SwipeDelegate: fix swipes that begin over a child item of a delegate

If the mouse was pressed over a child item of the delegate, the event's
position will be for that item, rather than the entire control. To
fix this, we need to set the correct pressPoint. To avoid duplicating
QQuickAbstractButton::mousePressEvent()'s code, we simply set the
correct pressPoint after calling it in
QQuickSwipeDelegatePrivate::handleMousePressEvent().

Task-number: QTBUG-57271
Change-Id: I7204d6176c755512eeeb0b1a57a920fbab40392c
Reviewed-by: J-P Nurmi <jpnurmi@qt.io>

2 files changed, 79 insertions, 0 deletions

diff --git a/src/quicktemplates2/qquickswipedelegate.cpp b/src/quicktemplates2/qquickswipedelegate.cpp
index 743f38ff..5430a4de 100644
--- a/src/quicktemplates2/qquickswipedelegate.cpp
+++ b/src/quicktemplates2/qquickswipedelegate.cpp
@@ -598,6 +598,10 @@ bool QQuickSwipeDelegatePrivate::handleMousePressEvent(QQuickItem *item, QMouseE
     // events will go through the regular channels (mousePressEvent()) until then.
     if (qFuzzyIsNull(swipePrivate->position)) {
         q->mousePressEvent(event);
+        // The press point could be incorrect if the press happened over a child item,
+        // so we correct it after calling the base class' mousePressEvent(), rather
+        // than having to duplicate its code just so we can set the pressPoint.
+        pressPoint = item->mapToItem(q, event->pos());
         return true;
     }
 
diff --git a/tests/auto/controls/data/tst_swipedelegate.qml b/tests/auto/controls/data/tst_swipedelegate.qml
index 42bbd00b..92f25e2a 100644
--- a/tests/auto/controls/data/tst_swipedelegate.qml
+++ b/tests/auto/controls/data/tst_swipedelegate.qml
@@ -1292,4 +1292,79 @@ TestCase {
         mouseRelease(control, control.width + 10, control.height / 2, Qt.LeftButton);
         verify(mouseSignalSequenceSpy.success);
     }
+
+    Component {
+        id: leftRightWithLabelsComponent
+
+        SwipeDelegate {
+            id: delegate
+            text: "SwipeDelegate"
+            width: 150
+
+            background.opacity: 0.5
+
+            swipe.left: Rectangle {
+                width: parent.width
+                height: parent.height
+                color: SwipeDelegate.pressed ? Qt.darker("green") : "green"
+
+                property alias label: label
+
+                Label {
+                    id: label
+                    text: "Left"
+                    color: "white"
+                    anchors.margins: 10
+                    anchors.left: parent.left
+                    anchors.verticalCenter: parent.verticalCenter
+                }
+
+                SwipeDelegate.onClicked: delegate.swipe.close()
+            }
+
+            swipe.right: Rectangle {
+                width: parent.width
+                height: parent.height
+                anchors.right: parent.right
+                color: SwipeDelegate.pressed ? Qt.darker("green") : "red"
+
+                property alias label: label
+
+                Label {
+                    id: label
+                    text: "Right"
+                    color: "white"
+                    anchors.margins: 10
+                    anchors.right: parent.right
+                    anchors.verticalCenter: parent.verticalCenter
+                }
+
+                SwipeDelegate.onClicked: delegate.swipe.close()
+            }
+        }
+    }
+
+    function test_beginSwipeOverRightItem() {
+        var control = leftRightWithLabelsComponent.createObject(testCase);
+        verify(control);
+
+        // Swipe to the left, exposing the right item.
+        swipe(control, 0.0, -1.0);
+
+        // Click to close it and go back to a position of 0.
+        mouseClick(control);
+
+        // TODO: Swipe to the left, with the mouse over the Label in the right item.
+        // The left item should not become visible at any point.
+        var rightLabel = control.swipe.rightItem.label;
+        var overDragDistance = Math.round(dragDistance * 1.1);
+        mousePress(rightLabel, rightLabel.width / 2, rightLabel.height / 2, Qt.rightButton);
+        mouseMove(rightLabel, rightLabel.width / 2 - overDragDistance, rightLabel.height / 2, Qt.LeftButton);
+        verify(!control.swipe.leftItem);
+
+        mouseRelease(rightLabel, rightLabel.width / 2 - overDragDistance, control.height / 2, Qt.LeftButton);
+        verify(!control.swipe.leftItem);
+
+        control.destroy();
+    }
 }