protected virtual void OnTextChanged(object sender, TextContentChangedEventArgs e)
{
int start, oldLength, newLength;
TextUtility.CombineChanges(e, out start, out oldLength, out newLength);
// check if change is still within current snapshot. the problem is that
// change could have been calculated against projected buffer and then
// host (HTML editor) could have dropped projections effectively
// shortening buffer to nothing.
var snapshot = this.TextBuffer.CurrentSnapshot;
if (start > snapshot.Length || start + newLength > snapshot.Length)
{
start = 0;
newLength = snapshot.Length;
}
OnTextChanged(start, oldLength, newLength);
}
protected virtual void OnTextBufferChanged(object sender, TextContentChangedEventArgs e)
{
// In order to provide nicer experience when user presser and holds
// ENTER or DELETE or just types really fast, we are going to track
// regions optimistically and report changes without going through
// async or idle processing. Idle/async is still going to hit later.
if (e.Changes.Count > 0)
{
int start, oldLength, newLength;
TextUtility.CombineChanges(e, out start, out oldLength, out newLength);
var changeStart = Int32.MaxValue;
var changeEnd = 0;
lock (this._regionsLock)
{
// Remove affected regions and shift the remaining ones. Outlining
// regions are not sorted and can overlap. Hence linear search.
for (var i = 0; i < this.CurrentRegions.Count; i++)
{
var region = this.CurrentRegions[i];
if (region.End <= start)
{
continue;
}
if (region.Contains(start) && region.Contains(start + oldLength))
{
region.Expand(0, newLength - oldLength);
}
else if (region.Start >= start + oldLength)
{
region.Shift(newLength - oldLength);
}
else
{
this.CurrentRegions.RemoveAt(i);
i--;
}
changeStart = Math.Min(changeStart, region.Start);
changeEnd = Math.Max(changeEnd, region.End);
}
if (changeStart < Int32.MaxValue)
{
this.CurrentRegions.TextBufferVersion = this.TextBuffer.CurrentSnapshot.Version.VersionNumber;
}
}
if (changeStart < Int32.MaxValue)
{
if (this.RegionsChanged != null)
{
this.RegionsChanged(this, new OutlineRegionsChangedEventArgs(this.CurrentRegions, TextRange.FromBounds(changeStart, changeEnd)));
}
}
}
}