QGraphicsSceneEvent 類提供基類為所有圖形視圖相關事件。 更多...
| 頭： | #include <QGraphicsSceneEvent> |
| qmake: | QT += widgets |
| Since: | Qt 4.2 |
| 繼承： | QEvent |
| 繼承者： |
QGraphicsSceneContextMenuEvent , QGraphicsSceneDragDropEvent , QGraphicsSceneHelpEvent , QGraphicsSceneHoverEvent , QGraphicsSceneMouseEvent , QGraphicsSceneMoveEvent , QGraphicsSceneResizeEvent ，和 QGraphicsSceneWheelEvent |
該類在 Qt 4.2 引入。
| virtual | ~QGraphicsSceneEvent () |
| QWidget * | widget () const |
當 QGraphicsView 接收 Qt 鼠標、鍵盤及拖放事件 ( QMouseEvent , QKeyEvent ，QDragEvent，等)，它將它們翻譯成 QGraphicsSceneEvent 子類實例並將它們轉發給 QGraphicsScene 由它顯示。然後，場景將事件轉發給相關項。
例如，當 QGraphicsView 接收 QMouseEvent of type MousePress as a response to a user click, the view sends a QGraphicsSceneMouseEvent 類型 GraphicsSceneMousePress to the underlying QGraphicsScene through its mousePressEvent() function. The default QGraphicsScene::mousePressEvent () implementation determines which item was clicked and forwards the event to QGraphicsItem::mousePressEvent ().
Subclasses such as QGraphicsSceneMouseEvent and QGraphicsSceneContextMenuEvent provide the coordinates from the original QEvent in screen, scene, and item coordinates (see screenPos() , scenePos() ，和 pos() ). The item coordinates are set by the QGraphicsScene before it forwards the event to the event to a QGraphicsItem . The mouse events also add the possibility to retrieve the coordinates from the last event received by the view (see lastScreenPos() , lastScenePos() ，和 lastPos() ).
另請參閱 QEvent .
[虛擬]
QGraphicsSceneEvent::
~QGraphicsSceneEvent
()
銷毀事件。
Returns the widget where the event originated, or
nullptr
if the event originates from another application.