Improve emission of FocusScope focusChanged signals.

Emit activeFocusChanged up the focus tree when an item receives a focus
event, rather than when the focusItem changes which happens before
internal state is sufficiently updated for hasFocus and hasActiveFocus
to return the correct values from within a changed signal handler.

There are some limitions to this. First the signals are not emitted
reliably when the scene is not active which makes sense for activeFocus
but not for focus.  The second is in some instances the focus and
activeFocus can update unnecessarily while the focus chain sorts itself
out.

QDeclarativeItem tests by Andreas Aardal Hanssen <andreas@hanssen.name>

Task-number: QTBUG-28288
Task-number: QTBUG-25644

Change-Id: Ib3d17c42754c15a08b34c3388f50b45cc1d2a831
Reviewed-by: Andreas Aardal Hanssen <andreas@hanssen.name>
Reviewed-by: Alan Alpert <aalpert@rim.com>

2 files changed, 29 insertions, 18 deletions

diff --git a/src/declarative/graphicsitems/qdeclarativeitem.cpp b/src/declarative/graphicsitems/qdeclarativeitem.cpp
index 99b3857d..c3bb5d9f 100644
--- a/src/declarative/graphicsitems/qdeclarativeitem.cpp
+++ b/src/declarative/graphicsitems/qdeclarativeitem.cpp
@@ -2744,9 +2744,27 @@ QDeclarativeItem *QDeclarativeItem::childAt(qreal x, qreal y) const
 void QDeclarativeItemPrivate::focusChanged(bool flag)
 {
     Q_Q(QDeclarativeItem);
-    if (!(flags & QGraphicsItem::ItemIsFocusScope) && parent)
-        emit q->activeFocusChanged(flag);   //see also QDeclarativeItemPrivate::subFocusItemChange()
-    emit q->focusChanged(flag);
+
+    if (hadActiveFocus != flag) {
+        hadActiveFocus = flag;
+        emit q->activeFocusChanged(flag);
+    }
+
+    QDeclarativeItem *focusItem = q;
+    for (QDeclarativeItem *p = q->parentItem(); p; p = p->parentItem()) {
+        if (p->flags() & QGraphicsItem::ItemIsFocusScope) {
+            if (!flag && QGraphicsItemPrivate::get(p)->focusScopeItem != focusItem)
+                break;
+            if (p->d_func()->hadActiveFocus != flag) {
+                p->d_func()->hadActiveFocus = flag;
+                emit p->activeFocusChanged(flag);
+            }
+            focusItem = p;
+        }
+    }
+
+    // For all but the top most focus scope/item this will be called for us by QGraphicsItem.
+    focusItem->d_func()->focusScopeItemChange(flag);
 }
 
 QDeclarativeListProperty<QObject> QDeclarativeItemPrivate::resources()
diff --git a/src/declarative/graphicsitems/qdeclarativeitem_p.h b/src/declarative/graphicsitems/qdeclarativeitem_p.h
index 8ef91887..20262307 100644
--- a/src/declarative/graphicsitems/qdeclarativeitem_p.h
+++ b/src/declarative/graphicsitems/qdeclarativeitem_p.h
@@ -128,8 +128,8 @@ public:
       componentComplete(true), keepMouse(false),
       smooth(false), transformOriginDirty(true), doneEventPreHandler(false),
       inheritedLayoutMirror(false), effectiveLayoutMirror(false), isMirrorImplicit(true),
-      inheritMirrorFromParent(false), inheritMirrorFromItem(false), keyHandler(0),
-      mWidth(0), mHeight(0), mImplicitWidth(0), mImplicitHeight(0), attachedLayoutDirection(0), hadSubFocusItem(false)
+      inheritMirrorFromParent(false), inheritMirrorFromItem(false), hadFocus(false), hadActiveFocus(false), keyHandler(0),
+      mWidth(0), mHeight(0), mImplicitWidth(0), mImplicitHeight(0), attachedLayoutDirection(0)
     {
         QGraphicsItemPrivate::acceptedMouseButtons = 0;
         isDeclarativeItem = 1;
@@ -289,6 +289,8 @@ public:
     bool isMirrorImplicit:1;
     bool inheritMirrorFromParent:1;
     bool inheritMirrorFromItem:1;
+    bool hadFocus:1;
+    bool hadActiveFocus:1;
 
     QDeclarativeItemKeyFilter *keyHandler;
 
@@ -299,7 +301,6 @@ public:
 
     QDeclarativeLayoutMirroringAttached* attachedLayoutDirection;
 
-    bool hadSubFocusItem;
 
     QPointF computeTransformOrigin() const;
 
@@ -312,22 +313,14 @@ public:
     }
 
     // Reimplemented from QGraphicsItemPrivate
-    virtual void subFocusItemChange()
-    {
-        bool hasSubFocusItem = subFocusItem != 0;
-        if (((flags & QGraphicsItem::ItemIsFocusScope) || !parent) && hasSubFocusItem != hadSubFocusItem)
-            emit q_func()->activeFocusChanged(hasSubFocusItem);
-        //see also QDeclarativeItemPrivate::focusChanged
-        hadSubFocusItem = hasSubFocusItem;
-    }
-
-    // Reimplemented from QGraphicsItemPrivate
     virtual void focusScopeItemChange(bool isSubFocusItem)
     {
-        emit q_func()->focusChanged(isSubFocusItem);
+        if (hadFocus != isSubFocusItem) {
+            hadFocus = isSubFocusItem;
+            emit q_func()->focusChanged(isSubFocusItem);
+        }
     }
 
-
     // Reimplemented from QGraphicsItemPrivate
     virtual void siblingOrderChange()
     {