Left-right arrow indicators over a ViewPager

Question

I want to show left and right arrows over my ViewPager, to indicate swiping.

I added two ImageButtons over the ViewPager-element but those areas then block the ViewPager

Answer 1

Implement left & right arrow buttons in your fragment. Then register their onClick in your activity and call viewpager's arrowScroll method to scroll the viewPager programmatically.

public void onRightClick(View view) {
    viewPager.arrowScroll(ViewPager.FOCUS_RIGHT);
}

public void onLeftClick(View view) {
    viewPager.arrowScroll(ViewPager.FOCUS_LEFT);
}

Create a method to toggle left/right arrow visibility in your fragment.

public void toggleArrowVisibility(boolean isAtZeroIndex, boolean isAtLastIndex) {
    if(isAtZeroIndex)
        leftBtn.setVisibility(View.INVISIBLE);
    else
        leftBtn.setVisibility(View.VISIBLE);
    if(isAtLastIndex)
        rightBtn.setVisibility(View.INVISIBLE);
    else
        rightBtn.setVisibility(View.VISIBLE);

}

Now implement ViewPager.OnPageChangeListener in your activity. Use SmartFragmentStatePagerAdapter to keep track of registered fragments in memory.

@Override
public void onPageSelected(int position) {
    MyFragment fragment = (MyFragment) smartAdapter.getRegisteredFragment(position);
    fragment.toggleArrowVisibility(position == 0, position == list.size() - 1);
}