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Is it possible to get the speed or velocity or acceleration of touch event in android with the existing api? I have gone through MotionEvent class and none of the fields in that class seem to retrieve information that i need. Any help would be greatly appreciated

user1253887
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  • MotionEvents don't track accelerometer events: see here: http://developer.android.com/reference/android/view/MotionEvent.html You need to get an instance of SensorManager for accelerometer events There's a great example here: http://www.techrepublic.com/blog/app-builder/a-quick-tutorial-on-coding-androids-accelerometer/472 – Jian Chen Apr 14 '12 at 19:52
  • I think he don't mean accelerometer. – Dmitry Zaytsev Apr 14 '12 at 19:59
  • Yes, i dont mean accelerometer. What i meant was speed or velocity of gesture – user1253887 Apr 14 '12 at 21:03

2 Answers2

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MotionEvent does not help you in this case. You can use VelocityTracker class. It gets MotionEvent instances and calculates velocity of recent touch events. You can take a look at its documentation here: http://developer.android.com/reference/android/view/VelocityTracker.html

First you have to get an instance by obtain() method:

VelocityTracker velocity = VelocityTracker.obtain();

then you can add ACTION_MOVE events to its queue:

    if(event.getAction() == MotionEvent.ACTION_MOVE)
    {
        velocity.addMovement(event);
    }

then you can compute velocity and extract x_velocity and y_velocity

velocity.computeCurrentVelocity(1000);
float x_velocity = velocity.getXVelocity();
float y_velocity = velocity.getYVelocity();

I hope it works for you.

Ali Samz
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You need to calculate velocity manually between each two events using System.nanoTime. Same way for acceleration (but using velocity instead of coordinates this time).

Dmitry Zaytsev
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