Recycler view with CollapsingToolbarLayout dosent work properly

Question

Im using a CollapsingToolbar Layout and a recycler below it, what i want is that when i start scrolling in the recylcer view the toolbar changes itself along with it . if i scroll up the toolbar gets small and if i scroll down the toolbar comes down with it , but right now . whats happening is the recycler view and the toolbar are both acting independently of each other . the recycler view scrolls but nothing happens to the toolbar . i have to drag the toolbar up and down myself.

Here is my xml file.

    <?xml version="1.0" encoding="utf-8"?>
<layout xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:android="http://schemas.android.com/apk/res/android">

    <data>

        <variable
            name="scoutingFragmentViewModel"
            type="com.resatech.android.navigationtest.viewModels.ScoutingFragmentViewModel" />

    </data>

    <android.support.design.widget.CoordinatorLayout
        android:id="@+id/htab_maincontent"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true">

        <android.support.design.widget.AppBarLayout
            android:id="@+id/htab_appbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?attr/colorPrimary"
            android:fitsSystemWindows="true"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

            <android.support.design.widget.CollapsingToolbarLayout
                android:id="@+id/htab_collapse_toolbar"
                android:layout_width="match_parent"
                android:layout_height="256dp"
                android:fitsSystemWindows="true"
                app:contentScrim="?attr/colorPrimary"
                app:layout_scrollFlags="scroll|exitUntilCollapsed|snap"
                app:titleEnabled="false">

                <ImageView
                    android:id="@+id/htab_header"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:background="@drawable/battery"
                    android:fitsSystemWindows="true"
                    android:scaleType="centerCrop"
                    app:layout_collapseMode="parallax"
                    />

                <android.support.v7.widget.Toolbar
                    android:id="@+id/htab_toolbar"
                    android:layout_width="match_parent"
                    android:layout_height="?attr/actionBarSize"
                    android:layout_gravity="top"
                    android:layout_marginBottom="48dp"
                    app:layout_collapseMode="pin"
                    app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

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



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

        <android.support.v7.widget.RecyclerView
            android:id="@+id/recycler_view"
            android:layout_width="match_parent"
            android:layout_height="260dp"
            app:layout_anchorGravity="bottom"
            android:layout_marginTop="10dp"
            android:layout_marginBottom="8dp"
            android:fadeScrollbars="false"
            android:scrollbars="vertical"
            app:layout_behavior="android.support.design.widget.AppBarLayout$ScrollingViewBehavior"

            >
        </android.support.v7.widget.RecyclerView>

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

</layout>

As you can see, the scrollbar still dosent go up by itself i have to drag it up manually even if the recycler view is at its bottom.

Answer 1

Replace this :

<android.support.v7.widget.RecyclerView
            android:id="@+id/recycler_view"
            android:layout_width="match_parent"
            android:layout_height="260dp"
            app:layout_anchorGravity="bottom"
            android:layout_marginTop="10dp"
            android:layout_marginBottom="8dp"
            android:fadeScrollbars="false"
            android:scrollbars="vertical"
            app:layout_behavior="android.support.design.widget.AppBarLayout$ScrollingViewBehavior"

            >
        </android.support.v7.widget.RecyclerView>

With this:

<RelativeLayout
                        android:layout_width="match_parent"
                        android:layout_height="match_parent"     
                        app:layout_behavior="@string/appbar_scrolling_view_behavior">

<android.support.v7.widget.RecyclerView
                android:id="@+id/recycler_view"
                android:layout_width="match_parent"
                android:layout_height="260dp"
                app:layout_anchorGravity="bottom"
                android:layout_marginTop="10dp"
                android:layout_marginBottom="8dp"
                android:fadeScrollbars="false"
                android:scrollbars="vertical">
            </android.support.v7.widget.RecyclerView>
  </RelativeLayout>

Answer 2

Try this

<?xml version="1.0" encoding="utf-8"?>
<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:fitsSystemWindows="true">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/app_bar"
        android:layout_width="match_parent"
        android:layout_height="180dp"
        android:fitsSystemWindows="true"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.design.widget.CollapsingToolbarLayout
            android:id="@+id/toolbar_layout"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:fitsSystemWindows="true"
            app:contentScrim="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|exitUntilCollapsed"
            app:toolbarId="@+id/toolbar">

            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                app:layout_collapseMode="pin"
                app:popupTheme="@style/AppTheme.PopupOverlay" />

        </android.support.design.widget.CollapsingToolbarLayout>
    </android.support.design.widget.AppBarLayout>

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

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

Then dont forget to set your default toolbar

Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);

Hope it helps.

Answer 3

Change your AppBarLayout as below

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="?attr/colorPrimary">
    <android.support.design.widget.CollapsingToolbarLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:contentScrim="?attr/colorPrimary"
        app:layout_scrollFlags="scroll|exitUntilCollapsed"
        app:expandedTitleTextAppearance="@style/TextAppearance.AppCompat.Title">

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="256dp"
            app:layout_collapseMode="parallax"/>
    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        app:layout_collapseMode="pin"
        android:layout_height="?attr/actionBarSize"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
        app:theme="@style/ToolBarStyle" />
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>

and add app:layout_behavior="@string/appbar_scrolling_view_behavior" to your RecyclerView