12-04-2011, 11:02 AM
[attachment=12073]
Google Android
Mobile Computing
Android is part of the ‘build a better phone’ process
Open Handset Alliance produces Android
Android is growing
Android makes mobile Java easier
Android applications are written in Java
package com.google.android.helloactivity;
import android.app.Activity;
import android.os.Bundle;
public class HelloActivity extends Activity {
public HelloActivity() {
}
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.hello_activity);
}
}
Android applications are compiled to Dalvik bytecode
The Dalvik runtime is optimised for mobile applications
Run multiple VMs efficiently
Android has many components
Can assume that most have android 2.1 or 2.2
Android has a working emulator
All applications are written in Java and available to each other
Android designed to enable reuse of components in other applications
Android applications have common structure
There is a common file structure for applications
Standard components form building blocks for Android apps
The AndroidManifest lists application details
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.androidapk/res/android"
package="com.my_domain.app.helloactivity">
<application android:label="@string/app_name">
<activity android:name=".HelloActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>
Activity is one thing you can do
Intent provides late running binding to other apps
It can be thought of as the glue between activities. It is basically a passive data structure holding an abstract description of an action to be performed.
Services declared in the manifest and provide support
Notifications let you know of background events
ContentProviders share data
UI layouts are in Java and XML
Security in Android follows standard Linux guidelines
