HeightTreeNode InsertAfter(HeightTreeNode node, DocumentLine newLine)
{
HeightTreeNode newNode = new HeightTreeNode(newLine, defaultLineHeight);
if (node.right == null) {
if (node.lineNode.collapsedSections != null) {
// we are inserting directly after node - so copy all collapsedSections
// that do not end at node.
foreach (CollapsedLineSection cs in node.lineNode.collapsedSections) {
if (cs.End != node.documentLine)
newNode.AddDirectlyCollapsed(cs);
}
}
InsertAsRight(node, newNode);
} else {
node = node.right.LeftMost;
if (node.lineNode.collapsedSections != null) {
// we are inserting directly before node - so copy all collapsedSections
// that do not start at node.
foreach (CollapsedLineSection cs in node.lineNode.collapsedSections) {
if (cs.Start != node.documentLine)
newNode.AddDirectlyCollapsed(cs);
}
}
InsertAsLeft(node, newNode);
}
return newNode;
}
// node removal:
// a node in the middle of the tree is removed as following:
// its successor is removed
// it is replaced with its successor
void BeforeNodeRemove(HeightTreeNode removedNode)
{
Debug.Assert(removedNode.left == null || removedNode.right == null);
var collapsed = removedNode.collapsedSections;
if (collapsed != null) {
HeightTreeNode childNode = removedNode.left ?? removedNode.right;
if (childNode != null) {
foreach (CollapsedLineSection cs in collapsed)
childNode.AddDirectlyCollapsed(cs);
}
}
if (removedNode.parent != null)
MergeCollapsedSectionsIfPossible(removedNode.parent);
}
void MergeCollapsedSectionsIfPossible(HeightTreeNode node)
{
Debug.Assert(node != null);
if (inRemoval) {
nodesToCheckForMerging.Add(node);
return;
}
// now check if we need to merge collapsedSections together
bool merged = false;
var collapsedL = node.lineNode.collapsedSections;
if (collapsedL != null) {
for (int i = collapsedL.Count - 1; i >= 0; i--) {
CollapsedLineSection cs = collapsedL[i];
if (cs.Start == node.documentLine || cs.End == node.documentLine)
continue;
if (node.left == null
|| (node.left.collapsedSections != null && node.left.collapsedSections.Contains(cs)))
{
if (node.right == null
|| (node.right.collapsedSections != null && node.right.collapsedSections.Contains(cs)))
{
// all children of node contain cs: -> merge!
if (node.left != null) node.left.RemoveDirectlyCollapsed(cs);
if (node.right != null) node.right.RemoveDirectlyCollapsed(cs);
collapsedL.RemoveAt(i);
node.AddDirectlyCollapsed(cs);
merged = true;
}
}
}
if (collapsedL.Count == 0)
node.lineNode.collapsedSections = null;
}
if (merged && node.parent != null) {
MergeCollapsedSectionsIfPossible(node.parent);
}
}