Challenge: Use the blank view when crimes is zero

Android Programming (3rd Edition) 13. The Toolbar
2

What I did was change the /layout/fragment_crime_list.xml

It turns out that if a FrameLayout has multiple children, those children will be drawn on top of one another.

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout     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:layout_width="match_parent"
    android:layout_height="match_parent">

    <!-- Layer 1 -->
    <android.support.v7.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/crime_recycler_view"/>

    <!-- Layer 2 -->
    <android.support.constraint.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/empty_list_layout">


        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/empty_list_text"
            android:layout_marginTop="16dp"
            app:layout_constraintTop_toTopOf="parent"
            android:layout_marginEnd="16dp"
            app:layout_constraintRight_toRightOf="parent"
            android:layout_marginStart="16dp"
            app:layout_constraintLeft_toLeftOf="parent" />

        <Button
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:id="@+id/add_crime_button"
            android:text="@string/new_crime"
            app:layout_constraintBottom_toBottomOf="parent"
            android:layout_marginBottom="16dp"
            android:layout_marginEnd="16dp"
            app:layout_constraintRight_toRightOf="parent"
            android:layout_marginStart="16dp"
            app:layout_constraintLeft_toLeftOf="parent" />
    </android.support.constraint.ConstraintLayout>

</FrameLayout>

I put an ID on the ConstraintLayout because I’ll be able to set its visibility to View.INVISIBLE when the list is not empty. The child Views will inherit this visibility change.

Now all of the changes you need to make are in CrimeListFragment.java

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