Basic, Basic, Basic Android

1. Basic, Basic, Basic Android

2. What are Packages? • Page 346 in text • Package statement goes before any import statements • Indicates that the class declared in the file is part of the specified package. • Convention for naming packages • Starts with Internet domain in reverse order • edu.uta.davis.packagename; • Compile the package class • javac –d . FileName.java • Import package into programs • Import edu.uta.davis.packagename;

3. What is XML? • Extensible Markup Language – set of rules for encoding documents electronically • Helps identify structures in documents • Can invent own tags • Not HTML • HTML tags are fixed – displays data • XML is a meta-language – transport and stores data

4. <bookstore>  <book category="CHILDREN">    <title>Harry Potter</title>    <author>J K. Rowling</author>    <year>2005</year>    <price>29.99</price>  </book>  <book category="WEB">    <title>Learning XML</title>    <author>Erik T. Ray</author>    <year>2003</year>    <price>39.95</price>  </book></bookstore>

5. Main Components in Android Application • Activities – building block of user interface; analogous to dialog box or window • Content providers – way to store data on device that is accessible by multiple applications • Services – designed to run indefinitely, independent of any activity (e.g., RSS feed, play back music • Intents – systems messages that can notify applications of various events from hardware state changes to incoming data to application events

6. Other Features • Storage • Network • Multimedia • Global positioning system • Phone services

7. What do you need? • Eclipse 3.5 (Galileo) • JDK 5 or JDK 6 • Android SDK starter package • http://developer.android.com/sdk/index.html • Android development tools • Android Virtual Device

8. What does an Android Project Look Like? • Project contents are in an Android package file (.apk) • Root Directory • AndroidManifest.xml • default.properties • assets • bin • gen • src • res

9. Root Directory (cont) • AndroidManifest.xml – describes application being built and which components are being supplied by the application • default.properties – used by built script • assets – holds other static files you want packaged with your application • bin – folder that holds compiled code • gen – where Android’s tools will place source code they generate • src - hold Java source code for application • res – holds resources that are packaged with the compiled Java in the application (icons, GUI layouts, etc)

11. package com.example.helloandroid; import android.app.Activity; import android.os.Bundle; import android.widget.TextView; public class HelloAndroid extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); TextView tv = new TextView(this); tv.setText("Hello Android"); setContentView(tv); } } <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.helloandroid" android:versionCode="1" android:versionName="1.0"> <application android:icon="@drawable/icon" android:label="@string/app_name"> <activity android:name=".HelloAndroid" android:label="@string/app_name"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>