Flickable shouldn't grab the mouse until it starts an effective move.

If the boundBehavior prevents the flickable from moving its content
item in response to a drag it shouldn't grab the mouse as that will
prevent a parent MouseArea or Flickable from handling the drag.

Task-number: 29718
Change-Id: Ief82ef7b898ea2581fd0b7e52548f451d887e2f1
Reviewed-by: Alan Alpert <aalpert@rim.com>

4 files changed, 136 insertions, 28 deletions

diff --git a/src/declarative/graphicsitems/qdeclarativeflickable.cpp b/src/declarative/graphicsitems/qdeclarativeflickable.cpp
index edbd9782..c0c7b2a0 100644
--- a/src/declarative/graphicsitems/qdeclarativeflickable.cpp
+++ b/src/declarative/graphicsitems/qdeclarativeflickable.cpp
@@ -789,9 +789,9 @@ void QDeclarativeFlickablePrivate::handleMouseMoveEvent(QGraphicsSceneMouseEvent
 
     if (q->yflick()) {
         int dy = int(event->pos().y() - pressPos.y());
+        if (vData.dragStartOffset == 0)
+            vData.dragStartOffset = dy;
         if (qAbs(dy) > QApplication::startDragDistance() || QDeclarativeItemPrivate::elapsed(pressTime) > 200) {
-            if (!vMoved)
-                vData.dragStartOffset = dy;
             qreal newY = dy + vData.pressPos - vData.dragStartOffset;
             const qreal minY = vData.dragMinBound;
             const qreal maxY = vData.dragMaxBound;
@@ -799,31 +799,28 @@ void QDeclarativeFlickablePrivate::handleMouseMoveEvent(QGraphicsSceneMouseEvent
                 newY = minY + (newY - minY) / 2;
             if (newY < maxY && maxY - minY <= 0)
                 newY = maxY + (newY - maxY) / 2;
-            if (boundsBehavior == QDeclarativeFlickable::StopAtBounds && (newY > minY || newY < maxY)) {
-                rejectY = true;
-                if (newY < maxY) {
-                    newY = maxY;
-                    rejectY = false;
-                }
-                if (newY > minY) {
-                    newY = minY;
-                    rejectY = false;
-                }
+            if (boundsBehavior == QDeclarativeFlickable::StopAtBounds && newY <= maxY) {
+                newY = maxY;
+                rejectY = vData.pressPos == maxY && dy < 0;
+            }
+            if (boundsBehavior == QDeclarativeFlickable::StopAtBounds && newY >= minY) {
+                newY = minY;
+                rejectY = vData.pressPos == minY && dy > 0;
             }
             if (!rejectY && stealMouse && dy != 0) {
                 vData.move.setValue(qRound(newY));
                 vMoved = true;
             }
-            if (qAbs(dy) > QApplication::startDragDistance())
+            if (!rejectY && qAbs(dy) > QApplication::startDragDistance())
                 stealY = true;
         }
     }
 
     if (q->xflick()) {
         int dx = int(event->pos().x() - pressPos.x());
+        if (hData.dragStartOffset == 0)
+            hData.dragStartOffset = dx;
         if (qAbs(dx) > QApplication::startDragDistance() || QDeclarativeItemPrivate::elapsed(pressTime) > 200) {
-            if (!hMoved)
-                hData.dragStartOffset = dx;
             qreal newX = dx + hData.pressPos - hData.dragStartOffset;
             const qreal minX = hData.dragMinBound;
             const qreal maxX = hData.dragMaxBound;
@@ -831,23 +828,20 @@ void QDeclarativeFlickablePrivate::handleMouseMoveEvent(QGraphicsSceneMouseEvent
                 newX = minX + (newX - minX) / 2;
             if (newX < maxX && maxX - minX <= 0)
                 newX = maxX + (newX - maxX) / 2;
-            if (boundsBehavior == QDeclarativeFlickable::StopAtBounds && (newX > minX || newX < maxX)) {
-                rejectX = true;
-                if (newX < maxX) {
-                    newX = maxX;
-                    rejectX = false;
-                }
-                if (newX > minX) {
-                    newX = minX;
-                    rejectX = false;
-                }
+            if (boundsBehavior == QDeclarativeFlickable::StopAtBounds && newX <= maxX) {
+                newX = maxX;
+                rejectX = hData.pressPos == maxX && dx < 0;
+            }
+            if (boundsBehavior == QDeclarativeFlickable::StopAtBounds && newX >= minX) {
+                newX = minX;
+                rejectX = hData.pressPos == minX && dx > 0;
             }
             if (!rejectX && stealMouse && dx != 0) {
                 hData.move.setValue(qRound(newX));
                 hMoved = true;
             }
 
-            if (qAbs(dx) > QApplication::startDragDistance())
+            if (!rejectX && qAbs(dx) > QApplication::startDragDistance())
                 stealX = true;
         }
     }
diff --git a/tests/auto/declarative/qdeclarativeflickable/data/nestedStopAtBounds.qml b/tests/auto/declarative/qdeclarativeflickable/data/nestedStopAtBounds.qml
new file mode 100644
index 00000000..6b28edf5
--- /dev/null
+++ b/tests/auto/declarative/qdeclarativeflickable/data/nestedStopAtBounds.qml
@@ -0,0 +1,38 @@
+import QtQuick 1.1
+
+Flickable {
+    id: outer
+    objectName: "outerFlickable"
+    width: 400
+    height: 400
+    contentX: 50
+    contentY: 50
+    contentWidth: 500
+    contentHeight: 500
+    flickableDirection: inner.flickableDirection
+
+    Rectangle {
+        x: 100
+        y: 100
+        width: 300
+        height: 300
+
+        color: "yellow"
+        Flickable {
+            id: inner
+            objectName: "innerFlickable"
+            anchors.fill: parent
+            contentX: 100
+            contentY: 100
+            contentWidth: 400
+            contentHeight: 400
+            boundsBehavior: Flickable.StopAtBounds
+
+            Rectangle {
+                anchors.fill: parent
+                anchors.margins: 100
+                color: "blue"
+            }
+        }
+    }
+}
diff --git a/tests/auto/declarative/qdeclarativeflickable/tst_qdeclarativeflickable.cpp b/tests/auto/declarative/qdeclarativeflickable/tst_qdeclarativeflickable.cpp
index d36e96f9..b0fa7bd6 100644
--- a/tests/auto/declarative/qdeclarativeflickable/tst_qdeclarativeflickable.cpp
+++ b/tests/auto/declarative/qdeclarativeflickable/tst_qdeclarativeflickable.cpp
@@ -75,6 +75,8 @@ private slots:
     void testQtQuick11Attributes_data();
     void wheel();
     void flickVelocity();
+    void nestedStopAtBounds();
+    void nestedStopAtBounds_data();
 
 private:
     QDeclarativeEngine engine;
@@ -524,6 +526,80 @@ void tst_qdeclarativeflickable::flick(QGraphicsView *canvas, const QPoint &from,
     QTest::mouseRelease(canvas->viewport(), Qt::LeftButton, 0, canvas->mapFromScene(to));
 }
 
+void tst_qdeclarativeflickable::nestedStopAtBounds_data()
+{
+    QTest::addColumn<bool>("transpose");
+    QTest::addColumn<bool>("invert");
+
+    QTest::newRow("left") << false << false;
+    QTest::newRow("right") << false << true;
+    QTest::newRow("top") << true << false;
+    QTest::newRow("bottom") << true << true;
+}
+
+void tst_qdeclarativeflickable::nestedStopAtBounds()
+{
+    QFETCH(bool, transpose);
+    QFETCH(bool, invert);
+
+    QDeclarativeView view;
+    view.setSource(QUrl::fromLocalFile(SRCDIR "/data/nestedStopAtBounds.qml"));
+    view.show();
+    view.activateWindow();
+    QVERIFY(QTest::qWaitForWindowExposed(&view));
+    QVERIFY(view.rootObject());
+
+    QDeclarativeFlickable *outer =  qobject_cast<QDeclarativeFlickable*>(view.rootObject());
+    QVERIFY(outer);
+
+    QDeclarativeFlickable *inner = outer->findChild<QDeclarativeFlickable*>("innerFlickable");
+    QVERIFY(inner);
+    inner->setFlickableDirection(transpose ? QDeclarativeFlickable::VerticalFlick : QDeclarativeFlickable::HorizontalFlick);
+    inner->setContentX(invert ? 0 : 100);
+    inner->setContentY(invert ? 0 : 100);
+
+    const int threshold = QApplication::startDragDistance();
+
+    QPoint position(200, 200);
+    int &axis = transpose ? position.ry() : position.rx();
+
+    QGraphicsSceneMouseEvent moveEvent(QEvent::GraphicsSceneMouseMove);
+    moveEvent.setButton(Qt::LeftButton);
+    moveEvent.setButtons(Qt::LeftButton);
+
+    // drag toward the aligned boundary.  Outer mouse area dragged.
+    QTest::mousePress(view.viewport(), Qt::LeftButton, 0, position);
+    QTest::qWait(10);
+    axis += invert ? threshold * 2 : -threshold * 2;
+    moveEvent.setScenePos(position);
+    QApplication::sendEvent(view.scene(), &moveEvent);
+    axis += invert ? threshold : -threshold;
+    moveEvent.setScenePos(position);
+    QApplication::sendEvent(view.scene(), &moveEvent);
+    QVERIFY(outer->contentX() != 50 || outer->contentY() != 50);
+    QVERIFY((inner->contentX() == 0 || inner->contentX() == 100)
+            && (inner->contentY() == 0 || inner->contentY() == 100));
+    QTest::mouseRelease(view.viewport(), Qt::LeftButton, 0, position);
+
+    axis = 200;
+    outer->setContentX(50);
+    outer->setContentY(50);
+
+    // drag away from the aligned boundary.  Inner mouse area dragged.
+    QTest::mousePress(view.viewport(), Qt::LeftButton, 0, position);
+    QTest::qWait(10);
+    axis += invert ? -threshold * 2 : threshold * 2;
+    moveEvent.setScenePos(position);
+    QApplication::sendEvent(view.scene(), &moveEvent);
+    axis += invert ? -threshold : threshold;
+    moveEvent.setScenePos(position);
+    QApplication::sendEvent(view.scene(), &moveEvent);
+    QVERIFY(outer->contentX() == 50 && outer->contentY() == 50);
+    QVERIFY((inner->contentX() != 0 && inner->contentX() != 100)
+            || (inner->contentY() != 0 && inner->contentY() != 100));
+    QTest::mouseRelease(view.viewport(), Qt::LeftButton, 0, position);
+}
+
 template<typename T>
 T *tst_qdeclarativeflickable::findItem(QGraphicsObject *parent, const QString &objectName)
 {
diff --git a/tests/auto/declarative/qdeclarativemousearea/tst_qdeclarativemousearea.cpp b/tests/auto/declarative/qdeclarativemousearea/tst_qdeclarativemousearea.cpp
index 855ad602..37e64d4d 100644
--- a/tests/auto/declarative/qdeclarativemousearea/tst_qdeclarativemousearea.cpp
+++ b/tests/auto/declarative/qdeclarativemousearea/tst_qdeclarativemousearea.cpp
@@ -597,8 +597,8 @@ void tst_QDeclarativeMouseArea::preventStealing()
     QVERIFY(!mouseArea->pressed());
 
     // Flickable content should have moved.
-    QCOMPARE(flickable->contentX(), 15.);
-    QCOMPARE(flickable->contentY(), 15.);
+    QCOMPARE(flickable->contentX(), 30.);
+    QCOMPARE(flickable->contentY(), 30.);
 
     QTest::mouseRelease(canvas->viewport(), Qt::LeftButton, 0, canvas->mapFromScene(QPoint(50, 50)));