Android libgdx swipe left and right detection using gesture listener

Question

I have displayed a image at the center of the screen with libgdx. If i swipe left the image should move left and if i swipe right image should move right.

Subsequent swipes to the left should move the image left. The same should happen for right. I used GestureListener.

It works to some extent in the sense if i swipe left first image moves left. But after that if i try to swipe right the image still moves left.

So how do i overcome this in libgdx??

    class MyGestureListener implements GestureListener {

        @Override
        public boolean fling(float arg0, float arg1, int arg2) {
            // TODO Auto-generated method stub


              if(arg0>0)
               iX += 20;
              else
             // else if(arg0*100>iX)
                  iX-=20;
               System.out.println("Hello..............."+iX);
            return true;
        }

   Gdx.input.setInputProcessor(new GestureDetector(0.0f, 0.0f,0.0f, 5f,new MyGestureListener()));

   batch.draw(splashTexture, iX, iY);

Answer 1

I used the example in this link. https://github.com/libgdx/libgdx/blob/master/tests/gdx-tests/src/com/badlogic/gdx/tests/GestureDetectorTest.java.

   @Override
   public boolean fling(float velocityX, float velocityY, int button) {
       if(Math.abs(velocityX)>Math.abs(velocityY)){
               if(velocityX>0){
                       iX+=20;//x cordinate
               }else if (velocityX<0){
                      iX-=20;
               } else {
                 // Do nothing.
               }
       }else{

          // Ignore the input, because we don't care about up/down swipes.
       }
 return true; 
}

Answer 2

    public class Test extends Activity{

private GestureDetector gesturedetector = null;

View layout;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.test);

layout = (LinearLayout)findViewById(R.id.container);

gesturedetector = new GestureDetector(new MyGestureListener());

layout.setOnTouchListener(new OnTouchListener() {

@Override

public boolean onTouch(View v, MotionEvent event) {

gesturedetector.onTouchEvent(event);

return true;

}

});

}

public boolean dispatchTouchEvent(MotionEvent ev){

super.dispatchTouchEvent(ev);

return gesturedetector.onTouchEvent(ev);

}

class MyGestureListener extends GestureDetector.SimpleOnGestureListener{

private static final int SWIPE_MIN_DISTANCE = 150;

private static final int SWIPE_MAX_OFF_PATH = 100;

private static final int SWIPE_THRESHOLD_VELOCITY = 100;

@Override

public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,

float velocityY) {

float dX = e2.getX()-e1.getX();

float dY = e1.getY()-e2.getY();

if (Math.abs(dY)<SWIPE_MAX_OFF_PATH &&

Math.abs(velocityX)>=SWIPE_THRESHOLD_VELOCITY &&

Math.abs(dX)>=SWIPE_MIN_DISTANCE ) {

if (dX>0) {

Toast.makeText(getApplicationContext(), “Right Swipe”, Toast.LENGTH_SHORT).show();

} else {

Toast.makeText(getApplicationContext(), “Left Swipe”, Toast.LENGTH_SHORT).show();

}

return true;

} else if (Math.abs(dX)<SWIPE_MAX_OFF_PATH &&

Math.abs(velocityY)>=SWIPE_THRESHOLD_VELOCITY &&

Math.abs(dY)>=SWIPE_MIN_DISTANCE ) {

if (dY>0) {

Toast.makeText(getApplicationContext(), “Up Swipe”, Toast.LENGTH_SHORT).show();

} else {

Toast.makeText(getApplicationContext(), “Down Swipe”, Toast.LENGTH_SHORT).show();

}

return true;

}

return false;

}

}

}