When using the CoordinatorLayout my ScrollView has an incorrect size

Question

I'm using a ScrollView in a layout, and am attempting to use the new CoordinatorLayout from the design support library.

My layout file looks like this:

<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">

  <ScrollView
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      app:layout_behavior="@string/appbar_scrolling_view_behavior">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
      ...
    </LinearLayout>
  </ScrollView>
  <android.support.design.widget.AppBarLayout
      android:layout_width="match_parent"
      android:layout_height="wrap_content">
    <android.support.v7.widget.Toolbar ... />
  </android.support.design.widget.AppBarLayout>
</android.support.design.widget.CoordinatorLayout>

When testing this the scrollview only occupies part of the screen. What went wrong?

Answer 1

The standard ScrollView is only meant to be used as a parent. You need to change the ScrollView to a android.support.v4.widget.NestedScrollView.

An example can be seen in the reference documentation for AppBarLayout.

Answer 2

NestedScrollView is just like ScrollView, but it supports acting as both a nested scrolling parent and child on both new and old versions of Android. Nested scrolling is enabled by default.

You can use a NestedScrollView within a parent ScrollView. NestedScrollView is used when there is a need for a scrolling view inside another scrolling view. This is where it is useful, when the system needs to decide which view to scroll.

Here is an example of NestedScrollView with CoordinatorLayout:

 <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.v4.widget.NestedScrollView
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             app:layout_behavior="@string/appbar_scrolling_view_behavior">

         <!-- Your scrolling content -->

     </android.support.v4.widget.NestedScrollView>

     <android.support.design.widget.AppBarLayout
             android:layout_height="wrap_content"
             android:layout_width="match_parent">

         <android.support.v7.widget.Toolbar
                 ...
                 app:layout_scrollFlags="scroll|enterAlways"/>

         <android.support.design.widget.TabLayout
                 ...
                 app:layout_scrollFlags="scroll|enterAlways"/>

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

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