Remove redundant touch processing in QtGui and widgets.

The duplicated hash tables in QGuiApplicationPrivate and
QApplicationPrivate are now unified into one single hash table in
QGuiApplicationPrivate. This also reduced the number of lookups.

The extra processing needed to keep the touch points' first/lastPos
values in sync is now done only once, in QGuiApplication. This
eliminates the performance penalty (for widget-based apps) that was
introduced during the QPA migration.

As an added bonus the patch adds support for touch events arriving
simultaenously from multiple devices. This was broken before: As there
is no guarantee that two devices/drivers will not send touch points
with the same ID, using structures with only the ID as key is
wrong. The proper key is composed of the device ID (that is, a
QTouchDevice pointer) and the touch point ID.

The exported internal function qt_translateRawTouchEvent() has been
removed. This function cannot work properly in the QPA world: It
injected touches into the widget subsystem (QApplication) only which
is wrong, and would result in half-filled touch events due to not
routing the injected data through QGuiApplication. Autotests using
this function are migrated to
QWindowSystemInterface::handleTouchEvent().

Change-Id: I7632781d77f9e0ac4626fd7c9933511c94492156
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>

1 files changed, 42 insertions, 93 deletions

diff --git a/src/widgets/kernel/qapplication.cpp b/src/widgets/kernel/qapplication.cpp
index 4c4cb4061c..a4a1aa860d 100644
--- a/src/widgets/kernel/qapplication.cpp
+++ b/src/widgets/kernel/qapplication.cpp
@@ -3904,7 +3904,7 @@ bool QApplication::notify(QObject *receiver, QEvent *e)
                 // the first widget to accept the TouchBegin gets an implicit grab.
                 for (int i = 0; i < touchEvent->touchPoints().count(); ++i) {
                     const QTouchEvent::TouchPoint &touchPoint = touchEvent->touchPoints().at(i);
-                    d->widgetForTouchPointId[touchPoint.id()] = widget;
+                    d->activeTouchPoints[QGuiApplicationPrivate::ActiveTouchPointsKey(touchEvent->device(), touchPoint.id())].target = widget;
                 }
                 break;
             } else if (p.isNull() || widget->isWindow() || widget->testAttribute(Qt::WA_NoMousePropagation)) {
@@ -5168,41 +5168,43 @@ void QApplicationPrivate::updateTouchPointsForWidget(QWidget *widget, QTouchEven
 
         rect.moveCenter(widget->mapFromGlobal(screenPos.toPoint()) + delta);
         touchPoint.d->rect = rect;
-        if (touchPoint.state() == Qt::TouchPointPressed) {
-            touchPoint.d->startPos = widget->mapFromGlobal(touchPoint.startScreenPos().toPoint()) + delta;
-            touchPoint.d->lastPos = widget->mapFromGlobal(touchPoint.lastScreenPos().toPoint()) + delta;
-        }
+        touchPoint.d->startPos = widget->mapFromGlobal(touchPoint.startScreenPos().toPoint()) + delta;
+        touchPoint.d->lastPos = widget->mapFromGlobal(touchPoint.lastScreenPos().toPoint()) + delta;
     }
 }
 
 void QApplicationPrivate::initializeMultitouch()
 {
-    widgetForTouchPointId.clear();
-    appCurrentTouchPoints.clear();
-
     initializeMultitouch_sys();
 }
 
 void QApplicationPrivate::cleanupMultitouch()
 {
     cleanupMultitouch_sys();
-
-    widgetForTouchPointId.clear();
-    appCurrentTouchPoints.clear();
 }
 
-int QApplicationPrivate::findClosestTouchPointId(const QPointF &screenPos)
+QWidget *QApplicationPrivate::findClosestTouchPointTarget(QTouchDevice *device, const QPointF &screenPos)
 {
     int closestTouchPointId = -1;
+    QObject *closestTarget = 0;
     qreal closestDistance = qreal(0.);
-    foreach (const QTouchEvent::TouchPoint &touchPoint, appCurrentTouchPoints) {
-        qreal distance = QLineF(screenPos, touchPoint.screenPos()).length();
-        if (closestTouchPointId == -1 || distance < closestDistance) {
-            closestTouchPointId = touchPoint.id();
-            closestDistance = distance;
+    QHash<ActiveTouchPointsKey, ActiveTouchPointsValue>::const_iterator it = activeTouchPoints.constBegin(),
+            ite = activeTouchPoints.constEnd();
+    while (it != ite) {
+        if (it.key().device == device) {
+            const QTouchEvent::TouchPoint &touchPoint = it->touchPoint;
+            qreal dx = screenPos.x() - touchPoint.screenPos().x();
+            qreal dy = screenPos.y() - touchPoint.screenPos().y();
+            qreal distance = dx * dx + dy * dy;
+            if (closestTouchPointId == -1 || distance < closestDistance) {
+                closestTouchPointId = touchPoint.id();
+                closestDistance = distance;
+                closestTarget = it.value().target.data();
+            }
         }
+        ++it;
     }
-    return closestTouchPointId;
+    return static_cast<QWidget *>(closestTarget);
 }
 
 void QApplicationPrivate::translateRawTouchEvent(QWidget *window,
@@ -5222,91 +5224,46 @@ void QApplicationPrivate::translateRawTouchEvent(QWidget *window,
         touchPoint.d = touchPoint.d->detach();
 
         // update state
-        QWeakPointer<QWidget> widget;
-        switch (touchPoint.state()) {
-        case Qt::TouchPointPressed:
-        {
+        QWeakPointer<QObject> target;
+        ActiveTouchPointsKey touchInfoKey(device, touchPoint.id());
+        ActiveTouchPointsValue &touchInfo = d->activeTouchPoints[touchInfoKey];
+        if (touchPoint.state() == Qt::TouchPointPressed) {
             if (device->type() == QTouchDevice::TouchPad) {
                 // on touch-pads, send all touch points to the same widget
-                widget = d->widgetForTouchPointId.isEmpty()
-                         ? QWeakPointer<QWidget>()
-                         : d->widgetForTouchPointId.constBegin().value();
+                target = d->activeTouchPoints.isEmpty()
+                        ? QWeakPointer<QObject>()
+                        : d->activeTouchPoints.constBegin().value().target;
             }
 
-            if (!widget) {
+            if (!target) {
                 // determine which widget this event will go to
                 if (!window)
                     window = QApplication::topLevelAt(touchPoint.screenPos().toPoint());
                 if (!window)
                     continue;
-                widget = window->childAt(window->mapFromGlobal(touchPoint.screenPos().toPoint()));
-                if (!widget)
-                    widget = window;
+                target = window->childAt(window->mapFromGlobal(touchPoint.screenPos().toPoint()));
+                if (!target)
+                    target = window;
             }
 
             if (device->type() == QTouchDevice::TouchScreen) {
-                int closestTouchPointId = d->findClosestTouchPointId(touchPoint.screenPos());
-                QWidget *closestWidget = d->widgetForTouchPointId.value(closestTouchPointId).data();
+                QWidget *closestWidget = d->findClosestTouchPointTarget(device, touchPoint.screenPos());
+                QWidget *widget = static_cast<QWidget *>(target.data());
                 if (closestWidget
-                    && (widget.data()->isAncestorOf(closestWidget) || closestWidget->isAncestorOf(widget.data()))) {
-                    widget = closestWidget;
+                        && (widget->isAncestorOf(closestWidget) || closestWidget->isAncestorOf(widget))) {
+                    target = closestWidget;
                 }
             }
 
-            d->widgetForTouchPointId[touchPoint.id()] = widget;
-            touchPoint.d->startScreenPos = touchPoint.screenPos();
-            touchPoint.d->lastScreenPos = touchPoint.screenPos();
-            touchPoint.d->startNormalizedPos = touchPoint.normalizedPos();
-            touchPoint.d->lastNormalizedPos = touchPoint.normalizedPos();
-            if (touchPoint.pressure() < qreal(0.))
-                touchPoint.d->pressure = qreal(1.);
-
-            d->appCurrentTouchPoints.insert(touchPoint.id(), touchPoint);
-            break;
-        }
-        case Qt::TouchPointReleased:
-        {
-            widget = d->widgetForTouchPointId.take(touchPoint.id());
-            if (!widget)
-                continue;
-
-            QTouchEvent::TouchPoint previousTouchPoint = d->appCurrentTouchPoints.take(touchPoint.id());
-            touchPoint.d->startScreenPos = previousTouchPoint.startScreenPos();
-            touchPoint.d->lastScreenPos = previousTouchPoint.screenPos();
-            touchPoint.d->startPos = previousTouchPoint.startPos();
-            touchPoint.d->lastPos = previousTouchPoint.pos();
-            touchPoint.d->startNormalizedPos = previousTouchPoint.startNormalizedPos();
-            touchPoint.d->lastNormalizedPos = previousTouchPoint.normalizedPos();
-            if (touchPoint.pressure() < qreal(0.))
-                touchPoint.d->pressure = qreal(0.);
-            break;
-        }
-        default:
-            widget = d->widgetForTouchPointId.value(touchPoint.id());
-            if (!widget)
+            touchInfo.target = target;
+        } else {
+            target = touchInfo.target;
+            if (!target)
                 continue;
-
-            Q_ASSERT(d->appCurrentTouchPoints.contains(touchPoint.id()));
-            QTouchEvent::TouchPoint previousTouchPoint = d->appCurrentTouchPoints.value(touchPoint.id());
-            touchPoint.d->startScreenPos = previousTouchPoint.startScreenPos();
-            touchPoint.d->lastScreenPos = previousTouchPoint.screenPos();
-            touchPoint.d->startPos = previousTouchPoint.startPos();
-            touchPoint.d->lastPos = previousTouchPoint.pos();
-            touchPoint.d->startNormalizedPos = previousTouchPoint.startNormalizedPos();
-            touchPoint.d->lastNormalizedPos = previousTouchPoint.normalizedPos();
-            if (touchPoint.pressure() < qreal(0.))
-                touchPoint.d->pressure = qreal(1.);
-            d->appCurrentTouchPoints[touchPoint.id()] = touchPoint;
-            break;
         }
-        Q_ASSERT(widget.data() != 0);
-
-        // make the *scene* functions return the same as the *screen* functions
-        touchPoint.d->sceneRect = touchPoint.screenRect();
-        touchPoint.d->startScenePos = touchPoint.startScreenPos();
-        touchPoint.d->lastScenePos = touchPoint.lastScreenPos();
+        Q_ASSERT(target.data() != 0);
 
-        StatesAndTouchPoints &maskAndPoints = widgetsNeedingEvents[widget.data()];
+        StatesAndTouchPoints &maskAndPoints = widgetsNeedingEvents[static_cast<QWidget *>(target.data())];
         maskAndPoints.first |= touchPoint.state();
         maskAndPoints.second.append(touchPoint);
     }
@@ -5345,7 +5302,7 @@ void QApplicationPrivate::translateRawTouchEvent(QWidget *window,
         updateTouchPointsForWidget(widget, &touchEvent);
         touchEvent.setTimestamp(timestamp);
         touchEvent.setWindow(window->windowHandle());
-        touchEvent.setTarget(window);
+        touchEvent.setTarget(widget);
 
         switch (touchEvent.type()) {
         case QEvent::TouchBegin:
@@ -5367,14 +5324,6 @@ void QApplicationPrivate::translateRawTouchEvent(QWidget *window,
     }
 }
 
-Q_WIDGETS_EXPORT void qt_translateRawTouchEvent(QWidget *window,
-                                                QTouchDevice *device,
-                                                const QList<QTouchEvent::TouchPoint> &touchPoints,
-                                                ulong timestamp)
-{
-    QApplicationPrivate::translateRawTouchEvent(window, device, touchPoints, timestamp);
-}
-
 #ifndef QT_NO_GESTURES
 QGestureManager* QGestureManager::instance()
 {