How to make bottom sheet (BottomSheetBehavior) expandable to arbitrary position?

user_608160 0
Viewed 9266

I have bottom sheet, and I want to change its behavior so it would work like on the main screen of Google Maps application, where you can expand it to any position and leave it there and it won't automatically stick to the bottom or to the top. Here's my layout with bottom sheet:

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

    <com.google.android.gms.maps.MapView
        android:id="@+id/map"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <View
        android:id="@+id/shadow"
        android:layout_width="match_parent"
        android:layout_height="16dp"
        android:background="@drawable/shape_gradient_top_shadow"
        app:layout_anchor="@+id/map_bottom_sheet" />


    <LinearLayout
        android:id="@+id/map_bottom_sheet"
        android:layout_width="match_parent"
        android:layout_height="300dp"
        android:fillViewport="false"
        android:orientation="vertical"
        app:behavior_peekHeight="50dp"
        android:background="@color/lightGray"
        app:layout_behavior="android.support.design.widget.BottomSheetBehavior">

        <include layout="@layout/bottom_sheet_top_buttons"/>
        <android.support.v4.widget.NestedScrollView
            android:id="@+id/bottom_sheet_content_fragment"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@color/lightGray"/>

    </LinearLayout>

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

What I need in essence is eliminate forcing of STATE_EXPANDED and STATE_COLLAPSED states when dragging is ended.

Here's a visual explanation of what I try to achieve:


As you can see, bottom sheet doesn't automatically anchor to the top or the bottom but stays at whatever position it was left.

bottom-sheet google-maps android
3 Answers

I have created a proof of concept originating from the orginal source code from the design library. You can view it here. The problem with the original behavior is it doesn't allow flings, and most methods are private so extending the class and overriding some methods in an attempt to achieve it won't get you very far either. My implementation allows for optional snapping behavior, transient states (don't automatically snap after drag) and customizations around setting peek height and max height.

user_37049880
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