LayoutFarm.Text.InternalTextLayerController.DoBackspace C# (CSharp) Method

        public bool DoBackspace()
        {
#if DEBUG

            if (dbugEnableTextManRecorder)
            {
                dbug_BackSpaceCount++;
                dbugTextManRecorder.WriteInfo("TxLMan::DoBackSpace");
                dbugTextManRecorder.BeginContext();
            }
#endif

            VisualSelectionRangeSnapShot removeSelRange = this.RemoveSelectedText();
            if (!removeSelRange.IsEmpty())
            {
                CancelSelect();
#if DEBUG
                if (dbugEnableTextManRecorder) dbugTextManRecorder.EndContext();
#endif
                return true;
            }
            else
            {
                updateJustCurrentLine = true;
                char deletedChar = textLineWriter.DoBackspace();
                if (deletedChar == '\0')
                {
                    if (!IsOnFirstLine)
                    {
                        CurrentLineNumber--;
                        DoEnd();
                        commandHistory.AddDocAction(
                            new DocActionJoinWithNextLine(
                                textLineWriter.LineNumber, textLineWriter.CharIndex));
                        JoinWithNextLine();
                    }
#if DEBUG
                    if (dbugEnableTextManRecorder) dbugTextManRecorder.EndContext();
#endif
                    return false;
                }
                else
                {
                    commandHistory.AddDocAction(
                            new DocActionDeleteChar(
                                deletedChar, textLineWriter.LineNumber, textLineWriter.CharIndex));
#if DEBUG
                    if (dbugEnableTextManRecorder) dbugTextManRecorder.EndContext();
#endif
                    return true;
                }
            }
        }
        public void DoEnd()

 public override void InvokeUndo(InternalTextLayerController textdom)
 {
     textdom.CurrentLineNumber = startLineNumber;
     textdom.CharIndex         = startCharIndex;
     textdom.DoBackspace();
 }