/// <summary>
/// Combines one text change with another
/// </summary>
public void Combine(TextChange other)
{
if (other.IsEmpty)
{
return;
}
FullParseRequired |= other.FullParseRequired;
TextChangeType |= other.TextChangeType;
if (OldRange == TextRange.EmptyRange || NewRange == TextRange.EmptyRange)
{
OldRange = other.OldRange;
NewRange = other.NewRange;
OldTextProvider = other.OldTextProvider;
NewTextProvider = other.NewTextProvider;
}
else
{
ITextSnapshotProvider oldSnapshotProvider = OldTextProvider as ITextSnapshotProvider;
ITextSnapshotProvider newSnapshotProvider = NewTextProvider as ITextSnapshotProvider;
ITextSnapshotProvider otherOldSnapshotProvider = other.OldTextProvider as ITextSnapshotProvider;
ITextSnapshotProvider otherNewSnapshotProvider = other.NewTextProvider as ITextSnapshotProvider;
bool changesAreFromNextSnapshot = false;
if ((oldSnapshotProvider != null) && (newSnapshotProvider != null) &&
(otherOldSnapshotProvider != null) && (otherNewSnapshotProvider != null))
{
ITextSnapshot newSnapshot = newSnapshotProvider.Snapshot;
ITextSnapshot otherOldSnapshot = otherOldSnapshotProvider.Snapshot;
if (newSnapshot.Version.ReiteratedVersionNumber == otherOldSnapshot.Version.ReiteratedVersionNumber)
{
changesAreFromNextSnapshot = true;
}
}
if (!changesAreFromNextSnapshot)
{
// Assume these changes are from the same snapshot
int oldStart = Math.Min(other.OldRange.Start, this.OldRange.Start);
int oldEnd = Math.Max(other.OldRange.End, this.OldRange.End);
int newStart = Math.Min(other.NewRange.Start, this.NewRange.Start);
int newEnd = Math.Max(other.NewRange.End, this.NewRange.End);
OldRange = TextRange.FromBounds(oldStart, oldEnd);
NewRange = TextRange.FromBounds(newStart, newEnd);
}
else
{
// the "other" change is from the subsequent snapshot. Merge the changes.
ITextSnapshot oldSnapshot = oldSnapshotProvider.Snapshot;
ITextSnapshot newSnapshot = newSnapshotProvider.Snapshot;
ITextSnapshot otherOldSnapshot = otherOldSnapshotProvider.Snapshot;
ITextSnapshot otherNewSnapshot = otherNewSnapshotProvider.Snapshot;
SnapshotSpan otherOldSpan = other.OldRange.ToSnapshotSpan(otherOldSnapshot);
SnapshotSpan oldSpan = otherOldSpan.TranslateTo(oldSnapshot, SpanTrackingMode.EdgeInclusive);
SnapshotSpan newSpan = NewRange.ToSnapshotSpan(newSnapshot);
SnapshotSpan otherNewSpan = newSpan.TranslateTo(otherNewSnapshot, SpanTrackingMode.EdgeInclusive);
OldRange = new TextRange(TextRange.Union(OldRange, oldSpan.ToTextRange()));
NewRange = new TextRange(TextRange.Union(other.NewRange, otherNewSpan.ToTextRange()));
NewTextProvider = other.NewTextProvider;
}
}
Version = Math.Max(this.Version, other.Version);
}
