Fixed MouseArea threshold with preventStealing

When preventStealing is true both keepMouseGrab() and
d->stealMouse are true. This in turn enable the dragging immediately
since the condition "keepMouseGrab() && d->stealMouse && !d->drag->active()"
is true.
Conversely when preventStealing is false the dragging is enabled in the
next move event since keepMouseGrab() and d->stealMouse are set true
inside the last "if" "!keepMouseGrab() && ...check threshold..".
This patch adds a new boolean flag for storing if we detected a drag motion
(so we exceeded the threshold) and enable the dragging iff this flag is true.
With this change:
- if preventStealing is true (and so keepMouseGrab() and d->stealMouse) the
additional d->overThresHold prevent the start of dragging. At the same time
the last if (!keepMouseGrab()) cannot be executed since keepMouseGrab is true
and we still check for the threshold being exceeded.
- if preventStealing is false, we still check for exceeding the threshold and
if this happen we enter in the last "if" since !keepMousegrab() && d->overThreshold
is true taking the mouseGrab as without this patch

Task-number: QTBUG-52534
Change-Id: I2b14d3048b6f8223c90ce5e2fd26e7ca706cb56a
Reviewed-by: Michael Brasser <michael.brasser@live.com>
Reviewed-by: Robin Burchell <robin.burchell@viroteck.net>
Reviewed-by: Shawn Rutledge <shawn.rutledge@theqtcompany.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/tests/auto/quick/qquickmousearea/tst_qquickmousearea.cpp b/tests/auto/quick/qquickmousearea/tst_qquickmousearea.cpp
index 82c053d76a..9cdfd21f9c 100644
--- a/tests/auto/quick/qquickmousearea/tst_qquickmousearea.cpp
+++ b/tests/auto/quick/qquickmousearea/tst_qquickmousearea.cpp
@@ -79,6 +79,7 @@ private slots:
     void dragging_data() { acceptedButton_data(); }
     void dragging();
     void dragSmoothed();
+    void dragThreshold_data();
     void dragThreshold();
     void invalidDrag_data() { rejectedButton_data(); }
     void invalidDrag();
@@ -375,8 +376,17 @@ void tst_QQuickMouseArea::dragSmoothed()
     QTest::mouseRelease(&window, Qt::LeftButton, 0, QPoint(100, 122));
 }
 
+void tst_QQuickMouseArea::dragThreshold_data()
+{
+    QTest::addColumn<bool>("preventStealing");
+    QTest::newRow("without preventStealing") << false;
+    QTest::newRow("with preventStealing") << true;
+}
+
 void tst_QQuickMouseArea::dragThreshold()
 {
+    QFETCH(bool, preventStealing);
+
     QQuickView window;
     QByteArray errorMessage;
     QVERIFY2(initView(window, testFileUrl("dragging.qml"), true, &errorMessage), errorMessage.constData());
@@ -386,6 +396,7 @@ void tst_QQuickMouseArea::dragThreshold()
     QVERIFY(window.rootObject() != 0);
 
     QQuickMouseArea *mouseRegion = window.rootObject()->findChild<QQuickMouseArea*>("mouseregion");
+    mouseRegion->setPreventStealing(preventStealing);
     QQuickDrag *drag = mouseRegion->drag();
 
     drag->setThreshold(5);