// InsertElement worker. Adds a TextElement to the tree.
// If element is already in a tree, we remove it, do a deep copy of its content,
// and insert that too.
internal void InsertElementInternal(TextPointer startPosition, TextPointer endPosition, TextElement element)
{
TextTreeTextElementNode elementNode;
int symbolOffset;
int childSymbolCount;
TextPointer startEdgePosition;
TextPointer endEdgePosition;
char[] elementText;
ExtractChangeEventArgs extractChangeEventArgs;
DependencyObject parentLogicalNode;
bool newElementNode;
int deltaCharCount;
Invariant.Assert(!this.PlainTextOnly);
Invariant.Assert(startPosition.TextContainer == this);
Invariant.Assert(endPosition.TextContainer == this);
DemandCreateText();
startPosition.SyncToTreeGeneration();
endPosition.SyncToTreeGeneration();
bool scopesExistingContent = startPosition.CompareTo(endPosition) != 0;
BeforeAddChange();
// Remove element from any previous tree.
// When called from a public method we already checked all the
// illegal cases in CanInsertElementInternal.
if (element.TextElementNode != null)
{
// This element is already in a tree. Remove it!
bool sameTextContainer = (this == element.TextContainer);
if (!sameTextContainer)
{
// This is a cross-tree extract.
// We need to start a change block now, so that we can
// raise a Changing event inside ExtractElementInternal
// before raising the LogicalTree events below.
// We'll make an EndChange call to wrap up below.
element.TextContainer.BeginChange();
}
bool exceptionThrown = true;
try
{
// ExtractElementInternal will raise LogicalTree events which
// could raise exceptions from external code.
elementText = element.TextContainer.ExtractElementInternal(element, true /* deep */, out extractChangeEventArgs);
exceptionThrown = false;
}
finally
{
if (exceptionThrown && !sameTextContainer)
{
// If an exception is thrown, make sure we close the
// change block we opened above before unwinding.
element.TextContainer.EndChange();
}
}
elementNode = element.TextElementNode;
deltaCharCount = extractChangeEventArgs.ChildIMECharCount;
if (sameTextContainer)
{
// Re-[....] the TextPointers in case we just extracted from this tree.
startPosition.SyncToTreeGeneration();
endPosition.SyncToTreeGeneration();
// We must add the extract change now, before we move on to the insert.
// (When !sameTextContainer we want to delay the notification in the extract
// tree until the insert tree is in an accessible state, ie at the end of this method.)
extractChangeEventArgs.AddChange();
// Don't re-raise the change below.
extractChangeEventArgs = null;
}
newElementNode = false;
}
else
{
// Allocate a node in the tree to hold the element.
elementText = null;
elementNode = new TextTreeTextElementNode();
deltaCharCount = 0;
newElementNode = true;
extractChangeEventArgs = null;
}
parentLogicalNode = startPosition.GetLogicalTreeNode();
// Invalidate any TextElementCollection that depends on the parent.
// Make sure we do that before raising any public events.
TextElementCollectionHelper.MarkDirty(parentLogicalNode);
// Link the TextElement to the TextElementNode.
if (newElementNode)
{
elementNode.TextElement = element;
element.TextElementNode = (TextTreeTextElementNode)elementNode;
}
// If the new element will become the parent of an old element,
// the old element may become a firstIMEVisibleSibling.
TextTreeTextElementNode newFirstIMEVisibleNode = null;
int newFirstIMEVisibleNodeCharDelta = 0;
if (scopesExistingContent)
{
newFirstIMEVisibleNode = startPosition.GetAdjacentTextElementNodeSibling(LogicalDirection.Forward);
if (newFirstIMEVisibleNode != null)
{
newFirstIMEVisibleNodeCharDelta = -newFirstIMEVisibleNode.IMELeftEdgeCharCount;
newFirstIMEVisibleNode.IMECharCount += newFirstIMEVisibleNodeCharDelta;
}
}
// Attach the element node.
childSymbolCount = InsertElementToSiblingTree(startPosition, endPosition, elementNode);
// Add the edge char count to our delta. We couldn't get this before
// because it depends on the position of the element in the tree.
deltaCharCount += elementNode.IMELeftEdgeCharCount;
TextTreeTextElementNode formerFirstIMEVisibleNode = null;
int formerFirstIMEVisibleNodeCharDelta = 0;
if (element.IsFirstIMEVisibleSibling && !scopesExistingContent)
{
formerFirstIMEVisibleNode = (TextTreeTextElementNode)elementNode.GetNextNode();
if (formerFirstIMEVisibleNode != null)
{
// The following node was the former first ime visible sibling.
// It just moved, and gains an edge character.
formerFirstIMEVisibleNodeCharDelta = formerFirstIMEVisibleNode.IMELeftEdgeCharCount;
formerFirstIMEVisibleNode.IMECharCount += formerFirstIMEVisibleNodeCharDelta;
}
}
// Ancester nodes gain the two edge symbols.
UpdateContainerSymbolCount(elementNode.GetContainingNode(), /* symbolCount */ elementText == null ? 2 : elementText.Length, deltaCharCount + formerFirstIMEVisibleNodeCharDelta + newFirstIMEVisibleNodeCharDelta);
symbolOffset = elementNode.GetSymbolOffset(this.Generation);
if (newElementNode)
{
// Insert text to account for the element edges.
TextTreeText.InsertElementEdges(_rootNode.RootTextBlock, symbolOffset, childSymbolCount);
}
else
{
// element already has an existing child, just copy over the corresponding text.
TextTreeText.InsertText(_rootNode.RootTextBlock, symbolOffset, elementText);
}
NextGeneration(false /* deletedContent */);
// Handle undo.
TextTreeUndo.CreateInsertElementUndoUnit(this, symbolOffset, elementText != null /* deep */);
// If we extracted the TextElement from another tree, raise that event now.
// We can't raise this event any earlier, because prior to now _this_ tree
// is in an invalid state and this tree could be referenced by a listener
// to changes on the other tree.
if (extractChangeEventArgs != null)
{
// Announce the extract from the old tree.
// NB: we already Removed the element from the original logical tree with LogicalTreeHelper,
// and did a BeginChange above.
extractChangeEventArgs.AddChange();
extractChangeEventArgs.TextContainer.EndChange();
}
// Raise the public event for the insert into this tree.
// During document load we won't have listeners and we can save
// an allocation on every insert. This can easily save 1000's of allocations during boot.
if (this.HasListeners)
{
//
startEdgePosition = new TextPointer(this, elementNode, ElementEdge.BeforeStart);
if (childSymbolCount == 0 || elementText != null)
{
AddChange(startEdgePosition, elementText == null ? 2 : elementText.Length, deltaCharCount, PrecursorTextChangeType.ContentAdded);
}
else
{
endEdgePosition = new TextPointer(this, elementNode, ElementEdge.BeforeEnd);
AddChange(startEdgePosition, endEdgePosition, elementNode.SymbolCount,
elementNode.IMELeftEdgeCharCount, elementNode.IMECharCount - elementNode.IMELeftEdgeCharCount,
PrecursorTextChangeType.ElementAdded, null, false);
}
if (formerFirstIMEVisibleNodeCharDelta != 0)
{
RaiseEventForFormerFirstIMEVisibleNode(formerFirstIMEVisibleNode);
}
if (newFirstIMEVisibleNodeCharDelta != 0)
{
RaiseEventForNewFirstIMEVisibleNode(newFirstIMEVisibleNode);
}
}
// Insert the element into a Framework logical tree
element.BeforeLogicalTreeChange();
try
{
LogicalTreeHelper.AddLogicalChild(parentLogicalNode, element);
}
finally
{
element.AfterLogicalTreeChange();
}
// Reparent all children.
// We only need to do this if we created a new element node.
if (newElementNode)
{
ReparentLogicalChildren(elementNode, elementNode.TextElement, parentLogicalNode /* oldParent */);
}
// Notify the TextElement of a content change if it was moved to parent new content. This
// can happen when Runs get merged.
if (scopesExistingContent)
{
element.OnTextUpdated();
}
}