/// <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, ITextSource text, OffsetChangeMap offsetChangeMap) { if (text == null) { throw new ArgumentNullException("text"); } text = text.CreateSnapshot(); if (offsetChangeMap != null) { offsetChangeMap.Freeze(); } // Ensure that all changes take place inside an update group. // Will also take care of throwing an exception if inDocumentChanging is set. BeginUpdate(); try { // protect document change against corruption by other changes inside the event handlers inDocumentChanging = true; try { // The range verification must wait until after the BeginUpdate() call because the document // might be modified inside the UpdateStarted event. ThrowIfRangeInvalid(offset, length); DoReplace(offset, length, text, offsetChangeMap); } finally { inDocumentChanging = false; } } finally { EndUpdate(); } }
/// <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 { var 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 var entry = new OffsetChangeMapEntry(offset + length - 1, 1, 1 + text.TextLength - length); Replace(offset, length, text, OffsetChangeMap.FromSingleElement(entry)); } else if (text.TextLength < length) { var 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"); } }