GestureComponent.java

package com.dronecontrol.perceptual.components;

import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import com.dronecontrol.perceptual.PerceptualPipeline;
import com.dronecontrol.perceptual.data.events.GestureData;
import com.dronecontrol.perceptual.listeners.GestureListener;
import intel.pcsdk.PXCMGesture;

import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

public class GestureComponent implements PerceptualQueryComponent {
    private static final int GESTURE_NUBMER_THRESHOLD = 2;

    private static final int NUMBER_OF_GESTURE_SAMPLES = 5;

    private Set<GestureListener> gestureListeners = Sets.newHashSet();

    private PXCMGesture.Gesture gesture;

    private List<Integer> lastGestureLabels = Lists.newArrayList();

    private GestureData.GestureType currentlyActiveGestureType;

    private final Map<Integer, GestureData.GestureType> gestureTypeMap = new LinkedHashMap<Integer, GestureData.GestureType>() {{
        put(PXCMGesture.Gesture.LABEL_ANY, GestureData.GestureType.NONE);
        put(PXCMGesture.Gesture.LABEL_POSE_THUMB_UP, GestureData.GestureType.THUMBS_UP);
        put(PXCMGesture.Gesture.LABEL_POSE_THUMB_DOWN, GestureData.GestureType.THUMBS_DOWN);
        put(PXCMGesture.Gesture.LABEL_POSE_BIG5, GestureData.GestureType.BIG_FIVE);
    }};

    public GestureComponent() {
        currentlyActiveGestureType = GestureData.GestureType.NONE;
    }

    @Override
    public void queryFeatures(PerceptualPipeline pipeline) {
        gesture = new PXCMGesture.Gesture();
        pipeline.QueryGesture(PXCMGesture.Gesture.LABEL_ANY, gesture);
    }

    @Override
    public void processFeatures() {
        addLabelToLastGestureLabels();
        Map<Integer, Integer> labelCountMap = determineLabelCountMap();
        Integer detectedLabel = getDetectedLabel(labelCountMap);

        if (!gestureTypeMap.containsKey(detectedLabel)) {
            return;
        }

        GestureData.GestureType gestureType = gestureTypeMap.get(detectedLabel);
        invokeGesture(gestureType);
    }

    private void addLabelToLastGestureLabels() {
        lastGestureLabels.add(gesture.label);
        while (lastGestureLabels.size() > NUMBER_OF_GESTURE_SAMPLES) {
            lastGestureLabels.remove(0);
        }
    }

    private Map<Integer, Integer> determineLabelCountMap() {
        Map<Integer, Integer> gestureLabelCount = Maps.newHashMap();
        for (Integer label : lastGestureLabels) {
            if (label == PXCMGesture.Gesture.LABEL_ANY) {
                continue;
            }

            if (!gestureLabelCount.containsKey(label)) {
                gestureLabelCount.put(label, 0);
            }

            int oldCount = gestureLabelCount.get(label);
            gestureLabelCount.put(label, oldCount + 1);
        }
        return gestureLabelCount;
    }

    private Integer getDetectedLabel(Map<Integer, Integer> gestureLabelCount) {
        Integer labelWithHighestEntryCount = PXCMGesture.Gesture.LABEL_ANY;
        Integer maxCount = 0;
        for (Map.Entry<Integer, Integer> entry : gestureLabelCount.entrySet()) {
            int currentLabel = entry.getKey();
            int currentCount = entry.getValue();

            if (currentCount > maxCount) {
                labelWithHighestEntryCount = currentLabel;
                maxCount = currentCount;
            }
        }
        return maxCount > GESTURE_NUBMER_THRESHOLD ? labelWithHighestEntryCount : PXCMGesture.Gesture.LABEL_ANY;
    }

    private void invokeGesture(GestureData.GestureType gestureType) {
        if (currentlyActiveGestureType != gestureType) {
            currentlyActiveGestureType = gestureType;
            invokeGestureListeners(new GestureData(gestureType));
        }
    }

    public void addGestureListener(GestureListener gestureListener) {
        if (!gestureListeners.contains(gestureListener)) {
            gestureListeners.add(gestureListener);
        }
    }

    public void removeGestureListener(GestureListener gestureListener) {
        if (gestureListeners.contains(gestureListener)) {
            gestureListeners.remove(gestureListener);
        }
    }

    private void invokeGestureListeners(GestureData data) {
        for (GestureListener listener : gestureListeners) {
            listener.onGesture(data);
        }
    }
}