Step #1: Supporting Screens

Android devices come in a wide range of shapes and sizes. Our app can support them all. However, we should advise Android that we are indeed willing to support any screen size. To do this, we need to add a <supports-screens> element to the manifest.

To do this, double-click on AndroidManifest.xml in the project explorer:

As a child of the root <manifest> element, add a <supports-screens> element as follows:

<supports-screens
    android:largeScreens="true"
    android:normalScreens="true"
    android:smallScreens="true"
    android:xlargeScreens="true"/>

At this point, the manifest should resemble:

<?xml version="1.0" encoding="utf-8"?>
<manifest package="com.commonsware.todo"
  xmlns:android="http://schemas.android.com/apk/res/android">

  <supports-screens
    android:largeScreens="true"
    android:normalScreens="true"
    android:smallScreens="true"
    android:xlargeScreens="true"/>

  <application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/Theme.ToDo">
    <activity android:name=".MainActivity">
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />

        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity>
  </application>

</manifest>