Android - Recycler view resizes when app is on background

Question

I have this very weird bug on my app. Every time I open my app my view works perfectly, but when I try to put my app in background and open my app again, my recycler view resizes.

Here's an image to describe it properly:

This is the correct image:

This is the image that messes up my recyclerview when the app is on background, then I open it again.

There are also times that all images in my recyclerview are gone. Here's a screenshot:

This is my onResume() code:

public void onResume()
 {
   Fragment fragment = getSupportFragmentManager().findFragmentById(R.id.fragment_container);
   if (fragment instanceof MenuFragment)
   {
     FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
     transaction.remove(fragment);
     transaction.commit();
     transaction = getSupportFragmentManager().beginTransaction();
     transaction.replace(R.id.fragment_container, fragment);
     transaction.addToBackStack(null);
     transaction.commit();

   }
 }

This is my view pager layout:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/app_background">
    <android.support.constraint.ConstraintLayout
        android:id="@+id/action_bar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <include
            android:id="@+id/nav_bar"
            layout="@layout/home_screen_navigation"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    </android.support.constraint.ConstraintLayout>

    <com.yotadevices.widget.RtlViewPager
        android:id="@+id/menuFragment_viewPager"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="@android:color/transparent"
        app:layout_constraintBottom_toTopOf="@+id/buttons"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/nav_bar"/>
    <include
        android:id="@+id/buttons"
        layout="@layout/navigation_layout"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/menuFragment_viewPager" />
</android.support.constraint.ConstraintLayout>

Here's my list layout:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/linearLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/transparent"
    android:orientation="vertical">
    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerview"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>
</android.support.constraint.ConstraintLayout>

What do you think is the problem here?

PS: The bug occurs only on selected phones. Not all. We've tested this on Samsung Galaxy s8+ and it works well.

Answer 1

If you are using only single child view, it's better to use FrameLayout. Then in RecyclerView use match_parent parameters in layout attribute, so your code should look like this:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/linearLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/transparent">
    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</FrameLayout>

By the way my best method to debug scenarios like this is to write android:background="#0000FF" in every view, to see how it inflates.

Answer 2

I have solved the problem by breaking part the included layouts. So instead of adding an included layout, I just transferred all the included in to the main XML layout.

Even though this fixed the problem, i still do not know why the bug occurred in the first place.