private static Highlighter Redraw()
{
var inputString = new string(_input.ToArray());
var newHighlighter = _originalHighlighter.Clone();
var currentColors = newHighlighter.Highlight(inputString);
SavePosition();
var length = Math.Max(currentColors.Length, _previousColors.Length);
int start = 0;
for (; start < length; start++)
{
if (start >= _previousColors.Length || start >= currentColors.Length)
{
break;
}
var prev = _previousColors[start];
var curr = currentColors[start];
if (prev.Character != curr.Character || prev.Color != curr.Color)
{
break;
}
}
Move(-_position + start);
ConsoleColor?prevColor = null;
for (var i = start; i < length; i++)
{
var curr = new ColoredCharacter(' ', ConsoleColor.Gray);
if (i < currentColors.Length)
{
curr = currentColors[i];
}
if (!prevColor.HasValue || prevColor.Value != curr.Color)
{
Console.ForegroundColor = curr.Color;
}
prevColor = curr.Color;
Console.Write(curr.Character);
_position++;
if (Console.CursorLeft == Console.BufferWidth - 1 && Console.CursorTop == Console.BufferHeight - 1)
{
Console.WriteLine();
Move(-1);
_position++;
}
}
RestorePosition();
_previousColors = currentColors;
return(newHighlighter);
}
public static string ReadLine(ref Highlighter highlighter)
{
highlighter = highlighter ?? new Highlighter();
_historyIndex = -1;
_current = "";
_position = 0;
_positions.Clear();
_input.Clear();
_caretIndex = 0;
_originalHighlighter = highlighter.Clone();
_previousColors = new ColoredCharacter[0];
SavePosition();
while (true)
{
var info = Console.ReadKey(true);
switch (info.Key)
{
case ConsoleKey.Enter:
var result = new string(_input.ToArray());
if (!string.IsNullOrWhiteSpace(result))
{
// add result to history
_history.Insert(0, result);
if (_history.Count > 50)
{
_history.RemoveAt(_history.Count - 1);
}
}
// restore console state
RestorePosition(_input.Count);
Console.ResetColor();
Console.WriteLine();
return(result);
case ConsoleKey.UpArrow:
if (_historyIndex >= _history.Count - 1)
{
continue;
}
if (_historyIndex == -1)
{
_current = new string(_input.ToArray());
}
_historyIndex++;
SetInput(_history[_historyIndex], out highlighter);
continue;
case ConsoleKey.DownArrow:
if (_historyIndex <= -1)
{
continue;
}
_historyIndex--;
var historyStr = _historyIndex == -1 ? _current : _history[_historyIndex];
SetInput(historyStr, out highlighter);
continue;
case ConsoleKey.LeftArrow:
if (_caretIndex == 0)
{
continue;
}
if (info.Modifiers.HasFlag(ConsoleModifiers.Control))
{
var diff = PreviousBoundary();
_caretIndex += diff;
Move(diff);
continue;
}
_caretIndex--;
Move(-1);
continue;
case ConsoleKey.RightArrow:
if (_caretIndex == _input.Count)
{
continue;
}
if (info.Modifiers.HasFlag(ConsoleModifiers.Control))
{
var diff = NextBoundary();
_caretIndex += diff;
Move(diff);
continue;
}
_caretIndex++;
Move(1);
continue;
case ConsoleKey.Home:
if (_caretIndex == 0)
{
continue;
}
Move(-_caretIndex);
_caretIndex = 0;
continue;
case ConsoleKey.End:
if (_caretIndex == _input.Count)
{
continue;
}
Move(_input.Count - _caretIndex);
_caretIndex = _input.Count;
continue;
case ConsoleKey.Backspace:
if (_caretIndex == 0)
{
continue;
}
if (info.Modifiers.HasFlag(ConsoleModifiers.Control))
{
var diff = PreviousBoundary();
_caretIndex += diff;
Move(diff);
_input.RemoveRange(_caretIndex, Math.Abs(diff));
highlighter = Redraw();
continue;
}
_caretIndex--;
_historyIndex = -1;
_input.RemoveAt(_caretIndex);
highlighter = Redraw();
Move(-1);
continue;
case ConsoleKey.Delete:
if (_caretIndex == _input.Count)
{
continue;
}
if (info.Modifiers.HasFlag(ConsoleModifiers.Control))
{
var diff = NextBoundary();
_input.RemoveRange(_caretIndex, diff);
highlighter = Redraw();
continue;
}
_historyIndex = -1;
_input.RemoveAt(_caretIndex);
highlighter = Redraw();
continue;
case ConsoleKey.Escape:
var count = _input.Count;
if (count == 0)
{
continue;
}
_input.Clear();
_caretIndex = 0;
_historyIndex = -1;
RestorePosition();
SavePosition();
highlighter = Redraw();
continue;
case ConsoleKey.Tab:
continue;
default:
if (info.KeyChar == 0)
{
continue;
}
break;
}
if (_caretIndex == _input.Count)
{
_input.Add(info.KeyChar);
}
else
{
_input.Insert(_caretIndex, info.KeyChar);
}
highlighter = Redraw();
Move(1);
_caretIndex++;
_historyIndex = -1;
}
}