Make Swap Vertical and Horizontal Work With Two Adapters

Question

So basically I\'m trying to make my app like snapchat where you can swipe left,right,up and down. My problem is that the app does not realize there are two adapters and only wor

Answer 1

Getting the base from here.

Create a GestureDetectorCompat object

GestureDetectorCompat gestureDetectorCompat;

and override onTouchEvent in the activity

 @Override
        public boolean onTouchEvent(MotionEvent event) {
            gestureDetectorCompat.onTouchEvent(event);
            return true;
        }

or if you want to detect on some view then you can Override onTouch

someView.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                gestureDetectorCompat.onTouchEvent(motionEvent);
                return false;
            }
        });

and initialize gestureDetectorCompat as follows somewhere preferably in onCreate() and you are done.

gestureDetectorCompat = new GestureDetectorCompat(this, new GestureDetector.SimpleOnGestureListener() {
        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
            float angle = (float) Math.toDegrees(Math.atan2(e1.getY() - e2.getY(), e2.getX() - e1.getX()));

            if (angle > -45 && angle <= 45) {
                if(goRight != 5) mainContainer.setCurrentItem(goRight);
                return true;
            }

            if (angle >= 135 && angle < 180 || angle < -135 && angle > -180) {
                if(goLeft != 5) mainContainer.setCurrentItem(goLeft);
                return true;
            }

            if (angle < -45 && angle >= -135) {
                if(goUp != 5)mainContainer.setCurrentItem(goUp);
                return true;
            }

            if (angle > 45 && angle <= 135) {
                if(goDown != 5)mainContainer.setCurrentItem(goDown);
                return true;
            }

            return false;
        }


    });

Then you can use mainContainer.setCurrentItem(number); to go to other position/fragment.

Don't forget that the number change if you are in different number. Like this

switch(adapter.getCurrentItem()){
    case 0:
        goRight = 2;
        goLeft = 4;
        goUp = 3;
        goDown = 1;
        break;
    case 1:
        goRight = 5;
        goLeft = 5;
        goUp = 0;
        goDown = 5;
        break;
    case 2:
        goRight = 5;
        goLeft = 0;
        goUp = 5;
        goDown = 5;
        break;
    case 3:
        goRight = 5;
        goLeft = 5;
        goUp = 5;
        goDown = 0;
        break;
    case 4:
        goRight = 0;
        goLeft = 5;
        goUp = 5;
        goDown = 5;
        break;
}

When you are in the fragment 4 you can only go to 0, not 2 if you swipe left-right.

And this should be your adapter

public class SwipeViewPager extends FragmentPagerAdapter {

public SwipeViewPager(FragmentManager fm) {
    super(fm);
}

@Override
public Fragment getItem(int position) {
    switch (position){
        case 0:
            return EmptyFragment.create();
        case 1:
            return StoryFragment.create();
        case 2:
            return ExtrasFragment.create();
        case 3:
            return ChatFragment.create();
        case 4:
            return SettingsFragment.create();
    }
    return null;
}


@Override
public int getCount() {
    return 5;
}