public static string FetchLine(Func <string, string> suggestionsCallback)
{
if (logStream != null)
{
throw new NotSupportedException("Log is redirected to file");
}
if (ConsoleUtils.IsOutputRedirected)
{
return(Console.ReadLine());
}
activeInput = true;
RenderInputPrompt();
Console.CursorVisible = true;
Console.TreatControlCAsInput = true;
int consoleWidth;
buffer = new StringBuilder();
bufferPosition = 0;
bufferLastLength = 0;
activeSuggestion = null;
if (inputHistory == null)
{
inputHistory = new History();
}
inputHistory.CursorToEnd();
inputHistory.Append("");
while (activeInput)
{
bool isChanged = false;
ConsoleModifiers mod;
ConsoleKeyInfo cki = Console.ReadKey(true);
if (cki.Key == ConsoleKey.Escape)
{
cki = Console.ReadKey(true);
mod = ConsoleModifiers.Alt;
}
else
{
mod = cki.Modifiers;
}
// Process input
switch (cki.Key)
{
case ConsoleKey.Enter: {
if (buffer.Length > 0)
{
activeInput = false;
isChanged = true;
}
break;
}
case ConsoleKey.LeftArrow: {
if (bufferPosition > 0)
{
bufferPosition--;
}
break;
}
case ConsoleKey.RightArrow: {
if (bufferPosition < buffer.Length)
{
bufferPosition++;
}
else if (activeSuggestion != null)
{
buffer.Clear();
buffer.Append(activeSuggestion);
bufferPosition = buffer.Length;
isChanged = true;
}
break;
}
case ConsoleKey.UpArrow: {
if (inputHistory != null && inputHistory.IsPreviousAvailable)
{
inputHistory.UpdateCurrent(buffer.ToString());
buffer.Clear();
buffer.Append(inputHistory.GetPrevious());
bufferPosition = buffer.Length;
isChanged = true;
}
break;
}
case ConsoleKey.DownArrow: {
if (inputHistory != null && inputHistory.IsNextAvailable)
{
inputHistory.UpdateCurrent(buffer.ToString());
buffer.Clear();
buffer.Append(inputHistory.GetNext());
bufferPosition = buffer.Length;
isChanged = true;
}
break;
}
case ConsoleKey.Home: {
bufferPosition = 0;
break;
}
case ConsoleKey.End: {
bufferPosition = buffer.Length;
break;
}
case ConsoleKey.Backspace: {
if (bufferPosition > 0)
{
bufferPosition--;
buffer.Remove(bufferPosition, 1);
isChanged = true;
}
break;
}
case ConsoleKey.Delete: {
if (bufferPosition < buffer.Length)
{
buffer.Remove(bufferPosition, 1);
isChanged = true;
}
break;
}
case ConsoleKey.Tab: {
if (activeSuggestion != null)
{
buffer.Clear();
buffer.Append(activeSuggestion);
bufferPosition = buffer.Length;
isChanged = true;
}
break;
}
default: {
if (mod == ConsoleModifiers.Control && cki.Key == ConsoleKey.C)
{
// CTRL+C: Close
activeInput = false;
buffer = null;
}
else if (mod == ConsoleModifiers.Control && cki.Key == ConsoleKey.L)
{
// CTRL+L: Clear screen
Console.Clear();
Console.SetCursorPosition(0, 0);
RenderInputPrompt();
isChanged = true;
}
else if (cki.KeyChar != (char)0 && !char.IsControl(cki.KeyChar))
{
buffer.Insert(bufferPosition, cki.KeyChar);
bufferPosition++;
isChanged = true;
}
break;
}
}
// Fetch suggestions
if (activeInput && isChanged && suggestionsCallback != null)
{
activeSuggestion = suggestionsCallback(buffer.ToString());
}
RenderInput(isChanged);
isChanged = false;
}
Console.TreatControlCAsInput = false;
Console.CursorVisible = false;
activeInput = false;
if (buffer != null)
{
// Set cursor position to the end and create a new line
consoleWidth = Console.BufferWidth;
Console.SetCursorPosition((activeInputX + buffer.Length) % consoleWidth, activeInputY + (activeInputX + buffer.Length) / consoleWidth);
Console.WriteLine();
string input = buffer.ToString();
if (string.IsNullOrEmpty(input))
{
inputHistory.Discard();
}
else
{
inputHistory.Accept(input);
}
return(input);
}
else
{
// Erase input line
Console.SetCursorPosition(0, activeInputY);
Console.ResetColor();
for (int i = 0; i <= activeInputX + bufferLastLength; i++)
{
Console.Write(' ');
}
Console.SetCursorPosition(0, activeInputY);
return(null);
}
}