MouseArea: use current value of drag.axis

If the drag.axis is changed while a drag operation is in progress, put
it into action immediately. This allows, for example, start a dragging
operation out of an item in a scrollable ListView to anywhere on the
screen.
See the linked bug number for an example.

Task-number: QTBUG-26440
Change-Id: I4ffa71c08b97a767aec7f69d19271000a2631327
Reviewed-by: Rick Stockton <rickstockton@reno-computerhelp.com>
Reviewed-by: Andrew den Exter <andrew.den-exter@nokia.com>

2 files changed, 101 insertions, 0 deletions

diff --git a/tests/auto/declarative/qdeclarativemousearea/data/changeAxis.qml b/tests/auto/declarative/qdeclarativemousearea/data/changeAxis.qml
new file mode 100644
index 00000000..45613b9b
--- /dev/null
+++ b/tests/auto/declarative/qdeclarativemousearea/data/changeAxis.qml
@@ -0,0 +1,22 @@
+import QtQuick 1.0
+Rectangle {
+    id: whiteRect
+    width: 200
+    height: 200
+    color: "white"
+    Rectangle {
+        id: blackRect
+        objectName: "blackrect"
+        color: "black"
+        y: 50
+        x: 50
+        width: 100
+        height: 100
+        MouseArea {
+            objectName: "mouseregion"
+            anchors.fill: parent
+            drag.target: blackRect
+            drag.axis: blackRect.x <= 75 ? Drag.XandYAxis : Drag.YAxis
+         }
+     }
+ }
diff --git a/tests/auto/declarative/qdeclarativemousearea/tst_qdeclarativemousearea.cpp b/tests/auto/declarative/qdeclarativemousearea/tst_qdeclarativemousearea.cpp
index 811fcd46..e81e01cb 100644
--- a/tests/auto/declarative/qdeclarativemousearea/tst_qdeclarativemousearea.cpp
+++ b/tests/auto/declarative/qdeclarativemousearea/tst_qdeclarativemousearea.cpp
@@ -75,6 +75,7 @@ private slots:
 #ifndef QT_NO_CONTEXTMENU
     void preventContextMenu();
 #endif // QT_NO_CONTEXTMENU
+    void changeAxis();
 
 private:
     QDeclarativeView *createView();
@@ -702,6 +703,84 @@ void tst_QDeclarativeMouseArea::preventContextMenu()
 }
 #endif // QT_NO_CONTEXTMENU
 
+void tst_QDeclarativeMouseArea::changeAxis()
+{
+    QDeclarativeView *canvas = createView();
+
+    canvas->setSource(QUrl::fromLocalFile(SRCDIR "/data/changeAxis.qml"));
+    canvas->show();
+    canvas->setFocus();
+    QVERIFY(canvas->rootObject() != 0);
+
+    QDeclarativeMouseArea *mouseRegion = canvas->rootObject()->findChild<QDeclarativeMouseArea*>("mouseregion");
+    QDeclarativeDrag *drag = mouseRegion->drag();
+    QVERIFY(mouseRegion != 0);
+    QVERIFY(drag != 0);
+
+    // target
+    QDeclarativeItem *blackRect = canvas->rootObject()->findChild<QDeclarativeItem*>("blackrect");
+    QVERIFY(blackRect != 0);
+    QVERIFY(blackRect == drag->target());
+
+    QVERIFY(!drag->active());
+
+    // Start a diagonal drag
+    QGraphicsScene *scene = canvas->scene();
+    QGraphicsSceneMouseEvent pressEvent(QEvent::GraphicsSceneMousePress);
+    pressEvent.setScenePos(QPointF(100, 100));
+    pressEvent.setButton(Qt::LeftButton);
+    pressEvent.setButtons(Qt::LeftButton);
+    QApplication::sendEvent(scene, &pressEvent);
+
+    QGraphicsSceneMouseEvent moveEvent(QEvent::GraphicsSceneMouseMove);
+    moveEvent.setScenePos(QPointF(111, 111));
+    moveEvent.setButton(Qt::LeftButton);
+    moveEvent.setButtons(Qt::LeftButton);
+    QApplication::sendEvent(scene, &moveEvent);
+
+    moveEvent.setScenePos(QPointF(122, 122));
+    moveEvent.setButton(Qt::LeftButton);
+    moveEvent.setButtons(Qt::LeftButton);
+    QApplication::sendEvent(scene, &moveEvent);
+
+    QVERIFY(drag->active());
+    QCOMPARE(blackRect->x(), 72.0);
+    QCOMPARE(blackRect->y(), 72.0);
+    QCOMPARE(drag->axis(), QDeclarativeDrag::XandYAxis);
+
+    /* When blackRect.x becomes bigger than 75, the drag axis is change to
+     * Drag.YAxis by the QML code. Verify that this happens, and that the drag
+     * movement is effectively constrained to the Y axis. */
+    moveEvent.setScenePos(QPointF(133, 133));
+    moveEvent.setButton(Qt::LeftButton);
+    moveEvent.setButtons(Qt::LeftButton);
+    QApplication::sendEvent(scene, &moveEvent);
+
+    QCOMPARE(blackRect->x(), 83.0);
+    QCOMPARE(blackRect->y(), 83.0);
+    QCOMPARE(drag->axis(), QDeclarativeDrag::YAxis);
+
+    moveEvent.setScenePos(QPointF(144, 144));
+    moveEvent.setButton(Qt::LeftButton);
+    moveEvent.setButtons(Qt::LeftButton);
+    QApplication::sendEvent(scene, &moveEvent);
+
+    QCOMPARE(blackRect->x(), 83.0);
+    QCOMPARE(blackRect->y(), 94.0);
+
+    QGraphicsSceneMouseEvent releaseEvent(QEvent::GraphicsSceneMouseRelease);
+    releaseEvent.setScenePos(QPointF(144, 144));
+    releaseEvent.setButton(Qt::LeftButton);
+    releaseEvent.setButtons(Qt::LeftButton);
+    QApplication::sendEvent(scene, &releaseEvent);
+
+    QVERIFY(!drag->active());
+    QCOMPARE(blackRect->x(), 83.0);
+    QCOMPARE(blackRect->y(), 94.0);
+
+    delete canvas;
+}
+
 QTEST_MAIN(tst_QDeclarativeMouseArea)
 
 #include "tst_qdeclarativemousearea.moc"