internal void RemoveOrphans(UIElement parent)
{
Request r = _head;
while (r != null)
{
UIElement child = r.Target;
Request next = r.Next;
ulong parentTreeLevel = parent.TreeLevel;
if ((child.TreeLevel == parentTreeLevel + 1) &&
(child.GetUIParentWithinLayoutIsland() == parent))
{
_removeRequest(getRequest(child));
setRequest(child, null);
}
r = next;
}
}
internal void Add(UIElement e)
{
if (getRequest(e) != null)
{
return;
}
if (e.CheckFlagsAnd(VisualFlags.IsLayoutSuspended))
{
return;
}
RemoveOrphans(e);
UIElement parent = e.GetUIParentWithinLayoutIsland();
if (parent != null && canRelyOnParentRecalc(parent))
{
return;
}
ContextLayoutManager layoutManager = ContextLayoutManager.From(e.Dispatcher);
if (layoutManager._isDead)
{
return;
}
//10 is arbitrary number here, simply indicates the queue is
//about to be filled. If not queue is not almost full, simply add
//the element to it. If it is almost full, start conserve entries
//by escalating invalidation to all the ancestors until the top of
//the visual tree, and only add root of visula tree to the queue.
if (_pocketSize > PocketReserve)
{
_addRequest(e);
}
else
{
//walk up until we are the topmost UIElement in the tree.
//on each step, mark the parent dirty and remove it from the queues
//only leave a single node in the queue - the root of visual tree
while (e != null)
{
UIElement p = e.GetUIParentWithinLayoutIsland();
invalidate(e); //invalidate in any case
if (p != null && p.Visibility != Visibility.Collapsed) //not yet a root or a collapsed node
{
Remove(e);
}
else //root of visual tree or a collapsed node
{
if (getRequest(e) == null)
{
RemoveOrphans(e);
_addRequest(e);
}
}
e = p;
}
}
layoutManager.NeedsRecalc();
}
internal void Add(UIElement e)
{
if(getRequest(e) != null) return;
if(e.CheckFlagsAnd(VisualFlags.IsLayoutSuspended)) return;
RemoveOrphans(e);
UIElement parent = e.GetUIParentWithinLayoutIsland();
if(parent != null && canRelyOnParentRecalc(parent)) return;
ContextLayoutManager layoutManager = ContextLayoutManager.From(e.Dispatcher);
if(layoutManager._isDead) return;
//10 is arbitrary number here, simply indicates the queue is
//about to be filled. If not queue is not almost full, simply add
//the element to it. If it is almost full, start conserve entries
//by escalating invalidation to all the ancestors until the top of
//the visual tree, and only add root of visula tree to the queue.
if(_pocketSize > PocketReserve)
{
_addRequest(e);
}
else
{
//walk up until we are the topmost UIElement in the tree.
//on each step, mark the parent dirty and remove it from the queues
//only leave a single node in the queue - the root of visual tree
while(e != null)
{
UIElement p = e.GetUIParentWithinLayoutIsland();
invalidate(e); //invalidate in any case
if (p != null) //not yet a root
{
Remove(e);
}
else //root of visual tree
{
if (getRequest(e) == null)
{
RemoveOrphans(e);
_addRequest(e);
}
}
e = p;
}
}
layoutManager.NeedsRecalc();
}