Make Swap Vertical and Horizontal Work With Two Adapters

问题

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 works one or the either(Vertically or Horrizontally).How do I make it so that I can swipe vertically as well as Horizontally on my

EmptyFragment

I currently have my VerticalViewPagerAdapter extending to a FragmentPagerAdapter

public class VerticalViewPager extends FragmentPagerAdapter {
public VerticalViewPager(FragmentManager fm) {
    super(fm);
}

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

@Override
public int getCount() {
    return 3;
}

As well as my HorizontalViewPagerAdapter

public class HorizontalViewPager extends FragmentPagerAdapter {

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

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


@Override
public int getCount() {
    return 3;
}

And somehow I cant have them in sync its either one or the other and I can alter if my app goes vertical or horizontal by changing my layoutfile

<View
android:id="@+id/am_background_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/green"/>
<android.support.v4.view.ViewPager
    android:id="@+id/am_view_pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>
<me.kaelaela.verticalviewpager.VerticalViewPager
    android:id="@+id/am_scrollView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

Im not sure if it has to do with my MainActivity which is

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    //VerticalViewPager
    me.kaelaela.verticalviewpager.VerticalViewPager verticalViewPager = findViewById(R.id.am_scrollView);
    VerticalViewPager scrollViewAdapter = new VerticalViewPager(getSupportFragmentManager());
    verticalViewPager.setAdapter(scrollViewAdapter);
    verticalViewPager.setPageTransformer(false, new DefaultTransformer());

    //HorizontalViewPager
    View background = findViewById(R.id.am_background_view);
    ViewPager viewPager = findViewById(R.id.am_view_pager);
    HorizontalViewPager adapter = new HorizontalViewPager(getSupportFragmentManager());
    viewPager.setAdapter(adapter);
    viewPager.setCurrentItem(1);

回答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;
}

来源：https://stackoverflow.com/questions/48131587/make-swap-vertical-and-horizontal-work-with-two-adapters