Android basics
About Android
 Linux based operating system
 Open source
 Designed for handheld devices
 Developed by
 Android Inc.
 Google (2005)
 Open Handset Alliance (2007)
 Very successful system (75% sales in 2012)
Top mobile operating systems
Android basics
 Can run Java code on Dalvik VM
 Multi-user system (each application is a different user)
 Unique user ID
 Has its own virtual machine
 Has its own Linux process
 Principle of least privilege
 Applications can share data
Application components
 Building blocks of an application
 4 types
 Activity

Single screen with UI
 Service

Backgroud process without UI
 Content provider

Manages a shared set of application data
 Broadcast receiver

Responds to system-wide broadcast announcements
Applications
 All components of an application runs in the same
process
 The system tries to keep a process as long as possible
 Applications are stored in a stack
 The systems duty to destroy the applications
 The system uses importance hierarchy
 Foreground processes
 Visible process
 Service process
 Background process
 Empty process
Activity
lifecycle
Android development
 Andriod SDK (http://developer.android.com/sdk)
 Java API libraries for different platforms
 SDK manager
 AVD Manager (emulator)
 Developer IDE
 Eclipse with ADT (Juno has it by default)
 Netbeans with NBAndroid plugin
 Android device
 USB Driver
 Enable USB debugging
 Useful link: http://developer.android.com
IDE basics
 NetBeans
 https://kenai.com/projects/nbandroid/pages/Install
 https://kenai.com/projects/nbandroid/pages/Intro
 Eclipse
 For ADT bundle everything is set up

http://developer.android.com/sdk/installing/bundle.html
 For Juno install is not required, for other existing
Eclipse installs:

http://developer.android.com/sdk/installing/addingpackages.html
 Add platforms and packages
 http://developer.android.com/sdk/installing/addingpackages.html
Set up virtual devices
Presets
Set up virtual
devices
API levels
API levels
New Project (NetBeans)
New Project
New Project
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="gamedev.android.UEngine.PlatformGame"
android:versionCode="1"
Our application version
android:versionName="1.0">
<application android:label="@string/app_name" >
Activity to start
<activity android:name="MainActivity"
android:label="@string/app_name">
Icon label of our
<intent-filter>
Activity
<action android:name="android.intent.action.MAIN"We
/> can change
this to e.g.: />
<category android:name="android.intent.category.LAUNCHER"
“MyPlatformGame”
</intent-filter>
</activity>
</application>
</manifest>
Start a virtual device
Build and run the project
MainActivity.java:
setContentView(R.layout.main);
Main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Hello World, MainActivity"
/>
</LinearLayout>
OpenGL ES – MainActivity.java
import android.app.Activity;
import android.opengl.GLSurfaceView;
import android.os.Bundle;
public class MainActivity extends Activity
{
private GLSurfaceView mGLView;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
mGLView = new MainSurfaceView(this);
setContentView(mGLView);
}
}
OpenGL ES – MainSurfaceView.java
package gamedev.android.UEngine.PlatformGame;
import android.content.Context;
import android.opengl.GLSurfaceView;
public class MainSurfaceView extends GLSurfaceView {
private MainRenderer mRenderer;
public MainSurfaceView(Context context)
{
super(context);
this.mRenderer = new MainRenderer(getContext());
setRenderer(this.mRenderer);
}
}
OpenGL ES – MainRenderer.java
package gamedev.android.UEngine.PlatformGame;
import android.content.Context;
import android.opengl.GLSurfaceView;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
public class MainRenderer implements GLSurfaceView.Renderer{
private Context context;
public MainRenderer(Context context) {
this.context = context;
}
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
gl.glClearColor(0.5F, 0.5F, 1.0F, 1.0F);
}
public void onDrawFrame(GL10 gl) {
gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT );
}
public void onSurfaceChanged(GL10 gl, int width, int height) {
gl.glViewport(0, 0, width, height);
}
}
Build and run
Draw something - MainRenderer
 New imports
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
 New data member
protected FloatBuffer VB = null;
public float rotAngle = 0;
Draw something - MainRenderer
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
gl.glClearColor(0.5F, 0.5F, 1.0F, 1.0F);
float[] VCoords = {
-1.0F, -1.0F, 0.0F,
1.0F, -1.0F, 0.0F,
1.0F, 1.0F, 0.0F,
-1.0F, -1.0F, 0.0F,
1.0F, 1.0F, 0.0F,
-1.0F, 1.0F, 0.0F };
ByteBuffer vbb = ByteBuffer.allocateDirect(VCoords.length * 4);
vbb.order(ByteOrder.nativeOrder());
this.VB = vbb.asFloatBuffer();
this.VB.put(VCoords);
this.VB.position(0);
}
Draw something - MainRenderer
public void onDrawFrame(GL10 gl) {
gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT );
gl.glMatrixMode(gl.GL_MODELVIEW);
gl.glLoadIdentity();
gl.glTranslatef(0,0,-6);
gl.glColor4f(1, 0, 0, 1);
gl.glRotatef(rotAngle, 0, 1, 0);
gl.glEnableClientState(gl.GL_VERTEX_ARRAY);
gl.glVertexPointer(3, gl.GL_FLOAT, 0, this.VB);
gl.glDrawArrays(gl.GL_TRIANGLES, 0, 6);
gl.glDisableClientState(gl.GL_VERTEX_ARRAY);
rotAngle += 2.5f;
}
Draw something - MainRenderer
public void onSurfaceChanged(GL10 gl, int width, int
height) {
gl.glViewport(0, 0, width, height);
float ratio = (float) width / height;
gl.glMatrixMode(gl.GL_PROJECTION);
gl.glLoadIdentity();
gl.glFrustumf(-ratio, ratio, -1, 1, 1.0f, 10);
}
Build and run
Input handling - MainSurfaceView
protected float lastX = -1;
public boolean onTouchEvent(MotionEvent e) {
float x = e.getX();
switch (e.getAction()) {
case MotionEvent.ACTION_MOVE:
float dx = lastX == -1 ? 0 : x - lastX;
mRenderer.rotAngle += dx * 1.0f;
break;
}
lastX = x;
return true;
}
Also remove rotAngle += 2.5f;
from
MainRenderer.onDrawFrame
Build and run
 Quad can be rotated with the mouse in emulator
Orientation – Full screen
 Fix orientation to landscape (typical in games)
Activity::onCreate():
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
 Set to full screen (typical in games)
Activity::onCreate():
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
 Rotate emulator to landscape mode: Ctrl+F12
Compile and run