Назад стрелка не видна, когда панель свернута

Question

Im, используя код folloaing создать разборную расположение панелей инструментов

<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:background="#EEEEEE" 
android:fitsSystemWindows="true"> 

<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:layout_below="@+id/appbar_layout" 
     android:orientation="vertical"> 

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

<android.support.design.widget.AppBarLayout 
    android:id="@+id/app_bar_layoutdetails" 
    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/toolbarCollapse" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:fitsSystemWindows="true" 
     android:minHeight="?attr/actionBarSize" 
     app:contentScrim="?attr/colorPrimary" 
     app:layout_scrollFlags="scroll|exitUntilCollapsed" 
     app:navigationIcon="?attr/homeAsUpIndicator" 
     app:title="Fealty" 
     app:titleEnabled="true"> 

     <RelativeLayout 
      android:layout_width="match_parent" 
      android:layout_height="wrap_content"> 

      <ImageView 
       android:id="@+id/imageView8" 
       android:layout_width="match_parent" 
       android:layout_height="190dp" 
       android:background="@android:color/darker_gray" 
       android:minHeight="190dp" 
       android:scaleType="fitXY" 
       android:src="@drawable/mlogin" 
       app:layout_collapseMode="parallax"/> 

      <TextView 
       android:id="@+id/title" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:layout_alignParentLeft="true" 
       android:layout_alignParentStart="true" 
       android:layout_alignTop="@+id/favourite" 
       android:layout_gravity="bottom|end" 
       android:layout_marginEnd="20dp" 
       android:layout_marginLeft="16dp" 
       android:layout_marginRight="16dp" 
       android:layout_marginStart="16dp" 
       android:layout_toLeftOf="@+id/favourite" 
       android:layout_toStartOf="@+id/favourite" 
       android:src="@drawable/ic_launcher" 
       android:text="App Name" 
       android:textAppearance="?android:attr/textAppearanceMedium" 
       app:layout_anchor="@+id/app_bar_layout" 
       app:layout_anchorGravity="bottom|end"/> 

      <android.support.design.widget.FloatingActionButton 
       android:id="@+id/favourite" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:layout_alignTop="@+id/share" 
       android:layout_gravity="bottom|end" 
       android:layout_marginEnd="20dp" 
       android:layout_marginLeft="16dp" 
       android:layout_marginRight="16dp" 
       android:layout_toLeftOf="@+id/share" 
       android:layout_toStartOf="@+id/share" 
       android:src="@drawable/heart_out" 
       app:backgroundTint="#E91E63" 
       app:borderWidth="0dp" 
       app:fabSize="mini" 
       app:layout_anchor="@+id/app_bar_layout" 
       app:layout_anchorGravity="bottom|end"/> 

      <android.support.design.widget.FloatingActionButton 
       android:id="@+id/share" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:layout_alignBottom="@+id/imageView8" 
       android:layout_alignParentEnd="true" 
       android:layout_alignParentRight="true" 
       android:layout_gravity="bottom|end" 
       android:layout_marginBottom="29dp" 
       android:layout_marginEnd="23dp" 
       android:layout_marginLeft="16dp" 
       android:layout_marginRight="16dp" 
       android:src="@drawable/ic_launcher" 
       app:backgroundTint="#E91E63" 
       app:borderWidth="0dp" 
       app:fabSize="mini" 
       app:layout_anchor="@+id/app_bar_layout" 
       app:layout_anchorGravity="bottom|end"/> 

      <android.support.v7.widget.Toolbar 
       android:id="@+id/toolbar" 
       android:layout_width="match_parent" 
       android:layout_height="?actionBarSize" 
       android:minHeight="?attr/actionBarSize" 
       app:navigationIcon="?attr/homeAsUpIndicator" 
       app:popupTheme="@style/ThemeOverlay.AppCompat.Light" 
       app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"> 
      </android.support.v7.widget.Toolbar> 
     </RelativeLayout> 
    </android.support.design.widget.CollapsingToolbarLayout> 
</android.support.design.widget.AppBarLayout> 

Проблема заключается в том, что когда складная панель инструментов не в складном состоянии, стрелка назад видна, но если она рухнула, стрелка назад не видна. почему так?

Answer 1

Убрать это android:fitsSystemWindows="true" в CoordinatorLayout.

Добавить это в Java setContentView ниже

Toolbar toolbar = (Toolbar) findViewById(R.id.mainToolbar); 
setSupportActionBar(toolbar); 
getSupportActionBar().setDisplayShowTitleEnabled(true); 
getSupportActionBar().setDisplayHomeAsUpEnabled(true);