// Demand creates a TextContainer if no tree is associated with this instance.
// Otherwise returns the exisiting tree, and clears the tree's DeadPositionList.
private TextContainer EnsureTextContainer()
{
TextContainer tree;
TextPointer start;
if (this.IsInTree)
{
tree = _textElementNode.GetTextTree();
tree.EmptyDeadPositionList();
}
else
{
tree = new TextContainer(null, false /* plainTextOnly */);
start = tree.Start;
tree.BeginChange();
try
{
tree.InsertElementInternal(start, start, this);
}
finally
{
// No event will be raised, since we know there are no listeners yet!
tree.EndChange();
}
Invariant.Assert(this.IsInTree);
}
return tree;
}
