Android move view to a touched position

Question

I'm trying to develop an android application similar to "on color measurement" or "color grab" which are already on google play. I have problem with getting the exact position of a view (which acts like focus square) and move it to the position where the user touches the screen. I have done a lot of searches but all of them ended in onTouchEvent() which I used it but it does not work properly or maybe I have done something wrong. Actually the view moves but it won't be placed exactly where the user touch, it will go below the touched area in y axis with a distance.

here is my code where the mFocusRectangle is the custom view which I want to move to the touched position:

@Override
public boolean onTouchEvent(MotionEvent event) {

    int action = event.getAction();
if (event.getPointerCount() > 1) {
        // handle multi-touch events

    } else {
        // handle single touch events
        if(action==MotionEvent.ACTION_DOWN){

        }
        if (action == MotionEvent.ACTION_UP) {
            int pointerId = event.getPointerId(0);
            int pointerIndex = event.findPointerIndex(pointerId);
            // Get the pointer's current position
            float x = event.getX(pointerIndex);
            float y = event.getY(pointerIndex);
            mFocusRectangle.showStart();
            mFocusRectangle.setX(x);
            mFocusRectangle.setY(y);

        }
    }
    return true;
}

I have also tried MotionEvent.ACTION_DOWN but the result is the same. Thanks in advance.

try this `float x = event.getX(0); float y = event.getY(0);` does that work? — The Badak, Aug 04 '15 at 13:58
@AwaisKing showStart() set a drawable to the mfocusRectangle. I've tried 'float x = event.getX(0); float y = event.getY(0);' but in this case also the view moves to a wrong position — elahe, Aug 04 '15 at 14:44
@elahe I am actually trying to find out are you using canvas and if yes where is it? — P-RAD, Aug 05 '15 at 05:43
becoz when we deal with canvas we can redraw the image rather than moving it( technically both are same though) — P-RAD, Aug 05 '15 at 05:44
@Dev no I did not use canvas. So what am I supposed to do now? — elahe, Aug 08 '15 at 04:12
Here is an example http://thegeekyland.blogspot.com/2015/12/android-animations-explained.html — Arlind Hajredinaj, Dec 06 '15 at 13:44

score 0 · Answer 1 · edited May 23 '17 at 12:04

0

try this

float x = event.getX(pointerIndex) - (mFocusRectangle.getWidth() / 2);
float y = event.getY(pointerIndex) - (mFocusRectangle.getHeight() / 2);

credits: Manitoba - Android move view on touch event

edited May 23 '17 at 12:04

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answered Aug 05 '15 at 11:17

The Badak

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Android move view to a touched position

1 Answers1