MoveGestureDetector.java 文件源码

/**
 * Determine (multi)finger focal point (a.k.a. center point between all
 * fingers)
 *
 * @return PointF focal point
 */
private PointF determineFocalPoint(MotionEvent e) {
    // Number of fingers on screen
    final int pCount = e.getPointerCount();
    float x = 0f;
    float y = 0f;

    for (int i = 0; i < pCount; i++) {
        x += e.getX(i);
        y += e.getY(i);
    }

    return new PointF(x / pCount, y / pCount);
}