FloatingActionButton between layouts with CollapsingToolbarLayout

Question

I would like to add a floating action button between two layouts with different elevation to get something like this:

This is my layout, but probably it's overcomplicated:

<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:theme="@style/AppTheme.NoActionBar">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/app_bar_layout"
        android:layout_width="match_parent"
        android:layout_height="250dp"
        android:fitsSystemWindows="true"
        android:theme="@style/ThemeOverlay.AppCompat.ActionBar">

        <android.support.design.widget.CollapsingToolbarLayout
            android:id="@+id/collapsing_toolbar"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:fitsSystemWindows="true"
            app:contentScrim="@color/color_primary"
            app:scrimAnimationDuration="300"
            app:titleEnabled="false"
            app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed">

            <ImageView
                android:id="@+id/trailer"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical"
                android:fitsSystemWindows="true"
                tools:ignore="ContentDescription" />

            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                app:popupTheme="@style/ThemeOverlay.AppCompat"
                app:layout_collapseMode="pin" />
        </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"
        android:clipToPadding="false"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

        <LinearLayout
            android:id="@+id/header"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

            <android.support.constraint.ConstraintLayout
                android:layout_width="match_parent"
                android:layout_height="150dp"
                android:background="@color/color_primary"
                android:elevation="16.0dp">

                <com.est.streamcorn.views.AspectRatioImageView
                    android:id="@+id/image"
                    android:layout_width="150dp"
                    android:layout_height="wrap_content"
                    app:layout_constraintTop_toTopOf="parent"
                    app:layout_constraintBottom_toBottomOf="parent"
                    android:scaleType="centerInside"
                    android:theme="@style/MoviePosterImage"
                    tools:ignore="ContentDescription"
                    app:elevation="6dp"/>

                <android.support.design.widget.FloatingActionButton
                    android:id="@+id/play"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:clickable="true"
                    android:focusable="true"
                    android:elevation="6dp"
                    app:srcCompat="@drawable/player_action_play"
                    app:layout_constraintTop_toBottomOf="parent"
                    app:layout_constraintBottom_toBottomOf="parent"
                    app:layout_constraintEnd_toEndOf="parent"/>

                <TextView
                    android:id="@+id/title"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    app:layout_constraintTop_toBottomOf="parent"
                    app:layout_constraintStart_toEndOf="@id/image"/>

                <TextView
                    android:id="@+id/link1"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    app:layout_constraintTop_toBottomOf="@id/title"
                    app:layout_constraintStart_toEndOf="@id/image"/>

            </android.support.constraint.ConstraintLayout>

            <android.support.constraint.ConstraintLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent">

                <TextView
                    android:id="@+id/text2"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
            </android.support.constraint.ConstraintLayout>

        </LinearLayout>

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

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

All the examples I found anchor the floating button to the coordinator layout, but I would like to have it fixed like the other elements inside the NestedScrollView. Mybe there is a better way to accomplish the different color and elevation without needing two different layouts?

Answer 1

At the end I was able to achieve this:

This is the 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:background="@color/colorPrimaryReverse"
    android:theme="@style/AppTheme.NoActionBar">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/app_bar_layout"
        android:layout_width="match_parent"
        android:layout_height="220dp"
        android:fitsSystemWindows="true"
        android:theme="@style/ThemeOverlay.AppCompat.ActionBar">

        <com.est.streamcorn.views.CustomCollapsingToolbarLayout
            android:id="@+id/collapsing_toolbar"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:fitsSystemWindows="true"
            app:contentScrim="?attr/colorPrimary"
            app:scrimAnimationDuration="250"
            app:titleEnabled="false"
            app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed">

            <ImageView
                android:id="@+id/trailer"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical"
                android:scaleType="centerCrop"
                tools:ignore="ContentDescription"
                android:fitsSystemWindows="true"
                app:layout_collapseMode="parallax"/>

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

                <TextView
                    android:id="@+id/toolbar_title"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:singleLine="true"
                    android:ellipsize="end"
                    android:layout_marginEnd="5dp"
                    style="@style/TextAppearance.AppCompat.Widget.ActionBar.Title" />

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

        </com.est.streamcorn.views.CustomCollapsingToolbarLayout>

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

    <android.support.v4.widget.NestedScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:behavior_overlapTop="40dp"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" >

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

            <android.support.design.widget.FloatingActionButton
                android:id="@+id/play"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:clickable="true"
                android:focusable="true"
                android:layout_margin="20dp"
                app:elevation="6dp"
                app:srcCompat="@drawable/player_action_play"
                app:backgroundTint="@color/colorAccent"
                app:layout_anchor="@id/header"
                app:layout_anchorGravity="bottom|right|end"/>

            <android.support.v7.widget.CardView
                android:id="@+id/image_container"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="15dp"
                app:cardElevation="6dp"
                app:cardCornerRadius="6dp"
                app:layout_anchor="@id/header"
                app:layout_anchorGravity="top|left|start">

                <com.est.streamcorn.views.AspectRatioImageView
                    android:id="@+id/image"
                    android:layout_width="110dp"
                    android:layout_height="wrap_content"
                    android:scaleType="centerCrop"
                    tools:ignore="ContentDescription"
                    app:aspectRatio="@dimen/movie_poster_aspect_ratio" />

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

            <FrameLayout
                android:id="@+id/header"
                android:layout_width="match_parent"
                android:layout_height="170dp"
                android:background="@android:color/transparent"
                android:elevation="4.0dp">

                <android.support.constraint.ConstraintLayout
                    android:layout_width="match_parent"
                    android:layout_height="130dp"
                    android:background="@color/colorPrimaryReverse"
                    android:orientation="vertical"
                    android:layout_gravity="bottom"
                    android:layout_marginBottom="0dp"
                    android:paddingEnd="0dp"
                    android:paddingStart="135dp">

                    <TextView
                        android:id="@+id/title"
                        android:layout_width="0dp"
                        android:layout_height="wrap_content"
                        android:layout_marginBottom="5dp"
                        android:ellipsize="end"
                        android:maxLines="2"
                        android:singleLine="false"
                        android:textAppearance="@style/MovieDetail.Title"
                        app:layout_constraintBottom_toTopOf="@id/text1"
                        app:layout_constraintStart_toStartOf="parent"
                        app:layout_constraintEnd_toStartOf="@id/download"
                        app:layout_constraintHorizontal_weight="0"
                        tools:text="The Martian - A Test Movie As Placeholder" />

                    <TextView
                        android:id="@+id/text1"
                        android:layout_width="0dp"
                        android:layout_height="wrap_content"
                        android:ellipsize="end"
                        android:singleLine="true"
                        android:textAppearance="@style/MovieDetail.Text1"
                        app:layout_constraintBottom_toTopOf="@id/text2"
                        app:layout_constraintStart_toStartOf="parent"
                        app:layout_constraintEnd_toStartOf="@id/download"
                        android:layout_marginBottom="5dp"
                        tools:text="2015" />

                    <TextView
                        android:id="@+id/text2"
                        android:layout_width="0dp"
                        android:layout_height="wrap_content"
                        android:ellipsize="end"
                        android:singleLine="true"
                        android:textAppearance="@style/MovieDetail.Text2"
                        app:layout_constraintBottom_toBottomOf="parent"
                        app:layout_constraintStart_toStartOf="parent"
                        app:layout_constraintEnd_toStartOf="@id/download"
                        android:layout_marginBottom="15dp"
                        tools:text="141 minutes" />

                    <android.support.design.widget.FloatingActionButton
                        android:id="@+id/download"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginEnd="20dp"
                        android:background="@android:color/transparent"
                        app:layout_constraintBottom_toBottomOf="@id/title"
                        app:layout_constraintTop_toTopOf="@id/title"
                        app:layout_constraintEnd_toEndOf="parent"
                        app:backgroundTint="@android:color/transparent"
                        app:borderWidth="0dp"
                        app:elevation="0dp"
                        app:srcCompat="@drawable/ic_download"
                        tools:ignore="ContentDescription" />

                </android.support.constraint.ConstraintLayout>

            </FrameLayout>

            <LinearLayout
                android:id="@+id/content"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_marginTop="150dp"
                android:background="@color/backgroundColorReverse"
                android:orientation="vertical"
                android:paddingEnd="15dp"
                android:paddingStart="15dp"
                android:paddingTop="60dp">

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginBottom="10dp"
                    android:textSize="16sp"
                    android:textAllCaps="true"
                    android:textColor="@color/textColorPrimaryReverse"
                    android:text="@string/description" />

                <TextView
                    android:id="@+id/description"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"/>
            </LinearLayout>

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

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

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

The custom view:

public class CustomCollapsingToolbarLayout extends CollapsingToolbarLayout {

    private Boolean previousShowing = true;

    public static interface Listener {
        public void onContentScrimAnimationStarted(boolean showing);
    }

    private Listener mListener;

    public CustomCollapsingToolbarLayout(Context context) {
        super(context);
    }

    public CustomCollapsingToolbarLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public CustomCollapsingToolbarLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    public void setScrimsShown(boolean shown, boolean animate) {
        super.setScrimsShown(shown, animate);
        if (animate && mListener != null && shown != previousShowing) {
            mListener.onContentScrimAnimationStarted(shown);
            previousShowing = shown;
        }
    }

    public void setListener(Listener listener) {
        mListener = listener;
    }
}

And in the activity OnCreate :

    setSupportActionBar(toolbar);
    getSupportActionBar().setTitle("");
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setDisplayShowHomeEnabled(true);

    TypedValue tv = new TypedValue();
    getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true);
    final int actionBarHeight = getResources().getDimensionPixelSize(tv.resourceId);
    collapsingToolbarLayout.setScrimVisibleHeightTrigger(actionBarHeight + 100);
    collapsingToolbarLayout.setListener(showing -> {
        if(showing){
            toolbarTitle.setVisibility(View.VISIBLE);
            toolbarTitle.animate().alpha(1).setDuration(250);
        }
        else{
            toolbarTitle.setVisibility(View.INVISIBLE);
            toolbarTitle.animate().alpha(0).setDuration(250);
        }
    });

The custom view is needed only if you want to make the title disappear when expanding the CollapsingToolbarLayout . For the layout maybe it's not a good solution but it's smooth. Better ideas are welcome.