SplitView: fix hoverable child items breaking handle hover state

Detect HoverEnter events by filtering the mouse events of child items,
and respond by clearing any hovered handle.

Change-Id: Ice7e7fe3cc4c9224064c2384cd832e4a7d91c4da
Fixes: QTBUG-79846
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

3 files changed, 71 insertions, 0 deletions

diff --git a/src/quicktemplates2/qquicksplitview.cpp b/src/quicktemplates2/qquicksplitview.cpp
index 45efdc75..219a6b08 100644
--- a/src/quicktemplates2/qquicksplitview.cpp
+++ b/src/quicktemplates2/qquicksplitview.cpp
@@ -80,6 +80,9 @@ QT_BEGIN_NAMESPACE
     \li \l{SplitHandle::pressed}{SplitHandle.pressed}
     \endlist
 
+    \note Handles should be purely visual and not handle events, as it can
+    interfere with their hovered and pressed states.
+
     The preferred size of items in a SplitView can be specified via
     \l{Item::}{implicitWidth} and \l{Item::}{implicitHeight} or
     \c SplitView.preferredWidth and \c SplitView.preferredHeight:
@@ -1091,6 +1094,7 @@ QQuickSplitView::QQuickSplitView(QQuickItem *parent)
     d->changeTypes |= QQuickItemPrivate::Visibility;
 
     setAcceptedMouseButtons(Qt::LeftButton);
+    setFiltersChildMouseEvents(true);
 }
 
 QQuickSplitView::QQuickSplitView(QQuickSplitViewPrivate &dd, QQuickItem *parent)
@@ -1100,6 +1104,7 @@ QQuickSplitView::QQuickSplitView(QQuickSplitViewPrivate &dd, QQuickItem *parent)
     d->changeTypes |= QQuickItemPrivate::Visibility;
 
     setAcceptedMouseButtons(Qt::LeftButton);
+    setFiltersChildMouseEvents(true);
 }
 
 QQuickSplitView::~QQuickSplitView()
@@ -1364,6 +1369,20 @@ void QQuickSplitView::hoverMoveEvent(QHoverEvent *event)
     d->updateHoveredHandle(hoveredItem);
 }
 
+bool QQuickSplitView::childMouseEventFilter(QQuickItem *item, QEvent *event)
+{
+    Q_D(QQuickSplitView);
+    qCDebug(qlcQQuickSplitViewMouse) << "childMouseEventFilter called with" << item << event;
+    if (event->type() != QEvent::HoverEnter)
+        return false;
+
+    // If a child item received a hover enter event, then it means our handle is no longer hovered.
+    // Handles should be purely visual and not accept hover events,
+    // so we should never get hover events for them here.
+    d->updateHoveredHandle(nullptr);
+    return false;
+}
+
 void QQuickSplitView::geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry)
 {
     Q_D(QQuickSplitView);
diff --git a/src/quicktemplates2/qquicksplitview_p.h b/src/quicktemplates2/qquicksplitview_p.h
index 99001615..2fa15588 100644
--- a/src/quicktemplates2/qquicksplitview_p.h
+++ b/src/quicktemplates2/qquicksplitview_p.h
@@ -99,6 +99,7 @@ protected:
 
     void componentComplete() override;
     void hoverMoveEvent(QHoverEvent *event) override;
+    bool childMouseEventFilter(QQuickItem *item, QEvent *event) override;
     void geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry) override;
 
     void itemAdded(int index, QQuickItem *item) override;
diff --git a/tests/auto/controls/data/tst_splitview.qml b/tests/auto/controls/data/tst_splitview.qml
index c125b99e..74e4c68e 100644
--- a/tests/auto/controls/data/tst_splitview.qml
+++ b/tests/auto/controls/data/tst_splitview.qml
@@ -2026,4 +2026,55 @@ TestCase {
         compare(control.repeater.count, 3)
         compare(control.contentChildren.length, 3)
     }
+
+    Component {
+        id: hoverableChildrenSplitViewComponent
+
+        SplitView {
+            handle: handleComponent
+            anchors.fill: parent
+
+            MouseArea {
+                objectName: "mouseArea1"
+                hoverEnabled: true
+
+                SplitView.preferredWidth: 200
+            }
+            MouseArea {
+                objectName: "mouseArea2"
+                hoverEnabled: true
+            }
+        }
+    }
+
+    function test_hoverableChilden() {
+        if (Qt.platform.pluginName === "offscreen" || Qt.platform.pluginName === "minimal")
+            skip("Mouse hovering not functional on offscreen/minimal platforms")
+
+        var control = createTemporaryObject(hoverableChildrenSplitViewComponent, testCase)
+        verify(control)
+
+        verify(isPolishScheduled(control))
+        verify(waitForItemPolished(control))
+
+        // Move the mouse over the handle.
+        var handles = findHandles(control)
+        var targetHandle = handles[0]
+        // Test fails if we don't do two moves for some reason...
+        mouseMove(targetHandle, targetHandle.width / 2, targetHandle.height / 2)
+        mouseMove(targetHandle, targetHandle.width / 2, targetHandle.height / 2)
+        verify(targetHandle.SplitHandle.hovered)
+
+        // Move the mouse to the MouseArea on the left. The handle should no longer be hovered.
+        mouseMove(control, 100, control.height / 2)
+        verify(!targetHandle.SplitHandle.hovered)
+
+        // Move the mouse back over the handle.
+        mouseMove(targetHandle, targetHandle.width / 2, targetHandle.height / 2)
+        verify(targetHandle.SplitHandle.hovered)
+
+        // Move the mouse to the MouseArea on the right. The handle should no longer be hovered.
+        mouseMove(control, control.width - 100, control.height / 2)
+        verify(!targetHandle.SplitHandle.hovered)
+    }
 }