private bool TryGetCurrentLanguageBufferExtent(IProjectionSnapshot projectionSnapshot, out Span result)
{
if (projectionSnapshot.SpanCount == 0)
{
result = default(Span);
return(false);
}
// the last source snapshot is always a projection of a language buffer:
var snapshot = projectionSnapshot.GetSourceSpan(projectionSnapshot.SpanCount - 1).Snapshot;
if (snapshot.TextBuffer != _currentLanguageBuffer)
{
result = default(Span);
return(false);
}
SnapshotPoint start = new SnapshotPoint(snapshot, 0);
SnapshotPoint end = new SnapshotPoint(snapshot, snapshot.Length);
// projection of the previous version of current language buffer snapshot:
var surfaceSpans = projectionSnapshot.MapFromSourceSnapshot(new SnapshotSpan(start, end));
// the language buffer might be projected to multiple surface lines:
Debug.Assert(surfaceSpans.Count > 0);
result = new Span(surfaceSpans[0].Start, surfaceSpans.Last().End);
return(true);
}
/// <remarks>
/// This should only be called from within the current language buffer. If there are
/// any output or standard input buffers between the specified line and the end of the
/// surface buffer, then the result will be incorrect.
/// </remarks>
private int GetProjectionSpanIndexFromEditableBufferPosition(IProjectionSnapshot surfaceSnapshot, int projectionSpansCount, int surfaceLineNumber)
{
// The current language buffer is projected to a set of projections interleaved regularly by prompt projections
// and ending at the end of the projection buffer, each language buffer projection is on a separate line:
// [prompt)[language)...[prompt)[language)<end of projection buffer>
int result = projectionSpansCount - (surfaceSnapshot.LineCount - surfaceLineNumber) * SpansPerLineOfInput + 1;
Debug.Assert(GetSpanKind(surfaceSnapshot.GetSourceSpan(result)) == ReplSpanKind.Language);
return(result);
}
/// <remarks>
/// This should only be called from within the current language buffer. If there are
/// any output or standard input buffers between the specified line and the end of the
/// surface buffer, then the result will be incorrect.
/// </remarks>
private int GetProjectionSpanIndexFromEditableBufferPosition(IProjectionSnapshot surfaceSnapshot, int projectionSpansCount, int surfaceLineNumber)
{
// The current language buffer is projected to a set of projections interleaved regularly by prompt projections
// and ending at the end of the projection buffer, each language buffer projection is on a separate line:
// [prompt)[language)...[prompt)[language)<end of projection buffer>
int result = projectionSpansCount - (surfaceSnapshot.LineCount - surfaceLineNumber) * SpansPerLineOfInput + 1;
Debug.Assert(GetSpanKind(surfaceSnapshot.GetSourceSpan(result)) == ReplSpanKind.Input);
return result;
}
private bool TryGetCurrentLanguageBufferExtent(IProjectionSnapshot projectionSnapshot, out Span result)
{
if (projectionSnapshot.SpanCount == 0)
{
result = default(Span);
return false;
}
// the last source snapshot is always a projection of a language buffer:
var snapshot = projectionSnapshot.GetSourceSpan(projectionSnapshot.SpanCount - 1).Snapshot;
if (snapshot.TextBuffer != CurrentLanguageBuffer)
{
result = default(Span);
return false;
}
SnapshotPoint start = new SnapshotPoint(snapshot, 0);
SnapshotPoint end = new SnapshotPoint(snapshot, snapshot.Length);
// projection of the previous version of current language buffer snapshot:
var surfaceSpans = projectionSnapshot.MapFromSourceSnapshot(new SnapshotSpan(start, end));
// the language buffer might be projected to multiple surface lines:
Debug.Assert(surfaceSpans.Count > 0);
result = new Span(surfaceSpans[0].Start, surfaceSpans.Last().End);
return true;
}