Android DrawerLayout with transparent toolbar

Question

I'm trying to create a DrawerLayout with a transparent Toolbar (with a hambuger icon) and a NavigationView.

This is the layout of my main_activty:

<android.support.v4.widget.DrawerLayout 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:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:openDrawer="start">

    <include
        layout="@layout/app_bar_map"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <android.support.design.widget.NavigationView
        android:id="@+id/nav_view"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:fitsSystemWindows="true"
        app:headerLayout="@layout/nav_header_main"
        app:menu="@menu/activity_main_drawer"
        app:itemTextColor="@color/primary"
        android:background="@color/secondary"/>

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

This is how I defined the app_bar_map layout:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.design.widget.CoordinatorLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".core.MainActivity">

        <FrameLayout
            android:id="@+id/fragment_container"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />

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

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@android:color/transparent"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true">

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

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

</RelativeLayout>

And finally, this is the code of the onCreate method:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    MapFragment mapFragment = new MapFragment();
    FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
    fragmentTransaction.replace(R.id.fragment_container, mapFragment);
    fragmentTransaction.commit();

    toolbar = (Toolbar) findViewById(R.id.toolbar);

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);

    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.app_name, R.string.app_name);
    drawer.setDrawerListener(toggle);
    toggle.syncState();

    navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);
}

This is the final result:

Note that there is a "border" on the transparent toolbar. and I don't know where it come from or how to resolve this.

Any ideas?

Answer 1

Thanks to @KeLiuyue I found a solution to this problem.

This is what I ended uo doing with AppBarLayout:

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@android:color/transparent"
    android:layout_alignParentStart="true"
    android:layout_alignParentTop="true"
    android:elevation="0dp"
    android:stateListAnimator="@null">