How to add bottom view to a Coordinator Layout with view pager?

Question

I want to add a bottom view to a Coordinator layout with view pager in it , Bottom View will be on top of fragment loaded by view pager and independent of it .

I added a linear layout with

layout_gravity = "bottom"

but bottom view linear layout is not showing at all

Following is my xml layout of the activity.

<android.support.design.widget.CoordinatorLayout

xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

    <android.support.v7.widget.Toolbar
        android:id="@+id/maintoolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:layout_scrollFlags="scroll|enterAlways"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
    <android.support.design.widget.TabLayout
        android:id="@+id/maintabs"
        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/mainviewpager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"  />


<LinearLayout
    android:id="@+id/completeBottomView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <ProgressBar
        android:id="@+id/progressBarBottomView"
        style="?android:attr/progressBarStyleHorizontal"
        android:layout_width="match_parent"
        android:layout_height="5dp"
        android:indeterminate="false"
        android:visibility="gone"
        android:max="100"
        android:progress="1"/>

    <HorizontalScrollView
        android:id="@+id/limiter_scroller"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|start"
        android:background="#FF3399"
        >
        <LinearLayout
            android:id="@+id/limiter_layout"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            android:onClick="clickFromBottomView"/>
    </HorizontalScrollView>

</LinearLayout>

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

Answer 1

Android CoordinatorLayout Bottom Layout Behaviour.

activity_bottom.xml

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/app_bar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimaryDark"
            app:layout_scrollFlags="scroll|enterAlways"
            app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" />
    </android.support.design.widget.AppBarLayout>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#C0C0C0"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:layout_gravity="bottom"            
        app:layout_behavior="com.utils.behaviour.BottomLayoutBehavior">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="#007432"
            android:gravity="center"
            android:text="Footer View"
            android:textColor="@android:color/white"
            android:textSize="25sp" />
    </LinearLayout>

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

BottomLayoutBehavior.kt

package com.utils.behaviour

import android.content.Context
import android.util.AttributeSet
import android.view.View
import androidx.coordinatorlayout.widget.CoordinatorLayout
import androidx.core.view.ViewCompat
import kotlin.math.max
import kotlin.math.min

class BottomLayoutBehavior<V : View>(context: Context?, attrs: AttributeSet?) :
    CoordinatorLayout.Behavior<V>(context, attrs) {

    override fun onStartNestedScroll(
        coordinatorLayout: CoordinatorLayout, child: V,
        directTargetChild: View, target: View, axes: Int, type: Int
    ): Boolean {
        return axes == ViewCompat.SCROLL_AXIS_VERTICAL
    }

    override fun onNestedPreScroll(
        coordinatorLayout: CoordinatorLayout, child: V,
        target: View, dx: Int, dy: Int, consumed: IntArray, type: Int
    ) {
        child.translationY = max(
            0f,
            min(child.height.toFloat(), child.translationY + dy)
        )
        super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed, type)
    }
}

Answer 2

This code worked for me. Change app:layout_scrollFlags="scroll|enterAlways" to app:layout_scrollFlags="scroll" attribute of android.support.v7.widget.Toolbar. More details here

Answer 3

As pointed out in comment by @Dhawal ....Solution is to wrap LinearLayout completeBottomView in a FrameLayout with android:layout_gravity="bottom"