private void AddChild(GraphElement child)
{
// Remove all holes from the sibling index list. Now the max index
// number is equal to the size of the children list.
this.EnsureSequentialSiblingIndex();
this.needSortChildren = true; // maybe false
child.siblingIndex = this.childCount;
//this.children.Add(child);
if (this.childCount == this.children.Length)
{
GraphElement[] childs;
if (this.childCount == 0)
{
childs = new GraphElement[4];
}
else
{
childs = new GraphElement[2 * this.childCount];
Array.Copy(this.children, 0, childs, 0, this.childCount);
}
this.children = childs;
}
this.children[this.childCount++] = child;
this.OnChildAdded(child);
System.Drawing.RectangleF invalid = child.ChildrenBoundingBox();
invalid.Offset(child.X, child.Y);
this.Invalidate(invalid);
}
private void RemoveChild(GraphElement child)
{
// When removing elements in the middle of the children list,
// there will be a "gap" in the list of sibling indexes (0,1,3,4).
if (!this.holesInSiblingIndex)
{
this.holesInSiblingIndex
= child.siblingIndex != this.childCount - 1;
}
if (this.sequentialOrdering && !this.holesInSiblingIndex)
{
//this.children.RemoveAt(child.siblingIndex);
this.childCount--;
Array.Copy(this.children, child.siblingIndex + 1,
this.children, child.siblingIndex,
this.childCount - child.siblingIndex);
this.children[this.childCount] = null;
}
else
{
//this.children.Remove(child);
int i;
for (i = 0; i < this.childCount; i++)
{
if (this.children[i] == child)
{
break;
}
}
if (i < this.childCount)
{
this.childCount--;
Array.Copy(this.children, i + 1,
this.children, i, this.childCount - i);
this.children[this.childCount] = null;
}
}
// NB! Do not use children.RemoveAt(child.siblingIndex) because
// the child is not guaranteed to be at the index after the list is sorted.
// (see ensureSortedChildren()).
child.siblingIndex = -1;
this.OnChildRemoved(child);
System.Drawing.RectangleF invalid = child.ChildrenBoundingBox();
invalid.Offset(child.X, child.Y);
this.Invalidate(invalid);
}