protected OutlineRegionBuilder(ITextBuffer textBuffer)
{
CurrentRegions = new OutlineRegionCollection(0);
TextBuffer = textBuffer;
TextBuffer.Changed += OnTextBufferChanged;
BackgroundTask = new IdleTimeAsyncTask(TaskAction, MainThreadAction);
BackgroundTask.DoTaskOnIdle(300);
}
public virtual object Clone()
{
var clone = new OutlineRegionCollection(this.TextBufferVersion);
foreach (var item in this)
{
clone.Add(item.Clone() as OutlineRegion);
}
return(clone);
}
protected virtual object TaskAction()
{
if (!IsDisposed())
{
var snapshot = TextBuffer.CurrentSnapshot;
var newRegions = new OutlineRegionCollection(snapshot.Version.VersionNumber);
BuildRegions(newRegions);
lock (_regionsLock) {
var changedRange = CompareRegions(newRegions, CurrentRegions, snapshot.Length);
return(new OutlineRegionsChange(changedRange, newRegions));
}
}
return(null);
}
protected static ITextRange CompareRegions(
OutlineRegionCollection newRegions,
OutlineRegionCollection oldRegions, int upperBound)
{
TextRangeCollection <OutlineRegion> oldClone = null;
TextRangeCollection <OutlineRegion> newClone = null;
if (oldRegions != null)
{
oldClone = oldRegions.Clone() as OutlineRegionCollection;
oldClone.Sort();
}
newClone = newRegions.Clone() as OutlineRegionCollection;
newClone.Sort();
return(newClone.RangeDifference(oldClone, 0, upperBound));
}
private void OnRegionsChanged(object sender, OutlineRegionsChangedEventArgs e)
{
var snapshot = this._textBuffer.CurrentSnapshot;
if (e.Regions.TextBufferVersion == this._textBuffer.CurrentSnapshot.Version.VersionNumber)
{
if (TagsChanged != null)
{
var start = Math.Min(e.ChangedRange.Start, snapshot.Length);
var end = Math.Min(e.ChangedRange.End, snapshot.Length);
TagsChanged(this, new SnapshotSpanEventArgs(
new SnapshotSpan(snapshot, Span.FromBounds(start, end))));
}
this._currentRegions = e.Regions;
}
}
protected abstract void BuildRegions(OutlineRegionCollection newRegions);
public OutlineRegionsChangedEventArgs(OutlineRegionCollection regions, ITextRange changedRange)
{
this.Regions = regions;
this.ChangedRange = changedRange;
}
private static void BuildRegions(OutlineRegionCollection newRegions, ITextSnapshot snapshot)
{
// Figure out regions based on line indent
if (snapshot.LineCount == 0)
{
return;
}
var regionStack = new Stack <CodeBlock>();
var lineLengths = new int[snapshot.LineCount];
var lastBlockIndent = 0;
for (var i = 0; i < snapshot.LineCount; i++)
{
var line = snapshot.GetLineFromLineNumber(i);
var lineText = line.GetText();
if (string.IsNullOrWhiteSpace(lineText))
{
lineLengths[i] = 0;
continue;
}
lineLengths[i] = line.Length;
var indent = GetLineIndent(line);
if (regionStack.Count > 0)
{
lastBlockIndent = regionStack.Peek().Indent;
}
else
{
lastBlockIndent = 0;
}
if (indent <= lastBlockIndent)
{
// We add regions optimistically since any line can
// start a new region if lines below it are indented
// deeper that this line.
while (regionStack.Count > 0)
{
// If we have line with the same indent, remove previously added region
// and replace it with a new one potentially starting with the current line.
var prevCodeBlock = regionStack.Pop();
var startLine = snapshot.GetLineNumberFromPosition(prevCodeBlock.Start);
// Trim empty lines
var j = i - 1;
for (; j >= 0; j--)
{
if (lineLengths[j] > 0)
{
break;
}
}
j++;
if (j > 0 && j - startLine >= _minLinesToOutline)
{
var prevLine = snapshot.GetLineFromLineNumber(j - 1);
if (prevCodeBlock.Start < prevLine.End)
{
newRegions.Add(OutlineRegion.FromBounds(snapshot.TextBuffer, prevCodeBlock.Start, prevLine.End));
}
}
if (regionStack.Count > 0)
{
prevCodeBlock = regionStack.Peek();
if (prevCodeBlock.Indent < indent)
{
break;
}
}
}
}
lastBlockIndent = indent;
regionStack.Push(new CodeBlock(line.Start, indent));
}
// Note that last region may be bogus since we add regions optimistically.
// Remove last region if its indent is the same as the line before it
if (regionStack.Count > 0)
{
var codeBlock = regionStack.Peek();
var lineNumber = snapshot.GetLineNumberFromPosition(codeBlock.Start);
if (lineNumber > 0)
{
var prevLine = snapshot.GetLineFromLineNumber(lineNumber - 1);
var indent = GetLineIndent(prevLine);
if (indent == codeBlock.Indent)
{
regionStack.Pop();
}
}
}
while (regionStack.Count > 0)
{
var codeBlock = regionStack.Pop();
var startLine = snapshot.GetLineNumberFromPosition(codeBlock.Start);
if (snapshot.LineCount - startLine >= _minLinesToOutline)
{
newRegions.Add(OutlineRegion.FromBounds(snapshot.TextBuffer, codeBlock.Start, snapshot.Length));
}
}
}
protected override void BuildRegions(OutlineRegionCollection newRegions)
{
BuildRegions(newRegions, this.TextBuffer.CurrentSnapshot);
}