diagramscene.cpp Example File

tools/undoframework/diagramscene.cpp
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#include <QtWidgets> #include "diagramscene.h" #include "diagramitem.h" DiagramScene::DiagramScene(QObject *parent) : QGraphicsScene(parent) { movingItem = 0; } void DiagramScene::mousePressEvent(QGraphicsSceneMouseEvent *event) { QPointF mousePos(event->buttonDownScenePos(Qt::LeftButton).x(), event->buttonDownScenePos(Qt::LeftButton).y()); const QList<QGraphicsItem *> itemList = items(mousePos); movingItem = itemList.isEmpty() ? 0 : itemList.first(); if (movingItem != 0 && event->button() == Qt::LeftButton) { oldPos = movingItem->pos(); } clearSelection(); QGraphicsScene::mousePressEvent(event); } void DiagramScene::mouseReleaseEvent(QGraphicsSceneMouseEvent *event) { if (movingItem != 0 && event->button() == Qt::LeftButton) { if (oldPos != movingItem->pos()) emit itemMoved(qgraphicsitem_cast<DiagramItem *>(movingItem), oldPos); movingItem = 0; } QGraphicsScene::mouseReleaseEvent(event); }