gistfile1.diff

diff --git a/Source/WebKit2/UIProcess/qt/QtTapGestureRecognizer.cpp b/Source/WebKit2/UIProcess/qt/QtTapGestureRecognizer.cpp
index d637366..17e8394 100644
--- a/Source/WebKit2/UIProcess/qt/QtTapGestureRecognizer.cpp
+++ b/Source/WebKit2/UIProcess/qt/QtTapGestureRecognizer.cpp
@@ -37,83 +37,73 @@ QtTapGestureRecognizer::QtTapGestureRecognizer(QtWebPageEventHandler* eventHandl
 {
 }
 
+static inline bool withinDistance(const QTouchEvent::TouchPoint& touchPoint, int distance)
+{
+    return QLineF(touchPoint.screenPos(), touchPoint.lastScreenPos()).length() < distance;
+}
+
 bool QtTapGestureRecognizer::recognize(const QTouchEvent* event, qint64 eventTimestampMillis)
 {
+    ASSERT(m_eventHandler);
+
     if (event->touchPoints().size() != 1) {
         reset();
         return false;
     }
 
+    const QTouchEvent::TouchPoint& touchPoint = event->touchPoints().first();
+
     switch (event->type()) {
     case QEvent::TouchBegin:
         ASSERT(m_tapState == NoTap);
-        ASSERT(!m_tapAndHoldTimer.isActive());
 
+        m_lastTouchEvent.clear(); // Cancel other single taps.
+
+        ASSERT(!m_tapAndHoldTimer.isActive());
         m_tapAndHoldTimer.start(tapAndHoldTime, this);
 
+        m_tapState = SingleTapStarted;
+
         if (m_doubleTapTimer.isActive()) {
-            // Might be double tap.
-            ASSERT(m_touchBeginEventForTap);
             m_doubleTapTimer.stop();
-            QPointF lastPosition = m_touchBeginEventForTap->touchPoints().first().screenPos();
-            QPointF newPosition = event->touchPoints().first().screenPos();
-            if (QLineF(lastPosition, newPosition).length() < maxDoubleTapDistance)
-                m_tapState = DoubleTapCandidate;
-            else {
-                // Received a new tap, that is unrelated to the previous one.
-                tapTimeout();
+
+            if (!withinDistance(touchPoint, maxDoubleTapDistance)) {
+                // Received a new tap, that is unrelated to the previous one. Ignore previous.
+                reset();
                 m_tapState = SingleTapStarted;
-            }
-        } else
-            m_tapState = SingleTapStarted;
-        m_touchBeginEventForTap = adoptPtr(new QTouchEvent(*event));
+            } else
+                m_tapState = DoubleTapCandidate;
+        }
 
         if (m_tapState == SingleTapStarted) {
-            const QTouchEvent::TouchPoint& touchPoint = event->touchPoints().first();
             m_eventHandler->handlePotentialSingleTapEvent(touchPoint);
+            m_doubleTapTimer.start(maxDoubleTapInterval, this);
+            m_lastTouchEvent = adoptPtr(new QTouchEvent(*event));
         }
+
         break;
+
     case QEvent::TouchUpdate:
         // If the touch point moves further than the threshold, we cancel the tap gesture.
-        if (m_tapState == SingleTapStarted) {
-            const QTouchEvent::TouchPoint& touchPoint = event->touchPoints().first();
-            QPointF offset(touchPoint.scenePos() - m_touchBeginEventForTap->touchPoints().first().scenePos());
-            const qreal distX = qAbs(offset.x());
-            const qreal distY = qAbs(offset.y());
-            if (distX > initialTriggerDistanceThreshold || distY > initialTriggerDistanceThreshold)
-                reset();
-        }
+        if (m_tapState == SingleTapStarted && !withinDistance(touchPoint, maxPanDistance))
+            reset();
         break;
+
     case QEvent::TouchEnd:
         m_tapAndHoldTimer.stop();
+
+        if (m_tapState == DoubleTapCandidate) {
+            m_doubleTapTimer.stop();
+            if (withinDistance(touchPoint, maxDoubleTapDistance))
+                m_eventHandler->handleDoubleTapEvent(touchPoint);
+        }
+
         if (m_tapState != NoTap)
             m_eventHandler->handlePotentialSingleTapEvent(QTouchEvent::TouchPoint());
 
-        switch (m_tapState) {
-        case DoubleTapCandidate:
-            {
-                ASSERT(!m_doubleTapTimer.isActive());
-                m_tapState = NoTap;
-
-                const QTouchEvent::TouchPoint& touchPoint = event->touchPoints().first();
-                QPointF startPosition = touchPoint.startScreenPos();
-                QPointF endPosition = touchPoint.screenPos();
-                if (QLineF(endPosition, startPosition).length() < maxDoubleTapDistance && m_eventHandler)
-                    m_eventHandler->handleDoubleTapEvent(touchPoint);
-                break;
-            }
-        case SingleTapStarted:
-            ASSERT(!m_doubleTapTimer.isActive());
-            m_doubleTapTimer.start(doubleClickInterval, this);
-            m_tapState = NoTap;
-            break;
-        case TapAndHold:
-            m_tapState = NoTap;
-            break;
-        default:
-            break;
-        }
+        m_tapState = NoTap;
         break;
+
     default:
         break;
     }
@@ -123,39 +113,37 @@ bool QtTapGestureRecognizer::recognize(const QTouchEvent* event, qint64 eventTim
 
 void QtTapGestureRecognizer::tapTimeout()
 {
-    m_doubleTapTimer.stop();
-    m_eventHandler->handleSingleTapEvent(m_touchBeginEventForTap->touchPoints().at(0));
-    m_touchBeginEventForTap.clear();
+    ASSERT(m_lastTouchEvent);
+
+    m_eventHandler->handlePotentialSingleTapEvent(QTouchEvent::TouchPoint());
+    m_eventHandler->handleSingleTapEvent(m_lastTouchEvent->touchPoints().first());
+    reset();
 }
 
 void QtTapGestureRecognizer::tapAndHoldTimeout()
 {
-    ASSERT(m_touchBeginEventForTap);
-    m_tapAndHoldTimer.stop();
+    ASSERT(m_lastTouchEvent);
+
     m_eventHandler->handlePotentialSingleTapEvent(QTouchEvent::TouchPoint());
+    reset();
+
 #if 0 // No support for synthetic context menus in WK2 yet.
     QTouchEvent::TouchPoint tapPoint = m_touchBeginEventForTap->touchPoints().at(0);
     WebGestureEvent gesture(WebEvent::GestureTapAndHold, tapPoint.pos().toPoint(), tapPoint.screenPos().toPoint(), WebEvent::Modifiers(0), 0);
     if (m_webPageProxy)
         m_webPageProxy->handleGestureEvent(gesture);
 #endif
-    m_touchBeginEventForTap.clear();
-    m_tapState = TapAndHold;
-
-    ASSERT(!m_doubleTapTimer.isActive());
-    m_doubleTapTimer.stop();
 }
 
 void QtTapGestureRecognizer::reset()
 {
-    if (m_tapState == NoTap)
-        return;
-
-    m_eventHandler->handlePotentialSingleTapEvent(QTouchEvent::TouchPoint());
+    if (m_tapState != NoTap)
+        m_eventHandler->handlePotentialSingleTapEvent(QTouchEvent::TouchPoint());
 
     m_tapState = NoTap;
-    m_touchBeginEventForTap.clear();
+    m_lastTouchEvent.clear();
     m_tapAndHoldTimer.stop();
+    m_doubleTapTimer.stop();
 
     QtGestureRecognizer::reset();
 }
diff --git a/Source/WebKit2/UIProcess/qt/QtTapGestureRecognizer.h b/Source/WebKit2/UIProcess/qt/QtTapGestureRecognizer.h
index a4ec41e..791dfda 100644
--- a/Source/WebKit2/UIProcess/qt/QtTapGestureRecognizer.h
+++ b/Source/WebKit2/UIProcess/qt/QtTapGestureRecognizer.h
@@ -38,10 +38,10 @@ class QTouchEvent;
 QT_END_NAMESPACE
 
 // FIXME: These constants should possibly depend on DPI.
-const qreal initialTriggerDistanceThreshold = 5;
-const qreal maxDoubleTapDistance = 120;
+const int maxPanDistance = 5;
+const int maxDoubleTapDistance = 120;
 const int tapAndHoldTime = 800;
-const int doubleClickInterval = 400;
+const int maxDoubleTapInterval = 400;
 
 class QtWebPageEventHandler;
 
@@ -61,7 +61,7 @@ protected:
 private:
     QBasicTimer m_doubleTapTimer;
     QBasicTimer m_tapAndHoldTimer;
-    OwnPtr<QTouchEvent> m_touchBeginEventForTap;
+    OwnPtr<QTouchEvent> m_lastTouchEvent;
 
     enum {
         NoTap,