andevcon android for java

8/10/2019 Andevcon Android for Java

1/64

2011

!"#$% '"#()*+"

,"#"$"*"-.%,

!"#$%

/%# 0"1" 2)1)3%4)#5


2/64

2011

67%8+ !"#$% '"#()*+"

Developer ofAndroid Bootcamp for Marakana.

Instructor for 1,000s of developers on Android at

Qualcomm, Cisco, Motorola, Texas Instruments, Sony-Ericsson, Sharp, NetGear, DoD and other great orgs.

Author of Learning Android published by OReilly.

Speaker at OSCON, ACM, IEEE, SDC, AnDevCon.

Founder of SFAndroid.org


3/64

2011

6()*9"

:;)


4/64

2011

!()*+,) -.!/0


5/64

2011

:;)


6/64

2011

H@*8I J)#*)3

Android runs on Linux.

Linux provides:

Hardware abstraction layerMemory management

Process managementNetworking

Users never see Linux sub system

The adb shell command opens

Linux shell

Linux Kernel

Libraries

Application Framework

Applications

Home Contacts Phone Browser Other

ActivityManager

WindowManager

ContentProviders

ViewSystem

PackageManager

TelephonyManager

ResourceManager

LocationManager

NotiicationManager

SurfaceManager

OpenGL

SGL

Media

Framework

FreeType

SSL

SQLite

WebKit

libc

Android Runtime

Core Libs

DelvikVM

DisplayDriver

KeypadDriver

CameraDriver

WiFiDriver

FlashDriver

AudioDriver

BinderDriver

PowerMgmt


7/64

2011

K"E1) H@7#"#@)5

Pieces borrowed from other

open source projects:

Bionic, a super fast and small

license-friendly libc library optimized

for Android

WebKit library for fast HTMLrendering

OpenGL for graphics

Media codecs offer support formajor audio/video codecs

SQLite database

Much more

Linux Kernel

Libraries


Applications


ActivityManager

WindowManager

ContentProviders

ViewSystem

PackageManager

TelephonyManager

ResourceManager

LocationManager

NotiicationManager

SurfaceManager

OpenGL

SGL

MediaFramework

FreeType

SSL

SQLite

WebKit

libc

Android Runtime

Core Libs

DelvikVM

DisplayDriver

KeypadDriver

CameraDriver

WiFiDriver

FlashDriver

AudioDriver

BinderDriver

PowerMgmt


8/64

2011

2"31@$

Dalvik VM is Android implementation of

Java VM

Dalvik is optimized for mobile devices: Battery consumption

CPU capabilities

Key Dalvik differences: Register-based versus stack-based VM Dalvik runs .dex files

More efficient and compact implementation

Different set of Java libraries than JDK


9/64

2011

6443@."E%* G#",)L%#$

The rich set of system services

wrapped in an intuitive Java API.

This ecosystem that developerscan easily tap into is what makes

writing apps for Android easy.

Location, web, telephony, WiFi,

Bluetooth, notifications, media,camera, just to name a few.

Linux Kernel

Libraries


Applications


ActivityManager

WindowManager

ContentProviders

ViewSystem

PackageManager

TelephonyManager

ResourceManager

LocationManager

NotiicationManager

SurfaceManager

OpenGL

SGL

MediaFramework

FreeType

SSL

SQLite

WebKit

libc

Android Runtime

Core Libs

DelvikVM

DisplayDriver

KeypadDriver

CameraDriver

WiFiDriver

FlashDriver

AudioDriver

BinderDriver

PowerMgmt


10/64

2011

6443@."E%*5

Dalvik Executable + Resources = APK

Must be signed (but debug key is okayfor development)

Many markets with different policies


11/64

2011

6*9#%@9 "*9 0"1"

Android Java

=

Java SE

AWT/Swing+

Android API


12/64

2011

1233+ 4+*3)5


13/64

2011

6*9#%@9 ;"+N5 C* :;) A%I

SDK

Tools

DocsPlatforms

Data

SkinsImages

SamplesAdd-ons

Google


14/64

2011

O#)"+) K)L P#%Q).+

Use the Eclipse tool to create a new

Android project.

Here are some key constructs:

P#%Q).+ R.3@45) .%*5+#8.+

:"#()+ ,@*@,8, +% #8*

644 *",) L;"+)1)#

P".$"() 0"1" 4".$"()

6.E1@+F 0"1" .3"55


15/64

2011

6*"+%,F%/ 6* 644

Java Code+

XML and Other

Resources

+

Manifest File

=

Android App


16/64

2011

:;) !"*@/)5+ G@3)


17/64

2011

:;) H"F%8+ S)5%8#.)


18/64

2011

:;) 0"1" G@3)

package com.marakana;

import android.app.Activity;

import android.os.Bundle;

public class HelloAndroid extends Activity {

/** Called when the activity is first created. */@Override

public void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);

setContentView(R.layout.main);}

}


19/64

2011

S8**@*( %* R,83"+%#

Emulator, not a simulator


20/64

2011

6!,( 78,3),(9 73+/0-


21/64

2011

T",7" 2),%

Lets see a real-world medium

complexity Android app in action:

Yamba: Yet Another Micro Blogging App


22/64

2011

6.E1@E)5

Android Application

Main Activity Another

Activity

Another

Activity

An Activity

represents a screen

or a window. Sort of.


23/64

2011

6.E1@+F H@/).F.3)

Activities have a well-defined lifecycle. The

Android OS managesyour activity by

changing its state.

You fill in the blanks.


24/64

2011

C*+)*+5

Intents represent

events or actions.

They are to

Android apps whathyperlinks are to

websites. Sort of.

Intents can beimplicit or explicit.


25/64

2011


26/64

2011


27/64

2011

S),%+)


28/64

2011

O%*+)*+ P#%1@9)#5

Content Providers share

content with applications

across application

boundaries.Examples of built-in

Content Providers are:

Contacts, MediaStore,

Settings and more.


29/64

2011

O%*+)*+ P#%1@9)# RI",43)


30/64

2011

A#%"9."5+ S).)@1)#5

An Intent-based publish-subscribe mechanism. Great for listening

system events such as SMS messages.


31/64

2011

6#.;@+).+8#) %/ 6* 644

An Android application is a collection of many different

building blocks. They are loosely coupled and can bereconfigured by the developer easily, or at least thats

the intention.

Lets look at 7 stages of Yamba next.


32/64

2011

T",7" P"#+ U


33/64

2011

T",7" P"#+ V


34/64

2011

T",7" P"#+ W


35/64

2011

T",7" P"#+ X


36/64

2011

T",7" P"#+ Y


37/64

2011

T",7" P"#+ Z


38/64

2011

T",7" P"#+ [


39/64

2011

!()*+,) 8-2* ,(.2*:!/2


40/64

2011

:L% BC 644#%".;)5

;$%$?@ )=


41/64

2011

\!HMA"5)9 B5)# C*+)#/".)

Use WYSIWYG tools to build powerful XML-based UI.

Easily customize it from Java. Separate concerns.


42/64

2011

]@)L5 "*9 H"F%8+5

Layouts contain widgets and other

layouts forming a composite pattern.


43/64

2011

H@*)"# H"F%8+

One of the most commonly

used layouts. It lays its

children next to each other,

either horizontally or vertically.


44/64

2011

S)3"E1) H"F%8+

Children of relative layout are

placed in relationship to each

other. This layout is efficient.


45/64

2011

:"73) H"F%8+

Table layout puts its children

into table rows and columns.

It is similar to an HTML table.


46/64

2011

G#",) H"F%8+

Frame layout places its

children on top of each other,

like a deck of cards. It is

useful for widgets such astabs or as a placeholder for

views added

programmatically.


47/64

2011

O%,,%* BC O%,4%*)*+5

Android UI includes many

common modern UI

widgets, such as Buttons,

Tabs, Progress Bars, Date

and Time Pickers, etc.


48/64

2011


49/64

2011

69"4+)#5

To make sure they run smoothly, Android uses

Adapters to connect them to their data sources. A

typical data source is an Array or a Database.

Data

Source

Adapter


50/64

2011

O%,43)I O%,4%*)*+5

Certain high-level components are simply

available just like Views. Adding a Map or a

Video to your application is almost like adding a

Button or a piece of text.


51/64

2011

!)*85 "*9 2@"3%(5


52/64

2011

'#"4;@.5 ^ 6*@,"E%*

Android has rich support for 2D graphics.

You can draw & animate from XML.

You can use OpenGL for 3D graphics.


53/64

2011

!83E,)9@"

AudioPlayer lets you simply specify

the audio resource and play it.

VideoView is a View that you candrop anywhere in your activity, point

to a video file and play it.

XML:


54/64


55/64

2011

G@3)


56/64

2011

O3%89 +% 2)1@.) P85;

Big deal for many pull-based apps. Will make devices use less battery.


57/64

2011

P#)/)#)*.)5

Your app can support complex

preferences quite easily.

You define your preferences in anXML file and the corresponding UI and

data storage is done for free.


58/64

2011


59/64

2011

)27899,(9

!()*+,) !;;-


60/64

2011

H%(O"+

The universal, most

versatile way to trackwhat is going on in

your app.

Can be viewed via

command line orEclipse.

Logs can be

generated both from

SDK Java code, or

low-level C code viaBionic libc extension.


61/64

2011

2)78(()#

Your standard debugger is included in SDK, with all the usual bells & whistles.


62/64

2011

:#".)]@)L

TraceView helps you profile you application and find bottlenecks. It shows

execution of various calls through the entire stack. You can zoom into specificcalls.


63/64

2011

=@)#"#.;F ]@)L)#

Hierarchy Viewer helps

you analyze your UserInterface.

Base UI tends to be the

most expensive part of

your application, this toolis very useful.


64/64

andevcon android for java

Documents