Collapsing layout during scrolling in Android

Question

I would like to have custom view collapsed with a transition during scrolling.

I have AppBarLayout with a Toolbar inside. Below that there is a custom view that I want to collapse.

Below custom view there is a NestedScrollView with LinearLayout.

Toolbar is green, custom layout is pink and scroll with linear is gray:

After scrolling down:

<android.support.design.widget.CoordinatorLayout 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:fitsSystemWindows="true">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        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/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
    </android.support.design.widget.AppBarLayout>


    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="170dp"
        android:layout_marginTop="?attr/actionBarSize"
        android:background="@drawable/background"
        android:gravity="center">
    </RelativeLayout>

    <ScrollView
        android:id="@+id/scroll"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="170dp"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

        <include
            layout="@layout/linear"
            android:layout_marginBottom="20dp"
            android:layout_marginTop="20dp"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

    </ScrollView>

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

Should I go with custom behavior and CoordinatorLayout or translation with NestedScroll with translation animation?

Answer 1

Use Observable ScrollView library https://github.com/ksoichiro/Android-ObservableScrollView

Answer 2

I've managed to do this without any library. The key was to have two app bar layouts - one with a placeholder and collapsing toolbar layout that was hidden under custom view, and the second normal one.

Then I've created two behaviors - one for changing nested layout height and second to manipulate inner views inside custom view.

Here is my layout:

<android.support.design.widget.CoordinatorLayout 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:fitsSystemWindows="true">

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

    <android.support.design.widget.CollapsingToolbarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_scrollFlags="scroll|exitUntilCollapsed"
        app:titleEnabled="false">

        <View
            android:id="@+id/vieItemDetailsPlaceholder"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="#00000000" />

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

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

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

    <android.support.v7.widget.Toolbar
        android:id="@+id/second_toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="@color/colorPrimary"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
</android.support.design.widget.AppBarLayout>

<android.support.v4.widget.NestedScrollView
    android:id="@+id/detailContent"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="com.example.detail.view.Det ailScrollBehavior">

    <include
        layout="@layout/content"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="20dp" />

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

<!-- second layout with behavior -->
<include layout="@layout/two_circles_layout" />

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

DetailScrollBehavior:

public class DetailScrollBehavior extends Behavior<NestedScrollView> {

    private final Context context;

    public DetailScrollBehavior(Context context, AttributeSet attrs) {
        this.context = context;
    }

    @Override
    public boolean layoutDependsOn(CoordinatorLayout parent, NestedScrollView child, View dependency) {
        return dependency.getId() != R.id.ablItemDetailsSecondToolbar && dependency instanceof AppBarLayout;
    }

    @Override
    public boolean onDependentViewChanged(CoordinatorLayout parent, NestedScrollView child, View dependency) {
        int minHeight = context.getResources().getDimensionPixelSize(R.dimen.some_min_height);
        int placeholderHeight = getPlaceholderHeight(dependency);
        int actionBarHeight = getActionBarHeight(context.getTheme());

        if (placeholderHeight < minHeight + actionBarHeight) {
            placeholderHeight = minHeight + actionBarHeight;
        }

        child.setPadding(0, placeholderHeight, 0, 0);

        return true;
    }
}

and part of two_circles_layout:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:id="@+id/relDetailsContainer"
    android:layout_width="match_parent"
    android:layout_height="@dimen/team_vs_details_height"
    android:layout_marginTop="?attr/actionBarSize"
    android:background="@drawable/background"
    android:gravity="center"
    app:layout_behavior="com.example.DetailBehavior"
    tools:showIn="@layout/activity_item_detail">


    [ ... ]

</RelativeLayout>