smccsharpgenerator.java

SMC takes a state machine stored in a .sm file and generates a State pattern in twelve programming l

        {
            _source.println();
            _source.println();
        }

        // End of transition.
        _source.print(_indent);
        _source.println("    return;");
        _source.print(_indent);
        _source.println("}");

        return;
    } // end of visit(SmcTransition)

    public void visit(SmcGuard guard)
    {
        SmcTransition transition = guard.getTransition();
        SmcState state = transition.getState();
        SmcMap map = state.getMap();
        String context = map.getFSM().getContext();
        String mapName = map.getName();
        String stateName = state.getClassName();
        int transType = guard.getTransType();
        boolean defaultFlag =
            stateName.equalsIgnoreCase("Default");
        boolean loopbackFlag = false;
        String indent2;
        String indent3;
        String indent4;
        String endStateName = guard.getEndState();
        String fqEndStateName = "";
        String pushStateName = guard.getPushState();
        String condition = guard.getCondition();
        List<SmcAction> actions = guard.getActions();
        boolean hasActions = !(actions.isEmpty());

        // If this guard's end state is not of the form
        // "map::state", then prepend the map name to the
        // state name.
        // DON'T DO THIS IF THIS IS A POP TRANSITION!
        // The "state" is actually a transition name.
        if (transType != Smc.TRANS_POP &&
            endStateName.length () > 0 &&
            endStateName.equals(NIL_STATE) == false)
        {
            endStateName = scopeStateName(endStateName, mapName);
        }

        // Qualify the state and push state names as well.
        stateName = scopeStateName(stateName, mapName);
        pushStateName = scopeStateName(pushStateName, mapName);

        loopbackFlag =
            isLoopback(transType, stateName, endStateName);

        // The guard code generation is a bit tricky. The first
        // question is how many guards are there? If there are
        // more than one, then we will need to generate the
        // proper "if-then-else" code.
        if (_guardCount > 1)
        {
            indent2 = _indent + "        ";

            // There are multiple guards.
            // Is this the first guard?
            if (_guardIndex == 0 && condition.length() > 0)
            {
                // Yes, this is the first. This means an "if"
                // should be used.
                _source.print(_indent);
                _source.print("    if (");
                _source.print(condition);
                _source.println(")");
                _source.print(_indent);
                _source.println("    {");
            }
            else if (condition.length() > 0)
            {
                // No, this is not the first transition but it
                // does have a condition. Use an "else if".
                _source.println();
                _source.print(_indent);
                _source.print("    else if (");
                _source.print(condition);
                _source.println(")");
                _source.print(_indent);
                _source.println("    {");
            }
            else
            {
                // This is not the first transition and it has
                // no condition.
                _source.println();
                _source.print(_indent);
                _source.println("    else");
                _source.print(_indent);
                _source.println("    {");
            }
        }
        // There is only one guard. Does this guard have
        // a condition?
        else if (condition.length() == 0)
        {
            // No. This is a plain, old. vanilla transition.
            indent2 = _indent + "    ";
        }
        else
        {
            // Yes there is a condition.
            indent2 = _indent + "        ";

            _source.print(_indent);
            _source.print("    if (");
            _source.print(condition);
            _source.println(")");
            _source.print(_indent);
            _source.println("    {");
        }

        // Now that the necessary conditions are in place, it's
        // time to dump out the transition's actions. First, do
        // the proper handling of the state change. If this
        // transition has no actions, then set the end state
        // immediately. Otherwise, unset the current state so
        // that if an action tries to issue a transition, it will
        // fail.
        if (hasActions == false && endStateName.length() != 0)
        {
            fqEndStateName = endStateName;
        }
        else if (hasActions == true)
        {
            // Save away the current state if this is a loopback
            // transition. Storing current state allows the
            // current state to be cleared before any actions are
            // executed. Remember: actions are not allowed to
            // issue transitions and clearing the current state
            // prevents them from doing do.
            if (loopbackFlag == true)
            {
                fqEndStateName = "endState";

                _source.print(indent2);
                _source.print(context);
                _source.print("State ");
                _source.print(fqEndStateName);
                _source.println(" = context.State;");
            }
            else
            {
                fqEndStateName = endStateName;
            }
        }

        // Decide if runtime loopback checking must be done.
        if (defaultFlag == true &&
            transType != Smc.TRANS_POP &&
            loopbackFlag == false)
        {
            _source.print(indent2);
            _source.println("bool loopbackFlag =");
            _source.print(indent2);
            _source.print(
                "    (context.State.Name == ");
            _source.print(fqEndStateName);
            _source.println(".Name);");
        }

        _source.println();

        // Dump out the exit actions if
        // 1) this is a standard, non-loopback transition or
        // 2) a pop transition.
        if (transType == Smc.TRANS_POP || loopbackFlag == false)
        {
            indent4 = indent2;

            // If this is a non-loopback, generic transition,
            // do runtime loopback checking.
            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                indent4 = indent2 + "    ";

                _source.print(indent2);
                _source.println("if (loopbackFlag == false)");
                _source.print(indent2);
                _source.println("{");
            }

            _source.print(indent4);
            _source.println("context.State.Exit(context);");

            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                _source.print(indent2);
                _source.println("}");
                _source.println();
            }
        }

        // Dump out this transition's actions.
        if (hasActions == false)
        {
            if (condition.length() > 0)
            {
                _source.print(indent2);
                _source.println("// No actions.");
            }

            indent3 = indent2;
        }
        else
        {
            // Now that we are in the transition, clear the
            // current state.
            _source.print(indent2);
            _source.println("context.ClearState();");

            // v. 2.0.0: Place the actions inside a try/finally
            // block. This way the state will be set before an
            // exception leaves the transition method.
            // v. 2.2.0: Check if the user has turned off this
            // feature first.
            if (Smc.isNoCatch() == false)
            {
                _source.println();
                _source.print(indent2);
                _source.println("try");
                _source.print(indent2);
                _source.println("{");

                indent3 = indent2 + "    ";
            }
            else
            {
                indent3 = indent2;
            }

            indent4 = _indent;
            _indent = indent3;
            for (SmcAction action: actions)
            {
                action.accept(this);
            }
            _indent = indent4;

            // v. 2.2.0: Check if the user has turned off this
            // feature first.
            if (Smc.isNoCatch() == false)
            {
                _source.print(indent2);
                _source.println("}");
                _source.print(indent2);
                _source.println("finally");
                _source.print(indent2);
                _source.println("{");
            }
        }

        // Print the state assignment if necessary. Do NOT
        // generate the state assignment if:
        // 1. The transition has no actions AND is a loopback OR
        // 2. This is a push or pop transition.
        if (transType == Smc.TRANS_SET &&
            (hasActions == true || loopbackFlag == false))
        {
            _source.print(indent3);
            _source.print("context.State = ");
            _source.print(fqEndStateName);
            _source.println(";");
        }
        else if (transType == Smc.TRANS_PUSH)
        {
            // Set the next state so this it can be pushed
            // onto the state stack. But only do so if a clear
            // state was done.
            // v. 4.3.0: If the full-qualified end state is
            // "nil", then don't need to do anything.
            if ((loopbackFlag == false || hasActions == true) &&
                fqEndStateName.equals(NIL_STATE) == false)
            {
                _source.print(indent3);
                _source.print("context.State = ");
                _source.print(fqEndStateName);
                _source.println(";");
            }

            // Before doing the push, execute the end state's
            // entry actions (if any) if this is not a loopback.
            if (loopbackFlag == false)
            {
                if (defaultFlag == true)
                {
                    indent4 = indent3 + "    ";

                    _source.println();
                    _source.print(indent3);
                    _source.println(
                        "if (loopbackFlag == false)");
                    _source.print(indent3);
                    _source.println("{");
                }
                else
                {
                    indent4 = indent3;
                }

                _source.print(indent4);
                _source.println("context.State.Entry(context);");

                if (defaultFlag == true)
                {
                    _source.print(indent3);
                    _source.println("}");
                }
            }

            _source.print(indent3);
            _source.print("context.PushState(");
            _source.print(pushStateName);
            _source.println(");");
        }
        else if (transType == Smc.TRANS_POP)
        {
            _source.print(indent3);
            _source.println("context.PopState();");
        }

        // Perform the new state's enty actions if:
        // 1) this is a standard, non-loopback transition or
        // 2) a push transition.
        if ((transType == Smc.TRANS_SET &&
              endStateName.equals(NIL_STATE) == false &&
              endStateName.equals(stateName) == false) ||
             transType == Smc.TRANS_PUSH)
        {
            indent4 = indent3;

            // If this is a non-loopback, generic transition,
            // do runtime loopback checking.
            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                indent4 = indent3 + "    ";

                _source.println();
                _source.print(indent3);
                _source.println("if (loopbackFlag == false)");
                _source.print(indent3);
                _source.println("{");
            }

            _source.print(indent4);
            _source.println("context.State.Entry(context);");

            if (transType == Smc.TRANS_SET &&
                defaultFlag == true)
            {
                _source.print(indent3);
                _source.println("}");
                _source.println();
            }
        }

        // If there was a try/finally, then put the closing
        // brace on the finally block.
        // v. 2.2.0: Check if the user has turned off this
        // feature first.
        if (hasActions == true && Smc.isNoCatch() == false)
        {
            _source.print(indent2);
            _source.println("}");
            _source.println();
        }

        // If there is a transition associated with the pop, then
        // issue that transition here.
        if (transType == Smc.TRANS_POP &&
            endStateName.equals(NIL_STATE) == false &&