Qt图形裁减
虾球xz 人气:0main.cpp
#include <QApplication> #include <QGraphicsItemGroup> #include <QGraphicsView> #include <QPushButton> #include <QVBoxLayout> class GraphicsItemGroup : public QGraphicsItemGroup { public: GraphicsItemGroup(QGraphicsItem *parent = 0) : QGraphicsItemGroup(parent) { setFlag(QGraphicsItem::ItemClipsChildrenToShape, true); } QPainterPath shape() const { if (mShape.isEmpty()) return QGraphicsItemGroup::shape(); return mShape; } void setShape(const QPainterPath &shape) { mShape = shape; update(); } private: QPainterPath mShape; }; int main(int argc, char *argv[]) { QApplication a(argc, argv); QWidget w; w.setLayout(new QVBoxLayout); QGraphicsView view; QPushButton button("click me"); w.layout()->addWidget(&view); w.layout()->addWidget(&button); view.setScene(new QGraphicsScene); GraphicsItemGroup group; view.scene()->addItem(&group); auto ellipse = new QGraphicsEllipseItem(QRectF(0, 0, 100, 100)); ellipse->setBrush(Qt::red); auto rect = new QGraphicsRectItem(QRect(150, 150, 100, 100)); rect->setBrush(Qt::blue); group.addToGroup(ellipse); group.addToGroup(rect); QObject::connect(&button, &QPushButton::clicked, [&group]() { QPainterPath shape; if (group.shape().boundingRect() == group.boundingRect()) { shape.addRect(0, 50, 250, 150); } group.setShape(shape); }); w.show(); return a.exec(); }
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