QQuickItem: item stays pressed after DoubleClicks

Amends 72651a50f8.
This commit decided to ignore double clicks in the virtual
QQuickItem::mouseDoubleClickEvent().
If a subclass inheriting from QQuickItem wants to not ignore
a double click, it should override mouseDoubleClickEvent()
and handle the double click event accordingly.

Fix QQuickMouseArea::mouseDoubleClickEvent(QMouseEvent *event) to *not*
call the base implementation in QQuickItem after handling a double
click, because QQuickItem sets that double-click MouseEvent back to
the ignored state.

This was leading to weird behavior on platforms with touch
screens like Android or IOS where buttons "got stuck" after
a double click.

Fixes: QTBUG-112434
Fixes: QTBUG-109393
Pick-to: 6.5
Change-Id: I774189fbcb356b07336f35f053e05a12c34ce602
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>

src/quick/items/qquickmousearea.cpp

@@ -795,6 +795,11 @@ void QQuickMouseArea::mouseDoubleClickEvent(QMouseEvent *event)
             d->propagate(&me, QQuickMouseAreaPrivate::DoubleClick);
         if (d->pressed)
             d->doubleClick = d->isDoubleClickConnected() || me.isAccepted();
+
+        // do not call the base implementation if the event is accepted
+        // because it will revert the event back to ignored state
+        if (me.isAccepted())
+            return;
     }
     QQuickItem::mouseDoubleClickEvent(event);
 }

tests/auto/quick/pointerhandlers/mousearea_interop/data/doubleClickInMouseArea.qml

@@ -0,0 +1,23 @@
+import QtQuick
+import QtQuick.Controls
+import QtQuick.Window
+
+Rectangle {
+    width: 200; height: 200
+    color: mouseArea.pressed ? "red" : "orange"
+
+    Popup {
+        visible: true
+        closePolicy: Popup.NoAutoClose
+        width: 100
+        height: 100
+        contentItem: MouseArea {
+            id: mouseArea
+
+            anchors.fill: parent
+        }
+        background: Rectangle {
+            color: "green"
+        }
+    }
+}

tests/auto/quick/pointerhandlers/mousearea_interop/tst_mousearea_interop.cpp

@@ -32,6 +32,7 @@ private slots:
     void dragHandlerInSiblingStealingGrabFromMouseAreaViaTouch();
     void hoverHandlerDoesntHoverOnPress();
     void doubleClickInMouseAreaWithDragHandlerInGrandparent();
+    void doubleClickInMouseArea();
 
 private:
     void createView(QScopedPointer<QQuickView> &window, const char *fileName);
@@ -204,6 +205,26 @@ void tst_MouseAreaInterop::doubleClickInMouseAreaWithDragHandlerInGrandparent()
     QCOMPARE(dragActiveSpy.size(), 0);
 }
 
+void tst_MouseAreaInterop::doubleClickInMouseArea()
+{
+    QQuickView window;
+    QVERIFY(QQuickTest::showView(window, testFileUrl("doubleClickInMouseArea.qml")));
+
+    auto *ma = window.rootObject()->findChild<QQuickMouseArea *>();
+    QVERIFY(ma);
+    QSignalSpy doubleClickSpy(ma, &QQuickMouseArea::doubleClicked);
+    QSignalSpy longPressSpy(ma, &QQuickMouseArea::pressAndHold);
+    QPoint p = ma->mapToScene(ma->boundingRect().center()).toPoint();
+
+    // check with normal double click
+    QTest::mouseDClick(&window, Qt::LeftButton, Qt::NoModifier, p);
+    QCOMPARE(doubleClickSpy.count(), 1);
+
+    // wait enough time for a wrong long press to happen
+    QTest::qWait(QGuiApplication::styleHints()->mousePressAndHoldInterval() + 10);
+    QCOMPARE(longPressSpy.count(), 0);
+}
+
 QTEST_MAIN(tst_MouseAreaInterop)
 
 #include "tst_mousearea_interop.moc"