Collapsing Action Bar but only shows when RecyclerView is fully displaying the first item

Question

I have a page that has a collapsing action bar effect, similar to this: http://xmodulo.com/hide-show-toolbar-scrolling-android.html. But I want the action bar to only show when the list is already showing the first item, not immediately whenever i scroll down. How can I achieve this?

Answer 1

The design library has a component called the AppBarLayout to accomplish this.

Include the library:

dependencies {
    compile 'com.android.support:design:22.2.0'
}

Wrap the Toolbar in an AppBarLayout with the scrollFlags set to 'scroll', wrap the entire layout in a CoordinatorLayout, and add set the layout_behavior of your scrolling view to @string/appbar_scrolling_view_behavior.

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

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        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/colorPrimary"
            app:layout_scrollFlags="scroll"/>

      <!-- If you have tabs you can include them below the toolbar -->
      <android.support.design.widget.TabLayout
            android:id="@+id/tabs"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

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

    <!-- If you use a ViewPager, just add the layout_behavior to it instead of the RecyclerView -->
    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"/>

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