Introduction to Android SDK Jordi Linares

Transcription

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2 Introduction to Android SDK

3 Introduction to Android SDK

4 Introduction to Android SDK Google -> OHA (Open Handset Alliance) The first truly open and comprehensive platform for mobile devices, all of the software to run a mobile phone but without the proprietary obstacles that have hindered mobile innovation Linux OS kernel (a specific version based on 2.6) Java programming Open source libraries: SQLite, WebKit, OpenGL GPL, BSD and Apache licenses (some proprietary elements)

5 Introduction to Android SDK OHA (Open Handset Alliance)

6 Introduction to Android SDK Android is a software stack for mobile devices that includes an operating system, middleware and key applications

7 Some advantages True Multi-tasking 3rd Party APIs allowed Inter-application communication UI Customization Multi-language support Java, C, C++ Interpreted language support Python, Lua, Ruby, JS

8 Some advantages A simple and powerful SDK No licensing, distribution, or development fees Development over many platforms Linux, Mac OS, windows Excellent documentation Thriving developer community

9 Some advantages Many markets and stores (Google market is just the important one) Install apps from any website or just copying the app Fully support of Adobe Flash (Why not?)

10 Some advantages Multi-screen Widgets

11 Some advantages Component-based

12 However NO, android is not linux! android is based on a linux kernel but it's not GNU/Linux no native windowing system no glibc support (bionic BSD license) not all GNU/Linux utilities

13 However NO, android is not java! android is not an implementation of any of the Java variants: uses the java language implements part of the Java5 SE specification runs on a dalvik virtual machine instead of JVM

14 Android fragmentation January 2012

15 Where should we start?

16 Android SDK architecture

20 Android main elements Views: Building blocks for user interface components. Activities A single, focused thing that the user can do. A single screen, your app is made up of one or several of them Interaction with users: creating a window to place UI full-screen windows, floating windows, embedded inside of another activity

21 Android main elements Services (Background) Ex: Network Operation Intent Inter-communication among activities or services Like a verb call number, open book etc. An asynchronous message between activities Resource Externalization of strings and graphics It is compiled into a class called R Notification signaling users: Light, sound, icon, dialog, notification Ex: new message arrives Content Providers share data between applications Data and API that any app can access

22 Installing everything

29 Installing everything API 7 (2.1) and the new one API 15 (4.0.3) it s a good starting point

30 Creating a virtual device

33 Our first project Creating a new project File->New->Project

34 Our first project Initial template

35 Our first project Our initial Activity

36 Our first project Run

37 Our first project Result

38 The application manifest

39 Interface by coding We can create the interface just coding: package edu.mobweb.helloworld; import android.app.activity; import android.os.bundle; import android.widget.textview; public class HelloWorld extends Activity { /** Called when the activity is first created. public void oncreate(bundle savedinstancestate) { super.oncreate(savedinstancestate); //setcontentview(r.layout.main); TextView tv = new TextView(this); tv.settext("hello, MobWeb"); setcontentview(tv); } }

40 Interface by XML However, this is not the way in Android: <?xml version="1.0" encoding="u/- 8"?> <LinearLayout xmlns:android="h5p://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orienta:on="verccal" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" /> </LinearLayout>

41 Layouts Activities need a View to dispay UI Layouts are important Views, which objective is basically be a container or other Views (or Layouts) The most important ones are: LinearLayout (elements in row or column) TableLayout RelativeLayout (relative positions regarding parent or siblings) FrameLayout (for dynamic changes of the elements)

42 Layouts LinearLayout <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android=" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView <Button </Button> android:layout_width="fill_parent" android:layout_height="wrap_content" /> android:text="button" android:layout_width="wrap_content" android:layout_height="wrap_content"> <DigitalClock android:text="digitalclock" android:layout_width="wrap_content" android:layout_height="wrap_content"> </DigitalClock> </LinearLayout>

43 Layouts TableLayout <?xml version="1.0" encoding="utf-8"?> <TableLayout android:layout_width="fill_parent" android:layout_height="fill_parent" xmlns:android=" <TableRow android:layout_width="wrap_content" android:layout_height="wrap_content"> <Button android:text="button" android:layout_height="wrap_content" android:layout_width="wrap_content"> </Button> <Button android:text="button" android:layout_height="wrap_content" android:layout_width="wrap_content"> </Button> </TableRow> <TableRow android:layout_width="wrap_content" android:layout_height="wrap_content"> <EditText android:text="edittext android:layout_width="wrap_content android:layout_height="wrap_content"> </EditText> <EditText android:text="edittext" android:layout_width="wrap_content" android:layout_height="wrap_content"> </EditText> </TableRow> </TableLayout>

44 Layouts RelativeLayout <RelativeLayout android:layout_width="fill_parent" android:layout_height="fill_parent" xmlns:android=" <Button android:text="button" android:layout_alignparentleft="true" android:layout_width="wrap_content" android:layout_height="wrap_content"> </Button> <EditText android:text="edittext" android:layout_width="wrap_content" android:layout_height="wrap_content" </EditText> <AnalogClock android:layout_width="wrap_content" android:layout_height="wrap_content" </AnalogClock> </RelativeLayout>

45 A draft for the MobWeb app

48 A draft for the MobWeb app main.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayout android:layout_width="fill_parent android:layout_height="fill_parent" xmlns:android=" android:orientation="vertical" android:gravity="center" android:padding="30dp"> <ImageView android:layout_height="wrap_content android:layout_gravity="center_horizontal" android:layout_width="fill_parent"> </ImageView> <Button android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_margintop="30dp"> </Button> <Button android:layout_width="fill_parent" android:layout_height="wrap_content" </Button> <Button android:layout_width="fill_parent" android:layout_height="wrap_content" </Button> </LinearLayout>

49 A draft for the MobWeb app description.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android=" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content"> </TextView> </LinearLayout>

50 A draft for the MobWeb app string.xml <?xml version="1.0" encoding="utf-8"?> <resources> <string name="hello">hello World, MobWeb!</string> <string name="app_name">mobweb</string> <string name="description">description</string> <string name="teaching">teaching</string> <string name="quit">quit</string> <string name="textdescription">welcome to the MobWeb Erasmus Intensive Programme website. The MobWeb IP is an exciting teaching activity that will take place in its first edition next February 2011 in Alcoi (Spain). The main coordinator is the Campus of Alcoi of the Universitat Politècnica de València and will have as partners the Universitatea din Oradea (Oradea, Rumania) and the Lahden Ammattikorkeakoulu (Lahti, Finland). </string> </resources>

51 A draft for the MobWeb app Description.java package edu.mobweb.mobweb; import android.app.activity; import android.os.bundle; public class Description extends Activity { /** Called when the activity is first created. public void oncreate(bundle savedinstancestate) { super.oncreate(savedinstancestate); setcontentview(r.layout.description); } }

52 A draft for the MobWeb app MobWeb.java package edu.mobweb.mobweb; import android.app.activity; import android.content.intent; import android.os.bundle; import android.view.view; import android.view.view.onclicklistener; import android.widget.button; public class MobWeb extends Activity { } public void LaunchDescription() { Intent i = new Intent(this, Description.class); startactivity(i); } /** Called when the activity is first created. public void oncreate(bundle savedinstancestate) { super.oncreate(savedinstancestate); setcontentview(r.layout.main); } Button bdescription = (Button) findviewbyid(r.id.button1); bdescription.setonclicklistener(new OnClickListener() { public void onclick(view view) { LaunchDescription(); } });

54 A draft for the MobWeb app AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android=" package="edu.mobweb.mobweb" android:versioncode="1" android:versionname="1.0"> <uses-sdk android:minsdkversion="7" /> <application <activity android:name=".mobweb" <intent-filter> <action android:name="android.intent.action.main" /> <category android:name="android.intent.category.launcher" /> </intent-filter> </activity> <activity android:name=".description"></activity> </application> </manifest>

55 A draft for the MobWeb app AndroidManifest.xml

56 A draft for the MobWeb app OnCreate Button bteaching = (Button) findviewbyid(r.id.button2); bteaching.setonclicklistener(new OnClickListener() { public void onclick(view view) { LaunchTeaching(); } }); Add this new function public void LaunchTeaching() { String url = " Intent i = new Intent(Intent.ACTION_VIEW); i.setdata(uri.parse(url)); startactivity(i); }

57 The GravityBall example Download the.zip file and extract it Import it to your workspace with import in Eclipse Run it Sorry, you cannot enjoy it in the emulator (although there s a complement you can install to simulate the movement of it)

58 The GravityBall example In uses the Orientation sensor to move the ball

59 The GravityBall example Some interesting parts of the code

61 The GravityBall example

65 The GravityBall example main.xml