void DoReplace(int offset, int length, ITextSource newText, OffsetChangeMap offsetChangeMap)
{
if (length == 0 && newText.TextLength == 0)
{
return;
}
// trying to replace a single character in 'Normal' mode?
// for single characters, 'CharacterReplace' mode is equivalent, but more performant
// (we don't have to touch the anchorTree at all in 'CharacterReplace' mode)
if (length == 1 && newText.TextLength == 1 && offsetChangeMap == null)
{
offsetChangeMap = OffsetChangeMap.Empty;
}
ITextSource removedText;
if (length == 0)
{
removedText = StringTextSource.Empty;
}
else if (length < 100)
{
removedText = new StringTextSource(rope.ToString(offset, length));
}
else
{
// use a rope if the removed string is long
removedText = new RopeTextSource(rope.GetRange(offset, length));
}
DocumentChangeEventArgs args = new DocumentChangeEventArgs(offset, removedText, newText, offsetChangeMap);
// fire DocumentChanging event
if (Changing != null)
{
Changing(this, args);
}
if (textChanging != null)
{
textChanging(this, args);
}
undoStack.Push(this, args);
cachedText = null; // reset cache of complete document text
fireTextChanged = true;
DelayedEvents delayedEvents = new DelayedEvents();
lock (lockObject) {
// create linked list of checkpoints
versionProvider.AppendChange(args);
// now update the textBuffer and lineTree
if (offset == 0 && length == rope.Length)
{
// optimize replacing the whole document
rope.Clear();
var newRopeTextSource = newText as RopeTextSource;
if (newRopeTextSource != null)
{
rope.InsertRange(0, newRopeTextSource.GetRope());
}
else
{
rope.InsertText(0, newText.Text);
}
lineManager.Rebuild();
}
else
{
rope.RemoveRange(offset, length);
lineManager.Remove(offset, length);
#if DEBUG
lineTree.CheckProperties();
#endif
var newRopeTextSource = newText as RopeTextSource;
if (newRopeTextSource != null)
{
rope.InsertRange(offset, newRopeTextSource.GetRope());
}
else
{
rope.InsertText(offset, newText.Text);
}
lineManager.Insert(offset, newText);
#if DEBUG
lineTree.CheckProperties();
#endif
}
}
// update text anchors
if (offsetChangeMap == null)
{
anchorTree.HandleTextChange(args.CreateSingleChangeMapEntry(), delayedEvents);
}
else
{
foreach (OffsetChangeMapEntry entry in offsetChangeMap)
{
anchorTree.HandleTextChange(entry, delayedEvents);
}
}
lineManager.ChangeComplete(args);
// raise delayed events after our data structures are consistent again
delayedEvents.RaiseEvents();
// fire DocumentChanged event
if (Changed != null)
{
Changed(this, args);
}
if (textChanged != null)
{
textChanged(this, args);
}
}
/// <summary>
/// Replaces text.
/// </summary>
/// <param name="offset">The starting offset of the text to be replaced.</param>
/// <param name="length">The length of the text to be replaced.</param>
/// <param name="text">The new text.</param>
/// <param name="offsetChangeMappingType">The offsetChangeMappingType determines how offsets inside the old text are mapped to the new text.
/// This affects how the anchors and segments inside the replaced region behave.</param>
public void Replace(int offset, int length, ITextSource text, OffsetChangeMappingType offsetChangeMappingType)
{
if (text == null)
{
throw new ArgumentNullException("text");
}
// Please see OffsetChangeMappingType XML comments for details on how these modes work.
switch (offsetChangeMappingType)
{
case OffsetChangeMappingType.Normal:
Replace(offset, length, text, null);
break;
case OffsetChangeMappingType.KeepAnchorBeforeInsertion:
Replace(offset, length, text, OffsetChangeMap.FromSingleElement(
new OffsetChangeMapEntry(offset, length, text.TextLength, false, true)));
break;
case OffsetChangeMappingType.RemoveAndInsert:
if (length == 0 || text.TextLength == 0)
{
// only insertion or only removal?
// OffsetChangeMappingType doesn't matter, just use Normal.
Replace(offset, length, text, null);
}
else
{
OffsetChangeMap map = new OffsetChangeMap(2);
map.Add(new OffsetChangeMapEntry(offset, length, 0));
map.Add(new OffsetChangeMapEntry(offset, 0, text.TextLength));
map.Freeze();
Replace(offset, length, text, map);
}
break;
case OffsetChangeMappingType.CharacterReplace:
if (length == 0 || text.TextLength == 0)
{
// only insertion or only removal?
// OffsetChangeMappingType doesn't matter, just use Normal.
Replace(offset, length, text, null);
}
else if (text.TextLength > length)
{
// look at OffsetChangeMappingType.CharacterReplace XML comments on why we need to replace
// the last character
OffsetChangeMapEntry entry = new OffsetChangeMapEntry(offset + length - 1, 1, 1 + text.TextLength - length);
Replace(offset, length, text, OffsetChangeMap.FromSingleElement(entry));
}
else if (text.TextLength < length)
{
OffsetChangeMapEntry entry = new OffsetChangeMapEntry(offset + text.TextLength, length - text.TextLength, 0, true, false);
Replace(offset, length, text, OffsetChangeMap.FromSingleElement(entry));
}
else
{
Replace(offset, length, text, OffsetChangeMap.Empty);
}
break;
default:
throw new ArgumentOutOfRangeException("offsetChangeMappingType", offsetChangeMappingType, "Invalid enum value");
}
}
/// <summary>
/// Replaces text.
/// </summary>
/// <param name="offset">The starting offset of the text to be replaced.</param>
/// <param name="length">The length of the text to be replaced.</param>
/// <param name="text">The new text.</param>
/// <param name="offsetChangeMap">The offsetChangeMap determines how offsets inside the old text are mapped to the new text.
/// This affects how the anchors and segments inside the replaced region behave.
/// If you pass null (the default when using one of the other overloads), the offsets are changed as
/// in OffsetChangeMappingType.Normal mode.
/// If you pass OffsetChangeMap.Empty, then everything will stay in its old place (OffsetChangeMappingType.CharacterReplace mode).
/// The offsetChangeMap must be a valid 'explanation' for the document change. See <see cref="OffsetChangeMap.IsValidForDocumentChange"/>.
/// Passing an OffsetChangeMap to the Replace method will automatically freeze it to ensure the thread safety of the resulting
/// DocumentChangeEventArgs instance.
/// </param>
public void Replace(int offset, int length, string text, OffsetChangeMap offsetChangeMap)
{
Replace(offset, length, new StringTextSource(text), offsetChangeMap);
}
public void Undo()
{
OffsetChangeMap map = change.OffsetChangeMapOrNull;
document.Replace(change.Offset, change.InsertionLength, change.RemovedText, map != null ? map.Invert() : null);
}