public static PreparedDecorationCollection Merge(PreparedDecorationCollection previous, PreparedDecorationCollection current, TextDelta td)
{
if (previous.mDecorations.Count == 0)
{
current.mDifferenceRange = current.Bounds();
return(current);
}
if (AreDecorationsSame(previous, current))
{
PreparedDecorationCollection merged = new PreparedDecorationCollection();
TextIndexList differenceRanges = new TextIndexList();
for (int i = 0; i < previous.Count; i++)
{
TextIndexList previousIndex = previous.Index(i);
TextIndexList currentIndex = current.Index(i);
TextIndex differenceRange = currentIndex.RangeDifferentFrom(previousIndex);
if (differenceRange != null && differenceRange.Length > 0)
{
differenceRanges.Add(differenceRange);
}
}
differenceRanges.Add(td.TextIndex);
merged.mDifferenceRange = differenceRanges.Bounds;
TextIndex activeArea = differenceRanges.Bounds;
if (activeArea != null)
{
for (int i = 0; i < previous.Count; i++)
{
TextIndexList currentIndex = current.Index(i);
TextIndexList projected = currentIndex.Projection(activeArea);
if (projected.IndexLengthUpperBound() > 0)// Are there and textindexes in projected that have a length > 0
{
merged.Add(current.Decoration(i), projected);
}
}
}
return(merged);
}
else
{
current.mAreDecorationsChanged = true;
return(current);
}
}
private static bool AreDecorationsSame(PreparedDecorationCollection previous, PreparedDecorationCollection current)
{
//please note that my comparison is by references to the Decorations
//Though a more thourough comparison could be made the trade off aginst this quicker comparison
//does not seem worhwhile
if (previous.Count == current.Count)
{
for (int i = 0; i < previous.Count; i++)
{
if (previous.Decoration(i) != current.Decoration(i))
{
return(false);
}
}
return(true);
}
else
{
return(false);
}
}
public void ApplyDecorations()
{
if (mDecorationInProgress)
{
return;
}
mDecorationInProgress = true;
string testText = this.Text;
if (testText.Trim() == "")//No text implies no need for decorations
{
mLastPrepared = new PreparedDecorationCollection();
mDecorationInProgress = false;;
return;
}
DecorationCollection dc = new DecorationCollection();
dc.Add(mDecorationScheme);
dc.Add(mDecorations);
PreparedDecorationCollection current = dc.Prepare(testText);
TextDelta td = new TextDelta(mLastText, testText);
if (td.DeltaType == TextDelta.EDeltaType.Insert || td.DeltaType == TextDelta.EDeltaType.Delete)
{
mLastPrepared.Shift(td.Start, td.DeltaLength);
}
PreparedDecorationCollection active = PreparedDecorationCollection.Merge(mLastPrepared, current, td);
//activeBounds refers to to the area where there a difference between the last and the current decorations
TextIndex activeBounds = active.DifferenceRange;
mLastPrepared = current;
if (mLastText != this.Text)
{
mUndoText = mLastText;
mLastText = this.Text;
}
if (activeBounds != null || active.AreDecorationsChanged)
{
//Prepare for decorating
int selStart = this.SelectionStart;
int selLength = this.SelectionLength;
Point origScroll = ScrollPosition;
LockWindowUpdate(this.Handle.ToInt32());
if (active.AreDecorationsChanged)
{
Select(0, testText.Length);
}
else
{
Select(activeBounds.Start, activeBounds.Length);
}
this.SelectionColor = this.ForeColor;
this.SelectionBackColor = this.BackColor;
for (int i = 0; i < active.Count; i++)
{
ApplyDecoration(active.Decoration(i), active.Index(i));
}
//restore from decorating
Select(selStart, selLength);
this.SelectionColor = this.ForeColor;
ScrollPosition = origScroll;
LockWindowUpdate(0);
}
mDecorationInProgress = false;
}