Introduction to Android - Google #DevFestLomb 2013 @ Università degli Studi di Milano Bicocca #DevFest

1. 2013.11.09
#DevFest Lombardia
#DevFestLomb
@ Università degli Studi Milano Bicocca

2. Who I Am
+MatteoGazzurelli
CEO / Android Developer
DUCKMA srl - Brescia
@gazzumatteo
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3. #devfestlomb
Introduction to Android
Android, the unknown...
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4. Android, questo sconosciuto...
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Mobile Operating System by Android Inc.
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Bought by Google in 2005
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Unveiled in 2007
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5. Why develop for Android?
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Is adaptable and functional
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Very good OS
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Good Business!
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6. Google’s Role
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Development & Support
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Google Play
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Nexus
Developers
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7. Android 101
In theory…. and in practice.
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8. Java Based
Java VM
Java
Hello World
Dalvik VM
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9. What do I need to know to be a programmer?
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OOP (Object Oriented Programming)
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Encapsulation, Inheritance,
Polymorphism
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Interfaces
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Listeners
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Packages structure
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10. Inside the Droid
Architecture & Theory
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11. Android Architecture
Application
Home, Contacts, Telephone, Browser, …
Application Framework
Managers for Activity, Window, Package, …
Libraries
SQLite, OpenGL, SSL, …
Runtime
Dalvik VM, Core libs
Kernel Linux
Driver for Display, Camera, Flash, Wifi, Audio, …
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12. Four pillars of Android
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Activities
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Services
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Broadcast Receivers
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Content Providers
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13. Activities
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Activity is the main component of Android, represent
a single screen whit a user interface
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Is like a form in traditional languages such as Visual
Basic or like a single HTML page
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14. Activity Lifecycle
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15. Introduction to Intents
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Intents are used as a message-passing mechanism
that works both within your application, and between
applications.
Interacts with every components in Android
Used for:
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Declare your intention that an Activity or Service be started to perform an
action, usually with a piece of data ( startActivity(Intent); )
Broadcast that an event (or action) has occurred
Explicity start a particular Service or Activity
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16. Services
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Application components that can perform longrunning operations in the background
Doesn’t provide a user interface
Service is not a separate process or thread
Service is a simple class, you must implement
separate threads by yourself
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17. Service Lifecycle
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18. Broadcast Receiver
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A Broadcast receiver is a component that does nothing
but receive and react to broadcast announcements
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Broadcast Intent
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Your app can:
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Receive and react to system services (ex. Battery low)
Receive and react to other apps broadcast announcements
Initiate broadcasts to other apps
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19. Content Provider
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Content Providers manage access to a structured set of
data
Are the standard interface that connects data in one
process with code running in another process
Any application with appropriate permission, can read and
write the data
Files, SQL Database
Expose a public URI that uniquely identifies its data set
“content://…”
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20. Content Provider
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21. Hands On
Down and dirty!
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22. Craftsman tools
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IDE
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Tools:
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Eclipse
Android Studio
ADT (Android Developer Tools)
Android SDK Tools
Android Platform Tools
AVD (Android Virtual Device) / Emulator
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23. Eclipse / Android Studio
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24. Android SDK Manager (via ADT)
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25. Android Virtual Device Manager (AVD)
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26. LogCat
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27. Debug
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28. Let’s start a new project
Gentlemen start your engines!
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29. File -> New Project
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30. Tutorial
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31. Project structure
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32. Src
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Java Classes
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Organized in Packages
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Activity
Fragment
Adapter
Models
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33. Activity
Sample Code
package com.example;
JAVA
import android.app.Activity;
import android.os.Bundle;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
protected void onPause(Bundle savedInstanceState) {
super.onPause();
}
}
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34. Fragments
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Since Android 3.0
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Represent a portion of the UI in an activity
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Can combine multiple fragment in a single activity
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Have their lifecycle
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Live in a ViewGroup
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35. Assets e Lib
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Assets
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Libs
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Not optimized and compiled resources
External libraries
Java o C
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36. Resources
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Any other information that are not code
Stored in config files external to code (but inside the final
apk package)
Contain
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Drawable
Layouts
Xml
Values
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37. Classe R.java
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Bridge between activities and resources
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In gen/
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Dynamically generated (by Android’s Eclipse plugin) and
contains numeric constant referred to every resources of
the project
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Contains only public fields (“public static final”)
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38. Resource Example
String.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
XML
<string name="app_name">Test</string>
<string name="action_settings" >Settings</string>
<string name="hello_world" >Hello world!</string>
</resources>
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39. Layout
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XML Files
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Defines the visual structure for a user interface
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Target many resolutions
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40. Layout Example
Activity_main.xml
<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=".MainActivity" >
XML
<TextView
android:layout_width="wrap_content”
android:layout_height="wrap_content"
android:text="@string/hello_world" />
</RelativeLayout>
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41. Widget
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Visual Components of Android
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Button
TextView
EditText
WebView
ImageView
…
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42. Widget Example
Button
JAVA
Button myButton = new Button(this);
myButton.setText(R.string.button_back);
myButton.setLayoutParams(new LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT
));
XML
<Button
android:id="@+id/button1”
android:layout_width="wrap_content”
android:layout_height="wrap_content”
android:layout_alignLeft="@+id/textView1”
android:layout_below="@+id/textView1”
android:layout_marginLeft="41dp”
android:text="Button” />
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43. Eclipse UI Builder
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44. Views
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Base component for UI (Widget)
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Layout
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View Groups
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Visual structure of the UI
Invisible Container that contains other View or ViewGroup
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45. Manifest
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Contains the essential information about the application
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Other elements to declare
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Version
Name
Icon
Permission
Features
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Activity
Services
Provider
Receiver
uses-sdk
uses-permission
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46. Design Pattern
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Model – View – Controller
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Model – View – Presenter
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In the official Android documentations doesn’t exists any
referral to these patterns
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Activity -> Controller
Activity -> View
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47. Fragmentation
‘minSdkVersion=“14”’
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48. Android Family Tree
1.5 Cupcake
1.6 Donut
2.0 Eclair
2.2 Froyo
2.3 Gingerbread
4.4 KitKat
3.0 Honeycomb
4.0 Ice Cream Sandwich
4.1 Jelly Bean
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49. November Fragmentation Status
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50. How many Display!
Screen Types
vs
Screen Sizes
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51. Suggestions (No Panic!)
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Choose the right target of your application
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Learn how to use correctly the res.
Support library
Test on at least two devices
Fragmentation can be an advantage
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minSdkVersion=“14”
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52. Publish
Make public your creations!
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53. Markets
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Google
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Samsung
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Amazon
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Any other market (your)
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54. Google Play Store
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55. Google Play Store - Publish
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56. Google Play Store - Stats
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57. Introduction to Android – The End
+MatteoGazzurelli
That’s me!
#devfestlomb
matteo@duckma.com
Thank You & Have Fun!
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58. Questions?
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59. Links
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Android Developer
http://developer.android.com
Android Design Guidelines
http://developer.android.com/design/
Play Store Publish
http://play.google.com/apps/publish/
Duckma
http://duckma.com
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60. Introduction to Android – The End
+MatteoGazzurelli
That’s me!
#devfestlomb
matteo@duckma.com
Thank You & Have Fun!
60