Propagate synthesized mouse events in parallel with touch.

The old way of event propagation inside QQuickCanvas was to send the
touch event through all elements, and if it was accepted along the
way, stop. Otherwise generate a mouse event and propagate it through
the items in the same way.

With this patch the behavior is changed instead to do the propagation
in parallel.  The idea is to first send a touch, then a mouse event to
each QML item (in paint order) that can potentially handle the events.
When items filter their child elements, the same logic applies.

Other changes/clarifications:
- mouse events no longer get synthesized for more than one touch point
- TouchPoints can be distributed to multiple Items
- if an item accepts a touch point, it always gets updates, even if
  the point is stationary
- events containing only stationary TouchPoints are discarded
- PinchArea must accept any initial single TouchPoint in order to
  receive subsequent updates, even though it's not pinching yet.
  This means if PA is on top, items underneath don't get touches.

New unit tests showing this behavior were added.

This patch was written by Frederik Gladhorn,
Laszlo Agocs and Shawn Rutledge.

Due to the complexity of the logic some refactoring was done.

QQuickMouseEventEx has been removed because it inherently relied on
using the QEvent d pointer.

Change-Id: If19ef687d7602e83cc11b18d2fecfbbdb4e44f5c
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@nokia.com>

2 files changed, 92 insertions, 67 deletions

diff --git a/tests/auto/quick/qquickpincharea/data/pinchproperties.qml b/tests/auto/quick/qquickpincharea/data/pinchproperties.qml
index 44d116184e..6665e2f597 100644
--- a/tests/auto/quick/qquickpincharea/data/pinchproperties.qml
+++ b/tests/auto/quick/qquickpincharea/data/pinchproperties.qml
@@ -4,6 +4,7 @@ Rectangle {
     property variant center
     property real scale
     property int pointCount: 0
+    property bool pinchActive: false
     width: 240; height: 320
     color: "white"
     Rectangle {
@@ -34,6 +35,7 @@ Rectangle {
                 whiteRect.center = pinch.center
                 whiteRect.scale = pinch.scale
                 whiteRect.pointCount = pinch.pointCount;
+                whiteRect.pinchActive = true;
             }
             onPinchUpdated: {
                 whiteRect.center = pinch.center
@@ -44,6 +46,7 @@ Rectangle {
                 whiteRect.center = pinch.center
                 whiteRect.scale = pinch.scale
                 whiteRect.pointCount = pinch.pointCount;
+                whiteRect.pinchActive = false;
             }
          }
      }
diff --git a/tests/auto/quick/qquickpincharea/tst_qquickpincharea.cpp b/tests/auto/quick/qquickpincharea/tst_qquickpincharea.cpp
index 27efdf7e28..e0e4b6c4d8 100644
--- a/tests/auto/quick/qquickpincharea/tst_qquickpincharea.cpp
+++ b/tests/auto/quick/qquickpincharea/tst_qquickpincharea.cpp
@@ -229,31 +229,41 @@ void tst_QQuickPinchArea::scale()
 
     QPoint p1(80, 80);
     QPoint p2(100, 100);
-
-    QTest::touchEvent(canvas, device).press(0, p1, canvas);
-    QTest::touchEvent(canvas, device).stationary(0).press(1, p2, canvas);
-    p1 -= QPoint(10,10);
-    p2 += QPoint(10,10);
-    QTest::touchEvent(canvas, device).move(0, p1,canvas).move(1, p2,canvas);
-
-    QCOMPARE(root->property("scale").toReal(), 1.0);
-
-    p1 -= QPoint(10,10);
-    p2 += QPoint(10,10);
-    QTest::touchEvent(canvas, device).move(0, p1,canvas).move(1, p2,canvas);
-
-    QCOMPARE(root->property("scale").toReal(), 1.5);
-    QCOMPARE(root->property("center").toPointF(), QPointF(40, 40)); // blackrect is at 50,50
-    QCOMPARE(blackRect->scale(), 1.5);
+    {
+        QTest::QTouchEventSequence pinchSequence = QTest::touchEvent(canvas, device);
+        pinchSequence.press(0, p1, canvas).commit();
+        // In order for the stationary point to remember its previous position,
+        // we have to reuse the same pinchSequence object.  Otherwise if we let it
+        // be destroyed and then start a new sequence, point 0 will default to being
+        // stationary at 0, 0, and PinchArea will filter out that touchpoint because
+        // it is outside its bounds.
+        pinchSequence.stationary(0).press(1, p2, canvas).commit();
+        p1 -= QPoint(10,10);
+        p2 += QPoint(10,10);
+        pinchSequence.move(0, p1,canvas).move(1, p2,canvas).commit();
+
+        QCOMPARE(root->property("scale").toReal(), 1.0);
+        QVERIFY(root->property("pinchActive").toBool());
+
+        p1 -= QPoint(10,10);
+        p2 += QPoint(10,10);
+        pinchSequence.move(0, p1,canvas).move(1, p2,canvas).commit();
+
+        QCOMPARE(root->property("scale").toReal(), 1.5);
+        QCOMPARE(root->property("center").toPointF(), QPointF(40, 40)); // blackrect is at 50,50
+        QCOMPARE(blackRect->scale(), 1.5);
+    }
 
     // scale beyond bound
     p1 -= QPoint(50,50);
     p2 += QPoint(50,50);
-    QTest::touchEvent(canvas, device).move(0, p1, canvas).move(1, p2, canvas);
-
-    QCOMPARE(blackRect->scale(), 2.0);
-
-    QTest::touchEvent(canvas, device).release(0, p1, canvas).release(1, p2, canvas);
+    {
+        QTest::QTouchEventSequence pinchSequence = QTest::touchEvent(canvas, device);
+        pinchSequence.move(0, p1, canvas).move(1, p2, canvas).commit();
+        QCOMPARE(blackRect->scale(), 2.0);
+        pinchSequence.release(0, p1, canvas).release(1, p2, canvas).commit();
+    }
+    QVERIFY(!root->property("pinchActive").toBool());
 
     delete canvas;
 }
@@ -282,21 +292,25 @@ void tst_QQuickPinchArea::pan()
 
     QPoint p1(80, 80);
     QPoint p2(100, 100);
-
-    QTest::touchEvent(canvas, device).press(0, p1, canvas);
-    QTest::touchEvent(canvas, device).stationary(0).press(1, p2, canvas);
-    p1 += QPoint(10,10);
-    p2 += QPoint(10,10);
-    QTest::touchEvent(canvas, device).move(0, p1, canvas).move(1, p2, canvas);
-
-    QCOMPARE(root->property("scale").toReal(), 1.0);
-
-    p1 += QPoint(10,10);
-    p2 += QPoint(10,10);
-    QTest::touchEvent(canvas, device).move(0, p1, canvas).move(1, p2, canvas);
+    {
+        QTest::QTouchEventSequence pinchSequence = QTest::touchEvent(canvas, device);
+        pinchSequence.press(0, p1, canvas).commit();
+        // In order for the stationary point to remember its previous position,
+        // we have to reuse the same pinchSequence object.
+        pinchSequence.stationary(0).press(1, p2, canvas).commit();
+        p1 += QPoint(10,10);
+        p2 += QPoint(10,10);
+        pinchSequence.move(0, p1,canvas).move(1, p2,canvas).commit();
+
+        QCOMPARE(root->property("scale").toReal(), 1.0);
+        QVERIFY(root->property("pinchActive").toBool());
+
+        p1 += QPoint(10,10);
+        p2 += QPoint(10,10);
+        pinchSequence.move(0, p1,canvas).move(1, p2,canvas).commit();
+    }
 
     QCOMPARE(root->property("center").toPointF(), QPointF(60, 60)); // blackrect is at 50,50
-
     QCOMPARE(blackRect->x(), 60.0);
     QCOMPARE(blackRect->y(), 60.0);
 
@@ -309,6 +323,7 @@ void tst_QQuickPinchArea::pan()
     QCOMPARE(blackRect->y(), 160.0);
 
     QTest::touchEvent(canvas, device).release(0, p1, canvas).release(1, p2, canvas);
+    QVERIFY(!root->property("pinchActive").toBool());
 
     delete canvas;
 }
@@ -341,57 +356,64 @@ void tst_QQuickPinchArea::retouch()
 
     QPoint p1(80, 80);
     QPoint p2(100, 100);
+    {
+        QTest::QTouchEventSequence pinchSequence = QTest::touchEvent(canvas, device);
+        pinchSequence.press(0, p1, canvas).commit();
+        // In order for the stationary point to remember its previous position,
+        // we have to reuse the same pinchSequence object.
+        pinchSequence.stationary(0).press(1, p2, canvas).commit();
+        p1 -= QPoint(10,10);
+        p2 += QPoint(10,10);
+        pinchSequence.move(0, p1,canvas).move(1, p2,canvas).commit();
 
-    QTest::touchEvent(canvas, device).press(0, p1, canvas);
-    QTest::touchEvent(canvas, device).stationary(0).press(1, p2, canvas);
-    p1 -= QPoint(10,10);
-    p2 += QPoint(10,10);
-    QTest::touchEvent(canvas, device).move(0, p1, canvas).move(1, p2, canvas);
-
-    QCOMPARE(root->property("scale").toReal(), 1.0);
+        QCOMPARE(root->property("scale").toReal(), 1.0);
+        QVERIFY(root->property("pinchActive").toBool());
 
-    p1 -= QPoint(10,10);
-    p2 += QPoint(10,10);
-    QTest::touchEvent(canvas, device).move(0, p1, canvas).move(1, p2, canvas);
+        p1 -= QPoint(10,10);
+        p2 += QPoint(10,10);
+        pinchSequence.move(0, p1,canvas).move(1, p2,canvas).commit();
 
-    QCOMPARE(startedSpy.count(), 1);
+        QCOMPARE(startedSpy.count(), 1);
 
-    QCOMPARE(root->property("scale").toReal(), 1.5);
-    QCOMPARE(root->property("center").toPointF(), QPointF(40, 40)); // blackrect is at 50,50
-    QCOMPARE(blackRect->scale(), 1.5);
+        QCOMPARE(root->property("scale").toReal(), 1.5);
+        QCOMPARE(root->property("center").toPointF(), QPointF(40, 40)); // blackrect is at 50,50
+        QCOMPARE(blackRect->scale(), 1.5);
 
-    QCOMPARE(canvas->rootObject()->property("pointCount").toInt(), 2);
+        QCOMPARE(canvas->rootObject()->property("pointCount").toInt(), 2);
 
-    QCOMPARE(startedSpy.count(), 1);
-    QCOMPARE(finishedSpy.count(), 0);
+        QCOMPARE(startedSpy.count(), 1);
+        QCOMPARE(finishedSpy.count(), 0);
 
-    QTest::touchEvent(canvas, device).stationary(0).release(1, p2, canvas);
+        // Hold down the first finger but release the second one
+        pinchSequence.stationary(0).release(1, p2, canvas).commit();
 
-    QCOMPARE(startedSpy.count(), 1);
-    QCOMPARE(finishedSpy.count(), 0);
+        QCOMPARE(startedSpy.count(), 1);
+        QCOMPARE(finishedSpy.count(), 0);
 
-    QCOMPARE(canvas->rootObject()->property("pointCount").toInt(), 1);
+        QCOMPARE(canvas->rootObject()->property("pointCount").toInt(), 1);
 
-    QTest::touchEvent(canvas, device).stationary(0).press(1, p2, canvas);
-    p1 -= QPoint(10,10);
-    p2 += QPoint(10,10);
-    QTest::touchEvent(canvas, device).move(0, p1, canvas).move(1, p2, canvas);
+        // Keep holding down the first finger and re-touch the second one, then move them both
+        pinchSequence.stationary(0).press(1, p2, canvas).commit();
+        p1 -= QPoint(10,10);
+        p2 += QPoint(10,10);
+        pinchSequence.move(0, p1, canvas).move(1, p2, canvas).commit();
 
-    // Lifting and retouching results in onPinchStarted being called again
-    QCOMPARE(startedSpy.count(), 2);
-    QCOMPARE(finishedSpy.count(), 0);
+        // Lifting and retouching results in onPinchStarted being called again
+        QCOMPARE(startedSpy.count(), 2);
+        QCOMPARE(finishedSpy.count(), 0);
 
-    QCOMPARE(canvas->rootObject()->property("pointCount").toInt(), 2);
+        QCOMPARE(canvas->rootObject()->property("pointCount").toInt(), 2);
 
-    QTest::touchEvent(canvas, device).release(0, p1, canvas).release(1, p2, canvas);
+        pinchSequence.release(0, p1, canvas).release(1, p2, canvas).commit();
 
-    QCOMPARE(startedSpy.count(), 2);
-    QCOMPARE(finishedSpy.count(), 1);
+        QVERIFY(!root->property("pinchActive").toBool());
+        QCOMPARE(startedSpy.count(), 2);
+        QCOMPARE(finishedSpy.count(), 1);
+    }
 
     delete canvas;
 }
 
-
 QQuickView *tst_QQuickPinchArea::createView()
 {
     QQuickView *canvas = new QQuickView(0);