/// <summary>
/// This method checks if the command line has a valid insert command at the valid position.
/// </summary>
/// <param name="commandLine">The command line the user has written.</param>
/// <exception cref="ArgumentNullException">
/// If the commandLine is null.
/// </exception>
/// <returns>An instanced insert command if the command is valid or null if the command is not valid.</returns>
public static IEditorCommand Parse(string commandLine)
{
if (commandLine == null)
{
throw new ArgumentNullException();
}
string[] possibleCommands = commandLine.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
if (possibleCommands.Length < 3)
{
return(null);
}
string value = possibleCommands[1];
int editorValue;
try
{
editorValue = int.Parse(value);
}
catch
{
return(null);
}
string[] newpossibleCommands = new string[possibleCommands.Length - 1];
newpossibleCommands[0] = possibleCommands[0];
if (newpossibleCommands.Length == 2)
{
newpossibleCommands[1] = possibleCommands[2];
}
else if (newpossibleCommands.Length == 3)
{
newpossibleCommands[1] = possibleCommands[2];
newpossibleCommands[2] = possibleCommands[3];
}
commandLine = string.Join(" ", newpossibleCommands);
string command = newpossibleCommands[1].ToLower();
ITurtleCommand turtleCommand = null;
switch (command)
{
case "move":
turtleCommand = MoveCommand.Parse(commandLine);
break;
case "rotate":
turtleCommand = RotateCommand.Parse(commandLine);
break;
case "sleep":
turtleCommand = SleepCommand.Parse(commandLine);
break;
case "penup":
turtleCommand = PenUpCommand.Parse(commandLine);
break;
case "pendown":
turtleCommand = PenDownCommand.Parse(commandLine);
break;
case "changecolor":
turtleCommand = ChangeColorCommand.Parse(commandLine);
break;
case "changetracksymbol":
turtleCommand = ChangeTrackSymbolCommand.Parse(commandLine);
break;
case "changeturtlesymbol":
turtleCommand = ChangeTurtleSymbolCommand.Parse(commandLine);
break;
}
if (turtleCommand != null && editorValue > 0)
{
turtleValue = turtleCommand.GetValue();
return(new InsertCommand(editorValue, turtleCommand));
}
else
{
return(null);
}
}
/// <summary>
/// This method checks if the command line has a valid add command at the valid position.
/// </summary>
/// <param name="commandLine">The command line the user has written.</param>
/// <exception cref="ArgumentNullException">
/// If the commandLine is null.
/// </exception>
/// <returns>An instanced add command if the command is valid or null if the command is not valid.</returns>
public static IEditorCommand Parse(string commandLine)
{
if (commandLine == null)
{
throw new ArgumentNullException();
}
string[] possibleCommands = commandLine.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
if (possibleCommands.Length <= 1 || possibleCommands.Length >= 4)
{
return(null);
}
string command = possibleCommands[1].ToLower();
ITurtleCommand turtleCommand = null;
switch (command)
{
case "move":
turtleCommand = MoveCommand.Parse(commandLine);
break;
case "rotate":
turtleCommand = RotateCommand.Parse(commandLine);
break;
case "sleep":
turtleCommand = SleepCommand.Parse(commandLine);
break;
case "penup":
turtleCommand = PenUpCommand.Parse(commandLine);
break;
case "pendown":
turtleCommand = PenDownCommand.Parse(commandLine);
break;
case "changecolor":
turtleCommand = ChangeColorCommand.Parse(commandLine);
break;
case "changetracksymbol":
turtleCommand = ChangeTrackSymbolCommand.Parse(commandLine);
break;
case "changeturtlesymbol":
turtleCommand = ChangeTurtleSymbolCommand.Parse(commandLine);
break;
}
if (turtleCommand != null)
{
return(new AddCommand(turtleCommand));
}
else
{
return(null);
}
}