canScroll not getting called on custom ViewPager - android-fragments

Question

I have a really crazy problem.
I want to prevent my custom ViewPager from scrolling with overriding the canScroll(View v, boolean checkV, int dx, int x, int y) method.
It works very well if I use my ProductsFragment. Even if I use it multiple times in the same ViewPager it works perfectly.
The problem is now, if I use another Fragment canScroll will not trigger on that specific Fragment.
But I want different Fragments in my App :D
ViewPager:
public class LockableViewPager extends ViewPager {
public LockableViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
protected boolean canScroll(View v, boolean checkV, int dx, int x, int y) {
Log.i("tag","id: "+getContext().getResources().getResourceEntryName(v.getId()));
return super.canScroll(v, checkV, dx, x, y);
}
Adapter:
public class AppointmentPagerAdapter extends FragmentPagerAdapter {
public AppointmentPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 2:
return new ProductsFragment(); //this works
case 3:
return new ProductsFragment(); //this works
case 1:
return new InfoFragment(); //this works Not
case 0:
return new ScheduleFragment(); //this works Not
default:
return null;
}
}
#Override
public int getCount() {
return 4;
}
#Override
public CharSequence getPageTitle(int position) {
return null;
}
ProductsFragment:
public class ProductsFragment extends Fragment {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView= inflater.inflate(R.layout.fragment_products, container, false);
ProductsRecycleAdapter adapter=new ProductsRecycleAdapter(getDummyData(), new ProductsRecycleAdapter.ClickHandler() {
#Override
public void addToCart(int position) {
Log.i("log","addToCart: "+position);
}
#Override
public void clicked(int position) {
Log.i("log","clicked: "+position);
}
});
RecyclerView recyclerView= (RecyclerView) rootView.findViewById(R.id.frag_products_recycle);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(adapter);
return rootView;
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
}
#Override
public void onDetach() {
super.onDetach();
}
ScheduleFragment:
public class ScheduleFragment extends Fragment {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView=inflater.inflate(R.layout.fragment_schedule, container, false);
return rootView;
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
}
#Override
public void onDetach() {
super.onDetach();
}
}
The output on the LogCat should be for example:
tag: id: act_appointment_pager
tag: id: fragment_products
tag: id: frag_products_recycle
tag: id: act_appointment_pager
tag: id: fragment_products
tag: id: frag_products_recycle
tag: id: act_appointment_pager
tag: id: fragment_products
tag: id: frag_products_recycle
But i get no output for other fragments than the ProductsFragment.
And yes, the views have IDs.
Isn't that weird?^^
I hope you can point me into the right direction.
Edit:
I forgot the entry point...
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_appointment);
setupToolbar();
AppointmentPagerAdapter adapter=new AppointmentPagerAdapter(getSupportFragmentManager());
LockableViewPager pager= (LockableViewPager) findViewById(R.id.act_appointment_pager);
pager.setAdapter(adapter);
}

Answer 1

Finally I figured it out and maybe someone wants to know how.
The setup is correct.
If the fragment has no scrolling content, the method canScroll(View v, boolean checkV, int dx, int x, int y) will not trigger.
I added some scrolling content and now it works.
But if there is a scolling content and a non-scrolling content in the fragment, the method only triggers on the scrolling content.
So it seems that if you swipe at a non-scrolling content, the method is simply ignored.
Additionally you should give each view in the layout an ID.
I think the things being said here are not documented, but correct me if I'm wrong about this.