Use backstack with ViewPager

Question

I am using a ViewPager to implement swiping in my android app. However, I would like the previous fragment to be shown when the user uses the back button instead of ending t

Answer 1

I have same issue and i follow this step (Edited my answer--- Certainly work for me, give it a try)

In the main activity where there are 3 fragment in viewpager i create stack and push and pop data.

private Stack stackkk;
private ViewPager mPager;
private int tabPosition = 0;



    mTabLayout.setupWithViewPager(mPager);
    mPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(mTabLayout));
    mTabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            tabPosition = tab.getPosition();
            mPager.setCurrentItem(tab.getPosition());

// here i have add the data into the stack in each tab click, as at first it will always be null so i add 0 position

            if (stackkk.empty())
                stackkk.push(0);

            if (stackkk.contains(tabPosition)) {
                stackkk.remove(stackkk.indexOf(tabPosition));
                stackkk.push(tabPosition);
            } else {
                stackkk.push(tabPosition);
            }
        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {
            tabPositionUnselected = tab.getPosition();
        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {
        }
    });
}

and in the onBackPressed in activity,

//OnbackPress i have first taken out the last one as it already and
//selected by poping it out then only set to the pager.
@Override
public void onBackPressed() {
    if (stackkk.size() > 1) {
        stackkk.pop();
        mPager.setCurrentItem(stackkk.lastElement());
    } else {
    }
}

Hope this may help or msg me.