Fragment from View Pager hiding behind Tab Bar

Question

I am having an issue with a Tab bar and ViewPager in my android project. What the app does it has an activity which hosts a tab layout and then has 2 fragment which represents each of the tabs.

When the activity is opened it posts to an API to get some data and puts the data into a data adapter for a Recycler View and Card layout in each of the fragments.

The recycler view will contain 3 items but only 2 are being shown as the first is being hidden under the toolbar and/or the tab bar as shown in the screenshot below.

Below is the layout file of my activity

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
    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"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context="com.BoardiesITSolution.CritiMonApp.AppsActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
        <include layout="@layout/toolbar" />
        <android.support.design.widget.TabLayout
            android:id="@+id/tabs"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:tabMode="fixed"
            app:tabGravity="fill" />
    </android.support.design.widget.AppBarLayout>

    <android.support.v4.view.ViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
        <!--app:layout_behaviour="@string/appbar_scrolling_view_behaviour" />-->
</android.support.design.widget.CoordinatorLayout>

Below is the layout of the fragment

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <view
        android:id="@+id/recycler_view"
        class="android.support.v7.widget.RecyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_centerInParent="true" />
</LinearLayout>

Below is the layout for card layout

<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:cardview="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="80dp"
    android:layout_margin="8dp">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:elevation="5dp">
        <TextView
            android:id="@+id/txtApplicationName"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:maxLines="3"
            android:padding="8dp"
            android:textColor="#222"
            android:textSize="15dp"
            android:layout_centerInParent="true"/>

    </RelativeLayout>
</android.support.v7.widget.CardView>

Below is the screenshot as mentioned above which shows the problem. I've pixelated some of the text but it should you what I mean, there should be 3 items but the first item is hiding underneath the tab bar.

Answer 1

Edit: As suggested below by @smeet and @hardik, adding the scroll behavior app:layout_behavior="@string/appbar_scrolling_view_behavior" should fix the problem while preserving the scroll behavior. Scroll behaviors only work if the view is a direct child of the coordinator layout.

---

Old Answer

Just Wrap your appbar layout and viewpager in a vertical LinearLayout

<android.support.design.widget.CoordinatorLayout
    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"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context="com.BoardiesITSolution.CritiMonApp.AppsActivity">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        //appbar layout

        //viewpager    


    </LinearLayout>

</android.support.design.widget.CoordinatorLayout>

From the docs, CoordinatorLayout is a super-powered FrameLayout. So you can expect the typical "lay views on top of other views" FrameLayout behavior.

Answer 2

Adding :

app:layout_behavior="@string/appbar_scrolling_view_behavior"

in ViewPager resolved issue in my case.