source: trunk/src/org/expeditee/gio/input/InputEventToGestureTranslatorSet.java@ 1127

package org.expeditee.gio.input;

import java.util.LinkedList;
import java.util.List;
import java.util.Set;

import org.expeditee.gio.gesture.Gesture;
import org.expeditee.gio.input.InputEvent.InputType;

/**
 * An input-event -> gesture translator that is the aggregation of a set of
 * other translators.
 * 
 * @author cts16
 */
public class InputEventToGestureTranslatorSet extends InputEventToGestureTranslator {
        /** The individual gesture recognisers. */
        private List<InputEventToGestureTranslator> _recognisers;

        public InputEventToGestureTranslatorSet() {
                _recognisers = new LinkedList<InputEventToGestureTranslator>();
        }

        /** Adds a sub-translator to this translator set. */
        public void addTranslator(InputEventToGestureTranslator translator) {
                if (translator == null)
                        return;

                _recognisers.add(translator);

                Set<InputType> recogniserMonitoredTypes = translator.getMonitoredInputTypes();
                if (recogniserMonitoredTypes != null)
                        _monitoredInputTypes.addAll(recogniserMonitoredTypes);
        }

        @Override
        public String details() {
                if (_recognisers.isEmpty())
                        return "";

                // Aggregate the details of the individual gesture recognisers
                String details = "";
                for (InputEventToGestureTranslator recogniser : _recognisers) {
                        String recogniserDetails = recogniser.details();
                        if (recogniserDetails != null && recogniserDetails != "") {
                                if (details != "")
                                        details += "\n";
                                details += recogniserDetails;
                        }
                }

                return details;
        }

        @Override
        public List<Gesture> onInputEvent(InputEvent event) {
                if (_recognisers.isEmpty())
                        return null;

                // Only interested in monitored events
                if (event == null || !isMonitoredType(event.getInputType()))
                        return null;

                // Aggregate the responses of all individual gesture listeners
                List<Gesture> gestures = new LinkedList<Gesture>();

                for (InputEventToGestureTranslator recogniser : _recognisers) {
                        if (recogniser.isMonitoredType(event.getInputType())) {
                                List<Gesture> recogniserGestures = recogniser.onInputEvent(event);
                                if (recogniserGestures != null) {
                                        gestures.addAll(recogniserGestures);
                                }
                        }
                }

                return gestures;
        }
}