Detect Viewpager Tab Change Inside Fragment

Detect ViewPager tab change inside Fragment

I did some digging and it turns out that ViewPager will call both: setUserVisibleHint and setMenuVisibility. I would override setUserVisibleHint since the documentation for setUserVisibleHint states:

Set a hint to the system about whether this fragment's UI is currently visible to the user. This hint defaults to true and is persistent across fragment instance state save and restore.
An app may set this to false to indicate that the fragment's UI is scrolled out of visibility or is otherwise not directly visible to the user. This may be used by the system to prioritize operations such as fragment lifecycle updates or loader ordering behavior.

Try putting this code in your fragment:

@Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);

// Make sure that we are currently visible
if (this.isVisible()) {
// If we are becoming invisible, then...
if (!isVisibleToUser) {
Log.d("MyFragment", "Not visible anymore. Stopping audio.");
// TODO stop audio playback
}
}
}

ViewPager with tabLayout - Child Fragment takes time to change

Change viewpager.setOffscreenPageLimit(2) or by default it is set to 1 and check the loading time as you don't need to keep every fragment in memory which leads to slow response of loading in view pager.

Check this for more info about setOffscreenPagLimit in viewpager https://developer.android.com/reference/android/support/v4/view/ViewPager.html#setOffscreenPageLimit%28int%29

Determine when a ViewPager changes pages

Use the ViewPager.onPageChangeListener:

viewPager.addOnPageChangeListener(new OnPageChangeListener() {
public void onPageScrollStateChanged(int state) {}
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {}

public void onPageSelected(int position) {
// Check if this is the page you want.
}
});

How to determine when Fragment becomes visible in ViewPager

How to determine when Fragment becomes visible in ViewPager

You can do the following by overriding setUserVisibleHint in your Fragment:

public class MyFragment extends Fragment {
@Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (isVisibleToUser) {
}
else {
}
}
}

Fragment re-created when change tab with ViewPager

It's been as easy as using method setOffscreenPageLimit() from ViewPager.

More info: http://developer.android.com/reference/android/support/v4/view/ViewPager.html#setOffscreenPageLimit(int)



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