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Qt for android触摸手势事件QGestureEvent
在触摸设备上可以使用Qt的手势事件
要激活手势事件,需要执行以下操作:
第一步,为QWidget控件注册手势事件
QList<Qt::GestureType> gestures;gestures << Qt::PanGesture;gestures << Qt::PinchGesture;gestures << Qt::SwipeGesture;gestures << Qt::TapGesture;gestures << Qt::TapAndHoldGesture;MainWindow w;w.grabGestures(gestures);第二步,在QWidget控件类中过滤事件bool MainWindow::event(QEvent *event){
if (event->type() == QEvent::Gesture)return gestureEvent(static_cast<QGestureEvent*>(event));return QWidget::event(event);}
bool MainWindow::gestureEvent(QGestureEvent *event){
qCDebug(lcExample) << "gestureEvent():" << event->gestures().size();if (QGesture *swipe = event->gesture(Qt::SwipeGesture))swipeTriggered(static_cast<QSwipeGesture *>(swipe));else if (QGesture *pan = event->gesture(Qt::PanGesture))panTriggered(static_cast<QPanGesture *>(pan));else if (QGesture *tap = event->gesture(Qt::TapGesture))tapTriggered(static_cast<QTapGesture *>(tap));else if (QGesture *tapAndHold = event->gesture(Qt::TapAndHoldGesture))tapAndHoldTriggered(static_cast<QTapAndHoldGesture *>(tapAndHold));if (QGesture *pinch = event->gesture(Qt::PinchGesture))pinchTriggered(static_cast<QPinchGesture *>(pinch));return true;}
//! [gesture event handler]void MainWindow::panTriggered(QPanGesture *gesture){
#ifndef QT_NO_CURSORswitch (gesture->state()) {case Qt::GestureStarted:case Qt::GestureUpdated:setCursor(Qt::SizeAllCursor);break;default:setCursor(Qt::ArrowCursor);}#endif
QPointF delta = gesture->delta();qCDebug(lcExample) << "panTriggered():" << delta;horizontalOffset += delta.x();verticalOffset += delta.y();}
void MainWindow::pinchTriggered(QPinchGesture *gesture){
QPinchGesture::ChangeFlags changeFlags = gesture->changeFlags();if (changeFlags & QPinchGesture::RotationAngleChanged) {const qreal value = gesture->property("rotationAngle").toReal();const qreal lastValue = gesture->property("lastRotationAngle").toReal();const qreal rotationAngleDelta = value - lastValue;rotationAngle += rotationAngleDelta;qCDebug(lcExample) << "pinchTriggered(): rotation by" << rotationAngleDelta << rotationAngle;}if (changeFlags & QPinchGesture::ScaleFactorChanged) {qreal value = gesture->property("scaleFactor").toReal();currentStepScaleFactor = value;qCDebug(lcExample) << "pinchTriggered(): " << currentStepScaleFactor;}if (gesture->state() == Qt::GestureFinished) {scaleFactor *= currentStepScaleFactor;currentStepScaleFactor = 1;}update();}
//! [swipe function]void MainWindow::swipeTriggered(QSwipeGesture *gesture){
if (gesture->state() == Qt::GestureFinished) {if (gesture->horizontalDirection() == QSwipeGesture::Left|| gesture->verticalDirection() == QSwipeGesture::Up) {qCDebug(lcExample) << "swipeTriggered(): swipe to previous";} else {qCDebug(lcExample) << "swipeTriggered(): swipe to next";}}}
//! [swipe function]void MainWindow::tapTriggered(QTapGesture *gesture){
qCDebug(lcExample) << "tapTriggered():" ;}
void MainWindow::tapAndHoldTriggered(QTapAndHoldGesture *gesture){
qCDebug(lcExample) << "tapAndHoldTriggered():";}
参考源代码 http://download.csdn.net/detail/liuguangzhou123/7616623
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