@Override
  public boolean onTouchEvent(MotionEvent event) {

    float mCurX;
    float mCurY;

    // API level 9 and above supports "Major" property on event which
    // gives
    // the size of the touch area at the point of contact
    // so for now we just hard code
    float TOUCH_AREA_SIZE = penWidth;

    int action = event.getAction();
    if (action != MotionEvent.ACTION_UP && action != MotionEvent.ACTION_CANCEL) {
      int N = event.getHistorySize();
      int P = event.getPointerCount();
      for (int i = 0; i < N; i++) {
        for (int j = 0; j < P; j++) {
          mCurX = event.getHistoricalX(j, i);
          mCurY = event.getHistoricalY(j, i);
          drawPoint(mCurX, mCurY, event.getHistoricalPressure(j, i), TOUCH_AREA_SIZE);
        }
      }
      for (int j = 0; j < P; j++) {
        mCurX = event.getX(j);
        mCurY = event.getY(j);
        drawPoint(mCurX, mCurY, event.getPressure(j), TOUCH_AREA_SIZE);
      }
    }
    unsaved = true;
    return true;
  }
  /**
   * Extracts the touch point data from a MotionEvent, converts each point into a marshallable
   * object and passes the set of points to the JNI layer to be transmitted to the remote host.
   *
   * @param event The event to send to the remote host for injection. NOTE: This object must be
   *     updated to represent the remote machine's coordinate system before calling this function.
   */
  public void sendTouchEvent(MotionEvent event) {
    int action = event.getActionMasked();
    TouchEventData.EventType touchEventType = TouchEventData.EventType.fromMaskedAction(action);
    List<TouchEventData> touchEventList = new ArrayList<TouchEventData>();

    if (action == MotionEvent.ACTION_MOVE) {
      // In order to process all of the events associated with an ACTION_MOVE event, we need
      // to walk the list of historical events in order and add each event to our list, then
      // retrieve the current move event data.
      int pointerCount = event.getPointerCount();
      int historySize = event.getHistorySize();
      for (int h = 0; h < historySize; ++h) {
        for (int p = 0; p < pointerCount; ++p) {
          touchEventList.add(
              new TouchEventData(
                  event.getPointerId(p),
                  event.getHistoricalX(p, h),
                  event.getHistoricalY(p, h),
                  event.getHistoricalSize(p, h),
                  event.getHistoricalSize(p, h),
                  event.getHistoricalOrientation(p, h),
                  event.getHistoricalPressure(p, h)));
        }
      }

      for (int p = 0; p < pointerCount; p++) {
        touchEventList.add(
            new TouchEventData(
                event.getPointerId(p),
                event.getX(p),
                event.getY(p),
                event.getSize(p),
                event.getSize(p),
                event.getOrientation(p),
                event.getPressure(p)));
      }
    } else {
      // For all other events, we only want to grab the current/active pointer.  The event
      // contains a list of every active pointer but passing all of of these to the host can
      // cause confusion on the remote OS side and result in broken touch gestures.
      int activePointerIndex = event.getActionIndex();
      touchEventList.add(
          new TouchEventData(
              event.getPointerId(activePointerIndex),
              event.getX(activePointerIndex),
              event.getY(activePointerIndex),
              event.getSize(activePointerIndex),
              event.getSize(activePointerIndex),
              event.getOrientation(activePointerIndex),
              event.getPressure(activePointerIndex)));
    }

    if (!touchEventList.isEmpty()) {
      mInjector.sendTouchEvent(touchEventType, touchEventList.toArray(new TouchEventData[0]));
    }
  }