Method CheckForUrgentCommand

src/GCodes/GCodeInput.cpp:118–204

Check a character for urgent commands: M112 (emergency stop), M122 (diagnostics) and M108 (cancel wait for temperature). Return true if an urgent command was handled and the buffer was reset

// Check a character for urgent commands: M112 (emergency stop), M122 (diagnostics) and M108 (cancel wait for temperature).
// Return true if an urgent command was handled and the buffer was reset
bool RegularGCodeInput::CheckForUrgentCommand(char c) noexcept
{
	if (writingFile)
	{
		return false;
	}

	switch (state)
	{
		case GCodeInputState::idle:
			if (c > ' ')
			{
				state = (c == 'M' || c == 'm') ? GCodeInputState::doingMCode : GCodeInputState::doingCode;
			}
			break;

		case GCodeInputState::doingCode:
			if (c == 0 || c == '\r' || c == '\n')
			{
				state = GCodeInputState::idle;
			}
			break;

		case GCodeInputState::doingMCode:
			state = (c == '1') ? GCodeInputState::doingMCode1 : GCodeInputState::doingCode;
			break;

		case GCodeInputState::doingMCode1:
			state = (c == '0') ? GCodeInputState::doingMCode10
				  : (c == '1') ? GCodeInputState::doingMCode11
				  : (c == '2') ? GCodeInputState::doingMCode12
				  : GCodeInputState::doingCode;
			break;

		case GCodeInputState::doingMCode10:
			state = (c == '8') ? GCodeInputState::doingMCode108 : GCodeInputState::doingCode;
			break;

		case GCodeInputState::doingMCode11:
			state = (c == '2') ? GCodeInputState::doingMCode112 : GCodeInputState::doingCode;
			break;

		case GCodeInputState::doingMCode12:
			state = (c == '2') ? GCodeInputState::doingMCode122 : GCodeInputState::doingCode;
			break;

		case GCodeInputState::doingMCode108:
			if (c < ' ' || c == ';')
			{
				reprap.GetGCodes().CancelWaitForTemperatures(false);
				// Normally we would call Reset and then return here to prevent the command being executed twice.
				// However, the host may be expecting an empty response, which we can't always send from here.
				// So we allow the command to be queued and executed again, which is harmless.
			}
			state = GCodeInputState::doingCode;
			break;

		case GCodeInputState::doingMCode112: