diagramscene.cpp Example File
tools/undoframework/diagramscene.cpp
#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);
}