Example usage for org.apache.commons.scxml SCInstance getContext

Introduction

In this page you can find the example usage for org.apache.commons.scxml SCInstance getContext.

Prototype

public Context getContext(final TransitionTarget transitionTarget) 

Source Link

Document

Get the Context for this TransitionTarget.

Usage

From source file:de.dfki.iui.mmds.scxml.engine.impl.SCXMLEngineImpl.java

@Override
public Map<String, Map<String, List<Object[]>>> getAvailableEventsStates() {
    Map<String, Map<String, List<Object[]>>> eventsStates = new HashMap<String, Map<String, List<Object[]>>>();
    if (engine.getCurrentStatus().isFinal())
        // stop the interpretation by sending an empty config/available
        // event states
        return eventsStates;

    String event, id;// w w  w. j  a v  a 2s  .  c  o  m
    Map<String, List<Object[]>> states;
    Map<String, Object> vars, rootVars;
    List<Object[]> state;
    int pos;
    SCInstance sci = engine.getSCInstance();
    Set<String> datas;

    for (TransitionTarget tt : engine.getCurrentStatus().getAllStates()) {
        id = tt.getId();
        pos = 0;
        for (Transition t : tt.getTransitionsList()) {
            event = t.getEvent();
            event = (event != null || engine.isSuperStep()) ? event : TriggerEvent.EMPTY_EVENT;
            if (event != null) {
                // 1. add all events to the configuration
                if (!eventsStates.containsKey(event)) {
                    eventsStates.put(event, new HashMap<String, List<Object[]>>());
                }

                // 2. add all active source states to the config
                states = eventsStates.get(event);
                if (!states.containsKey(id)) {
                    states.put(id, new LinkedList<Object[]>());
                }

                // 3. add the transition condition to the config
                state = states.get(id);

                /*
                 * the following 4 values in the Object array indicate: i)
                 * the position of the transition ii) the condition of the
                 * transition iii) that the evaluation of the transition's
                 * condition is not performed in the last step, i.e. it is
                 * 'UNKNOWN' // * iii) that the transition condition was not
                 * changed in the last step, i.e. no dynamical change and
                 * this is not a 'refresh' event
                 */
                state.add(new Object[] { pos, t.getCond() == null ? "" : t.getCond(), -1 });

                // 4. add all contexts to the config
                vars = new HashMap<String, Object>();
                while (tt != null) {
                    vars.putAll(sci.getContext(tt).getVars());
                    tt = tt.getParent();
                }
                rootVars = sci.getRootContext().getVars();
                if (rootVars != null) {
                    vars.putAll(rootVars);
                }

                // to skip double entries the names of all datas in the
                // state config are needed
                // the following set/for-loop could be removed if the used
                // list would check double occurrences itself -> exchange
                // LinkedList by something else
                datas = new HashSet<String>();
                for (Object[] data : state) {
                    if (data[0] instanceof String) {
                        datas.add((String) data[0]);
                    }
                }
                for (Entry<String, Object> e : vars.entrySet()) {
                    /*
                     * the following 3 values in the Object array indicate:
                     * i) the name of the data ii) the current value of the
                     * data iii) that the data value was not changed in the
                     * last step, i.e. no dynamical change and this is not a
                     * 'refresh' event
                     */
                    if (!datas.contains(e.getKey())) {
                        state.add(new Object[] { e.getKey(), e.getValue(), false });
                        datas.add(e.getKey());
                    }
                }
            }
            pos++;
        }
    }
    return eventsStates;
}

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