.
mapToParent
in interface QGraphicsItemInterface
public final QPolygonF mapToParent(QRectF rect)
mapToScene()
, mapToItem()
, mapFromParent()
, and The Graphics View Coordinate System.
mapToParent
in interface QGraphicsItemInterface
public final QPointF mapToParent(double x, double y)
QPointF
(x, y)).
mapToParent
in interface QGraphicsItemInterface
public final QPolygonF mapToParent(double x, double y, double w, double h)
QRectF
(x, y, w, h)).
mapToParent
in interface QGraphicsItemInterface
public final QPainterPath mapToScene(QPainterPath path)
mapToParent()
, mapToItem()
, mapFromScene()
, and The Graphics View Coordinate System.
mapToScene
in interface QGraphicsItemInterface
public final QPointF mapToScene(QPointF point)
mapToItem()
, mapToParent()
, transform()
, mapFromScene()
, and The Graphics View Coordinate System.
mapToScene
in interface QGraphicsItemInterface
public final QPolygonF mapToScene(QPolygonF polygon)
mapToParent()
, mapToItem()
, mapFromScene()
, and The Graphics View Coordinate System.
mapToScene
in interface QGraphicsItemInterface
public final QPolygonF mapToScene(QRectF rect)
mapToParent()
, mapToItem()
, mapFromScene()
, and The Graphics View Coordinate System.
mapToScene
in interface QGraphicsItemInterface
public final QPointF mapToScene(double x, double y)
QPointF
(x, y)).
mapToScene
in interface QGraphicsItemInterface
public final QPolygonF mapToScene(double x, double y, double w, double h)
QRectF
(x, y, w, h)).
mapToScene
in interface QGraphicsItemInterface
public final double maximumHeight()
setMaximumHeight()
, setMaximumSize()
, and maximumSize()
.
maximumHeight
in interface QGraphicsLayoutItemInterface
public final QSizeF maximumSize()
setMaximumSize()
, minimumSize()
, preferredSize()
, Qt::MaximumSize
, and sizeHint()
.
maximumSize
in interface QGraphicsLayoutItemInterface
public final double maximumWidth()
setMaximumWidth()
, setMaximumSize()
, and maximumSize()
.
maximumWidth
in interface QGraphicsLayoutItemInterface
public final double minimumHeight()
setMinimumHeight()
, setMinimumSize()
, and minimumSize()
.
minimumHeight
in interface QGraphicsLayoutItemInterface
public final QSizeF minimumSize()
setMinimumSize()
, preferredSize()
, maximumSize()
, Qt::MinimumSize
, and sizeHint()
.
minimumSize
in interface QGraphicsLayoutItemInterface
public final double minimumWidth()
setMinimumWidth()
, setMinimumSize()
, and minimumSize()
.
minimumWidth
in interface QGraphicsLayoutItemInterface
public final void moveBy(double dx, double dy)
setPos
(pos()
+ QPointF
(dx, dy)).
moveBy
in interface QGraphicsItemInterface
public final QPalette palette()
QPalette::Button
) and states (e.g., QPalette::Inactive
), loosely defining the general look of the widget and its children. QPalette
consists of color groups that have been explicitly defined, and groups that are implicitly inherited from the widget's parent. Because of this, palette()
can return a different palette than what has been set with setPalette()
. This scheme allows you to define single entries in a palette without affecting the palette's inherited entries.
When a widget's palette changes, it resolves its entries against its parent widget, or if it doesn't have a parent widget, it resolves against the scene. It then sends itself a PaletteChange
event, and notifies all its descendents so they can resolve their palettes as well.
QApplication::palette()
, QGraphicsScene::palette
, and QPalette::resolve()
.
public final QGraphicsItemInterface parentItem()
setParentItem()
, and children().
parentItem
in interface QGraphicsItemInterface
public final QGraphicsLayoutItemInterface parentLayoutItem()
QGraphicsLayoutItem
, or 0 if there is no parent, or if the parent does not inherit from QGraphicsLayoutItem
(QGraphicsLayoutItem
is often used through multiple inheritance with QObject
-derived classes). setParentLayoutItem()
.
parentLayoutItem
in interface QGraphicsLayoutItemInterface
public final QGraphicsWidget parentWidget()
parentItem()
, and childItems()
.
parentWidget
in interface QGraphicsItemInterface
public final QPointF pos()
The position of the item describes its origin (local coordinate (0, 0)) in parent coordinates; this function returns the same as mapToParent
(0, 0).
For convenience, you can also call scenePos()
to determine the item's position in scene coordinates, regardless of its parent.
x()
, y()
, setPos()
, matrix(), and The Graphics View Coordinate System.
pos
in interface QGraphicsItemInterface
public final double preferredHeight()
setPreferredHeight()
, setPreferredSize()
, and preferredSize()
.
preferredHeight
in interface QGraphicsLayoutItemInterface
public final QSizeF preferredSize()
setPreferredSize()
, minimumSize()
, maximumSize()
, Qt::PreferredSize
, and sizeHint()
.
preferredSize
in interface QGraphicsLayoutItemInterface
public final double preferredWidth()
setPreferredWidth()
, setPreferredSize()
, and preferredSize()
.
preferredWidth
in interface QGraphicsLayoutItemInterface
public final void prepareGeometryChange()
QGraphicsScene
's index up to date. prepareGeometryChange()
will call update()
if this is necessary.
Example:
The following code example is written in c++.
void CircleItem::setRadius(qreal newRadius) { if (radius != newRadius) { prepareGeometryChange(); radius = newRadius; } }
boundingRect()
.
prepareGeometryChange
in interface QGraphicsItemInterface
public final QRectF rect()
QRectF
. This function is equivalent to QRectF
(QPointF(), size()
). setGeometry()
, and resize()
.
public final void removeFromIndex()
removeFromIndex
in interface QGraphicsItemInterface
public final void removeSceneEventFilter(QGraphicsItemInterface filterItem)
installSceneEventFilter()
.
removeSceneEventFilter
in interface QGraphicsItemInterface
public final void resetTransform()
setTransform()
, and transform()
.
resetTransform
in interface QGraphicsItemInterface
public final void resize(QSizeF size)
minimumSize()
and maximumSize()
. This property only affects the widget's width and height (e.g., its right and bottom edges); the widget's position and top-left corner remains unaffected. Resizing a widget triggers the widget to immediately receive a GraphicsSceneResize
event with the widget's old and new size. If the widget has a layout assigned when this event arrives, the layout will be activated and it will automatically update any child widgets's geometry.
This property does not affect any layout of the parent widget. If the widget itself is managed by a parent layout, e.g., it has a parent widget with a layout assigned, that layout will not activate.
setGeometry()
, QGraphicsSceneResizeEvent
, and QGraphicsLayout
.
public final void resize(double w, double h)
minimumSize()
and maximumSize()
. This property only affects the widget's width and height (e.g., its right and bottom edges); the widget's position and top-left corner remains unaffected. Resizing a widget triggers the widget to immediately receive a GraphicsSceneResize
event with the widget's old and new size. If the widget has a layout assigned when this event arrives, the layout will be activated and it will automatically update any child widgets's geometry.
This property does not affect any layout of the parent widget. If the widget itself is managed by a parent layout, e.g., it has a parent widget with a layout assigned, that layout will not activate.
setGeometry()
, QGraphicsSceneResizeEvent
, and QGraphicsLayout
.
public final void rotate(double angle)
setTransform()
. Example:
The following code example is written in c++.
// Rotate an item 45 degrees around (0, 0). item->rotate(45); // Rotate an item 45 degrees around (x, y). item->setTransform(QTransform().translate(x, y).rotate(45).translate(-x, -y));
setTransform()
, transform()
, scale()
, shear()
, and translate()
.
rotate
in interface QGraphicsItemInterface
public final void scale(double sx, double sy)
setTransform()
. Example:
The following code example is written in c++.
// Scale an item by 3x2 from its origin item->scale(3, 2); // Scale an item by 3x2 from (x, y) item->setTransform(QTransform().translate(x, y).scale(3, 2).translate(-x, -y));
setTransform()
, transform()
, rotate()
, shear()
, and translate()
.
scale
in interface QGraphicsItemInterface
public final QGraphicsScene scene()
To add or move an item to a scene, call QGraphicsScene::addItem()
.
scene
in interface QGraphicsItemInterface
public final QRectF sceneBoundingRect()
sceneTransform()
with boundingRect()
. boundingRect()
, and The Graphics View Coordinate System.
sceneBoundingRect
in interface QGraphicsItemInterface
public final QPointF scenePos()
pos()
, sceneTransform()
, and The Graphics View Coordinate System.
scenePos
in interface QGraphicsItemInterface
public final QTransform sceneTransform()
Example:
The following code example is written in c++.
QGraphicsRectItem rect; rect.setPos(100, 100); rect.sceneTransform().map(QPointF(0, 0)); // returns QPointF(100, 100); rect.sceneTransform().inverted().map(QPointF(100, 100)); // returns QPointF(0, 0);Unlike
transform()
, which returns only an item's local transformation, this function includes the item's (and any parents') position. transform()
, setTransform()
, scenePos()
, and The Graphics View Coordinate System.
sceneTransform
in interface QGraphicsItemInterface
public final void scroll(double dx, double dy, QRectF rect)
Scrolling provides a fast alternative to simply redrawing when the contents of the item (or parts of the item) are shifted vertically or horizontally. Depending on the current transformation and the capabilities of the paint device (i.e., the viewport), this operation may consist of simply moving pixels from one location to another using memmove()
. In most cases this is faster than rerendering the entire area.
After scrolling, the item will issue an update for the newly exposed areas. If scrolling is not supported (e.g., you are rendering to an OpenGL
viewport, which does not benefit from scroll optimizations), this function is equivalent to calling update(rect).
boundingRect()
.
scroll
in interface QGraphicsItemInterface
public final void setAcceptDrops(boolean on)
acceptDrops()
.
setAcceptDrops
in interface QGraphicsItemInterface
public final void setAcceptHoverEvents(boolean enabled)
Hover events are delivered when there is no current mouse grabber item. They are sent when the mouse cursor enters an item, when it moves around inside the item, and when the cursor leaves an item. Hover events are commonly used to highlight an item when it's entered, and for tracking the mouse cursor as it hovers over the item (equivalent to QWidget::mouseTracking
).
Parent items receive hover enter events before their children, and leave events after their children. The parent does not receive a hover leave event if the cursor enters a child, though; the parent stays "hovered" until the cursor leaves its area, including its children's areas.
If a parent item handles child events (setHandlesChildEvents()
), it will receive hover move, drag move, and drop events as the cursor passes through its children, but it does not receive hover enter and hover leave, nor drag enter and drag leave events on behalf of its children.
A QGraphicsWidget
with window decorations will accept hover events regardless of the value of acceptHoverEvents()
.
acceptHoverEvents()
, hoverEnterEvent()
, hoverMoveEvent()
, and hoverLeaveEvent()
.
setAcceptHoverEvents
in interface QGraphicsItemInterface
public final void setAcceptedMouseButtons(Qt.MouseButtons buttons)
By default, all mouse buttons are accepted. If an item accepts a mouse button, it will become the mouse grabber item when a mouse press event is delivered for that button. However, if the item does not accept the mouse button, QGraphicsScene
will forward the mouse events to the first item beneath it that does.
To disable mouse events for an item (i.e., make it transparent for mouse events), call setAcceptedMouseButtons
(0).
acceptedMouseButtons()
, and mousePressEvent()
.
setAcceptedMouseButtons
in interface QGraphicsItemInterface
public final void setAcceptsHoverEvents(boolean enabled)
setAcceptsHoverEvents
in interface QGraphicsItemInterface
public final void setAttribute(Qt.WidgetAttribute attribute)
See the class documentation for QGraphicsWidget
for a complete list of which attributes are supported, and what they are for.
testAttribute()
, and QWidget::setAttribute()
.
public final void setAttribute(Qt.WidgetAttribute attribute, boolean on)
See the class documentation for QGraphicsWidget
for a complete list of which attributes are supported, and what they are for.
testAttribute()
, and QWidget::setAttribute()
.
public final void setBoundingRegionGranularity(double granularity)
The granularity is used by boundingRegion()
to calculate how fine the bounding region of the item should be. The highest achievable granularity is 1, where boundingRegion()
will return the finest outline possible for the respective device (e.g., for a QGraphicsView
viewport, this gives you a pixel-perfect bounding region). The lowest possible granularity is 0. The value of granularity describes the ratio between device resolution and the resolution of the bounding region (e.g., a value of 0.25 will provide a region where each chunk corresponds to 4x4 device units / pixels).
boundingRegionGranularity()
.
setBoundingRegionGranularity
in interface QGraphicsItemInterface
public final void setCacheMode(QGraphicsItem.CacheMode mode, QSize cacheSize)
The optional logicalCacheSize argument is used only by ItemCoordinateCache
mode, and describes the resolution of the cache buffer; if logicalCacheSize is (100, 100), QGraphicsItem
will fit the item into 100x100 pixels in graphics memory, regardless of the logical size of the item itself. By default QGraphicsItem
uses the size of boundingRect()
. For all other cache modes than ItemCoordinateCache
, logicalCacheSize is ignored.
Caching can speed up rendering if your item spends a significant time redrawing itself. In some cases the cache can also slow down rendering, in particular when the item spends less time redrawing than QGraphicsItem
spends redrawing from the cache. When enabled, the item's paint()
function will be called only once for each call to update()
; for any subsequent repaint requests, the Graphics View framework will redraw from the cache. This approach works particularly well with QGLWidget
, which stores all the cache as OpenGL
textures.
Be aware that QPixmapCache
's cache limit may need to be changed to obtain optimal performance.
You can read more about the different cache modes in the CacheMode
documentation.
cacheMode()
, CacheMode
, and QPixmapCache::setCacheLimit()
.
setCacheMode
in interface QGraphicsItemInterface
public final void setContentsMargins(double left, double top, double right, double bottom)
Contents margins are used by the assigned layout to define the placement of subwidgets and layouts. Margins are particularily useful for widgets that constrain subwidgets to only a section of its own geometry. For example, a group box with a layout will place subwidgets inside its frame, but below the title.
Changing a widget's contents margins will always trigger an update()
, and any assigned layout will be activated automatically. The widget will then receive a ContentsRectChange
event.
getContentsMargins()
, and setGeometry()
.
public final void setCursor(QCursor cursor)
list of predefined cursor objects
for a range of useful shapes. An editor item might want to use an I-beam cursor:
The following code example is written in c++.
item->setCursor(Qt::IBeamCursor);If no cursor has been set, the cursor of the item beneath is used.
cursor()
, hasCursor()
, unsetCursor()
, QWidget::cursor
, and QApplication::overrideCursor()
.
setCursor
in interface QGraphicsItemInterface
public final void setData(int key, java.lang.Object value)
Custom item data is useful for storing arbitrary properties for any item. Qt does not use this feature for storing data; it is provided solely for the convenience of the user.
data()
.
setData
in interface QGraphicsItemInterface
public final void setEnabled(boolean enabled)
Disabled items are visible, but they do not receive any events, and cannot take focus nor be selected. Mouse events are discarded; they are not propagated unless the item is also invisible, or if it does not accept mouse events (see acceptedMouseButtons()
). A disabled item cannot become the mouse grabber, and as a result of this, an item loses the grab if it becomes disabled when grabbing the mouse, just like it loses focus if it had focus when it was disabled.
Disabled items are traditionally drawn using grayed-out colors (see QPalette::Disabled
).
If you disable a parent item, all its children will also be disabled. If you enable a parent item, all children will be enabled, unless they have been explicitly disabled (i.e., if you call setEnabled
(false) on a child, it will not be reenabled if its parent is disabled, and then enabled again).
Items are enabled by default.
Note: If you install an event filter, you can still intercept events before they are delivered to items; this mechanism disregards the item's enabled state.
isEnabled()
.
setEnabled
in interface QGraphicsItemInterface
public final void setFlag(QGraphicsItem.GraphicsItemFlag flag, boolean enabled)
flags()
, and setFlags()
.
setFlag
in interface QGraphicsItemInterface
public final void setFlags(QGraphicsItem.GraphicsItemFlags flags)
If the item had focus and flags does not enable ItemIsFocusable
, the item loses focus as a result of calling this function. Similarly, if the item was selected, and flags does not enabled ItemIsSelectable
, the item is automatically unselected.
By default, no flags are enabled.
flags()
, and setFlag()
.
setFlags
in interface QGraphicsItemInterface
public final void setFocus(Qt.FocusReason focusReason)
Only items that set the ItemIsFocusable
flag can accept keyboard focus.
If this item is not visible (i.e., isVisible()
returns false), not enabled, not associated with a scene, or if it already has input focus, this function will do nothing.
As a result of calling this function, this item will receive a focus in event with focusReason. If another item already has focus, that item will first receive a focus out event indicating that it has lost input focus.
clearFocus()
, and hasFocus()
.
setFocus
in interface QGraphicsItemInterface
public final void setFocusPolicy(Qt.FocusPolicy policy)
Qt::TabFocus
if the widget accepts keyboard focus by tabbing, Qt::ClickFocus
if the widget accepts focus by clicking, Qt::StrongFocus
if it accepts both, and Qt::NoFocus
(the default) if it does not accept focus at all. You must enable keyboard focus for a widget if it processes keyboard events. This is normally done from the widget's constructor. For instance, the QLineEdit
constructor calls setFocusPolicy
(Qt::StrongFocus
).
If you enable a focus policy (i.e., not Qt::NoFocus
), QGraphicsWidget
will automatically enable the ItemIsFocusable
flag. Setting Qt::NoFocus
on a widget will clear the ItemIsFocusable
flag. If the widget currently has keyboard focus, the widget will automatically lose focus.
focusInEvent()
, focusOutEvent()
, keyPressEvent()
, keyReleaseEvent()
, and enabled.
public final void setFont(QFont font)
QFont
consists of font properties that have been explicitly defined and properties implicitly inherited from the widget's parent. Hence, font()
can return a different font compared to the one set with setFont()
. This scheme allows you to define single entries in a font without affecting the font's inherited entries.
When a widget's font changes, it resolves its entries against its parent widget. If the widget does not have a parent widget, it resolves its entries against the scene. The widget then sends itself a FontChange
event and notifies all its descendants so that they can resolve their fonts as well.
QApplication::font()
, QGraphicsScene::font
, and QFont::resolve()
.
public final void setGeometry(double x, double y, double w, double h)
QRectF
( x, y, w, h)). geometry()
, and resize()
.
public final void setGroup(QGraphicsItemGroup group)
group()
, and QGraphicsScene::createItemGroup()
.
setGroup
in interface QGraphicsItemInterface
public final void setHandlesChildEvents(boolean enabled)
This property is useful for item groups; it allows one item to handle events on behalf of its children, as opposed to its children handling their events individually.
If a child item accepts hover events, its parent will receive hover move events as the cursor passes through the child, but it does not receive hover enter and hover leave events on behalf of its child.
handlesChildEvents()
.
setHandlesChildEvents
in interface QGraphicsItemInterface
public final void setLayout(QGraphicsLayout layout)
All widgets that are currently managed by layout or all of its sublayouts, are automatically reparented to this item. The layout is then invalidated, and the child widget geometries are adjusted according to this item's geometry()
and contentsMargins()
. Children who are not explicitly managed by layout remain unaffected by the layout after it has been assigned to this widget.
QGraphicsWidget
takes ownership of layout.
layout()
, QGraphicsLinearLayout::addItem()
, and QGraphicsLayout::invalidate()
.
public final void setLayoutDirection(Qt.LayoutDirection direction)
Qt::WA_RightToLeft
attribute. It also sets this widget's Qt::WA_SetLayoutDirection
attribute. The widget's layout direction determines the order in which the layout manager horizontally arranges subwidgets of this widget. The default value depends on the language and locale of the application, and is typically in the same direction as words are read and written. With Qt::LeftToRight
, the layout starts placing subwidgets from the left side of this widget towards the right. Qt::RightToLeft
does the opposite - the layout will place widgets starting from the right edge moving towards the left.
Subwidgets inherit their layout direction from the parent. Top-level widget items inherit their layout direction from QGraphicsScene::layoutDirection
. If you change a widget's layout direction by calling setLayoutDirection()
, the widget will send itself a LayoutDirectionChange
event, and then propagate the new layout direction to all its descendants.
QWidget::layoutDirection
, and QApplication::layoutDirection
.
public final void setMaximumHeight(double height)
maximumHeight()
, setMaximumSize()
, and maximumSize()
.
setMaximumHeight
in interface QGraphicsLayoutItemInterface
public final void setMaximumSize(QSizeF size)
sizeHint()
for Qt::MaximumSize
and ensures that effectiveSizeHint()
will never return a size larger than size. In order to unset the maximum size, use an invalid size. maximumSize()
, minimumSize()
, preferredSize()
, Qt::MaximumSize
, and sizeHint()
.
setMaximumSize
in interface QGraphicsLayoutItemInterface
public final void setMaximumSize(double w, double h)
QSizeF
(w, h)). maximumSize()
, setMinimumSize()
, setPreferredSize()
, and sizeHint()
.
setMaximumSize
in interface QGraphicsLayoutItemInterface
public final void setMaximumWidth(double width)
maximumWidth()
, setMaximumSize()
, and maximumSize()
.
setMaximumWidth
in interface QGraphicsLayoutItemInterface
public final void setMinimumHeight(double height)
minimumHeight()
, setMinimumSize()
, and minimumSize()
.
setMinimumHeight
in interface QGraphicsLayoutItemInterface
public final void setMinimumSize(QSizeF size)
sizeHint()
for Qt::MinimumSize
and ensures that effectiveSizeHint()
will never return a size smaller than size. In order to unset the minimum size, use an invalid size. minimumSize()
, maximumSize()
, preferredSize()
, Qt::MinimumSize
, sizeHint()
, setMinimumWidth()
, and setMinimumHeight()
.
setMinimumSize
in interface QGraphicsLayoutItemInterface
public final void setMinimumSize(double w, double h)
QSizeF
(w, h)). minimumSize()
, setMaximumSize()
, setPreferredSize()
, and sizeHint()
.
setMinimumSize
in interface QGraphicsLayoutItemInterface
public final void setMinimumWidth(double width)
minimumWidth()
, setMinimumSize()
, and minimumSize()
.
setMinimumWidth
in interface QGraphicsLayoutItemInterface
public final void setPalette(QPalette palette)
QPalette::Button
) and states (e.g., QPalette::Inactive
), loosely defining the general look of the widget and its children. QPalette
consists of color groups that have been explicitly defined, and groups that are implicitly inherited from the widget's parent. Because of this, palette()
can return a different palette than what has been set with setPalette()
. This scheme allows you to define single entries in a palette without affecting the palette's inherited entries.
When a widget's palette changes, it resolves its entries against its parent widget, or if it doesn't have a parent widget, it resolves against the scene. It then sends itself a PaletteChange
event, and notifies all its descendents so they can resolve their palettes as well.
QApplication::palette()
, QGraphicsScene::palette
, and QPalette::resolve()
.
public final void setParentItem(QGraphicsItemInterface parent)
parentItem()
, and children().
setParentItem
in interface QGraphicsItemInterface
public final void setParentLayoutItem(QGraphicsLayoutItemInterface parent)
QGraphicsLayoutItem
to parent. parentLayoutItem()
.
setParentLayoutItem
in interface QGraphicsLayoutItemInterface
public final void setPos(QPointF pos)
The position of the item describes its origin (local coordinate (0, 0)) in parent coordinates.
pos()
, scenePos()
, and The Graphics View Coordinate System.
setPos
in interface QGraphicsItemInterface
public final void setPos(double x, double y)
QPointF
(x, y)).
setPos
in interface QGraphicsItemInterface
public final void setPreferredHeight(double height)
preferredHeight()
, preferredWidth()
, setPreferredSize()
, and preferredSize()
.
setPreferredHeight
in interface QGraphicsLayoutItemInterface
public final void setPreferredSize(QSizeF size)
sizeHint()
for Qt::PreferredSize
and provides the default value for effectiveSizeHint()
. In order to unset the preferred size, use an invalid size. preferredSize()
, minimumSize()
, maximumSize()
, Qt::PreferredSize
, and sizeHint()
.
setPreferredSize
in interface QGraphicsLayoutItemInterface
public final void setPreferredSize(double w, double h)
QSizeF
(w, h)). preferredSize()
, setMaximumSize()
, setMinimumSize()
, and sizeHint()
.
setPreferredSize
in interface QGraphicsLayoutItemInterface
public final void setPreferredWidth(double width)
preferredWidth()
, preferredHeight()
, setPreferredSize()
, and preferredSize()
.
setPreferredWidth
in interface QGraphicsLayoutItemInterface
public final void setSelected(boolean selected)
If the item is in a group, the whole group's selected state is toggled by this function. If the group is selected, all items in the group are also selected, and if the group is not selected, no item in the group is selected.
Only visible, enabled, selectable items can be selected. If selected is true and this item is either invisible or disabled or unselectable, this function does nothing.
By default, items cannot be selected. To enable selection, set the ItemIsSelectable
flag.
This function is provided for convenience, allowing individual toggling of the selected state of an item. However, a more common way of selecting items is to call QGraphicsScene::setSelectionArea()
, which will call this function for all visible, enabled, and selectable items within a specified area on the scene.
isSelected()
, and QGraphicsScene::selectedItems()
.
setSelected
in interface QGraphicsItemInterface
public final void setSizePolicy(QSizePolicy.Policy hPolicy, QSizePolicy.Policy vPolicy, QSizePolicy.ControlType controlType)
QSizePolicy
(hPolicy, vPolicy, controlType)). sizePolicy()
, and QWidget::sizePolicy()
.
setSizePolicy
in interface QGraphicsLayoutItemInterface
public final void setSizePolicy(QSizePolicy policy)
QGraphicsLayoutItem
's default size policy is (QSizePolicy::Fixed
, QSizePolicy::Fixed
, QSizePolicy::DefaultType
), but it is common for subclasses to change the default. For example, QGraphicsWidget
defaults to (QSizePolicy::Preferred
, QSizePolicy::Preferred
, QSizePolicy::DefaultType
).
sizePolicy()
, and QWidget::sizePolicy()
.
setSizePolicy
in interface QGraphicsLayoutItemInterface
public final void setStyle(QStyle style)
QGraphicsWidget
does not take ownership of style. If no style is assigned, or style is 0, the widget will use QGraphicsScene::style()
(if this has been set). Otherwise the widget will use QApplication::style()
.
This function sets the Qt::WA_SetStyle
attribute if style is not 0; otherwise it clears the attribute.
style()
.
public final void setToolTip(java.lang.String toolTip)
toolTip()
, and QToolTip
.
setToolTip
in interface QGraphicsItemInterface
public final void setTransform(QTransform matrix, boolean combine)
If combine is true, then matrix is combined with the current matrix; otherwise, matrixreplaces the current matrix. combine is false by default.
To simplify interation with items using a transformed view, QGraphicsItem
provides mapTo
... and mapFrom
... functions that can translate between items' and the scene's coordinates. For example, you can call mapToScene()
to map an item coordiate to a scene coordinate, or mapFromScene()
to map from scene coordinates to item coordinates.
transform()
, rotate()
, scale()
, shear()
, translate()
, and The Graphics View Coordinate System.
setTransform
in interface QGraphicsItemInterface
public final void setVisible(boolean visible)
QGraphicsScene
's item location functions. If an item becomes invisible while grabbing the mouse, (i.e., while it is receiving mouse events,) it will automatically lose the mouse grab, and the grab is not regained by making the item visible again; it must receive a new mouse press to regain the mouse grab.
Similarly, an invisible item cannot have focus, so if the item has focus when it becomes invisible, it will lose focus, and the focus is not regained by simply making the item visible again.
If you hide a parent item, all its children will also be hidden. If you show a parent item, all children will be shown, unless they have been explicitly hidden (i.e., if you call setVisible
(false) on a child, it will not be reshown even if its parent is hidden, and then shown again).
Items are visible by default; it is unnecessary to call setVisible()
on a new item.
isVisible()
, show()
, and hide()
.
setVisible
in interface QGraphicsItemInterface
public final void setWindowFlags(Qt.WindowType... wFlags)
Qt::Dialog
) and several flags giving hints on the behaviour of the window. The behaviour is platform dependent.
public final void setWindowFlags(Qt.WindowFlags wFlags)
Qt::Dialog
) and several flags giving hints on the behaviour of the window. The behaviour is platform dependent.
public final void setWindowFrameMargins(double left, double top, double right, double bottom)
If you would like to draw your own window decoration, you can set your own frame margins to override the default margins.
unsetWindowFrameMargins()
, getWindowFrameMargins()
, and windowFrameRect()
.
public final void setWindowTitle(java.lang.String title)
public final void setZValue(double z)
The Z-value does not affect the item's size in any way.
The default Z-value is 0.
zValue()
.
setZValue
in interface QGraphicsItemInterface
public final void shear(double sh, double sv)
setTransform()
, transform()
, rotate()
, scale()
, and translate()
.
shear
in interface QGraphicsItemInterface
public final void show()
This convenience function is equivalent to calling setVisible(true).
hide()
, and setVisible()
.
show
in interface QGraphicsItemInterface
public final QSizeF size()
minimumSize()
and maximumSize()
. This property only affects the widget's width and height (e.g., its right and bottom edges); the widget's position and top-left corner remains unaffected. Resizing a widget triggers the widget to immediately receive a GraphicsSceneResize
event with the widget's old and new size. If the widget has a layout assigned when this event arrives, the layout will be activated and it will automatically update any child widgets's geometry.
This property does not affect any layout of the parent widget. If the widget itself is managed by a parent layout, e.g., it has a parent widget with a layout assigned, that layout will not activate.
setGeometry()
, QGraphicsSceneResizeEvent
, and QGraphicsLayout
.
public final QSizePolicy sizePolicy()
setSizePolicy()
, and QWidget::sizePolicy()
.
sizePolicy
in interface QGraphicsLayoutItemInterface
public final QStyle style()
QApplication::style()
. setStyle()
.
public final boolean testAttribute(Qt.WidgetAttribute attribute)
setAttribute()
.
public final java.lang.String toolTip()
setToolTip()
, and QToolTip
.
toolTip
in interface QGraphicsItemInterface
public final QGraphicsItemInterface topLevelItem()
parentItem()
.
topLevelItem
in interface QGraphicsItemInterface
public final QGraphicsWidget topLevelWidget()
topLevelWidget
in interface QGraphicsItemInterface
public final QTransform transform()
setTransform()
, and sceneTransform()
.
transform
in interface QGraphicsItemInterface
public final void translate(double dx, double dy)
If all you want is to move an item, you should call moveBy()
or setPos()
instead; this function changes the item's translation, which is conceptually separate from its position.
setTransform()
, transform()
, rotate()
, scale()
, and shear()
.
translate
in interface QGraphicsItemInterface
public final void ungrabKeyboard()
grabKeyboard()
, and ungrabMouse()
.
ungrabKeyboard
in interface QGraphicsItemInterface
public final void ungrabMouse()
grabMouse()
, and ungrabKeyboard()
.
ungrabMouse
in interface QGraphicsItemInterface
public final void unsetCursor()
hasCursor()
, and setCursor()
.
unsetCursor
in interface QGraphicsItemInterface
public final void unsetLayoutDirection()
Qt::WA_RightToLeft
attribute. It also sets this widget's Qt::WA_SetLayoutDirection
attribute. The widget's layout direction determines the order in which the layout manager horizontally arranges subwidgets of this widget. The default value depends on the language and locale of the application, and is typically in the same direction as words are read and written. With Qt::LeftToRight
, the layout starts placing subwidgets from the left side of this widget towards the right. Qt::RightToLeft
does the opposite - the layout will place widgets starting from the right edge moving towards the left.
Subwidgets inherit their layout direction from the parent. Top-level widget items inherit their layout direction from QGraphicsScene::layoutDirection
. If you change a widget's layout direction by calling setLayoutDirection()
, the widget will send itself a LayoutDirectionChange
event, and then propagate the new layout direction to all its descendants.
QWidget::layoutDirection
, and QApplication::layoutDirection
.
public final void unsetWindowFrameMargins()
setWindowFrameMargins()
, getWindowFrameMargins()
, and windowFrameRect()
.
public final void update(QRectF rect)
This function does not cause an immediate paint; instead it schedules a paint request that is processed by QGraphicsView
after control reaches the event loop. The item will only be redrawn if it is visible in any associated view.
As a side effect of the item being repainted, other items that overlap the area rect may also be repainted.
If the item is invisible (i.e., isVisible()
returns false), this function does nothing.
paint()
, and boundingRect()
.
update
in interface QGraphicsItemInterface
public final void update(double x, double y, double width, double height)
QRectF
(x, y, width, height)).
update
in interface QGraphicsItemInterface
public final QGraphicsWidget window()
QGraphicsWidget::isWindow()
.
window
in interface QGraphicsItemInterface
public final Qt.WindowFlags windowFlags()
Qt::Dialog
) and several flags giving hints on the behaviour of the window. The behaviour is platform dependent.
public final QRectF windowFrameGeometry()
windowFrameRect()
, getWindowFrameMargins()
, and setWindowFrameMargins()
.
public final QRectF windowFrameRect()
windowFrameGeometry()
, getWindowFrameMargins()
, and setWindowFrameMargins()
.
public final java.lang.String windowTitle()
public final Qt.WindowType windowType()
public final double x()
pos()
.x()
. y()
.
x
in interface QGraphicsItemInterface
public final double y()
pos()
.y()
. x()
.
y
in interface QGraphicsItemInterface
public final double zValue()
The default Z-value is 0.
setZValue()
.
zValue
in interface QGraphicsItemInterface
public void advance(int phase)
QGraphicsScene::advance()
slot. In the first phase, all items are called with phase == 0, indicating that items on the scene are about to advance, and then all items are called with phase == 1. Reimplement this function to update your item if you need simple scene-controlled animation. The default implementation does nothing.
For individual item animation, an alternative to this function is to either use QGraphicsItemAnimation
, or to multiple-inherit from QObject
and QGraphicsItem
, and animate your item using QObject::startTimer()
and QObject::timerEvent()
.
QGraphicsItemAnimation
, and QTimeLine
.
advance
in interface QGraphicsItemInterface
public QRectF boundingRect()
QGraphicsView
uses this to determine whether the item requires redrawing. Although the item's shape can be arbitrary, the bounding rect is always rectangular, and it is unaffected by the items' transformation (scale()
, rotate()
, etc.).
If you want to change the item's bounding rectangle, you must first call prepareGeometryChange()
. This notifies the scene of the imminent change, so that its can update its item geometry index; otherwise, the scene will be unaware of the item's new geometry, and the results are undefined (typically, rendering artifacts are left around in the view).
Reimplement this function to let QGraphicsView
determine what parts of the widget, if any, need to be redrawn.
Note: For shapes that paint an outline / stroke, it is important to include half the pen width in the bounding rect. It is not necessary to compensate for antialiasing, though.
Example:
The following code example is written in c++.
QRectF CircleItem::boundingRect() const { qreal penWidth = 1; return QRectF(-radius - penWidth / 2, -radius - penWidth / 2, diameter + penWidth, diameter + penWidth); }
boundingRegion()
, shape()
, contains()
, The Graphics View Coordinate System, and prepareGeometryChange()
.
boundingRect
in interface QGraphicsItemInterface
protected void changeEvent(QEvent event)
The state being changed in this event can be retrieved through event.
Change events include: QEvent::ActivationChange
, QEvent::EnabledChange
, QEvent::FontChange
, QEvent::StyleChange
, QEvent::PaletteChange
, QEvent::ParentChange
, QEvent::LayoutDirectionChange
, and QEvent::ContentsRectChange
.
protected void closeEvent(QCloseEvent event)
close()
, and QCloseEvent
.
public boolean collidesWithItem(QGraphicsItemInterface other, Qt.ItemSelectionMode mode)
Qt::IntersectsItemShape
; other collides with this item if it either intersects, contains, or is contained by this item's shape. The default implementation is based on shape intersection, and it calls shape()
on both items. Because the complexity of arbitrary shape-shape intersection grows with an order of magnitude when the shapes are complex, this operation can be noticably time consuming. You have the option of reimplementing this function in a subclass of QGraphicsItem
to provide a custom algorithm. This allows you to make use of natural constraints in the shapes of your own items, in order to improve the performance of the collision detection. For instance, two untransformed perfectly circular items' collision can be determined very efficiently by comparing their positions and radii.
Keep in mind that when reimplementing this function and calling shape()
or boundingRect()
on other, the returned coordinates must be mapped to this item's coordinate system before any intersection can take place.
contains()
, and shape()
.
collidesWithItem
in interface QGraphicsItemInterface
public boolean collidesWithPath(QPainterPath path, Qt.ItemSelectionMode mode)
The collision is determined by mode. The default value for mode is Qt::IntersectsItemShape
; path collides with this item if it either intersects, contains, or is contained by this item's shape.
collidesWithItem()
, contains()
, and shape()
.
collidesWithPath
in interface QGraphicsItemInterface
public boolean contains(QPointF point)
QGraphicsView
to determine what item is under the cursor, and for that reason, the implementation of this function should be as light-weight as possible. By default, this function calls shape()
, but you can reimplement it in a subclass to provide a (perhaps more efficient) implementation.
shape()
, boundingRect()
, and collidesWithPath()
.
contains
in interface QGraphicsItemInterface
public void contextMenuEvent(QGraphicsSceneContextMenuEvent event)
If you ignore the event, (i.e., by calling QEvent::ignore()
,) event will propagate to any item beneath this item. If no items accept the event, it will be ignored by the scene, and propagate to the view.
It's common to open a QMenu
in response to receiving a context menu event. Example:
The following code example is written in c++.
void CustomItem::contextMenuEvent(QGraphicsSceneContextMenuEvent *event) { QMenu menu; QAction *removeAction = menu.addAction("Remove"); QAction *markAction = menu.addAction("Mark"); QAction *selectedAction = menu.exec(event->screenPos()); // ... }The default implementation ignores the event.
sceneEvent()
.
contextMenuEvent
in interface QGraphicsItemInterface
public void dragEnterEvent(QGraphicsSceneDragDropEvent event)
By accepting the event, (i.e., by calling QEvent::accept()
,) the item will accept drop events, in addition to receiving drag move and drag leave. Otherwise, the event will be ignored and propagate to the item beneath. If the event is accepted, the item will receive a drag move event before control goes back to the event loop.
A common implementation of dragEnterEvent
accepts or ignores event depending on the associated mime data in event. Example:
The following code example is written in c++.
CustomItem::CustomItem() { setAcceptDrops(true); ... } void CustomItem::dragEnterEvent(QGraphicsSceneDragDropEvent *event) { event->setAccepted(event->mimeData()->hasFormat("text/plain")); }Items do not receive drag and drop events by default; to enable this feature, call setAcceptDrops(true).
The default implementation does nothing.
dropEvent()
, dragMoveEvent()
, and dragLeaveEvent()
.
dragEnterEvent
in interface QGraphicsItemInterface
public void dragLeaveEvent(QGraphicsSceneDragDropEvent event)
Calling QEvent::ignore()
or QEvent::accept()
on event has no effect.
Items do not receive drag and drop events by default; to enable this feature, call setAcceptDrops(true).
The default implementation does nothing.
dragEnterEvent()
, dropEvent()
, and dragMoveEvent()
.
dragLeaveEvent
in interface QGraphicsItemInterface
public void dragMoveEvent(QGraphicsSceneDragDropEvent event)
Calling QEvent::ignore()
or QEvent::accept()
on event toggles whether or not the item will accept drops at the position from the event. By default, event is accepted, indicating that the item allows drops at the specified position.
Items do not receive drag and drop events by default; to enable this feature, call setAcceptDrops(true).
The default implementation does nothing.
dropEvent()
, dragEnterEvent()
, and dragLeaveEvent()
.
dragMoveEvent
in interface QGraphicsItemInterface
public void dropEvent(QGraphicsSceneDragDropEvent event)
Calling QEvent::ignore()
or QEvent::accept()
on event has no effect.
Items do not receive drag and drop events by default; to enable this feature, call setAcceptDrops(true).
The default implementation does nothing.
dragEnterEvent()
, dragMoveEvent()
, and dragLeaveEvent()
.
dropEvent
in interface QGraphicsItemInterface
public boolean event(QEvent event)
event
in class QObject
public java.lang.Object extension(java.lang.Object variant)
extension
in interface QGraphicsItemInterface
public void focusInEvent(QFocusEvent event)
ensureVisible()
. focusOutEvent()
, and sceneEvent()
.
focusInEvent
in interface QGraphicsItemInterface
protected boolean focusNextPrevChild(boolean next)
Sometimes, you will want to reimplement this function to provide special focus handling for your widget and its subwidgets. For example, a web browser might reimplement it to move its current active link forward or backward, and call the base implementation only when it reaches the last or first link on the page.
Child widgets call focusNextPrevChild()
on their parent widgets, but only the window that contains the child widgets decides where to redirect focus. By reimplementing this function for an object, you gain control of focus traversal for all child widgets.
focusPolicy()
.
public void focusOutEvent(QFocusEvent event)
focusInEvent()
, and sceneEvent()
.
focusOutEvent
in interface QGraphicsItemInterface
protected void grabKeyboardEvent(QEvent event)
Qt::GrabKeyboard
events. grabKeyboard()
, and grabMouse()
.
protected void grabMouseEvent(QEvent event)
Qt::GrabMouse
events. grabMouse()
, and grabKeyboard()
.
protected void hideEvent(QHideEvent event)
Hide
events, is delivered after the widget has been hidden, for example, setVisible
(false) has been called for the widget or one of its ancestors when the widget was previously shown. You can reimplement this event handler to detect when your widget is hidden. Calling QEvent::accept()
or QEvent::ignore()
on event has no effect.
showEvent()
, QWidget::hideEvent()
, and ItemVisibleChange
.
public void hoverEnterEvent(QGraphicsSceneHoverEvent event)
update()
; otherwise it does nothing. Calling QEvent::ignore()
or QEvent::accept()
on event has no effect.
hoverMoveEvent()
, hoverLeaveEvent()
, sceneEvent()
, and setAcceptHoverEvents()
.
hoverEnterEvent
in interface QGraphicsItemInterface
public void hoverLeaveEvent(QGraphicsSceneHoverEvent event)
update()
; otherwise it does nothing. Calling QEvent::ignore()
or QEvent::accept()
on event has no effect.
hoverEnterEvent()
, hoverMoveEvent()
, sceneEvent()
, and setAcceptHoverEvents()
.
hoverLeaveEvent
in interface QGraphicsItemInterface
public void hoverMoveEvent(QGraphicsSceneHoverEvent event)
Calling QEvent::ignore()
or QEvent::accept()
on event has no effect.
hoverEnterEvent()
, hoverLeaveEvent()
, sceneEvent()
, and setAcceptHoverEvents()
.
hoverMoveEvent
in interface QGraphicsItemInterface
protected void initStyleOption(QStyleOption option)
state & QStyle::State_Enabled | Corresponds to QGraphicsItem::isEnabled() . |
state & QStyle::State_HasFocus | Corresponds to QGraphicsItem::hasFocus() . |
state & QStyle::State_MouseOver | Corresponds to QGraphicsItem::isUnderMouse() . |
direction | Corresponds to QGraphicsWidget::layoutDirection() . |
rect | Corresponds to QGraphicsWidget::rect() .toRect(). |
palette | Corresponds to QGraphicsWidget::palette() . |
fontMetrics | Corresponds to QFontMetrics (QGraphicsWidget::font() ). |
QGraphicsWidget
should call the base implementation, and then test the type of option using qstyleoption_cast
<>() or test QStyleOption::Type
before storing widget-specific options. For example:
The following code example is written in c++.
void MyGroupBoxWidget::initStyleOption(QStyleOption *option) const { QGraphicsWidget::initStyleOption(option); if (QStyleOptionGroupBox *box = qstyleoption_cast<QStyleOptionGroupBox *>(option)) { // Add group box specific state. box->flat = isFlat(); ... } }
QStyleOption::initFrom()
.
public void inputMethodEvent(QInputMethodEvent event)
inputMethodQuery()
, and sceneEvent()
.
inputMethodEvent
in interface QGraphicsItemInterface
public java.lang.Object inputMethodQuery(Qt.InputMethodQuery query)
inputMethodEvent()
.
inputMethodQuery
in interface QGraphicsItemInterface
public boolean isObscuredBy(QGraphicsItemInterface item)
The base implementation maps item's opaqueArea()
to this item's coordinate system, and then checks if this item's boundingRect()
is fully contained within the mapped shape.
You can reimplement this function to provide a custom algorithm for determining whether this item is obscured by item.
opaqueArea()
, and isObscured()
.
isObscuredBy
in interface QGraphicsItemInterface
public java.lang.Object itemChange(QGraphicsItem.GraphicsItemChange change, java.lang.Object value)
QGraphicsItem
to notify custom items that some part of the item's state changes. By reimplementing this function, your can react to a change, and in some cases, (depending on change,) adjustments can be made. change is the parameter of the item that is changing. value is the new value; the type of the value depends on change.
Example:
The following code example is written in c++.
QVariant Component::itemChange(GraphicsItemChange change, const QVariant &value) { if (change == ItemPositionChange && scene()) { // value is the new position. QPointF newPos = value.toPointF(); QRectF rect = scene()->sceneRect(); if (!rect.contains(newPos)) { // Keep the item inside the scene rect. newPos.setX(qMin(rect.right(), qMax(newPos.x(), rect.left()))); newPos.setY(qMin(rect.bottom(), qMax(newPos.y(), rect.top()))); return newPos; } } return QGraphicsItem::itemChange(change, value); }The default implementation does nothing, and returns value.
Note: Certain QGraphicsItem
functions cannot be called in a reimplementation of this function; see the GraphicsItemChange
documentation for details.
GraphicsItemChange
.
itemChange
in interface QGraphicsItemInterface
public void keyPressEvent(QKeyEvent event)
Calling QEvent::ignore()
or QEvent::accept()
on event has no effect.
Note that key events are only received for items that set the ItemIsFocusable
flag, and that have keyboard input focus.
keyReleaseEvent()
, setFocus()
, QGraphicsScene::setFocusItem()
, and sceneEvent()
.
keyPressEvent
in interface QGraphicsItemInterface
public void keyReleaseEvent(QKeyEvent event)
Calling QEvent::ignore()
or QEvent::accept()
on event has no effect.
Note that key events are only received for items that set the ItemIsFocusable
flag, and that have keyboard input focus.
keyPressEvent()
, setFocus()
, QGraphicsScene::setFocusItem()
, and sceneEvent()
.
keyReleaseEvent
in interface QGraphicsItemInterface
public void mouseDoubleClickEvent(QGraphicsSceneMouseEvent event)
When doubleclicking an item, the item will first receive a mouse press event, followed by a release event (i.e., a click), then a doubleclick event, and finally a release event.
Calling QEvent::ignore()
or QEvent::accept()
on event has no effect.
The default implementation calls mousePressEvent()
. If you want to keep the base implementation when reimplementing this function, call QGraphicsItem::mouseDoubleClickEvent()
in your reimplementation.
mousePressEvent()
, mouseMoveEvent()
, mouseReleaseEvent()
, and sceneEvent()
.
mouseDoubleClickEvent
in interface QGraphicsItemInterface
public void mouseMoveEvent(QGraphicsSceneMouseEvent event)
Calling QEvent::ignore()
or QEvent::accept()
on event has no effect.
The default implementation handles basic item interaction, such as selection and moving. If you want to keep the base implementation when reimplementing this function, call QGraphicsItem::mouseMoveEvent()
in your reimplementation.
mousePressEvent()
, mouseReleaseEvent()
, mouseDoubleClickEvent()
, and sceneEvent()
.
mouseMoveEvent
in interface QGraphicsItemInterface
public void mousePressEvent(QGraphicsSceneMouseEvent event)
setAcceptedMouseButtons()
. The mouse press event decides which item should become the mouse grabber (see QGraphicsScene::mouseGrabberItem()
). If you do not reimplement this function, the press event will propagate to any topmost item beneath this item, and no other mouse events will be delivered to this item.
If you do reimplement this function, event will by default be accepted (see QEvent::accept()
), and this item is then the mouse grabber. This allows the item to receive future move, release and doubleclick events. If you call QEvent::ignore()
on event, this item will lose the mouse grab, and event will propagate to any topmost item beneath. No further mouse events will be delivered to this item unless a new mouse press event is received.
The default implementation handles basic item interaction, such as selection and moving. If you want to keep the base implementation when reimplementing this function, call QGraphicsItem::mousePressEvent()
in your reimplementation.
mouseMoveEvent()
, mouseReleaseEvent()
, mouseDoubleClickEvent()
, and sceneEvent()
.
mousePressEvent
in interface QGraphicsItemInterface
public void mouseReleaseEvent(QGraphicsSceneMouseEvent event)
Calling QEvent::ignore()
or QEvent::accept()
on event has no effect.
The default implementation handles basic item interaction, such as selection and moving. If you want to keep the base implementation when reimplementing this function, call QGraphicsItem::mouseReleaseEvent()
in your reimplementation.
mousePressEvent()
, mouseMoveEvent()
, mouseDoubleClickEvent()
, and sceneEvent()
.
mouseReleaseEvent
in interface QGraphicsItemInterface
protected void moveEvent(QGraphicsSceneMoveEvent event)
GraphicsSceneMove
events, is delivered after the widget has moved (e.g., its local position has changed). This event is only delivered when the item is moved locally. Calling setTransform()
or moving any of the item's ancestors does not affect the item's local position.
You can reimplement this event handler to detect when your widget has moved. Calling QEvent::accept()
or QEvent::ignore()
on event has no effect.
ItemPositionChange
, and ItemPositionHasChanged
.
public QPainterPath opaqueArea()
This function is used by isObscuredBy()
, which is called by underlying items to determine if they are obscured by this item.
The default implementation returns an empty QPainterPath
, indicating that this item is completely transparent and does not obscure any other items.
isObscuredBy()
, isObscured()
, and shape()
.
opaqueArea
in interface QGraphicsItemInterface
public void paint(QPainter painter, QStyleOptionGraphicsItem option, QWidget widget)
QGraphicsView
, paints the contents of an item in local coordinates. Reimplement this function in a QGraphicsItem
subclass to provide the item's painting implementation, using painter. The option parameter provides style options for the item, such as its state, exposed area and its level-of-detail hints. The widget argument is optional. If provided, it points to the widget that is being painted on; otherwise, it is 0. For cached painting, widget is always 0.
The following code example is written in c++.
void RoundRectItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) { painter->drawRoundedRect(-10, -10, 20, 20, 5, 5); }The painter's pen is 0-width by default, and its pen is initialized to the
QPalette::Text
brush from the paint device's palette. The brush is initialized to QPalette::Window
. Make sure to constrain all painting inside the boundaries of boundingRect()
to avoid rendering artifacts (as QGraphicsView
does not clip the painter for you). In particular, when QPainter
renders the outline of a shape using an assigned QPen
, half of the outline will be drawn outside, and half inside, the shape you're rendering (e.g., with a pen width of 2 units, you must draw outlines 1 unit inside boundingRect()
). QGraphicsItem
does not support use of cosmetic pens with a non-zero width.
All painting is done in local coordinates.
setCacheMode()
, QPen::width()
, and Item Coordinates.
paint
in interface QGraphicsItemInterface
public final void paintWindowFrame(QPainter painter, QStyleOptionGraphicsItem option)
QGraphicsScene
to draw the window frame for windows using painter, option, and widget, in local coordinates. The base implementation uses the current style to render the frame and title bar. You can reimplement this function in a subclass of QGraphicsWidget
to provide custom rendering of the widget's window frame.
QGraphicsItem::paint()
.
public void paintWindowFrame(QPainter painter, QStyleOptionGraphicsItem option, QWidget widget)
QGraphicsScene
to draw the window frame for windows using painter, option, and widget, in local coordinates. The base implementation uses the current style to render the frame and title bar. You can reimplement this function in a subclass of QGraphicsWidget
to provide custom rendering of the widget's window frame.
QGraphicsItem::paint()
.
protected void polishEvent()
The base implementation does nothing.
protected java.lang.Object propertyChange(java.lang.String propertyName, java.lang.Object value)
protected void resizeEvent(QGraphicsSceneResizeEvent event)
GraphicsSceneResize
events, is delivered after the widget has been resized (i.e., its local size has changed). event contains both the old and the new size. This event is only delivered when the widget is resized locally; calling setTransform()
on the widget or any of its ancestors or view, does not affect the widget's local size.
You can reimplement this event handler to detect when your widget has been resized. Calling QEvent::accept()
or QEvent::ignore()
on event has no effect.
geometry()
, and setGeometry()
.
public boolean sceneEvent(QEvent event)
contextMenuEvent()
, focusInEvent()
, focusOutEvent()
, hoverEnterEvent()
, hoverMoveEvent()
, hoverLeaveEvent()
, keyPressEvent()
, keyReleaseEvent()
, mousePressEvent()
, mouseReleaseEvent()
, mouseMoveEvent()
, and mouseDoubleClickEvent()
. Returns true if the event was recognized and handled; otherwise, (e.g., if the event type was not recognized,) false is returned.
event is the intercepted event.
sceneEvent
in interface QGraphicsItemInterface
public boolean sceneEventFilter(QGraphicsItemInterface watched, QEvent event)
Reimplementing this function in a subclass makes it possible for the item to be used as an event filter for other items, intercepting all the events send to those items before they are able to respond.
Reimplementations must return true to prevent further processing of a given event, ensuring that it will not be delivered to the watched item, or return false to indicate that the event should be propagated further by the event system.
installSceneEventFilter()
.
sceneEventFilter
in interface QGraphicsItemInterface
public void setExtension(QGraphicsItem.Extension extension, java.lang.Object variant)
setExtension
in interface QGraphicsItemInterface
public void setGeometry(QRectF rect)
QGraphicsLayoutItem
to rect, which is in parent coordinates (e.g., the top-left corner of rect is equivalent to the item's position in parent coordinates). Reimplement this function in a subclass of QGraphicsLayoutItem
to enable your item to receive geometry updates.
If rect is outside of the bounds of minimumSize
and maximumSize
, it will be adjusted to its closest size so that it is within the legal bounds.
geometry()
.
setGeometry
in interface QGraphicsLayoutItemInterface
public QPainterPath shape()
QPainterPath
in local coordinates. The shape is used for many things, including collision detection, hit tests, and for the QGraphicsScene::items()
functions. The default implementation calls boundingRect()
to return a simple rectangular shape, but subclasses can reimplement this function to return a more accurate shape for non-rectangular items. For example, a round item may choose to return an elliptic shape for better collision detection. For example:
The following code example is written in c++.
QPainterPath RoundItem::shape() const { QPainterPath path; path.addEllipse(boundingRect()); return path; }The outline of a shape can vary depending on the width and style of the pen used when drawing. If you want to include this outline in the item's shape, you can create a shape from the stroke using
QPainterPathStroker
. This function is called by the default implementations of contains()
and collidesWithPath()
.
boundingRect()
, contains()
, prepareGeometryChange()
, and QPainterPathStroker
.
shape
in interface QGraphicsItemInterface
protected void showEvent(QShowEvent event)
Show
events, is delivered before the widget has been shown, for example, setVisible
(true) has been called for the widget or one of its ancestors when the widget was previously hidden. You can reimplement this event handler to detect when your widget is shown. Calling QEvent::accept()
or QEvent::ignore()
on event has no effect.
hideEvent()
, QWidget::showEvent()
, and ItemVisibleChange
.
public QSizeF sizeHint(Qt.SizeHint which, QSizeF constraint)
QGraphicsLayoutItem
, using the width or height of constraint to constrain the output. Reimplement this function in a subclass of QGraphicsLayoutItem
to provide the necessary size hints for your items.
effectiveSizeHint()
.
sizeHint
in interface QGraphicsLayoutItemInterface
public boolean supportsExtension(QGraphicsItem.Extension extension)
supportsExtension
in interface QGraphicsItemInterface
public int type()
The default implementation (in QGraphicsItem
) returns UserType.
To enable use of qgraphicsitem_cast() with a custom item, reimplement this function and declare a Type enum value equal to your custom item's type. Custom items must return a value larger than or equal to UserType (65536).
For example:
The following code example is written in c++.
class CustomItem : public QGraphicsItem { ... enum { Type = UserType + 1 }; int type() const { // Enable the use of qgraphicsitem_cast with this item. return Type; } ... };
type
in interface QGraphicsItemInterface
protected void ungrabKeyboardEvent(QEvent event)
Qt::UngrabKeyboard
events. ungrabKeyboard()
, and ungrabMouse()
.
protected void ungrabMouseEvent(QEvent event)
Qt::UngrabMouse
events. ungrabMouse()
, and ungrabKeyboard()
.
public void updateGeometry()
sizeHint()
function. Subclasses must always call the base implementation when reimplementing this function. effectiveSizeHint()
.
updateGeometry
in interface QGraphicsLayoutItemInterface
public void wheelEvent(QGraphicsSceneWheelEvent event)
If you ignore the event, (i.e., by calling QEvent::ignore()
,) it will propagate to any item beneath this item. If no items accept the event, it will be ignored by the scene, and propagate to the view (e.g., the view's vertical scroll bar).
The default implementation ignores the event.
sceneEvent()
.
wheelEvent
in interface QGraphicsItemInterface
protected boolean windowFrameEvent(QEvent e)
You can reimplement this handler in a subclass of QGraphicsWidget
to provide your own custom window frame interaction support.
Returns true if event has been recognized and processed; otherwise, returns false.
event()
.
protected Qt.WindowFrameSection windowFrameSectionAt(QPointF pos)
Qt::NoWindowFrameSection
if there is no window frame section at this position. This function is used in QGraphicsWidget
's base implementation for window frame interaction.
You can reimplement this function if you want to customize how a window can be interactively moved or resized. For instance, if you only want to allow a window to be resized by the bottom right corner, you can reimplement this function to return Qt::NoSection
for all sections except Qt::BottomRightSection
.
windowFrameEvent()
, paintWindowFrame()
, and windowFrameGeometry()
.
public static void setTabOrder(QGraphicsWidget first, QGraphicsWidget second)
Note that since the tab order of the second widget is changed, you should order a chain like this:
The following code example is written in c++.
setTabOrder(a, b); // a to b setTabOrder(b, c); // a to b to c setTabOrder(c, d); // a to b to c to dnot like this:
// WRONG setTabOrder(c, d); // c to d setTabOrder(a, b); // a to b AND c to d setTabOrder(b, c); // a to b to c, but not c to dIf first is 0, this indicates that second should be the first widget to receive input focus should the scene gain Tab focus (i.e., the user hits Tab so that focus passes into the scene). If second is 0, this indicates that first should be the first widget to gain focus if the scene gained
BackTab
focus. By default, tab order is defined implicitly using widget creation order.
focusPolicy
, and Keyboard Focus.
public static QGraphicsWidget fromNativePointer(QNativePointer nativePointer)
public long __qt_cast_to_QGraphicsItem(long ptr)
__qt_cast_to_QGraphicsItem
in interface QGraphicsItemInterface
public long __qt_cast_to_QGraphicsLayoutItem(long ptr)
__qt_cast_to_QGraphicsLayoutItem
in interface QGraphicsLayoutItemInterface
public final QMarginsF getWindowFrameMargins()
public final QMarginsF getContentsMargins()
QGraphicsLayoutItemInterface
QGraphicsLayoutItem
. The default implementation assumes all contents margins are 0. The parameters point to values stored in qreals. If any of the pointers is 0, that value will not be updated. QGraphicsWidget::setContentsMargins()
.
getContentsMargins
in interface QGraphicsLayoutItemInterface
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