I want the toolbar and imageview to collapse, when the user scrolls up. Since I'm not using a recyclerview, a suggested workaround was to wrap the imageview in a NestedScrollView.
All of the content below the AppBarLayout, is made up of imageviews, textviews, and many kinds of layouts. By default such content does not scroll, so I wrapped it in a NestedScrollView. This makes the content scroll-able. the problem is, that scrolling up now only makes the bottom NestedScrollView move, and the toolbar does not collapse.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.solidcolorlabs.android.solid.activities.ExampleActivity">
<android.support.design.widget.AppBarLayout
android:id="@+id/app_bar"
android:layout_width="match_parent"
android:layout_height="200dp">
<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/collapsingToolbarLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:contentScrim="?attr/colorPrimary"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
app:layout_collapseMode="parallax"
app:layout_scrollFlags="scroll">
<ImageView
android:id="@+id/venue_image"
android:layout_width="match_parent"
android:layout_height="200dp" />
</android.support.v4.widget.NestedScrollView>
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?android:attr/actionBarSize"
android:minHeight="?attr/actionBarSize"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:layout_collapseMode="pin"
app:navigationContentDescription="@string/abc_action_bar_up_description"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light">
</android.support.v7.widget.Toolbar>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
app:layout_collapseMode="parallax"
app:layout_scrollFlags="scroll">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
...
</LinearLayout>
</android.support.v4.widget.NestedScrollView>
</LinearLayout>
