private void CheckIfTagsChanged(SnapshotRegions oldSnapshotRegions, SnapshotRegions newSnapshotRegions)
{
ITextSnapshot oldSnapshot = oldSnapshotRegions.Snapshot;
IReadOnlyList <Region> oldRegions = oldSnapshotRegions.Regions;
ITextSnapshot newSnapshot = newSnapshotRegions.Snapshot;
IReadOnlyList <Region> newRegions = newSnapshotRegions.Regions;
// Determine the changed spans and send a changed event with the new spans.
List <Span> oldSpans = new List <Span>(
oldRegions.Select(r => AsSnapshotSpan(r, oldSnapshot).TranslateTo(newSnapshot, SpanTrackingMode.EdgeExclusive).Span));
List <Span> newSpans = new List <Span>(newRegions.Select(r => AsSnapshotSpan(r, newSnapshot).Span));
NormalizedSpanCollection oldSpanCollection = new NormalizedSpanCollection(oldSpans);
NormalizedSpanCollection newSpanCollection = new NormalizedSpanCollection(newSpans);
// The changed regions are regions that appear in one set or the other, but not both.
NormalizedSpanCollection removed = NormalizedSpanCollection.Difference(oldSpanCollection, newSpanCollection);
int changeStart = int.MaxValue;
int changeEnd = -1;
if (removed.Count > 0)
{
changeStart = removed[0].Start;
changeEnd = removed[removed.Count - 1].End;
}
if (newSpans.Count > 0)
{
changeStart = Math.Min(changeStart, newSpans[0].Start);
changeEnd = Math.Max(changeEnd, newSpans[newSpans.Count - 1].End);
}
if (changeStart <= changeEnd)
{
var handler = this.TagsChanged;
if (handler != null)
{
var args = new SnapshotSpanEventArgs(new SnapshotSpan(newSnapshot, Span.FromBounds(changeStart, changeEnd)));
handler(this, args);
}
}
}
public OutliningTagger(ITextBuffer buffer, ScanInfo scanInfo)
{
this.buffer = buffer;
if (scanInfo != null)
{
// Our RegionHandler's GetRegionBeginRegex only looks for single line comment tokens
// when doing Collapse/ExpandAllRegions, so we'll use the same restriction here.
this.startExpressions = scanInfo.GetTokenRegexes(StartToken, true).ToList();
this.endExpressions = scanInfo.GetTokenRegexes(EndToken, true).Concat(scanInfo.GetTokenRegexes(AltEndToken, true)).ToList();
}
else
{
// If we don't have scan info, then we can't provide tags.
this.startExpressions = CollectionUtility.EmptyArray <Regex>();
this.endExpressions = CollectionUtility.EmptyArray <Regex>();
}
this.snapshotRegions = new SnapshotRegions(buffer.CurrentSnapshot, CollectionUtility.EmptyArray <Region>());
this.buffer.Changed += this.BufferChanged;
this.BackgroundReparse();
}
private void Reparse()
{
ITextSnapshot newSnapshot = this.buffer.CurrentSnapshot;
List <Region> newRegions = new List <Region>();
// Keep the current (deepest) partial region, which will have references to any parent partial regions.
PartialRegion currentRegion = null;
foreach (var line in newSnapshot.Lines)
{
string text = line.GetText();
// Lines that match a start regex denote the start of a new region.
Match startMatch = this.startExpressions.Select(regex => regex.Match(text)).FirstOrDefault(m => m.Success);
if (startMatch != null)
{
int matchStartIndex = startMatch.Index;
int currentLevel = (currentRegion != null) ? currentRegion.Level : 1;
int newLevel = currentLevel + 1;
// Levels are the same, and we have an existing region;
// End the current region and start the next.
if (currentLevel == newLevel && currentRegion != null)
{
newRegions.Add(new Region()
{
Level = currentRegion.Level,
StartLine = currentRegion.StartLine,
StartOffset = currentRegion.StartOffset,
EndLine = line.LineNumber
});
currentRegion = new PartialRegion()
{
Level = newLevel,
StartLine = line.LineNumber,
StartOffset = matchStartIndex,
PartialParent = currentRegion.PartialParent
};
}
else
{
// This is a new (sub)region
currentRegion = new PartialRegion()
{
Level = newLevel,
StartLine = line.LineNumber,
StartOffset = matchStartIndex,
PartialParent = currentRegion
};
}
}
else
{
// Lines that match an end regex denote the end of a region
Match endMatch = this.endExpressions.Select(regex => regex.Match(text)).FirstOrDefault(m => m.Success);
if (endMatch != null)
{
int currentLevel = (currentRegion != null) ? currentRegion.Level : 1;
int closingLevel = currentLevel;
// The regions match
if (currentRegion != null && currentLevel == closingLevel)
{
newRegions.Add(new Region()
{
Level = currentLevel,
StartLine = currentRegion.StartLine,
StartOffset = currentRegion.StartOffset,
EndLine = line.LineNumber
});
currentRegion = currentRegion.PartialParent;
}
}
}
}
SnapshotRegions newSnapshotRegions = new SnapshotRegions(newSnapshot, newRegions);
SnapshotRegions oldSnapshotRegions;
lock (this.resourceLock)
{
oldSnapshotRegions = this.snapshotRegions;
this.snapshotRegions = newSnapshotRegions;
}
this.CheckIfTagsChanged(oldSnapshotRegions, newSnapshotRegions);
}