2009 android demian neidetcher

8/9/2019 2009 Android Demian Neidetcher

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Me First

dataStuff

ComputerStuff

http://stuff

x 10

neidetcher.com/android.html


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Why Android?


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Big Picture


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No Money | iPhone Dominates

simplyhired.com

dice.com

indeed.com

monster.com

careerbuilder.com

0 200 400 600 800 1000 1200 1400 1600

Job Listing ComparisonMay 9, 2009

android javaiPhone

j2me


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No Money | Hackable & Pervasive? Canonical is creating framework to run Android apps

on Ubuntu (netbook remix?)http://www.engadget.com/2009/05/26/canonical-giving-ubuntu-the-gift-of-android-apps/

XML VM is porting Android apps to iPhone http://www.xmlvm.org/android/

ASE to script for and on the phone (Lua, Python) http://code.google.com/p/android-scripting/

iPhone vs Android Dev Comparisonhttp://greensopinion.blogspot.com/2009/07/android-versus-iphone-development.html

Garmin Adopts Androidhttp://techgeist.net/2009/06/garmin-officially-adopts-android-ditches-in-house-linux-os/

Android on a Sony?http://www.engadget.com/2009/06/08/sony-building-android-based-walkman-and-pnd-for-2010-launch/ http://phandroid.com/2009/07/04/sony-ericsson-making-xperia-android-holy-smokes/
http://www.xmlvm.org/android/http://code.google.com/p/android-scripting/http://www.engadget.com/2009/06/08/sony-building-android-based-walkman-and-pnd-for-2010-launch/http://www.engadget.com/2009/06/08/sony-building-android-based-walkman-and-pnd-for-2010-launch/http://www.engadget.com/2009/06/08/sony-building-android-based-walkman-and-pnd-for-2010-launch/http://code.google.com/p/android-scripting/http://www.xmlvm.org/android/


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Android | Timeline 2001: Google starts filing mobile patents 2005 July: Google Acquires Android Inc 2005 Oct: Dan Bornstein joins Google to work on Dalvik 2007 Nov: Open Handset Alliance is formed and Android

SDK is released 2008 Oct: T-Mobile G1 is released 2009 Jan: Palm Pre announced 2009 Feb: Pay apps available on market 2009 Jun: Samsung Android phones in EU 2009 Nov: Motorola releasing Android phone 2009 Aug: new T-Mobile Android phone

2009: Possible Acer, Dell and HP net-books


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Android | Open Handset Alliance

47 Companies

Sprint, T-Mobile,Telecom Italia,

Vodafone, Intel, TexasInstruments, NVIDIA,Asus, Garmin, HTC,LG, Motorola,Samsung, Sony,Toshiba...


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Android | MarketAndroid | Market

http://market.android.com/publish/Home


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Android Built on Linux Not POSIX Custom C library

(bionic)

http://source.android.com/download

Androidis a Linux

Dalvik VM

Android has many Dalvik VMsDalvik VM

Dalvik VM


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Android | Open Source

Linux: GPLv2

WebKit: LGPLv2SQLite: Public Domain

Eclipse: EPL

QEMU: LGPL

Bionic: BSDAndroid: Apache2

Apache Harmony: Apache2

Development StackRuntime Stack

JFree Chart: LGPL

JCommon: BSD


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Android | Architecture

Dalvik VM

Core Libraries

WiFi Driver PowerWiFi Camera Keypad

WebKit

WiFi

OpenGLWebKitSQLite OpenGL bionic

ActivityTelephony NotificationActivity Location Package

Contacts

Telephony

Home Phone Browser EmailMap

Display


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Android | Google IO

3 types of agreements 3 Ways to code 20 handsets in 2009 Oprah moment Donut

Universal search where universe is phone Text to speech Gestures/ handwriting recognition

http://www.flickr.com/photos/francois/3959737/


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Dalvik

Differentbeast

Not Java

byte code Not JVM


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Dalvik | Background

Dan Bornstein joinedGoogle 2005

Made for low end

machines low ram (no disk swap

space) battery

Register based (notstack based)

No JIT (it's on the roadmap) http://www.flickr.com/photos/fremat/447395038/sizes/l/


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Dalvik | .dex vs .class

Single constant poolfor all classes

Uncompressed More pointing

More sharing

http://retrodev.com/android/dexformat.html

uncompressed jar compressed jar uncompressed dex0

20

40

60

80

100

120

libsbrowser appalarm app

http://sites.google.com/site/io/dalvik-vm-internals (handouts)

Compression


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Dalvik | Other Languages?Dalvik | Other Languages?

Java FX runs on Android (JavaOne2008)

Anything that dynamically reads .classfiles or dynamically manipulates Javabinaries won't work without Android

specific tweaks scala works

http://www.youtube.com/watch?v=BtUX-GS36o8&feature=related http://www.ibm.com/developerworks/opensource/library/os-eclipse-scala/
http://www.ibm.com/developerworks/opensource/library/os-eclipse-scala/http://www.ibm.com/developerworks/opensource/library/os-eclipse-scala/


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Dalvik | SandboxDalvik | Sandbox

Every app is a processEvery app is a process process gets its ownprocess gets its own

user iduser id files is sandboxedfiles is sandboxed SQLite DB isSQLite DB is

sandboxedsandboxed (just files(just files

anyways)anyways)

http://www.flickr.com/photos/bauchidgw/2820627227/http://www.flickr.com/photos/bauchidgw/2820627227/


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Dalvik | Zygote

Android creates Zygote at startup Zygote loads up system libraries Zygote finds out new app is starting Zygote forks process, giving all Dalvik VMs

(and apps) access to system libraries

Every new app isn't a VM cold startMinimize memory requirements by

sharing what we can

SystemLibraries

Zygote

Home

ApplicationCode

SystemLibrariesSystemLibraries

ApplicationCode

ApplicationCode

ApplicationCode

Email

Browser

Map


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Dalvik | Application Stack

Home

Email

Browser

Map

ActivityManager

Low memory killer will look at LRU apps

to destroy

Back buttondoes a popon the stack


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Dev elopment

It's easy Write code in Java

Lots of tooling Lots of documentation


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Dev | Books

Amazon has 7 books total (Jun 14, 2009)


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Dev | Get Started

Android SDKAndroid SDK http://developer.android.com/sdkhttp://developer.android.com/sdk local documentationlocal documentation toolstools

Eclipse pluginEclipse plugin http://dl-ssl.google.com/android/eclipse/http://dl-ssl.google.com/android/eclipse/


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Dev | APIshttp://developer.android.com/reference/packages.html

java.awt.font java.beans java.io java.lang java.lang.annotation java.lang.ref java.lang.reflect java.math java.net java.nio java.security java.sql java.text java.util java.util.concurrent java.util.jar

junit.framework junit.runnerorg.apache.httporg.jsonorg.w3c.domorg.xml.saxorg.xmlpull.v1org.xmlpull.v1.sax2

android.*dalvik.*

java.util.logging java.util.prefs java.util.regex java.util.zip javax.crypto javax.microedition.khronos.egl javax.microedition.khronos.opengles javax.net javax.security.auth javax.security.auth.callback javax.security.auth.login javax.security.auth.x500 javax.security.cert javax.sql javax.xml

...but


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Dev | 3 rd Party & Workaround

SCMXL (Apache State Chart XML project) has a good write-up

http://commons.apache.org/scxml/usecases/scxml-stopwatch-on-android.html

You can use 3 rd Party APIs If you need J2SE APIs that

aren't there then include themfrom Apache Harmony


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Dev | Resource Class

mk19:~/code/scrumpoker>tree.|-- ...|-- res| |-- drawable| | `-- refresh .png| |-- layout| | |-- display .xml| | `-- main .xml

| `-- values| `-- str ings .xml`-- src

`-- ...

mk19:~/code/scrumpoker>cat src/com/neidetcher/scrumpoker/R.java/* AUTO-GENERATED FILE. DO NOT MODIFY.

** This class was automatically generated by the* aapt tool from the resource data it found. It* should not be modified by hand.*/

package com.neidetcher.scrumpoker;

public final class R {public static final class attr {}public static final class drawable {

public static final int refresh =0x7f020000;}public static final class id {

public static final int displayPointsTextView=0x7f050000;

public static final int pointsListView=0x7f050001;}public static final class layout {

public static final int display =0x7f030000;public static final int main =0x7f030001;

}public static final class string {

public static final int app_name=0x7f040000;}

}aapt


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Dev | Activity


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Dev | View

public class DisplayActivity extends Activity{

TextView myTextView = null;

@Overridepublic void onCreate(Bundle savedInstanceState){

super.onCreate(savedInstanceState);setContentView(R.layout.display);

// set value for the textmyTextView = (TextView) findViewById(

R.id. displayPointsTextView );String points = getIntent().getExtras().getString(

ScrumPokerActivity.SELECTED_POINTS);if (points.equals("100")){

myTextView.setTextSize(180);}

myTextView.setText(points) ;

}}


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Dev | IntentsActivity1 Intent Activity2

create(Activity2)

putExtra(key, value)

startActivity(intent)

onCreategetIntent()

getExtras.get(key):value

Open Intentshttp://www.openintents.org/en/


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Dev | Intents & Mashability

TzChangeReceiverActivity

YourApp

AndroidManifext.xml

receiver

classes.dex

intent:ACTION_TIMEZONE_CHANGED

LocationManager

NarcissisticProxy

InterTubes

wheels down in PSTFTW!!!


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Dev | Packaging

.java

.java

.java

javac

.class

.class

.class

dx

classes.dex

.xml

.xml

.png

aapt

.xml

.xml

.png

classes.dex

.apk


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Dev | apk

shiv:~/play>jar -xvf "Scrum Poker.apk"shiv:~/play>tree.|-- AndroidManifest.xml|-- Scrum Poker.apk|-- classes.dex|-- res| |-- drawable| | `-- refresh.png| `-- layout| |-- display.xml| `-- main.xml`-- resources.arsc

3 directories, 7 files

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


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Dev | dexdumpVirtual methods -

#0 : (in Lcom/neidetcher/scrumpoker/ScrumPoker;)name : 'onCreate'type : '(Landroid/os/Bundle;)V'access : 0x0001 (PUBLIC)code -registers : 5ins : 2outs : 4insns size : 47 16-bit code units

000ad8: |[000ad8] com.neidetcher.scrumpoker.ScrumPoker.onCreate:(Landroid/os/Bundle;)V000ae8: 6f20 0100 4300 |0000: invoke-super {v3, v4}, Landroid/app/Activity;.onCreate:(Landroid/os/Bundle;)V // metho000aee: 1401 0100 037f |0003: const v1, #float 174128887730233583002069148843976425472.000000 // #7f030001000af4: 6e20 1e00 1300 |0006: invoke-virtual {v3, v1}, Lcom/neidetcher/scrumpoker/ScrumPoker;.setContentView:(I)V //000afa: 1401 0100 057f |0009: const v1, #float 176787343721803414747876762964537114624.000000 // #7f050001000b00: 6e20 1c00 1300 |000c: invoke-virtual {v3, v1}, Lcom/neidetcher/scrumpoker/ScrumPoker;.findViewById:(I)Landro000b06: 0c01 |000f: move-result-object v1000b08: 1f01 0d00 |0010: check-cast v1, Landroid/widget/ListView; // class@000d000b0c: 5b31 0d00 |0012: iput-object v1, v3, Lcom/neidetcher/scrumpoker/ScrumPoker;.myListView:Landroid/widget/000b10: 1400 0300 0901 |0014: const v0, #float 0.000000 // #01090003000b16: 2201 0b00 |0017: new-instance v1, Landroid/widget/ArrayAdapter; // class@000b000b1a: 5432 0800 |0019: iget-object v2, v3, Lcom/neidetcher/scrumpoker/ScrumPoker;.POINTS:[Ljava/lang/String;000b1e: 7040 0700 3120 |001b: invoke-direct {v1, v3, v0, v2}, Landroid/widget/ArrayAdapter;.:(Landroid/content000b24: 5b31 0c00 |001e: iput-object v1, v3, Lcom/neidetcher/scrumpoker/ScrumPoker;.myArrayAdapter:Landroid/wid000b28: 5431 0d00 |0020: iget-object v1, v3, Lcom/neidetcher/scrumpoker/ScrumPoker;.myListView:Landroid/widget/000b2c: 5432 0c00 |0022: iget-object v2, v3, Lcom/neidetcher/scrumpoker/ScrumPoker;.myArrayAdapter:Landroid/wid000b30: 6e20 0800 2100 |0024: invoke-virtual {v1, v2}, Landroid/widget/ListView;.setAdapter:(Landroid/widget/ListAda000b36: 5431 0d00 |0027: iget-object v1, v3, Lcom/neidetcher/scrumpoker/ScrumPoker;.myListView:Landroid/widget/000b3a: 5432 0b00 |0029: iget-object v2, v3, Lcom/neidetcher/scrumpoker/ScrumPoker;.mMessageClickedHandler:Landfield@000b000b3e: 6e20 0900 2100 |002b: invoke-virtual {v1, v2}, Landroid/widget/ListView;.setOnItemClickListener:(Landroid/wi000b44: 0e00 |002e: return-void

catches : (none)positions :

@Overridepublic void onCreate(Bundle savedInstanceState){

super.onCreate(savedInstanceState);setContentView(R.layout.main);

displayPointsListView = (ListView) findViewById(R.id.pointsListView);int layoutId = android.R.layout.simple_list_item_1;

// populate the list view with an arrayArrayAdapter arrayAdapter = new ArrayAdapter(this,

layoutId, POINTS);displayPointsListView.setAdapter(arrayAdapter);displayPointsListView.setOnItemClickListener(mMessageClickedHandler);

}

shiv:~/play>~/opt/android-sdk-linux_x86-1.0_r2/tools/dexdump -d classes.dex


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Dev | Install Time What happens when you install the

software... there is no JIT security verification of dex files Optimization

specific to hardware inlining pruning static linking

http://www.netmite.com/android/mydroid/dalvik/docs/dexopt.html

.odex

.dex

dexopt


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Dev | Good Android Code sleep, react quickly, sleep avoid allocation

Address[] addressArray = mgr.findAddresses()for(int ii = 0; ii < addressArray.length; ii++)

Address[] addressArray = mgr.findAddresses()for(Address currAddress : addressArray)

List addresses = mgr.findAddresses();for(Address currAddress : addresses)

http://kohlerm.blogspot.com/2009/04/analyzing-memory-usage-off-your-android.html


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Dev | Gotchas

I accidentally imported the "super R" instead ofmy locally generated R. (2 hours)

View layouts can't be camel cased. (30 minutes) The tools directory in the Android SDK needs be

set to executable to run and for the Eclipseplug-in to work. (10 minutes)

If your install didn't work on the phone you see adeceptive green check-mark. (10 minutes) Don't put heavy object graphs in putExtra() Development upgrade to Cupcake was kludgy for me


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One More Thing | NDK

Native Dev Kit C/ C++ Consistent libs Docs, tutorials, code Transparent to user

http://www.flickr.com/photos/sin_agua/2208439930/

http://android-developers.blogspot.com/2009/06/introducing-android-15-ndk-release-1.html


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Dev | Eclipse Plugin

Logging Emulator Hierarchy Viewer ADB


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Questions?http://neidetcher.com/android.htmlhttp://neidetcher.com/android.html

2009 android demian neidetcher

Documents