How to build a basic WorldWind Android ‘app’

This tutorial sets up a project from scratch and inserts a WorldWind globe in a FrameLayout.

1. Create a new Android Studio Project

1. Select File > New > New Project… to run the ne project wizard
2. Configure your new project:
   • You can use the default values
3. Select the form factors your app will run on:
   • Choose Phone/Tablet
   • Choose Minimum SDK: API 19: Android 4.4 (KitKat)
4. Add an Activity
   • Choose an Empty Activity
5. Customize the Activity:
   • You can use the default values
   • Activity Name: MainActivity
   • Generate Layout File: checked
   • Layout Name: activity_main

2. Run the ‘app’ to verify it works

1. Select Run > Run ‘app’
2. Choose an Available Emulator or Device and select OK
3. If Required, create a new emulator to run the ‘app’
   • Select hardware device: Default Nexus 5X
   • Select and download a System Image: Default: Marshmallow (wait for download to complete)
   • Configure Android Virtual Device (AVD)

3. Add the WorldWind library to your project

• Follow the directions in Get Started to add the library via Gradle.

4. Add a WorldWindow globe to the MainActivity

We'll make three simple changes to your 'app' to add a basic globe.

First, edit the activity_main.xml layout file and replace the TextView with the following FrameLayout. The FrameLayout is assigned the globe id which will be referenced in the MainActivity.
```xml
<!--WorldWindow Globe panel-->
<FrameLayout
    android:id="@+id/globe"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_alignParentLeft="true"
    android:layout_alignParentRight="true"
    android:layout_alignParentTop="true"></FrameLayout>
```
Second, create an instance of a WorldWindow in MainActivity.java and attach to the FrameLayout. The following code snippet should be added to the MainActivity's onCreate() method.
```java
// Create a WorldWindow (a GLSurfaceView)...
WorldWindow wwd = new WorldWindow(getApplicationContext());
// ... and add some map layers
wwd.getLayers().addLayer(new BackgroundLayer());
wwd.getLayers().addLayer(new BlueMarbleLandsatLayer());
// Add the WorldWindow view object to the layout that was reserved for the globe.
FrameLayout globeLayout = (FrameLayout) findViewById(R.id.globe);
globeLayout.addView(wwd);
```
And finally, add the following network access permissions to the AndroidManifest.xml so that the globe can download its imagery.
```xml
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
```

• activity_main.xml

  <?xml version="1.0" encoding="utf-8"?>
  <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:paddingBottom="@dimen/activity_vertical_margin"
          android:paddingLeft="@dimen/activity_horizontal_margin"
          android:paddingRight="@dimen/activity_horizontal_margin"
          android:paddingTop="@dimen/activity_vertical_margin"
          tools:context="com.example.myapplication.MainActivity">
  
      <!--WorldWindow Globe panel-->
      <FrameLayout
              android:id="@+id/globe"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:layout_alignParentLeft="true"
              android:layout_alignParentRight="true"
              android:layout_alignParentTop="true"></FrameLayout>
  </RelativeLayout>
  

• MainActivity.java

  package com.example.myapplication;
  
  import android.support.v7.app.AppCompatActivity;
  import android.os.Bundle;
  import android.widget.FrameLayout;
  
  import gov.nasa.worldwind.WorldWindow;
  import gov.nasa.worldwind.layer.BackgroundLayer;
  import gov.nasa.worldwind.layer.BlueMarbleLandsatLayer;
  
  public class MainActivity extends AppCompatActivity {
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
  
          // Create a WorldWindow (a GLSurfaceView)...
          WorldWindow wwd = new WorldWindow(getApplicationContext());
          // ... and add some map layers
          wwd.getLayers().addLayer(new BackgroundLayer());
          wwd.getLayers().addLayer(new BlueMarbleLandsatLayer());
          // Add the WorldWindow view object to the layout that was reserved for the globe.
          FrameLayout globeLayout = (FrameLayout) findViewById(R.id.globe);
          globeLayout.addView(wwd);
      }
  }
  

• AndroidManifest.xml

  <?xml version="1.0" encoding="utf-8"?>
  <manifest package="com.example.myapplication"
          xmlns:android="http://schemas.android.com/apk/res/android">
  
      <uses-permission android:name="android.permission.INTERNET"></uses>
      <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses>
  
      <application
              android:allowBackup="true"
              android:icon="@mipmap/ic_launcher"
              android:label="@string/app_name"
              android:supportsRtl="true"
              android:theme="@style/AppTheme">
          <activity android:name=".MainActivity">
              <intent-filter>
                  <action android:name="android.intent.action.MAIN"></action>
  
                  <category android:name="android.intent.category.LAUNCHER"></category>
              </intent-filter>
          </activity>
      </application>
  </manifest>
  

5. Run the ‘app’ with the globe

1. Select Run > Run ‘app’
2. Choose an Available Emulator or Device and select OK