Kotlin FragmentStatePagerAdapter shows empty views - kotlin

Question

I am trying to set up ViewPager adapter inside a fragment to show another fragments. The problem is that when called ViewPager automatically calls the first two fragments while displaying only blank page.
This is how ViewPager is set:
class SwipePagerFragment : Fragment() {
private lateinit var pager: ViewPager
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
val view = inflater.inflate(R.layout.fragment_swipe_pager, container, false)
pager = view.findViewById(R.id.fragmentSwipePager_pager)
val pagerAdapter = ScreenSlidePagerAdapter(childFragmentManager)
pager.adapter = pagerAdapter
return view
}
private inner class ScreenSlidePagerAdapter(fm: FragmentManager) : FragmentStatePagerAdapter(fm) {
override fun getCount(): Int = 3
override fun getItem(position: Int): Fragment = when (position) {
0 -> MeFragment()
1 -> AccountFragment()
3 -> SearchFragment()
else -> ContactsFragment()
}
}
override fun onDestroyView() {
val frContainer = (activity as MainActivity).findViewById<View>(R.id.activityMain_fragment) as ViewGroup
frContainer.removeAllViews()
super.onDestroyView()
}
}
This is what I get in logcat:
... D/FRG ME: # onCreateView
... D/FRG Account: # onCreateView

Answer 1

I think you are trying to add 4 fragments in ViewPager and provided getCount() = 3
override fun getCount(): Int = 4
Also, make changes in Adapter as follows,
private inner class ScreenSlidePagerAdapter(fm: FragmentManager) :
FragmentStatePagerAdapter(fm) {
override fun getCount(): Int = 4
override fun getItem(position: Int): Fragment = when (position) {
0 -> MeFragment()
1 -> AccountFragment()
2 -> SearchFragment()
else -> ContactsFragment()
}
}

Answer 2

Oh, LOL, I have figured it out.
I have set layout for Fragment I used for ViewPager as follows:
<?xml version="1.0" encoding="utf-8"?>
<ScrollView
android:id="#+id/fragmentSwipePager_rootScroll"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="5dp"
tools:context=".SwipePagerFragment">
<android.support.v4.view.ViewPager
android:id="#+id/fragmentSwipePager_pager"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</android.support.v4.view.ViewPager>
</ScrollView>
The problem was in "layout_height" property of ScrollView as it was set to "wrap_content" and with no actual content with non-zero height inside it resulted in drawing zero-height line and displaying Fragments contents inside it. Changing "layout_height" to "match_parent" solves my problem.