using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel.Composition;
using Microsoft.VisualStudio.Text.Outlining;
using Microsoft.VisualStudio.Text.Tagging;
using Microsoft.VisualStudio.Utilities;
using Microsoft.VisualStudio.Text;
string startHide = "["; //the characters that start the outlining region
string endHide = "]"; //the characters that end the outlining region
string ellipsis = "..."; //the characters that are displayed when the region is collapsed
string hoverText = "hover text"; //the contents of the tooltip for the collapsed span
ITextBuffer buffer;
ITextSnapshot snapshot;
List<Region> regions;
'the characters that start the outlining region
Private startHide As String = "["
'the characters that end the outlining region
Private endHide As String = "]"
'the characters that are displayed when the region is collapsed
Private ellipsis As String = "..."
'the contents of the tooltip for the collapsed span
Private hoverText As String = "hover text"
Private buffer As ITextBuffer
Private snapshot As ITextSnapshot
Private regions As List(Of Region)
public OutliningTagger(ITextBuffer buffer)
{
this.buffer = buffer;
this.snapshot = buffer.CurrentSnapshot;
this.regions = new List<Region>();
this.ReParse();
this.buffer.Changed += BufferChanged;
}
Public Sub New(ByVal buffer As ITextBuffer)
Me.buffer = buffer
Me.snapshot = buffer.CurrentSnapshot
Me.regions = New List(Of Region)()
Me.ReParse()
AddHandler Me.buffer.Changed, AddressOf BufferChanged
End Sub
public IEnumerable<ITagSpan<IOutliningRegionTag>> GetTags(NormalizedSnapshotSpanCollection spans)
{
if (spans.Count == 0)
yield break;
List<Region> currentRegions = this.regions;
ITextSnapshot currentSnapshot = this.snapshot;
SnapshotSpan entire = new SnapshotSpan(spans[0].Start, spans[spans.Count - 1].End).TranslateTo(currentSnapshot, SpanTrackingMode.EdgeExclusive);
int startLineNumber = entire.Start.GetContainingLine().LineNumber;
int endLineNumber = entire.End.GetContainingLine().LineNumber;
foreach (var region in currentRegions)
{
if (region.StartLine <= endLineNumber &&
region.EndLine >= startLineNumber)
{
var startLine = currentSnapshot.GetLineFromLineNumber(region.StartLine);
var endLine = currentSnapshot.GetLineFromLineNumber(region.EndLine);
//the region starts at the beginning of the "[", and goes until the *end* of the line that contains the "]".
yield return new TagSpan<IOutliningRegionTag>(
new SnapshotSpan(startLine.Start + region.StartOffset,
endLine.End),
new OutliningRegionTag(false, false, ellipsis, hoverText));
}
}
}
Public Function GetTags(ByVal spans As NormalizedSnapshotSpanCollection) As IEnumerable(Of ITagSpan(Of IOutliningRegionTag)) Implements ITagger(Of Microsoft.VisualStudio.Text.Tagging.IOutliningRegionTag).GetTags
If spans.Count = 0 Then
Return Nothing
Exit Function
End If
Dim currentRegions As List(Of Region) = Me.regions
Dim currentSnapshot As ITextSnapshot = Me.snapshot
Dim entire As SnapshotSpan = New SnapshotSpan(spans(0).Start, spans(spans.Count - 1).[End]).TranslateTo(currentSnapshot, SpanTrackingMode.EdgeExclusive)
Dim startLineNumber As Integer = entire.Start.GetContainingLine().LineNumber
Dim endLineNumber As Integer = entire.[End].GetContainingLine().LineNumber
Dim list As List(Of ITagSpan(Of IOutliningRegionTag))
list = New List(Of ITagSpan(Of IOutliningRegionTag))()
For Each region In currentRegions
If region.StartLine <= endLineNumber AndAlso region.EndLine >= startLineNumber Then
Dim startLine = currentSnapshot.GetLineFromLineNumber(region.StartLine)
Dim endLine = currentSnapshot.GetLineFromLineNumber(region.EndLine)
'the region starts at the beginning of the "[", and goes until the *end* of the line that contains the "]".
list.Add(New TagSpan(Of IOutliningRegionTag)(New SnapshotSpan(startLine.Start + region.StartOffset, endLine.End),
New OutliningRegionTag(False, False, ellipsis, hoverText)))
End If
Next
Return list
End Function
void BufferChanged(object sender, TextContentChangedEventArgs e)
{
// If this isn't the most up-to-date version of the buffer, then ignore it for now (we'll eventually get another change event).
if (e.After != buffer.CurrentSnapshot)
return;
this.ReParse();
}
Private Sub BufferChanged(ByVal sender As Object, ByVal e As TextContentChangedEventArgs)
' If this isn't the most up-to-date version of the buffer, then ignore it for now (we'll eventually get another change event).
If e.After IsNot buffer.CurrentSnapshot Then
Exit Sub
End If
Me.ReParse()
End Sub
void ReParse()
{
ITextSnapshot newSnapshot = 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)
{
int regionStart = -1;
string text = line.GetText();
//lines that contain a "[" denote the start of a new region.
if ((regionStart = text.IndexOf(startHide, StringComparison.Ordinal)) != -1)
{
int currentLevel = (currentRegion != null) ? currentRegion.Level : 1;
int newLevel;
if (!TryGetLevel(text, regionStart, out newLevel))
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 = regionStart,
PartialParent = currentRegion.PartialParent
};
}
//this is a new (sub)region
else
{
currentRegion = new PartialRegion()
{
Level = newLevel,
StartLine = line.LineNumber,
StartOffset = regionStart,
PartialParent = currentRegion
};
}
}
//lines that contain "]" denote the end of a region
else if ((regionStart = text.IndexOf(endHide, StringComparison.Ordinal)) != -1)
{
int currentLevel = (currentRegion != null) ? currentRegion.Level : 1;
int closingLevel;
if (!TryGetLevel(text, regionStart, out closingLevel))
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;
}
}
}
//determine the changed span, and send a changed event with the new spans
List<Span> oldSpans =
new List<Span>(this.regions.Select(r => AsSnapshotSpan(r, this.snapshot)
.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);
}
this.snapshot = newSnapshot;
this.regions = newRegions;
if (changeStart <= changeEnd)
{
ITextSnapshot snap = this.snapshot;
if (this.TagsChanged != null)
this.TagsChanged(this, new SnapshotSpanEventArgs(
new SnapshotSpan(this.snapshot, Span.FromBounds(changeStart, changeEnd))));
}
}
Private Sub ReParse()
Dim newSnapshot As ITextSnapshot = buffer.CurrentSnapshot
Dim newRegions As New List(Of Region)()
'keep the current (deepest) partial region, which will have
' references to any parent partial regions.
Dim currentRegion As PartialRegion = Nothing
For Each line In newSnapshot.Lines
Dim regionStart As Integer = -1
Dim text As String = line.GetText()
'lines that contain a "[" denote the start of a new region.
If text.IndexOf(startHide, StringComparison.Ordinal) <> -1 Then
regionStart = text.IndexOf(startHide, StringComparison.Ordinal)
Dim currentLevel As Integer = If((currentRegion IsNot Nothing), currentRegion.Level, 1)
Dim newLevel As Integer
If Not TryGetLevel(text, regionStart, newLevel) Then
newLevel = currentLevel + 1
End If
'levels are the same and we have an existing region;
'end the current region and start the next
If currentLevel = newLevel AndAlso currentRegion IsNot Nothing Then
Dim newRegion = New Region()
newRegion.Level = currentRegion.Level
newRegion.StartLine = currentRegion.StartLine
newRegion.StartOffset = currentRegion.StartOffset
newRegion.EndLine = line.LineNumber
newRegions.Add(newRegion)
currentRegion = New PartialRegion()
currentRegion.Level = newLevel
currentRegion.StartLine = line.LineNumber
currentRegion.StartOffset = regionStart
currentRegion.PartialParent = currentRegion.PartialParent
Else
'this is a new (sub)region
currentRegion = New PartialRegion()
currentRegion.Level = newLevel
currentRegion.StartLine = line.LineNumber
currentRegion.StartOffset = regionStart
currentRegion.PartialParent = currentRegion
End If
'lines that contain "]" denote the end of a region
ElseIf (text.IndexOf(endHide, StringComparison.Ordinal)) <> -1 Then
regionStart = text.IndexOf(endHide, StringComparison.Ordinal)
Dim currentLevel As Integer = If((currentRegion IsNot Nothing), currentRegion.Level, 1)
Dim closingLevel As Integer
If Not TryGetLevel(text, regionStart, closingLevel) Then
closingLevel = currentLevel
End If
'the regions match
If currentRegion IsNot Nothing AndAlso currentLevel = closingLevel Then
Dim newRegion As Region
newRegion = New Region()
newRegion.Level = currentLevel
newRegion.StartLine = currentRegion.StartLine
newRegion.StartOffset = currentRegion.StartOffset
newRegion.EndLine = line.LineNumber
newRegions.Add(newRegion)
currentRegion = currentRegion.PartialParent
End If
End If
Next
'determine the changed span, and send a changed event with the new spans
Dim oldSpans As New List(Of Span)(Me.regions.[Select](Function(r) AsSnapshotSpan(r, Me.snapshot).TranslateTo(newSnapshot, SpanTrackingMode.EdgeExclusive).Span))
Dim newSpans As New List(Of Span)(newRegions.[Select](Function(r) AsSnapshotSpan(r, newSnapshot).Span))
Dim oldSpanCollection As New NormalizedSpanCollection(oldSpans)
Dim newSpanCollection As New NormalizedSpanCollection(newSpans)
'the changed regions are regions that appear in one set or the other, but not both.
Dim removed As NormalizedSpanCollection = NormalizedSpanCollection.Difference(oldSpanCollection, newSpanCollection)
Dim changeStart As Integer = Integer.MaxValue
Dim changeEnd As Integer = -1
If removed.Count > 0 Then
changeStart = removed(0).Start
changeEnd = removed(removed.Count - 1).[End]
End If
If newSpans.Count > 0 Then
changeStart = Math.Min(changeStart, newSpans(0).Start)
changeEnd = Math.Max(changeEnd, newSpans(newSpans.Count - 1).[End])
End If
Me.snapshot = newSnapshot
Me.regions = newRegions
If changeStart <= changeEnd Then
Dim snap As ITextSnapshot = Me.snapshot
RaiseEvent TagsChanged(Me, New SnapshotSpanEventArgs(New SnapshotSpan(Me.snapshot, Span.FromBounds(changeStart, changeEnd))))
End If
End Sub
static bool TryGetLevel(string text, int startIndex, out int level)
{
level = -1;
if (text.Length > startIndex + 3)
{
if (int.TryParse(text.Substring(startIndex + 1), out level))
return true;
}
return false;
}
Private Shared Function TryGetLevel(ByVal text As String, ByVal startIndex As Integer, ByRef level As Integer) As Boolean
level = -1
If text.Length > startIndex + 3 Then
If Integer.TryParse(text.Substring(startIndex + 1), level) Then
Return True
End If
End If
Return False
End Function
static SnapshotSpan AsSnapshotSpan(Region region, ITextSnapshot snapshot)
{
var startLine = snapshot.GetLineFromLineNumber(region.StartLine);
var endLine = (region.StartLine == region.EndLine) ? startLine
: snapshot.GetLineFromLineNumber(region.EndLine);
return new SnapshotSpan(startLine.Start + region.StartOffset, endLine.End);
}
Private Shared Function AsSnapshotSpan(ByVal region As Region, ByVal snapshot As ITextSnapshot) As SnapshotSpan
Dim startLine = snapshot.GetLineFromLineNumber(region.StartLine)
Dim endLine = If((region.StartLine = region.EndLine), startLine, snapshot.GetLineFromLineNumber(region.EndLine))
Return New SnapshotSpan(startLine.Start + region.StartOffset, endLine.[End])
End Function
class PartialRegion
{
public int StartLine { get; set; }
public int StartOffset { get; set; }
public int Level { get; set; }
public PartialRegion PartialParent { get; set; }
}
class Region : PartialRegion
{
public int EndLine { get; set; }
}
Private Class PartialRegion
Private _StartLine As Integer
Public Property StartLine() As Integer
Get
Return _StartLine
End Get
Set(ByVal value As Integer)
_StartLine = value
End Set
End Property
Private _StartOffset As Integer
Public Property StartOffset() As Integer
Get
Return _StartOffset
End Get
Set(ByVal value As Integer)
_StartOffset = value
End Set
End Property
Private _Level As Integer
Public Property Level() As Integer
Get
Return _Level
End Get
Set(ByVal value As Integer)
_Level = value
End Set
End Property
Private _PartialParent As PartialRegion
Public Property PartialParent() As PartialRegion
Get
Return _PartialParent
End Get
Set(ByVal value As PartialRegion)
_PartialParent = value
End Set
End Property
End Class
Private Class Region
Inherits PartialRegion
Private _EndLine As Integer
Public Property EndLine() As Integer
Get
Return _EndLine
End Get
Set(ByVal value As Integer)
_EndLine = value
End Set
End Property
End Class
public ITagger<T> CreateTagger<T>(ITextBuffer buffer) where T : ITag
{
//create a single tagger for each buffer.
Func<ITagger<T>> sc = delegate() { return new OutliningTagger(buffer) as ITagger<T>; };
return buffer.Properties.GetOrCreateSingletonProperty<ITagger<T>>(sc);
}
Public Function CreateTagger(Of T As ITag)(ByVal buffer As ITextBuffer) As ITagger(Of T) Implements ITaggerProvider.CreateTagger
'create a single tagger for each buffer.
Dim sc As Func(Of ITagger(Of T)) = Function() TryCast(New OutliningTagger(buffer), ITagger(Of T))
Return buffer.Properties.GetOrCreateSingletonProperty(Of ITagger(Of T))(sc)
End Function