How to distinguish between move and click in onTouchEvent()?

Question

In my application, I need to handle both move and click events.

A click is a sequence of one ACTION_DOWN action, several ACTION_MOVE actions and one ACTION_UP action

Answer 1

Taking Jonik's lead I built a slightly more fine tuned version, that doesn't register as a click if you move your finger and then return to the spot before letting go:

So here is my solution:

/**
 * Max allowed duration for a "click", in milliseconds.
 */
private static final int MAX_CLICK_DURATION = 1000;

/**
 * Max allowed distance to move during a "click", in DP.
 */
private static final int MAX_CLICK_DISTANCE = 15;

private long pressStartTime;
private float pressedX;
private float pressedY;
private boolean stayedWithinClickDistance;

@Override
public boolean onTouchEvent(MotionEvent e) {
     switch (e.getAction()) {
        case MotionEvent.ACTION_DOWN: {
            pressStartTime = System.currentTimeMillis();                
            pressedX = e.getX();
            pressedY = e.getY();
            stayedWithinClickDistance = true;
            break;
        }
        case MotionEvent.ACTION_MOVE: {
            if (stayedWithinClickDistance && distance(pressedX, pressedY, e.getX(), e.getY()) > MAX_CLICK_DISTANCE) {
                stayedWithinClickDistance = false;
            }
            break;
        }     
        case MotionEvent.ACTION_UP: {
            long pressDuration = System.currentTimeMillis() - pressStartTime;
            if (pressDuration < MAX_CLICK_DURATION && stayedWithinClickDistance) {
                // Click event has occurred
            }
        }     
    }
}

private static float distance(float x1, float y1, float x2, float y2) {
    float dx = x1 - x2;
    float dy = y1 - y2;
    float distanceInPx = (float) Math.sqrt(dx * dx + dy * dy);
    return pxToDp(distanceInPx);
}

private static float pxToDp(float px) {
    return px / getResources().getDisplayMetrics().density;
}