Bottom App Bar is introduced in material theme-2( check usage in material.io). The main advantage of bottom bar is it’s positioning bottom of the screen.You can use it with the default drawer-layout or with bottom sheet(You can check here). Both work flawlessly with bottom bar. In order to make the look and feel great of the app we are using bottom sheet.
Adding Bottom App Bar
First step is to add the Bottom App Bar to the layout in order to use this App Bar. The project must be converted to AndroidX (Option for this is available in Refactor menu in Android Studio. Add below code to your xml.
You can check out the source code
Adding option menu to bottom bar
Normally added option menus are not visible on the bottom bar, You need to set it by making the bottom bar as the default toolbar.Below code will help you achieve that.
BottomAppBar bar=findViewById(R.id.bar); setSupportActionBar(bar);
Styling bottom bar and bottom sheet
For achieving the desired look Both the bottom bar and bottom sheet need styling.So style file require few more lines of code.