public static int GetLinesCount(this ITextAreaDataSource src)
{
lock (src.LockObject)
{
return(src.Lines.Count == 0 ? 0 : src.Lines.Keys.Last());
}
}
private static void RemoveLine(this ITextAreaDataSource src, int lineNo)
{
lock (src.LockObject)
{
if (src.Lines.ContainsKey(lineNo))
{
src.Lines.Remove(lineNo);
}
}
}
private static void PutGapIntoLine(this ITextAreaDataSource src, int lineNo)
{
var linesToMoveDown = src.Lines.Where(itm => itm.Key > lineNo).OrderByDescending(itm => itm.Key).ToArray();
foreach (var lineToMoveDown in linesToMoveDown)
{
src.Lines.Remove(lineToMoveDown.Key);
src.Lines.Add(lineToMoveDown.Key + 1, lineToMoveDown.Value);
}
}
private void HandleLineInsert(ITextAreaDataSource textAreaDataSource)
{
var lineNo = GetTextLineByScreenLine(CursorY);
var positionNo = GetTextPositionByScreenLine(CursorX);
var line = textAreaDataSource.GetLine(lineNo) ?? string.Empty;
var positionOffset = line.GetPositionOffset();
textAreaDataSource.InsertLine(positionNo, lineNo, positionOffset);
CursorX = positionOffset;
HandleDownArrow();
}
public static string GetLine(this ITextAreaDataSource src, int lineNo)
{
lock (src.LockObject)
{
if (lineNo < 0)
{
return(null);
}
return(src.Lines.ContainsKey(lineNo) ? src.Lines[lineNo] : null);
}
}
public static void Update(this ITextAreaDataSource src, int lineNo, string value)
{
value = value?.TrimEnd();
if (string.IsNullOrEmpty(value))
{
src.RemoveLine(lineNo);
}
else
{
src.UpdateLine(lineNo, value);
}
}
private static void UpdateLine(this ITextAreaDataSource src, int lineNo, string value)
{
lock (src.LockObject)
{
if (src.Lines.ContainsKey(lineNo))
{
src.Lines[lineNo] = value;
}
else
{
src.Lines.Add(lineNo, value);
}
}
}
public static void InsertLine(this ITextAreaDataSource src, int positionNo, int lineNo, int positionOffset)
{
lock (src.LockObject)
{
var line = src.Lines.ContainsKey(lineNo) ? src.Lines[lineNo] : null;
src.PutGapIntoLine(lineNo);
if (line != null)
{
var(line1, line2) = SplitEnterLine(line, positionNo);
src.Update(lineNo, line1);
src.Update(lineNo + 1, new string(' ', positionOffset) + line2);
}
}
}
private void HandleBackspace(ITextAreaDataSource textAreaDataSource)
{
var cursorPosition = GetTextPositionByScreenLine(CursorX);
if (cursorPosition <= 0)
{
HandleLinesMerge(textAreaDataSource);
return;
}
var textLineNo = GetTextLineByScreenLine(CursorY);
var str = textAreaDataSource.GetLine(textLineNo);
str = str.BackspaceTextArea(cursorPosition);
CursorX--;
textAreaDataSource.Update(textLineNo, str);
}
public static void MergeLines(this ITextAreaDataSource src, int lineNo)
{
lock (src.LockObject)
{
var line1 = src.GetLine(lineNo - 1) ?? string.Empty;
var line2 = src.GetLine(lineNo) ?? string.Empty;
if (!string.IsNullOrEmpty(line1))
{
line1 += " ";
}
src.Update(lineNo - 1, line1 + line2);
src.DeleteLine(lineNo);
}
}
public static void DeleteLine(this ITextAreaDataSource src, int lineNo)
{
lock (src.LockObject)
{
if (src.Lines.ContainsKey(lineNo))
{
src.Lines.Remove(lineNo);
}
var linesToMoveUp = src.Lines.Where(itm => itm.Key > lineNo).ToArray();
foreach (var(lineId, value) in linesToMoveUp)
{
src.Lines.Remove(lineId);
src.Lines.Add(lineId - 1, value);
}
}
}
private void HandleLinesMerge(ITextAreaDataSource textAreaDataSource)
{
var linePos = GetTextLineByScreenLine(CursorY);
if (linePos == 0)
{
return;
}
var line = textAreaDataSource.GetLine(linePos - 1) ?? string.Empty;
textAreaDataSource.MergeLines(linePos);
HandleUpArrow();
CursorX = line.Length;
if (line.Length > 0)
{
CursorX++;
}
}
private void FindPreviousWord(ITextAreaDataSource textAreaDataSource)
{
var line = GetCurrentLine();
if (line == null)
{
return;
}
var xPosition = GetTextXPosition();
var newXPosition = line.GetPrevWordPosition(xPosition);
for (var i = xPosition; i > newXPosition; i--)
{
HandleLeftArrow(textAreaDataSource);
}
}
private void HandleLeftArrow(ITextAreaDataSource textAreaDataSource)
{
if (CursorX == 0 && XOffset == 0)
{
GetPreviousLinePosition(textAreaDataSource);
return;
}
if (CursorX > 0)
{
CursorX--;
return;
}
if (XOffset > 0)
{
XOffset--;
}
}
private void GetPreviousLinePosition(ITextAreaDataSource textAreaDataSource)
{
var lineNo = GetTextLineByScreenLine(CursorY);
if (lineNo == 0)
{
return;
}
var line = textAreaDataSource.GetLine(lineNo - 1) ?? string.Empty;
HandleUpArrow();
CursorX = line.Length;
if (CursorX > Width)
{
XOffset = CursorX - Width;
CursorX = Width;
}
}
public void SetDataSource(ITextAreaDataSource dataSource)
{
_textAreaDataSource = dataSource;
}
