AppBarLayout change offset programmatically

Question

How can I change the offset of the AppBarLayout programmatically?

I want a certain offset to the AppBarLayout(partially expanded) when the Activity first loads, then the user could expand it more or collapse it. The current behaviour is that it's fully expanded when the Activity first loads.

my.xml

<android.support.design.widget.AppBarLayout
        android:id="@+id/app_bar_layout"
        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:clickable="true"
            android:fitsSystemWindows="true"
            app:expandedTitleMarginEnd="64dp"
            app:expandedTitleMarginStart="48dp"
            app:layout_collapseParallaxMultiplier="0.7"
            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"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:scaleType="centerCrop"
                    android:src="@drawable/pic"/>

                <View
                    android:id="@+id/overlay"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:background="@drawable/overlay"
                    app:layout_collapseMode="pin"/>
            </FrameLayout>

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

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

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

Need to support API 16+

Thanks!

Answer 1

Use this: ScrollableAppBar

You just have to replace your AppBarLayout with:

<it.michelelacorte.scrollableappbar.ScrollableAppBar
android:id="@+id/appbar"
android:layout_width="match_parent"
android:layout_height="380dp"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
android:fitsSystemWindows="true">
</it.michelelacorte.scrollableappbar.ScrollableAppBar>

and than:

ScrollableAppBar appBarLayout = (ScrollableAppBar) findViewById(R.id.appbar);

//To give the effect "in the middle" of the image (like gif)
appBarLayout.collapseToolbar();

Output: