Android Programming: Introduction & Overview. CS 3: Computer Programming in Java

Transcription

1 Android Programming: Introduction & Overview CS 3: Computer Programming in Java

2 Objectives What is Android? Layout its architectures Feature some of those features A little history Talk about devices, apps, and the fight for market share vs. Apple Discuss the development environment, including the Android SDK and emulator Producing an Android application

3 What Is Android Programming? A software stack for mobile devices that includes An operating system Middleware Key Applications Uses Linux to provide core system services Security Memory management Process management Power management Hardware drivers

4 Android Architecture

5 Features of Android Application framework enabling reuse and replacement of components Dalvik virtual machine optimized for mobile devices Integrated browser based on the open source WebKit engine Optimized graphics powered by a custom 2D graphics library; 3D graphics based on the OpenGL ES 1.0 specification (hardware acceleration optional) SQLite for structured data storage

6 Features of Android (2) Media support for common audio, video, and still image formats (MPEG4, H.264, MP3, AAC, AMR, JPG, PNG, GIF) GSM Telephony (hardware dependent) Bluetooth, EDGE, 3G, and WiFi (hardware dependent) Camera, GPS, compass, and accelerometer (hardware dependent) Rich development environment including a device emulator, tools for debugging, memory and performance profiling, a plugin for the Eclipse IDE, and Android Studio

7 A Brief History of Android Palm Kyocera 6035, combing PDA and phone Blackberry smartphone released Google acquires startup Android Inc. to start Android platform. Work on Dalvik VM begins

8 A Brief History of Android (2) Open Handset Alliance announced Early look at SDK June, iphone released Google sponsors 1st Android Developer Challenge T-Mobile G1 announced, released fall SDK 1.0 released Android released open source (Apache License) Android Dev Phone 1 released

9 A Brief History of Android (3) SDK 1.5 (Cupcake) New soft keyboard with autocomplete feature SDK 1.6 (Donut) Support Wide VGA SDK 2.0/2.0.1/2.1 (Eclair) Revamped UI, browser Nexus One released to the public SDK 2.2 (Froyo) Flash support, tethering SDK 2.3 (Gingerbread) UI update, system-wide copy-paste

10 A Brief History of Android (4) 2011 SDK 3.0 (Honeycomb) for tablets only New UI for tablets, support multi-core processors, fragments SDK 3.1 and 3.2 Hardware support and UI improvements SDK 4.0 (Ice Cream Sandwich) For Q4, combination of Gingerbread and Honeycomb

11 A Brief History of Android (5) Android 4.1, "Jelly Bean" released in July 24 th Android 4.4, KitKat released October 31 st Android 5.1, Lollipop released March 9 th Android 6.0, Marshmallow released October 5 th

12 Top Smartphone Platforms Top Smartphone Platforms 3 Month Avg. Ending Dec vs. 3 Month Avg. Ending Sep Total U.S. Smartphone Subscribers Age 13+ Source: comscore MobiLens Share (%) of Smartphone Subscribers Sep-15 Dec-15 Point Change Total Smartphone Subscribers 100.0% 100.0% N/A Android 52.3% 53.3% 1.0 Apple 43.6% 42.9% -0.7 Microsoft 2.9% 2.9% 0.0 BlackBerry 1.2% 0.9% -0.3

13 About Android Devices and Device Distribution Based on active devices Forward compatible Not necessarily backward compatible Based on device visits to Google Play

14 Device Distribution February 2015

15 Device Distribution August 2015

16 Device Distribution November 2015

17 Device Distribution April 2016

18 Android Devices Estimated 1 billion+ as of Sept activated devices M, M Estimated 1.5M new activations per day M 2014 expected to ship 1 billion devices this year

19 Android Applications Google Play (formerly Android Market) > 1,000,000 apps 600,000 apps, June /3 free, 1/3 paid Apple App Store, >825,000 apps April 2013 Apple and Google each claim 50,000,000,000 downloads What's old is new - Mac vs. PC iphone vs. Android???

20 Yes, iphone vs. Android

21 Developer Revenue BUSINESS STRATEGY: attract developers with comparison of revenue generated by applications, average revenue per user, etc.

22 Apple Still Dominates the Current Revenue, But

23 the Forecast Is Trending Towards Android Part of the reason is the sheer # of Android devices available in the world

24 Setup Development Environment Install JDK 7 Either install: Android Studio 2.0 or Eclipse Mars (current Eclipse standard) Also need to install Android Development Tools (ADT) plugin for Eclipse Download and unpack the Android SDK Detailed install instructions available on Android site

25 Android SDK Manager

26 Android AVD Manager

27 About the Android AVD Manager or Emulator Emulator is essential to testing app but is not a substitute for a real device Emulators are called Android Virtual Devices (AVDs) Android SDK and AVD Manager allows you to create AVDs that target any Android API level AVD have configurable resolutions, RAM, SD cards, skins, and other hardware

28 Android Emulator 1.6

29 Android Emulator 2.2

30 Android Emulator 3.0

31 Android Emulator 4.0

32 Emulator Basics Host computer s keyboard works Host s mouse acts as finger Uses host s Internet connection Other buttons work: Home, Menu, Back, Search, volume up and down, etc. Ctrl-F11 toggle landscape portrait Alt-Enter toggle full-screen mode More info at

33 Emulator Limitations No support for placing or receiving actual phone calls Simulate phone calls (placed and received) through the emulator console No support for USB connections No support for camera/video capture (input) No support for device-attached headphones No support for determining connected state

34 Emulator Limitations (2) No support for determining battery charge level and AC charging state No support for determining SD card insert/eject No support for Bluetooth No support for simulating the accelerometer Use OpenIntents s Sensor Simulator That why we need development phones and tablets!

35 Creating An AVD Using AVD Manager Can also use the command line:

36 Android Runtime: Dalvik VM Subset of Java developed by Google Optimized for mobile devices (better memory management, battery utilization, etc.) Dalvik runs.dex files that are compiled from.class files Introduces new libraries Does not support some Java libraries like AWT, Swing

37 Running Android From the Command Line C:\android-sdk-windows\tools>android create avd -n MyDevice -t android-8 Android 2.2 is a basic Android platform. Do you wish to create a custom hardware profile [no] Created AVD 'MyDevice2' based on Android 2.2, with the following hardware config: hw.lcd.density=240 vm.heapsize=24 MyDevice is the device name; android-8 is the target platform C:\android-sdk-windows\tools>emulator -avd MyDevice This will launch the actual device

38 Applications Are Boxed By default, each app is run in its own Linux process Process started when app s code needs to be executed Threads can be started to handle time-consuming operations Each process has its own Dalvik VM By default, each app is assigned unique Linux ID Permissions are set so app s files are only visible to that app

39 Producing an Android App Visual Java code javac Byte code.class dx Dalvik exe classes.dex aapt Byte code Other.class files <xml> AndroidManifest.xml <str > Resources

40 Android Manifest Every application must have an AndroidManifest.xml file (with precisely that name) in its root directory The manifest presents essential information about the application to the Android system, information the system must have before it can run any of the application's code Among other things, the manifest does the following: It names the Java package for the application The package name serves as a unique identifier for the application It describes the components of the application the activities, services, broadcast receivers, and content providers that the application is composed of Names the classes that implement each of the components and publishes their capabilities (for example, which Intent messages they can handle) These declarations let the Android system know what the components are and under what conditions they can be launched

41 What the Android Manifest Does It names the Java package for the application The package name serves as a unique identifier for the application It describes the components of the application the activities, services, broadcast receivers, and content providers that the application is composed of Names the classes that implement each of the components and publishes their capabilities (for example, which Intent messages they can handle) These declarations let the Android system know what the components are and under what conditions they can be launched It determines which processes will host application components

42 What the Android Manifest Does (2) It declares which permissions the application must have in order to access protected parts of the API and interact with other applications It also declares the permissions that others are required to have in order to interact with the application's components It lists the Instrumentation classes that provide profiling and other information as the application is running These declarations are present in the manifest only while the application is being developed and tested; they're removed before the application is published It declares the minimum level of the Android API that the application requires It lists the libraries that the application must be linked against

43 Other Android Developer Tools Android Debug Bridge Part of SDK Command line tool to communicate with an emulator or connected Android device Check devices attached / running Install apk's, Android Package files, "executables", can find samples on places besides Google Play And more!

44 Dalvik Debug Monitor Server (DDMS) Debugging tool Provides screen capture on the device, thread and heap information on the device, logcat, process, and radio state information, incoming call and SMS spoofing, location data spoofing, and more Can interact with DDMS via Eclipse plugin, another view in Eclipse

45 Visual of DDMS

46 Summary What is Android? Laid out its architectures Featured some of those features Gave a little history Talked about devices, apps, and the fight for market share vs. Apple Discussed the development environment, including the Android SDK and emulator Showed how to produce an Android application