Merge pull request #5280 from amcasey/ReadonlyCleanup

Tracking span and readonly region cleanup

src/InteractiveWindow/Editor/CustomTrackingSpan.cs

@@ -17,10 +17,10 @@ internal sealed class CustomTrackingSpan : ITrackingSpan
         private readonly ITrackingPoint _start;
         private readonly ITrackingPoint _end;
 
-        public CustomTrackingSpan(ITextSnapshot snapshot, Span span, PointTrackingMode startTrackingMode, PointTrackingMode endTrackingMode)
+        public CustomTrackingSpan(ITextSnapshot snapshot, Span span, bool canAppend = false)
         {
-            _start = snapshot.CreateTrackingPoint(span.Start, startTrackingMode);
-            _end = snapshot.CreateTrackingPoint(span.End, endTrackingMode);
+            _start = snapshot.CreateTrackingPoint(span.Start, PointTrackingMode.Negative);
+            _end = snapshot.CreateTrackingPoint(span.End, canAppend ? PointTrackingMode.Positive : PointTrackingMode.Negative);
         }
 
         #region ITrackingSpan Members

src/InteractiveWindow/Editor/InteractiveWindow.UIThreadOnly.cs

@@ -427,7 +427,7 @@ private void MakeStandardInputReadonly()
 
                 // replace previous span w/ a span that won't grow...
                 var oldSpan = sourceSpans[index];
-                var newSpan = new CustomTrackingSpan(oldSpan.Snapshot, oldSpan.Span, PointTrackingMode.Negative, PointTrackingMode.Negative);
+                var newSpan = new CustomTrackingSpan(oldSpan.Snapshot, oldSpan.Span);
 
                 ReplaceProjectionSpan(index, newSpan);
                 ApplyProtection(StandardInputBuffer, _standardInputProtection, allowAppend: true);
@@ -671,8 +671,7 @@ private void AppendInput(string text)
                 var replSpan = new CustomTrackingSpan(
                     buffer.CurrentSnapshot,
                     new Span(span.Start, span.Length + text.Length),
-                    PointTrackingMode.Negative,
-                    PointTrackingMode.Positive);
+                    canAppend: true);
                 ReplaceProjectionSpan(spanCount - 1, replSpan);
 
                 TextView.Caret.EnsureVisible();
@@ -884,9 +883,7 @@ private void NewOutputBuffer()
                 Debug.Assert(GetSpanKind(sourceSpan) == ReplSpanKind.Output);
                 var nonGrowingSpan = new CustomTrackingSpan(
                     sourceSpan.Snapshot,
-                    sourceSpan.Span,
-                    PointTrackingMode.Negative,
-                    PointTrackingMode.Negative);
+                    sourceSpan.Span);
                 ReplaceProjectionSpan(_currentOutputProjectionSpan, nonGrowingSpan);
 
                 AppendNewOutputProjectionBuffer();
@@ -899,8 +896,7 @@ private void AppendNewOutputProjectionBuffer()
                 var trackingSpan = new CustomTrackingSpan(
                     currentSnapshot,
                     new Span(currentSnapshot.Length, 0),
-                    PointTrackingMode.Negative,
-                    PointTrackingMode.Positive);
+                    canAppend: true);
 
                 _currentOutputProjectionSpan = AppendProjectionSpan(trackingSpan);
             }
@@ -1330,8 +1326,7 @@ private void AddLanguageBuffer()
                 var languageSpan = new CustomTrackingSpan(
                     CurrentLanguageBuffer.CurrentSnapshot,
                     new Span(0, 0),
-                    PointTrackingMode.Negative,
-                    PointTrackingMode.Positive);
+                    canAppend: true);
 
                 // projection buffer update must be the last operation as it might trigger event that accesses prompt line mapping:
                 AppendProjectionSpans(promptSpan, languageSpan);
@@ -1590,7 +1585,7 @@ private object CreateTrackingSpan(SnapshotSpan snapshotSpan)
                 {
                     return snapshotSpan.GetText();
                 }
-                return new CustomTrackingSpan(snapshot, snapshotSpan.Span, PointTrackingMode.Negative, PointTrackingMode.Negative);
+                return new CustomTrackingSpan(snapshot, snapshotSpan.Span);
             }
 
             private ITrackingSpan CreateLanguageSpanForLine(ITextSnapshotLine languageLine)
@@ -1600,8 +1595,7 @@ private ITrackingSpan CreateLanguageSpanForLine(ITextSnapshotLine languageLine)
                 return new CustomTrackingSpan(
                     CurrentLanguageBuffer.CurrentSnapshot,
                     span,
-                    PointTrackingMode.Negative,
-                    lastLine ? PointTrackingMode.Positive : PointTrackingMode.Negative);
+                    canAppend: lastLine);
             }
 
             private void ScrollToCaret()
@@ -2562,8 +2556,7 @@ private void AddStandardInputSpan()
                 var inputSpan = new CustomTrackingSpan(
                     currentSnapshot,
                     new Span(currentSnapshot.Length, 0),
-                    PointTrackingMode.Negative,
-                    PointTrackingMode.Positive);
+                    canAppend: true);
                 AppendProjectionSpans(promptSpan, inputSpan);
             }