// Returns the index of an entry in the list, or -1 if not present.
// Caller must hold a lock on _cleanParentList!
private static int GetCleanParentIndex(DependencyObject parent, object collection, out int firstFreeIndex)
{
int index = -1;
firstFreeIndex = -1;
for (int i = 0; i < _cleanParentList.Length; i++)
{
if (_cleanParentList[i] == null)
{
if (firstFreeIndex == -1)
{
firstFreeIndex = i;
}
}
else
{
ParentCollectionPair pair = (ParentCollectionPair)_cleanParentList[i].Target;
if (pair == null)
{
// WeakReference is dead, remove it.
_cleanParentList[i] = null;
if (firstFreeIndex == -1)
{
firstFreeIndex = i;
}
}
else if (pair.Parent == parent && pair.Collection == collection)
{
// Found a match. Keep going to clean up any dead WeakReferences
// or set firstFreeIndex.
index = i;
}
}
}
return(index);
}
//-------------------------------------------------------------------
//
// Internal Methods
//
//-------------------------------------------------------------------
#region Internal Methods
// Invalidates any collection tracking parent's children.
// Called by the TextContainer.
internal static void MarkDirty(DependencyObject parent)
{
if (parent == null)
{
return;
}
lock (_cleanParentList)
{
for (int i = 0; i < _cleanParentList.Length; i++)
{
if (_cleanParentList[i] != null)
{
ParentCollectionPair pair = (ParentCollectionPair)_cleanParentList[i].Target;
if (pair == null || pair.Parent == parent)
{
_cleanParentList[i] = null;
}
}
}
}
}
