Handle TouchCancel in gui and widgets

Change-Id: I31739840348d88ae408ac1aae2399f6328ccdd43
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>

9 files changed, 109 insertions, 3 deletions

diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index d41c90636b..b17cf5824c 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -184,7 +184,8 @@ QGuiApplication::~QGuiApplication()
 QGuiApplicationPrivate::QGuiApplicationPrivate(int &argc, char **argv, int flags)
     : QCoreApplicationPrivate(argc, argv, flags),
       styleHints(0),
-      inputMethod(0)
+      inputMethod(0),
+      lastTouchType(QEvent::TouchEnd)
 {
     self = this;
     application_type = QCoreApplication::GuiClient;
@@ -950,8 +951,53 @@ Q_GUI_EXPORT bool operator==(const QGuiApplicationPrivate::ActiveTouchPointsKey
 
 void QGuiApplicationPrivate::processTouchEvent(QWindowSystemInterfacePrivate::TouchEvent *e)
 {
-    QWindow *window = e->window.data();
     QGuiApplicationPrivate *d = self;
+
+    if (e->touchType == QEvent::TouchCancel) {
+        // The touch sequence has been canceled (e.g. by the compositor).
+        // Send the TouchCancel to all windows with active touches and clean up.
+        QTouchEvent touchEvent(QEvent::TouchCancel, e->device, e->modifiers);
+        touchEvent.setTimestamp(e->timestamp);
+        QHash<ActiveTouchPointsKey, ActiveTouchPointsValue>::const_iterator it
+                = self->activeTouchPoints.constBegin(), ite = self->activeTouchPoints.constEnd();
+        QSet<QWindow *> windowsNeedingCancel;
+        while (it != ite) {
+            QWindow *w = it->window.data();
+            if (w)
+                windowsNeedingCancel.insert(w);
+            ++it;
+        }
+        for (QSet<QWindow *>::const_iterator winIt = windowsNeedingCancel.constBegin(),
+             winItEnd = windowsNeedingCancel.constEnd(); winIt != winItEnd; ++winIt) {
+            touchEvent.setWindow(*winIt);
+            QGuiApplication::sendSpontaneousEvent(*winIt, &touchEvent);
+        }
+        if (!self->synthesizedMousePoints.isEmpty() && !e->synthetic) {
+            for (QHash<QWindow *, SynthesizedMouseData>::const_iterator synthIt = self->synthesizedMousePoints.constBegin(),
+                 synthItEnd = self->synthesizedMousePoints.constEnd(); synthIt != synthItEnd; ++synthIt) {
+                QWindowSystemInterfacePrivate::MouseEvent fake(synthIt.key(),
+                                                               e->timestamp,
+                                                               synthIt->pos,
+                                                               synthIt->screenPos,
+                                                               Qt::NoButton,
+                                                               e->modifiers);
+                fake.synthetic = true;
+                processMouseEvent(&fake);
+            }
+            self->synthesizedMousePoints.clear();
+        }
+        self->activeTouchPoints.clear();
+        self->lastTouchType = e->touchType;
+        return;
+    }
+
+    // Prevent sending ill-formed event sequences: Cancel can only be followed by a Begin.
+    if (self->lastTouchType == QEvent::TouchCancel && e->touchType != QEvent::TouchBegin)
+        return;
+
+    self->lastTouchType = e->touchType;
+
+    QWindow *window = e->window.data();
     typedef QPair<Qt::TouchPointStates, QList<QTouchEvent::TouchPoint> > StatesAndTouchPoints;
     QHash<QWindow *, StatesAndTouchPoints> windowsNeedingEvents;
 
@@ -1101,6 +1147,8 @@ void QGuiApplicationPrivate::processTouchEvent(QWindowSystemInterfacePrivate::To
             // exclude touchpads as those generate their own mouse events
             if (touchEvent.device()->type() != QTouchDevice::TouchPad) {
                 Qt::MouseButtons b = eventType == QEvent::TouchEnd ? Qt::NoButton : Qt::LeftButton;
+                if (b == Qt::NoButton)
+                    self->synthesizedMousePoints.clear();
 
                 QList<QTouchEvent::TouchPoint> touchPoints = touchEvent.touchPoints();
                 if (eventType == QEvent::TouchBegin)
@@ -1109,6 +1157,9 @@ void QGuiApplicationPrivate::processTouchEvent(QWindowSystemInterfacePrivate::To
                 for (int i = 0; i < touchPoints.count(); ++i) {
                     const QTouchEvent::TouchPoint &touchPoint = touchPoints.at(i);
                     if (touchPoint.id() == m_fakeMouseSourcePointId) {
+                        if (b != Qt::NoButton)
+                            self->synthesizedMousePoints.insert(w, SynthesizedMouseData(
+                                                                    touchPoint.pos(), touchPoint.screenPos()));
                         QWindowSystemInterfacePrivate::MouseEvent fake(w, e->timestamp,
                                                                        touchPoint.pos(),
                                                                        touchPoint.screenPos(),
diff --git a/src/gui/kernel/qguiapplication_p.h b/src/gui/kernel/qguiapplication_p.h
index d9444ebe95..3ca007fb36 100644
--- a/src/gui/kernel/qguiapplication_p.h
+++ b/src/gui/kernel/qguiapplication_p.h
@@ -199,6 +199,13 @@ public:
         QTouchEvent::TouchPoint touchPoint;
     };
     QHash<ActiveTouchPointsKey, ActiveTouchPointsValue> activeTouchPoints;
+    QEvent::Type lastTouchType;
+    struct SynthesizedMouseData {
+        SynthesizedMouseData(const QPointF &p, const QPointF &sp) : pos(p), screenPos(sp) { }
+        QPointF pos;
+        QPointF screenPos;
+    };
+    QHash<QWindow *, SynthesizedMouseData> synthesizedMousePoints;
 
 private:
     void init();
diff --git a/src/gui/kernel/qwindow.cpp b/src/gui/kernel/qwindow.cpp
index b451a6ee33..43b7e39103 100644
--- a/src/gui/kernel/qwindow.cpp
+++ b/src/gui/kernel/qwindow.cpp
@@ -943,6 +943,7 @@ bool QWindow::event(QEvent *ev)
     case QEvent::TouchBegin:
     case QEvent::TouchUpdate:
     case QEvent::TouchEnd:
+    case QEvent::TouchCancel:
         touchEvent(static_cast<QTouchEvent *>(ev));
         break;
 
diff --git a/src/gui/kernel/qwindowsysteminterface_qpa.cpp b/src/gui/kernel/qwindowsysteminterface_qpa.cpp
index ae94b75076..f4f7551c04 100644
--- a/src/gui/kernel/qwindowsysteminterface_qpa.cpp
+++ b/src/gui/kernel/qwindowsysteminterface_qpa.cpp
@@ -296,6 +296,22 @@ void QWindowSystemInterface::handleTouchEvent(QWindow *tlw, ulong timestamp, QTo
     QWindowSystemInterfacePrivate::queueWindowSystemEvent(e);
 }
 
+void QWindowSystemInterface::handleTouchCancelEvent(QWindow *w, QTouchDevice *device,
+                                                    Qt::KeyboardModifiers mods)
+{
+    unsigned long time = QWindowSystemInterfacePrivate::eventTime.elapsed();
+    handleTouchCancelEvent(w, time, device, mods);
+}
+
+void QWindowSystemInterface::handleTouchCancelEvent(QWindow *w, ulong timestamp, QTouchDevice *device,
+                                                    Qt::KeyboardModifiers mods)
+{
+    QWindowSystemInterfacePrivate::TouchEvent *e =
+            new QWindowSystemInterfacePrivate::TouchEvent(w, timestamp, QEvent::TouchCancel, device,
+                                                         QList<QTouchEvent::TouchPoint>(), mods);
+    QWindowSystemInterfacePrivate::queueWindowSystemEvent(e);
+}
+
 void QWindowSystemInterface::handleScreenOrientationChange(QScreen *screen, Qt::ScreenOrientation orientation)
 {
     QWindowSystemInterfacePrivate::ScreenOrientationEvent *e =
diff --git a/src/gui/kernel/qwindowsysteminterface_qpa.h b/src/gui/kernel/qwindowsysteminterface_qpa.h
index b99363eda7..28ec68ec59 100644
--- a/src/gui/kernel/qwindowsysteminterface_qpa.h
+++ b/src/gui/kernel/qwindowsysteminterface_qpa.h
@@ -101,6 +101,8 @@ public:
                                  const QList<struct TouchPoint> &points, Qt::KeyboardModifiers mods = Qt::NoModifier);
     static void handleTouchEvent(QWindow *w, ulong timestamp, QTouchDevice *device,
                                  const QList<struct TouchPoint> &points, Qt::KeyboardModifiers mods = Qt::NoModifier);
+    static void handleTouchCancelEvent(QWindow *w, QTouchDevice *device, Qt::KeyboardModifiers mods = Qt::NoModifier);
+    static void handleTouchCancelEvent(QWindow *w, ulong timestamp, QTouchDevice *device, Qt::KeyboardModifiers mods = Qt::NoModifier);
 
     static void handleGeometryChange(QWindow *w, const QRect &newRect);
     static void handleSynchronousGeometryChange(QWindow *w, const QRect &newRect);
diff --git a/src/widgets/kernel/qapplication.cpp b/src/widgets/kernel/qapplication.cpp
index d2b4e01c0b..8d776e2f29 100644
--- a/src/widgets/kernel/qapplication.cpp
+++ b/src/widgets/kernel/qapplication.cpp
@@ -5200,6 +5200,28 @@ void QApplicationPrivate::translateRawTouchEvent(QWidget *window,
     }
 }
 
+void QApplicationPrivate::translateTouchCancel(QTouchDevice *device, ulong timestamp)
+{
+    QTouchEvent touchEvent(QEvent::TouchCancel, device, QApplication::keyboardModifiers());
+    touchEvent.setTimestamp(timestamp);
+    QHash<ActiveTouchPointsKey, ActiveTouchPointsValue>::const_iterator it
+            = self->activeTouchPoints.constBegin(), ite = self->activeTouchPoints.constEnd();
+    QSet<QWidget *> widgetsNeedingCancel;
+    while (it != ite) {
+        QWidget *widget = static_cast<QWidget *>(it->target.data());
+        if (widget)
+            widgetsNeedingCancel.insert(widget);
+        ++it;
+    }
+    for (QSet<QWidget *>::const_iterator widIt = widgetsNeedingCancel.constBegin(),
+         widItEnd = widgetsNeedingCancel.constEnd(); widIt != widItEnd; ++widIt) {
+        QWidget *widget = *widIt;
+        touchEvent.setWindow(widget->windowHandle());
+        touchEvent.setTarget(widget);
+        QApplication::sendSpontaneousEvent(widget, &touchEvent);
+    }
+}
+
 #ifndef QT_NO_GESTURES
 QGestureManager* QGestureManager::instance()
 {
diff --git a/src/widgets/kernel/qapplication_p.h b/src/widgets/kernel/qapplication_p.h
index d9d184d51a..b4cd22df13 100644
--- a/src/widgets/kernel/qapplication_p.h
+++ b/src/widgets/kernel/qapplication_p.h
@@ -386,6 +386,7 @@ public:
                                        QTouchDevice *device,
                                        const QList<QTouchEvent::TouchPoint> &touchPoints,
                                        ulong timestamp);
+    static void translateTouchCancel(QTouchDevice *device, ulong timestamp);
 
 private:
 #ifdef Q_WS_QWS
diff --git a/src/widgets/kernel/qwidget.cpp b/src/widgets/kernel/qwidget.cpp
index 008f0391bc..cd3669717d 100644
--- a/src/widgets/kernel/qwidget.cpp
+++ b/src/widgets/kernel/qwidget.cpp
@@ -7776,6 +7776,7 @@ bool QWidget::event(QEvent *event)
         case QEvent::TouchBegin:
         case QEvent::TouchUpdate:
         case QEvent::TouchEnd:
+        case QEvent::TouchCancel:
         case QEvent::ContextMenu:
 #ifndef QT_NO_WHEELEVENT
         case QEvent::Wheel:
@@ -8178,6 +8179,7 @@ bool QWidget::event(QEvent *event)
     case QEvent::TouchBegin:
     case QEvent::TouchUpdate:
     case QEvent::TouchEnd:
+    case QEvent::TouchCancel:
     {
         event->ignore();
         break;
diff --git a/src/widgets/kernel/qwidgetwindow_qpa.cpp b/src/widgets/kernel/qwidgetwindow_qpa.cpp
index e7ba4853a0..c2524567f1 100644
--- a/src/widgets/kernel/qwidgetwindow_qpa.cpp
+++ b/src/widgets/kernel/qwidgetwindow_qpa.cpp
@@ -110,6 +110,7 @@ bool QWidgetWindow::event(QEvent *event)
     case QEvent::TouchBegin:
     case QEvent::TouchUpdate:
     case QEvent::TouchEnd:
+    case QEvent::TouchCancel:
         handleTouchEvent(static_cast<QTouchEvent *>(event));
         return true;
 
@@ -289,7 +290,10 @@ void QWidgetWindow::handleMouseEvent(QMouseEvent *event)
 
 void QWidgetWindow::handleTouchEvent(QTouchEvent *event)
 {
-    QApplicationPrivate::translateRawTouchEvent(m_widget, event->device(), event->touchPoints(), event->timestamp());
+    if (event->type() == QEvent::TouchCancel)
+        QApplicationPrivate::translateTouchCancel(event->device(), event->timestamp());
+    else
+        QApplicationPrivate::translateRawTouchEvent(m_widget, event->device(), event->touchPoints(), event->timestamp());
 }
 
 void QWidgetWindow::handleKeyEvent(QKeyEvent *event)