Android Overview

Marko Gargenta marakana.com

Developer of Android Bootcamp for Marakana.

Instructor for 1,000s of developers on Android at Qualcomm, Cisco, Motorola, DoD and other great orgs.

Author of Learning Android published by O’Reilly.

Speaker at OSCON (3x), ACM, IEEE, SDC, AnDevCon.

Co-Founder of SFAndroid.org

Co-Chair of Android Open conference: AndroidOpen.com

• Android Then & Now • Hello World! • Android versions • Main Building Blocks • Android @Work • Architecng an App • The Stack • Android UI • Operang System Features • Android Security • Building Custom ROM • Summary

2005 Google buys Android, Inc. Work on Dalvik starts 2007 Open Handset Alliance announced Early Soware Development Kit 2008 HTC G1 Announced SDK 1.0 Released 2009 G2 + 20 other phones released Cupcake, Donut, Éclair 2010 Zillion devices FroYo, Gingerbread, JIT 2011 Games, Tablets, TVs

Future? Beyond phones

40%

35%

30% Android 25% Blackberry Apple iOS 20% Windows Palm 15% Symbian

10%

0% Qtr2 2009 Qtr3 2009 Qtr4 2009 Qtr1 2010 Qtr2 2010

Android grows to 36% of US (Big 4) Smartphone Share, surpassing RIM – and growth will continue to accelerate over time

© 2011 Plaorm Versions Version API Level Nickname Android 1.0 1 Android Android 1.1 2 Android Android 1.5 3 Cupcake Android 1.6 4 Donut Android 2.0 5 Éclair Android 2.01 6 Éclair Android 2.1 7 Éclair Android 2.2 8 FroYo Android 2.3 9 Gingerbread Android 2.3.3 10 Gingerbread Android 3.0 11 Honeycomb Android X.X XX Ice cream

Source: Android.com

SenseUI TouchWiz MotoBlur

New skin, new apps new widgets. All backed with an online service. Very social-centric.

More intuitive home screen, but real crown jewel is Swype.

Devices that have “with Google” add-on feature a set of Google’s proprietary applications, such as Maps, Gmail, Gtalk, and many others.

OEMs and carriers typically enter into a licensing agreement with Google in order to distribute Google version of Android.

Android Compatibility Test Suite: Defines “Android Compatible” Prevents incompatible releases Provides self testing

Fragmentations lines include: - Versions of Android - Add-ons by OEMs/Carriers - Device capabilities

Best practices in app development eliminate these issues. CTS ensures compliance.

© 2011 Hardware Requirements • Must have a screen of any size. • Must have a so keyboard. Hardware keyword is oponal. • Must support touch screen input • Should have the following sensors: Accelerometer, Magnetometer, GPS, Gyroscope. • Should include WiFi, Bluetooth. Telephony oponal.

© 2011 Hardware Requirements (cont’d) • Should include Near Field Communicaon. • Must have some network capability. • Should have rear-facing camera. Front camera is oponal. • Memory must be: 125MB+ (system), 150MB+ (user data), 1GB+ (storage) • Must implement USB port.

• New User Features – Updated Home, Camera, Gallery, Portable hotspot – Support for Exchange (security, remote wipe, calendars, auto-discovery, global addresses) • New Plaorm Technologies – Media (hp/progressive streaming) and Bluetooth • New Developer Services and APIs – Cloud to Device Messaging – Apps on SDCard, media framework, graphics, backup, device manager, UI frameworks

© 2011 Gingerbread: Gaming New User Features • Updated user interface • Power management, app control • Download manager for long downloads • Storage manager for private content on sdcard • Improved power management and app control • Mulple camera support • Copy-paste features • Redesigned keyboard

© 2011 Gingerbread: Gaming New Developer Features • Performance improvements for gaming • Improved sensor support • Nave acvity support • Near-Field Communicaon (NFC) • WebM/VP8 playback and AAC encoding • SIP VoIP support • Support for extra-large screen (WXGA++) • Ext4 instead of yaﬀs ﬁle system

© 2011 Honeycomb: Tablets • Honeycomb is Tablet-opmized Android • As-is will not be supported on mobile phones • Currently two separate paths for Android • Source code likely won’t be available • Will merge in ice cream

© 2011 Honeycomb: Designed for Tables Opmized for devices with larger screen sizes, parcularly tablets • Brand new, truly virtual and “holographic” 3d- like UI design • Elegant, content-focused interacon model • Support for mul-core devices • Hardware acceleraon

© 2011 Redesigned keyboard • Entering text faster and more accurate on larger screen • Reshaped and reposioned keys for improved targeng • New keys such as Tab • Touch-hold menus • Voice/keyboard input mode switching • Improved text selecon, copy and paste

© 2011 New connecvity opons • Built-in Media/Photo Transfer Protocol for fast USB connecon to cameras and computers • Support for external keyboard via USB or Bluetooth • Faster Wiﬁ scanning • Bluetooth tethering so other devices can share network

© 2011 Updated set of standard apps • Contacts – Two-pane UI and Fast Scroll to easily organize and locate contacts – Card-like UI for easier reading and eding of contacts – Improved support for internaonal number formats • Email – New two-pane UI for more eﬃcient emailing – Sync aachments for later viewing

Applications

Home Contacts Phone Browser Other

Application Framework

Activity Window Content View Manager Manager Providers System

Package Telephony Resource Location Notiication Manager Manager Manager Manager Manager

Libraries Surface Media SQLite Android Runtime Manager Framework Core Libs OpenGL FreeType WebKit

Dalvik VM SGL SSL libc

Display Camera Linux Kernel Flash Binder Driver Driver Driver Driver

Android™ Stack Android runs on Linux. Applications

Home Contacts Phone Browser Other Linux provides: Hardware abstraction layer Memory management Application Framework Activity Window Content View Process management Manager Manager Providers System Networking Package Telephony Resource Location Notiication Manager Manager Manager Manager Manager

Users never see Linux sub system Libraries Surface Media SQLite Android Runtime Manager Framework The adb shell command opens Core Libs Linux shell OpenGL FreeType WebKit Dalvik VM SGL SSL libc

Display Camera Linux Kernel Flash Binder Driver Driver Driver Driver

Keypad WiFi Audio Power Driver Driver Driver Mgmt

Pieces borrowed from other Applications

open source projects: Home Contacts Phone Browser Other

Bionic, a super fast and small Application Framework license-friendly libc library optimized Activity Window Content View for Android Manager Manager Providers System

Package Telephony Resource Location Notiication Manager Manager Manager Manager Manager WebKit library for fast HTML rendering Libraries Surface Media SQLite Android Runtime Manager Framework OpenGL for graphics Core Libs OpenGL FreeType WebKit

Dalvik VM Media codecs offer support for SGL SSL libc major audio/video codecs

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

Applications The rich set of system services wrapped in an intuitive Java API. Home Contacts Phone Browser Other

This ecosystem that developers Application Framework

can easily tap into is what makes Activity Window Content View writing apps for Android easy. Manager Manager Providers System Package Telephony Resource Location Notiication Manager Manager Manager Manager Manager Location, web, telephony, WiFi, Bluetooth, notifications, media, Libraries Surface Media SQLite Android Runtime camera, just to name a few. Manager Framework Core Libs OpenGL FreeType WebKit

Dalvik VM SGL SSL libc

Display Camera Linux Kernel Flash Binder Driver Driver Driver Driver

Keypad WiFi Audio Power Driver Driver Driver Mgmt

Dalvik Executable + Resources = APK Must be signed (but debug key is okay for development) Many markets with different policies

AudioPlayer lets you simply specify the audio resource and play it.

VideoView is a View that you can drop anywhere in your activity, point to a video file and play it.

XML:

Audio AAC LC/LTP, HE-AACv1 (AAC+), HE- AACv2, AMR-NB, AMR-WB, MP3, MIDI, RTTTL/RTX, Ogg, PCM/WAVE

Video H.263, H.264, MPEG-4, VP8

Image JPEG, GIF, PNG, BMP

RTSP and HTTP progressive streaming. HTTP live streaming coming soon. More native support in the works.

Native support available via Khronos OpenMax IL

The file system has three main mount points. One for system, one for the apps, and one for whatever.

Each app has its own sandbox easily accessible to it. No one else can access its data. The sandbox is in /data/data/com.marakana.yamba/

SDCard is expected to always be there. It’s a good place for large files, such as movies and music. Everyone can access it.

System partition is where the entire Android operating system is, customized by OEM or not.

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

Wireless synchronization with Exchange. Supports Email, Calendar, Contacts. Administrators can set login policies and remotely wipe the data.

SSL Support Remote Wipe Wipe on incorrect password aempts Aachments Enabled Max Aachment Size Require Manual Sync When Roaming Allow HTML Email Max Email Age Filter Max Email Body Truncaon Size Max Email HTML Body Truncaon Size Device Password Enabled Alphanumeric Device Password Required Min Device Password Length Max Inacvity Time Device Lock Max Device Password Failed Aempts Allow Simple Device Password Device Password Expiraon SSL/Cert issues on Device Password History some devices © 2011 VPN Support

Support for VPN built-in: PPTP, L2TP, L2TP/IPSec PSK VPN, L2TP/IPsec CRT VPN

Still not Enterprise-Grade. “VPNs are dangerous because they can monitor all traffic”. Up to OEMs to work it out. Cisco and Motorola are.

Third Party VNP solutions: Cisco AnyConnect: Available on some devices already Juniper Junos Pulse: available today SonicWall VPN: available today Checkpoint, Nortel, etc. May require “rooted” device due to need to access system.

New in FroYo: Android Device Admin API.

Administrator can set: Enable passwords Set password quality Max failed logins Prompt for new password Remotely wipe device data Lock the device

App requests Device Admin permissions. If granted, admin policies apply. If not, app doesn’t work.

Policies could be hard-coded or dynamic.

© 2011 Policy Management Process • User intervenon is required to “bootstrap” a device into a fully-configured, secure configuraon – Allow paral progress, and restarts – Use noficaons & dialogs when restarng the security flow - tell the user what’s happening

SDK

Tools Docs Platforms Data Skins Images Samples Add-ons Google

Use the Eclipse tool to create a new Android project.

Here are some key constructs:

Project Eclipse construct Target minimum to run App name whatever Package Java package Acvity Java class

Java Code + XML and Other Resources + Manifest File = Android App

Let’s see a real-world medium complexity Android app in action:

Yamba: Yet Another Micro Blogging App

Android Application An Activity Another Another Main Activity represents a screen Activity Activity or a window. Sort of.

Intents represent events or actions.

They are to Android apps what hyperlinks are to websites. Sort of.

Intents can be implicit or explicit.

Services are code that runs in the background. They can be started and stopped. Services doesn’t have UI.

Service also has a lifecycle, but it’s much simpler than activity’s.

An activity typically starts and stops a service to do some work for it in the background, such as play music, check for new tweets, etc.

Services can be bound or unbound.

Content Providers share content with applications across application boundaries. Examples of built-in Content Providers are: Contacts, MediaStore, Settings and more.

An Intent-based publish-subscribe mechanism. Great for listening system events such as SMS messages.

An Android application is a collection of many different building blocks. They are loosely coupled and can be reconfigured by the developer easily, or at least that’s the intention.

Let’s look at 7 stages of Yamba next.

Procedural Declarave

You write Java code You write XML code Similar to Swing or AWT Similar to HTML of a web page

You can mix and match both styles. Best practice:

• Start with XML and declare most of UI • Switch to Java and implement the UI logic

Use WYSIWYG tools to build powerful XML-based UI. Easily customize it from Java. Separate concerns.

Layouts contain widgets and other layouts forming a “composite” pattern.

One of the most commonly used layouts. It lays its children next to each other, either horizontally or vertically.

Children of relative layout are placed in relationship to each other. This layout is efficient.

Table layout puts its children into table rows and columns. It is similar to an HTML table.

Frame layout places its children on top of each other, like a deck of cards. It is useful for widgets such as tabs or as a placeholder for views added programmatically.

Android UI includes many common modern UI widgets, such as Buttons, Tabs, Progress Bars, Date and Time Pickers, etc.

Some UI widgets may be linked to zillion pieces of data. Examples are ListView and Spinners (pull-downs).

Adapter Data Source

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.

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.

Android has rich support for 2D graphics. You can draw & animate from XML. You can use OpenGL for 3D graphics.

AudioPlayer lets you simply specify the audio resource and play it.

VideoView is a View that you can drop anywhere in your activity, point to a video file and play it.

XML:

No app can adversely impact other apps, user, or OS Cannot read/write user’s private data Cannot read other app’s data Cannot perform network access Cannot keep device awake, and so on

Each application is its own sandbox To share resources, apps need to request permissions User must grant permissions at install time

Linux manages security Not up to Dalvik (Java) but outsourced to Linux Native code (NDK) also adheres to sandboxing

An application is an island on its own.

It contains any number of Activities, Services, Receivers and Providers.

It has its own file system, database, place to store native libraries.

No other app can access any of its data without prior permission.

A component that does something potentially dangerous can require callers to have permission to access it.

App that wants to use it must have user grant it permission.

Permissions are granted at install time. All or nothing. Forever.

ACCESS_COARSE_LOCATION ACCESS_FINE_LOCATION ACCESS_NETWORK_STATE ACCESS_WIFI_STATE BATTERY_STATS BLUETOOTH CALL_PHONE CALL_PRIVILEGED CAMERA DEVICE_POWER GET_ACCOUNTS GET_TASKS INSTALL_PACKAGES INTERNET KILL_BACKGROUND_PROCESSES NFC READ_CALENDAR READ_CONTACTS RECEIVE_SMS RECORD_AUDIO WRITE_EXTERNAL_STORAGE WRITE_SETTINGS

© 2011 Customizing The Build • Building from source • Source code overview • Adding applicaons • Adding nave Libraries • Changing startup process • Changing permissions • Modifying frameworks • Linux kernel

© 2011 Source Overview • /bionic/ is where bionic library is • /build/ is the main make ﬁle system • /dalvik/ is where Dalvik VM and dex compiler are • /development/ is for development tools and sample apps • /device/ is for device-speciﬁc code • /external/ is where most of Nave Libraries live

© 2011 Source Overview (cont’d) • /frameworks/ is where all the Android Frameworks are • /hardware/ is for HAL (hardware-abstracon layer) and other hardware-speciﬁc code • /out/ is where the ﬁnal build is placed • /packages/ is where default apps and similar goes • /prebuilt/ is for pre-build code, such as Linux Kernel

© 2011 Adding Apps • Place your app project source code in / packages/apps/! • Create Android.mk ﬁle for the app • Edit /build/target/product/ core.mk (or similar) and add your applicaon in the list of PRODUCT_PACKAGES! • Run mm in the directory of the app • Run make snod in the root of the source

© 2011 Adding Nave Libraries • Place your nave library source code in / external/! • Create Android.mk ﬁle for the library • Edit /build/target/product/ core.mk (or similar) and add your applicaon in the list of PRODUCT_PACKAGES! • Run make

© 2011 Modifying Frameworks • Look for Java Manager in /frameworks/ base/ ! • Start from Java and track it to lower levels • Keep in mind Java Nave Interface (JNI) calls and Binder Inter Process Communicaon (IPC) calls

© 2011 Example: Sensors Framework • Java Manager: /frameworks/base/core/java/ android/hardware/SensorManager.java • JNI: /frameworks/base/core/jni/ android_hardware_SensorManager.cpp • C Code: /hardware/libhardware/include/ hardware/sensors.h

LOCAL_PATH := $(call my-dir) include $(CLEAR_VARS)

LOCAL_MODULE := libaudio

LOCAL_SHARED_LIBRARIES := \ libcutils \ libutils \ libmedia \ libhardware

LOCAL_SRC_FILES += MyAudioHardware.cpp

LOCAL_CFLAGS +=

LOCAL_C_INCLUDES +=

LOCAL_STATIC_LIBRARIES += libaudiointerface

include $(BUILD_SHARED_LIBRARY)

© 2011 Building Camera Library • Create shared library that implements CameraHardwareInterface.h • Name it libcamera.so • Place libcamera source and Android.mk ﬁle in vendor/acme/chipset_or_board/libcamera/ • See frameworks/base/services/camera for fake camera

LOCAL_PATH := $(call my-dir) include $(CLEAR_VARS)

LOCAL_MODULE := libcamera

LOCAL_SHARED_LIBRARIES := \ libutils \ librpc \ liblog

LOCAL_SRC_FILES += MyCameraHardware.cpp

LOCAL_CFLAGS +=

LOCAL_C_INCLUDES +=

LOCAL_STATIC_LIBRARIES += \ libcamera-common \ libclock-rpc \ libcommondefs-rpc

include $(BUILD_SHARED_LIBRARY)

Android is open and complete system for mobile development. It is based on Java and augmented with XML.

Android is being adopted very quickly both by users, carriers, and manufacturers.

It takes about 3-5 days of intensive training to learn Android application development for someone who has basic Java (or similar) experience.

Marko Gargenta, Marakana.com [email protected] +1-415-647-7000