Return the correct type from Item::mapToItem/Item::mapFromItem.

Previously we were returning a JavaScript object with x/y/width/height
properties, instead of a point/rect. This meant that the type couldn't
be converted to a point/rect because we don't support duck typing,
where we would deduce the type based on the properties.

One example of a broken use case that this patch fixes is when QML is
unable to convert the return type to a point in a property declaration:

property point p: mouseArea.mapToItem(child, mouseArea.mouseX, mouseArea.mouseY)

Another is using the result of the function to pass to another function:

child.contains(mouseArea.mapToItem(child, mouseArea.mouseX, mouseArea.mouseY))

Change-Id: I3ce82f10175f904dd02c8af6b5e42cee14b2ebb2
Task-number: QTBUG-41452
Reviewed-by: Liang Qi <liang.qi@theqtcompany.com>
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/tests/auto/quick/qquickitem/data/contains.qml b/tests/auto/quick/qquickitem/data/contains.qml
new file mode 100644
index 0000000000..72fd8bdc91
--- /dev/null
+++ b/tests/auto/quick/qquickitem/data/contains.qml
@@ -0,0 +1,26 @@
+import QtQuick 2.3
+
+Item {
+    id: root
+    width: 300
+    height: 300
+
+    function childContainsViaMapToItem(x, y) {
+        var childLocalPos = root.mapToItem(child, x, y);
+        return child.contains(childLocalPos);
+    }
+
+    function childContainsViaMapFromItem(x, y) {
+        var childLocalPos = child.mapFromItem(root, x, y);
+        return child.contains(childLocalPos);
+    }
+
+    Item {
+        id: child
+        x: 50
+        y: 50
+        width: 50
+        height: 50
+    }
+}
+