Add QGraphicsItem::ItemAutoDetectsFocusProxy and improve subfocus support.

If you set this flag on an item, and descendant item that gains input
focus will become this item's focus proxy. This simplifies how focus
proxy items are assigned from QML; instead of binding the possible
focusProxy property to a named child widget, this assignment happens
automatically as you set the focus property of a descendant to true.

As part of this change, QGraphicsWidget::focusWidget behavior has been
improved and moved into QGraphicsItem. For example, if you set focus on
an item that it's part of a scene, it can gain focus once the parent
has been assigned (which is how object trees are built in QML).

Autotests are included.

Reviewed-by: Michael Brasser

1 files changed, 7 insertions, 2 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem_p.h b/src/gui/graphicsview/qgraphicsitem_p.h
index 1cf188e..c208b99 100644
--- a/src/gui/graphicsview/qgraphicsitem_p.h
+++ b/src/gui/graphicsview/qgraphicsitem_p.h
@@ -123,6 +123,7 @@ public:
         siblingIndex(-1),
         depth(0),
         focusProxy(0),
+        subFocusItem(0),
         acceptedMouseButtons(0x1f),
         visible(1),
         explicitlyHidden(0),
@@ -391,6 +392,9 @@ public:
                || (childrenCombineOpacity() && isFullyTransparent());
     }
 
+    void setSubFocus();
+    void clearSubFocus();
+
     inline QTransform transformToParent() const;
     inline void ensureSortedChildren();
 
@@ -411,6 +415,7 @@ public:
     int siblingIndex;
     int depth;
     QGraphicsItem *focusProxy;
+    QGraphicsItem *subFocusItem;
 
     // Packed 32 bytes
     quint32 acceptedMouseButtons : 5;
@@ -440,7 +445,7 @@ public:
 
     // New 32 bits
     quint32 fullUpdatePending : 1;
-    quint32 flags : 13;
+    quint32 flags : 14;
     quint32 dirtyChildrenBoundingRect : 1;
     quint32 paintedViewBoundingRectsNeedRepaint : 1;
     quint32 dirtySceneTransform : 1;
@@ -453,7 +458,7 @@ public:
     quint32 acceptedTouchBeginEvent : 1;
     quint32 filtersDescendantEvents : 1;
     quint32 sceneTransformTranslateOnly : 1;
-    quint32 unused : 6; // feel free to use
+    quint32 unused : 5; // feel free to use
 
     // Optional stacking order
     int globalStackingOrder;