QGraphicsWidget

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SUMMARY:

java.lang.Object
  com.trolltech.qt.internal.QSignalEmitterInternal
      com.trolltech.qt.QSignalEmitter
          com.trolltech.qt.QtJambiObject
              com.trolltech.qt.core.QObject
                  com.trolltech.qt.gui.QGraphicsWidget

All Implemented Interfaces:: QGraphicsItemInterface, QGraphicsLayoutItemInterface, QtJambiInterface

Direct Known Subclasses:: QGraphicsProxyWidget

public class QGraphicsWidget
extends QObject
implements QGraphicsItemInterface, QGraphicsLayoutItemInterface
extends QObject
implements QGraphicsItemInterface, QGraphicsLayoutItemInterface

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:

Provides a palette, a font and a style().
Has a defined geometry().
Supports layouts with setLayout() and layout().
Supports shortcuts and actions with grabShortcut() and insertAction()

Unlike 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 drag and drop framework, different from `QWidget`.	Standard drag and drop 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()`.
`Qt::WA_SetPalette`	Set by `setPalette()`.
`Qt::WA_SetFont`	Set by `setPalette()`.
`Qt::WA_WindowPropagation`	Enables propagation to window widgets.

Although 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.

Constructor Detail