Ensure hover enter events are dispatched on mouse press.

This change ensures that mouse presses received by the scene when there
are no current mouse grabbers trigger hover event delivery. This is
useful when the scene only receives presses, and no mouse moves (e.g.,
disabling mouse tracking on the viewport, or on systems where the
mouse press is the first received event).

Reviewed-by: Michael Brasser

2 files changed, 76 insertions, 0 deletions

diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index e54efe040f..a846cf6801 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -3682,6 +3682,13 @@ void QGraphicsScene::keyReleaseEvent(QKeyEvent *keyEvent)
 void QGraphicsScene::mousePressEvent(QGraphicsSceneMouseEvent *mouseEvent)
 {
     Q_D(QGraphicsScene);
+    if (d->mouseGrabberItems.isEmpty()) {
+        // Dispatch hover events
+        QGraphicsSceneHoverEvent hover;
+        _q_hoverFromMouseEvent(&hover, mouseEvent);
+        d->dispatchHoverEvent(&hover);
+    }
+
     d->mousePressEventHandler(mouseEvent);
 }
 
diff --git a/tests/auto/qgraphicsscene/tst_qgraphicsscene.cpp b/tests/auto/qgraphicsscene/tst_qgraphicsscene.cpp
index f7ea4cecc8..4ef1cdd80f 100644
--- a/tests/auto/qgraphicsscene/tst_qgraphicsscene.cpp
+++ b/tests/auto/qgraphicsscene/tst_qgraphicsscene.cpp
@@ -255,6 +255,7 @@ private slots:
     void sendEvent();
     void inputMethod_data();
     void inputMethod();
+    void dispatchHoverOnPress();
 
     // task specific tests below me
     void task139710_bspTreeCrash();
@@ -3719,5 +3720,73 @@ void tst_QGraphicsScene::inputMethod()
     QCOMPARE(item->queryCalls, 0);
 }
 
+void tst_QGraphicsScene::dispatchHoverOnPress()
+{
+    QGraphicsScene scene;
+    EventTester *tester1 = new EventTester;
+    tester1->setAcceptHoverEvents(true);
+    EventTester *tester2 = new EventTester;
+    tester2->setAcceptHoverEvents(true);
+    tester2->setPos(30, 30);
+    scene.addItem(tester1);
+    scene.addItem(tester2);
+
+    tester1->eventTypes.clear();
+    tester2->eventTypes.clear();
+
+    {
+        QGraphicsSceneMouseEvent me(QEvent::GraphicsSceneMousePress);
+        me.setButton(Qt::LeftButton);
+        me.setButtons(Qt::LeftButton);
+        QGraphicsSceneMouseEvent me2(QEvent::GraphicsSceneMouseRelease);
+        me2.setButton(Qt::LeftButton);
+        qApp->sendEvent(&scene, &me);
+        qApp->sendEvent(&scene, &me2);
+        QCOMPARE(tester1->eventTypes, QList<QEvent::Type>()
+                 << QEvent::GraphicsSceneHoverEnter
+                 << QEvent::GraphicsSceneHoverMove
+                 << QEvent::GrabMouse
+                 << QEvent::GraphicsSceneMousePress
+                 << QEvent::UngrabMouse);
+        tester1->eventTypes.clear();
+        qApp->sendEvent(&scene, &me);
+        qApp->sendEvent(&scene, &me2);
+        QCOMPARE(tester1->eventTypes, QList<QEvent::Type>()
+                 << QEvent::GraphicsSceneHoverMove
+                 << QEvent::GrabMouse
+                 << QEvent::GraphicsSceneMousePress
+                 << QEvent::UngrabMouse);
+    }
+    {
+        QGraphicsSceneMouseEvent me(QEvent::GraphicsSceneMousePress);
+        me.setScenePos(QPointF(30, 30));
+        me.setButton(Qt::LeftButton);
+        me.setButtons(Qt::LeftButton);
+        QGraphicsSceneMouseEvent me2(QEvent::GraphicsSceneMouseRelease);
+        me2.setScenePos(QPointF(30, 30));
+        me2.setButton(Qt::LeftButton);
+        tester1->eventTypes.clear();
+        qApp->sendEvent(&scene, &me);
+        qApp->sendEvent(&scene, &me2);
+        qDebug() << tester1->eventTypes;
+        QCOMPARE(tester1->eventTypes, QList<QEvent::Type>()
+                 << QEvent::GraphicsSceneHoverLeave);
+        QCOMPARE(tester2->eventTypes, QList<QEvent::Type>()
+                 << QEvent::GraphicsSceneHoverEnter
+                 << QEvent::GraphicsSceneHoverMove
+                 << QEvent::GrabMouse
+                 << QEvent::GraphicsSceneMousePress
+                 << QEvent::UngrabMouse);
+        tester2->eventTypes.clear();
+        qApp->sendEvent(&scene, &me);
+        qApp->sendEvent(&scene, &me2);
+        QCOMPARE(tester2->eventTypes, QList<QEvent::Type>()
+                 << QEvent::GraphicsSceneHoverMove
+                 << QEvent::GrabMouse
+                 << QEvent::GraphicsSceneMousePress
+                 << QEvent::UngrabMouse);
+    }
+}
+
 QTEST_MAIN(tst_QGraphicsScene)
 #include "tst_qgraphicsscene.moc"