If you want the subtitle to go to Toolbar when the AppBar is fully collapsed you should create your custom CoordinatorLayout.Behaviour Like this: Github Guide

But if you just want a smaller text behind the title when the AppBar is expanded you can try this layout:

<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:fitsSystemWindows="true">
    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        android:layout_width="match_parent"
        android:layout_height="300dp"
        android:fitsSystemWindows="true"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.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="?attr/colorPrimary"
            app:expandedTitleMarginBottom="160dp"
            app:expandedTitleMarginEnd="64dp"
            app:expandedTitleMarginStart="48dp"
            app:layout_scrollFlags="scroll|exitUntilCollapsed">
            <ImageView
                android:id="@+id/header"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="@drawable/quila2"
                android:fitsSystemWindows="true"
                android:scaleType="centerCrop"
                app:layout_collapseMode="parallax" />
            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:textSize="16sp"
                android:textColor="@android:color/white"
                android:layout_marginBottom="32dp"
                android:layout_marginEnd="64dp"
                android:layout_marginStart="48dp"
                app:layout_collapseMode="parallax"
                android:layout_gravity="bottom"
                android:text="Lorem Ipsum Iran Lorem Ipsum Iran Lorem Ipsum Iran Lorem Ipsum Iran Lorem Ipsum Iran Lorem Ipsum Iran Lorem Ipsum Iran Lorem Ipsum Iran "/>
            <android.support.v7.widget.Toolbar
                android:id="@+id/anim_toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                app:layout_collapseMode="pin"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
        </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:scrollbars="none"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="16dp"
            android:lineSpacingExtra="8dp"
            android:text="@string/lorem"
            android:textSize="18sp"/>

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

    <android.support.design.widget.FloatingActionButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:clickable="true"
        android:src="@drawable/abc_ic_search_api_mtrl_alpha"
        app:layout_anchor="@+id/appbar"
        app:layout_anchorGravity="bottom|right|end" />

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

Notice that here I set the AppBar height as 300dp and the app:expandedTitleMarginBottom is 160dp so the title won't go down and conflict with the out subtitle. In this example you should set CollapsingToolbarTitle dynamically in the runtime with collapsingToolbarTitle.setTitle("My Title"); method.

The result will be something like this:

enter image description here


Subtitle support in a CollapsingToolbarLayout is a feature that I also long for, so I created a library collapsingtoolbarlayout-subtitle:

enter image description here

Use it like you would on any CollapsingToolbarLayout, just add subtitle attribute on it:

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

        <com.hendraanggrian.widget.SubtitleCollapsingToolbarLayout
            android:id="@+id/subtitlecollapsingtoolbarlayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:contentScrim="?colorPrimary"
            app:layout_scrollFlags="scroll|exitUntilCollapsed"
            app:subtitle="CollapsingToolbarLayout"
            app:title="Subtitle">

            <!-- collapsing toolbar content goes here -->

            <android.support.v7.widget.Toolbar
                android:layout_width="match_parent"
                android:layout_height="?actionBarSize"
                app:layout_collapseMode="pin"/>
        </com.hendraanggrian.widget.SubtitleCollapsingToolbarLayout>
    </android.support.design.widget.AppBarLayout>

    <!-- content goes here -->

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

Try something like this, it work for me I have created custom ViewBehavior

@Override
public boolean layoutDependsOn(CoordinatorLayout parent, HeaderView child, View dependency) {
    return dependency instanceof AppBarLayout;
}

@Override
public boolean onDependentViewChanged(CoordinatorLayout parent, HeaderView child, View dependency) {
    shouldInitProperties(child, dependency);

    int maxScroll = ((AppBarLayout) dependency).getTotalScrollRange();
    float percentage = Math.abs(dependency.getY()) / (float) maxScroll;

    float childPosition = dependency.getHeight()
            + dependency.getY()
            - child.getHeight()
            - (getToolbarHeight() - child.getHeight()) * percentage / 2;


    childPosition = childPosition - mStartMarginBottom * (1f - percentage);

    CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams) child.getLayoutParams();
    lp.leftMargin = (int) (percentage * mEndMargintLeft) + mStartMarginLeft;
    lp.rightMargin = mMarginRight;
    child.setLayoutParams(lp);

    child.setY(childPosition);

    ...
    return true;
}

and this 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"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
>


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

    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapsing_toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:fitsSystemWindows="true"
        app:contentScrim="?attr/colorPrimary"
        app:layout_scrollFlags="scroll|exitUntilCollapsed"
        >

        <ImageView
            android:id="@+id/image"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:fitsSystemWindows="true"
            android:scaleType="centerCrop"
            android:src="@drawable/img_nature"
            app:layout_collapseMode="parallax"
            />

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


            <include
                android:id="@+id/toolbar_header_view"
                layout="@layout/header_view"
                android:layout_height="wrap_content"
                android:layout_width="match_parent"
                android:layout_marginRight="@dimen/header_view_end_margin_right"
                android:visibility="gone"
                />

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

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

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

<android.support.v4.widget.NestedScrollView
    android:id="@+id/scroll"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:clipToPadding="false"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        >

      ...

    </LinearLayout>

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

<include
    android:id="@+id/float_header_view"
    layout="@layout/header_view"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
        app:layout_behavior="com.subtitlebehavoir.harcopro.simple.ViewBehavior"
    />

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

ViewHeader layout:

<?xml version="1.0" encoding="utf-8"?>
<com.subtitlebehavoir.harcopro.simple.HeaderView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
>

<!-- Title -->
<TextView
    android:id="@+id/header_view_title"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textColor="@android:color/white"
    android:textSize="18sp"
    />

<!-- Subtitle -->
<TextView
    android:id="@+id/header_view_sub_title"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textColor="@android:color/white"
    android:textSize="16sp"
    />


</com.subtitlebehavoir.harcopro.simple.HeaderView>

Here is the modified version of Harco's implmentation (this) given above which will also change the size of title as we expand and collapse the layout.

ViewBehavior.java

public class ViewBehavior extends CoordinatorLayout.Behavior<HeaderView> {

    private static final float MAX_SCALE = 0.5f;

    private Context mContext;

    private int mStartMarginLeft;
    private int mEndMargintLeft;
    private int mMarginRight;
    private int mStartMarginBottom;
    private boolean isHide;

    public ViewBehavior(Context context, AttributeSet attrs) {
        mContext = context;
    }

    @Override
    public boolean layoutDependsOn(CoordinatorLayout parent, HeaderView child, View dependency) {
        return dependency instanceof AppBarLayout;
    }

    @Override
    public boolean onDependentViewChanged(CoordinatorLayout parent, HeaderView child, View dependency) {
        shouldInitProperties(child, dependency);

        int maxScroll = ((AppBarLayout) dependency).getTotalScrollRange();
        float percentage = Math.abs(dependency.getY()) / (float) maxScroll;

        // Set scale for the title
        float size = ((1 - percentage) * MAX_SCALE) + 1;
        child.setScaleXTitle(size);
        child.setScaleYTitle(size);

        // Set position for the header view
        float childPosition = dependency.getHeight()
                + dependency.getY()
                - child.getHeight()
                - (getToolbarHeight() - child.getHeight()) * percentage / 2;

        childPosition = childPosition - mStartMarginBottom * (1f - percentage);

        CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams) child.getLayoutParams();
        lp.leftMargin = (int) (percentage * mEndMargintLeft) + mStartMarginLeft;
        lp.rightMargin = mMarginRight;
        child.setLayoutParams(lp);

        child.setY(childPosition);

        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
            if (isHide && percentage < 1) {
                child.setVisibility(View.VISIBLE);
                isHide = false;
            } else if (!isHide && percentage == 1) {
                child.setVisibility(View.GONE);
                isHide = true;
            }
        }
        return true;
    }

    private void shouldInitProperties(HeaderView child, View dependency) {

        if (mStartMarginLeft == 0)
            mStartMarginLeft = mContext.getResources().getDimensionPixelOffset(R.dimen.header_view_start_margin_left);

        if (mEndMargintLeft == 0)
            mEndMargintLeft = mContext.getResources().getDimensionPixelOffset(R.dimen.header_view_end_margin_left);

        if (mStartMarginBottom == 0)
            mStartMarginBottom = mContext.getResources().getDimensionPixelOffset(R.dimen.header_view_start_margin_bottom);

        if (mMarginRight == 0)
            mMarginRight = mContext.getResources().getDimensionPixelOffset(R.dimen.header_view_end_margin_right);
    }


    public int getToolbarHeight() {
        int result = 0;
        TypedValue tv = new TypedValue();
        if (mContext.getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true)) {
            result = TypedValue.complexToDimensionPixelSize(tv.data, mContext.getResources().getDisplayMetrics());
        }
        return result;
    }
}

HeaderView.java

public class HeaderView extends LinearLayout {

    @Bind(R.id.header_view_title)
    TextView title;

    @Bind(R.id.header_view_sub_title)
    TextView subTitle;

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

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

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

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public HeaderView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }

    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();
        ButterKnife.bind(this);
    }

    public void bindTo(String title) {
        bindTo(title, "");
    }

    public void bindTo(String title, String subTitle) {
        hideOrSetText(this.title, title);
        hideOrSetText(this.subTitle, subTitle);
    }

    private void hideOrSetText(TextView tv, String text) {
        if (text == null || text.equals(""))
            tv.setVisibility(GONE);
        else
            tv.setText(text);
    }

    public void setScaleXTitle(float scaleXTitle) {
        title.setScaleX(scaleXTitle);
        title.setPivotX(0);
    }

    public void setScaleYTitle(float scaleYTitle) {
        title.setScaleY(scaleYTitle);
        title.setPivotY(30);
    }
}

I also had the same issue. In the end I made a LinearLayout that contains the title and subtitle and then set the expandedTitleTextAppearance to be transparent - effectively hiding the Toolbar title when the Layout is expanded. Using this approach the toolbar collapses over the LinearLayout and in the end only shows the title in the collapsed state.

The full xml is here:

<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="@dimen/series_detail_header_height"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
    app:layout_scrollFlags="scroll|exitUntilCollapsed">
    <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="?attr/colorPrimary"
        app:expandedTitleMarginEnd="64dp"
        app:expandedTitleMarginStart="48dp"
        app:expandedTitleTextAppearance="@style/TransparentText"
        app:layout_scrollFlags="scroll|exitUntilCollapsed">
        <FrameLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_collapseMode="parallax">
            <ImageView
                android:id="@+id/image_view"
                android:layout_width="match_parent"
                android:layout_height="@dimen/series_detail_header_image_height"
                android:scaleType="centerCrop"/>
            <LinearLayout
                android:id="@+id/header_text_layout"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="bottom"
                android:background="?attr/colorPrimary"
                android:gravity="center_vertical"
                android:minHeight="@dimen/series_detail_text_layout_height"
                android:orientation="vertical"
                android:paddingLeft="20dp"
                android:paddingRight="10dp"
                android:paddingTop="10dp">
                <TextView
                    android:id="@+id/title"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:text="My title"
                    android:textColor="@android:color/white"
                    android:textSize="24sp"/>
                <TextView
                    android:id="@+id/subtitle"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:textColor="@android:color/white"
                    android:textSize="17sp"/>
            </LinearLayout>
        </FrameLayout>
        <View
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="@drawable/shape_toolbar_black_gradient"
            app:layout_collapseMode="pin"/>
        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:layout_gravity="top"
            app:layout_collapseMode="pin"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
            />
    </android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
    android:id="@+id/show_view_pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/white"
    android:paddingTop="@dimen/toolbar_height"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"/></android.support.design.widget.CoordinatorLayout>

Make sure that your style also extends TextAppearance or the app will crash if your Design Support Library is v22.2.0 :

<style name="TransparentText" parent="@android:style/TextAppearance">
    <item name="android:textColor">#00666666</item>
</style>

This bug appears to be fixed in v22.2.1 (https://code.google.com/p/android/issues/detail?id=178674):