Changed setting state in a QGesture

Instead of having a protected setter for the state and forcing the application
developer to emit signals manually (which leads to misunderstanding - i.e. if
the started() signal should be emitted only once, or of the triggered() signal
should be emitted before the finished() signal, etc). So I've added an
protected updateState(state) function that sets the internal state and emits
appropriate signals depending on the old and new states.

Reviewed-by: Volker Hilsheimer
Reviewed-by: Richard Moe Gustavsen

1 files changed, 12 insertions, 31 deletions

diff --git a/src/gui/kernel/qstandardgestures.cpp b/src/gui/kernel/qstandardgestures.cpp
index 2a5e7e8..89de7c8 100644
--- a/src/gui/kernel/qstandardgestures.cpp
+++ b/src/gui/kernel/qstandardgestures.cpp
@@ -114,9 +114,7 @@ bool QPanGesture::event(QEvent *event)
             killTimer(d->panFinishedTimer);
             d->panFinishedTimer = 0;
             d->lastOffset = QSize(0, 0);
-            setState(Qt::GestureFinished);
-            emit triggered();
-            setState(Qt::NoGesture);
+            updateState(Qt::GestureFinished);
         }
     }
 #endif
@@ -127,6 +125,7 @@ bool QPanGesture::event(QEvent *event)
 bool QPanGesture::eventFilter(QObject *receiver, QEvent *event)
 {
 #ifdef Q_WS_WIN
+    Q_D(QPanGesture);
     if (receiver->isWidgetType() && event->type() == QEvent::NativeGesture) {
         QNativeGestureEvent *ev = static_cast<QNativeGestureEvent*>(event);
         QApplicationPrivate *qAppPriv = getQApplicationPrivateInternal();
@@ -135,30 +134,28 @@ bool QPanGesture::eventFilter(QObject *receiver, QEvent *event)
         if (it == qAppPriv->widgetGestures.end())
             return false;
         QPanGesture *gesture = it.value().pan;
-        if (!gesture)
+        if (this != gesture)
             return false;
-        Qt::GestureState nextState = state();
+        Qt::GestureState nextState = Qt::NoGesture;
         switch(ev->gestureType) {
         case QNativeGestureEvent::GestureBegin:
             // next we might receive the first gesture update event, so we
             // prepare for it.
-            setState(Qt::GestureStarted);
+            d->state = Qt::NoGesture;
             return false;
         case QNativeGestureEvent::Pan:
             nextState = Qt::GestureUpdated;
+            event->accept();
             break;
         case QNativeGestureEvent::GestureEnd:
-            if (state() != QNativeGestureEvent::Pan)
+            if (state() == Qt::NoGesture)
                 return false; // some other gesture has ended
-            setState(Qt::GestureFinished);
             nextState = Qt::GestureFinished;
             break;
         default:
             return false;
         }
-        QPanGesturePrivate *d = gesture->d_func();
-        if (state() == Qt::GestureStarted) {
-            d->lastPosition = ev->position;
+        if (state() == Qt::NoGesture) {
             d->lastOffset = d->totalOffset = QSize();
         } else {
             d->lastOffset = QSize(ev->position.x() - d->lastPosition.x(),
@@ -166,14 +163,7 @@ bool QPanGesture::eventFilter(QObject *receiver, QEvent *event)
             d->totalOffset += d->lastOffset;
         }
         d->lastPosition = ev->position;
-
-        if (state() == Qt::GestureStarted)
-            emit gesture->started();
-        emit gesture->triggered();
-        if (state() == Qt::GestureFinished)
-            emit gesture->finished();
-        event->accept();
-        gesture->setState(nextState);
+        gesture->updateState(nextState);
         return true;
     }
 #endif
@@ -193,7 +183,6 @@ bool QPanGesture::filterEvent(QEvent *event)
         d->lastOffset = d->totalOffset = QSize();
     } else if (event->type() == QEvent::TouchEnd) {
         if (state() != Qt::NoGesture) {
-            setState(Qt::GestureFinished);
             if (!ev->touchPoints().isEmpty()) {
                 QTouchEvent::TouchPoint p = ev->touchPoints().at(0);
                 const QPoint pos = p.pos().toPoint();
@@ -202,10 +191,8 @@ bool QPanGesture::filterEvent(QEvent *event)
                 d->lastOffset = QSize(pos.x() - lastPos.x(), pos.y() - lastPos.y());
                 d->totalOffset = QSize(pos.x() - startPos.x(), pos.y() - startPos.y());
             }
-            emit triggered();
-            emit finished();
+            updateState(Qt::GestureFinished);
         }
-        setState(Qt::NoGesture);
         reset();
     } else if (event->type() == QEvent::TouchUpdate) {
         QTouchEvent::TouchPoint p = ev->touchPoints().at(0);
@@ -216,11 +203,7 @@ bool QPanGesture::filterEvent(QEvent *event)
         d->totalOffset = QSize(pos.x() - startPos.x(), pos.y() - startPos.y());
         if (d->totalOffset.width() > 10  || d->totalOffset.height() > 10 ||
             d->totalOffset.width() < -10 || d->totalOffset.height() < -10) {
-            if (state() == Qt::NoGesture)
-                setState(Qt::GestureStarted);
-            else
-                setState(Qt::GestureUpdated);
-            emit triggered();
+            updateState(Qt::GestureUpdated);
         }
     }
 #ifdef Q_OS_MAC
@@ -239,16 +222,14 @@ bool QPanGesture::filterEvent(QEvent *event)
         d->lastOffset = wev->orientation() == Qt::Horizontal ? QSize(offset, 0) : QSize(0, offset);
 
         if (state() == Qt::NoGesture) {
-            setState(Qt::GestureStarted);
             d->totalOffset = d->lastOffset;
         } else {
-            setState(Qt::GestureUpdated);
             d->totalOffset += d->lastOffset;
         }
 
         killTimer(d->panFinishedTimer);
         d->panFinishedTimer = startTimer(200);
-        emit triggered();
+        updateState(Qt::GestureUpdated);
 #endif
         return true;
     }