Programming Android Smart Phones. Tom Chothia Internet Computing Workshop

Transcription

1 Programming Android Smart Phones Tom Chothia Internet Computing Workshop

2 What is Android? A mobile phone operating system. Best selling smart phone OS. Runs on a range of hardware Based on Linux and Java Open source

3 Why Smart Phone Programming? Smart Phones will be many peoples main connection to the Internet. Smart phone apps are going to be big business. Good area for your M.Sc. projects.

4 Android vs. iphone Android: Open source smart phone platform from Google et al. Program in Java. Easy to get started. Open App store. Most apps free. iphone Closed source owned by Apple. Uses GUI tools and Objective C. Need a certificate to run code on phones. Apple controlled app store. People pay for apps.

5 Other phone platforms Blackberry, Very secure, used by business, not much third party support. Windows Mobile Not very popular Symbian, Intelligent System Architecture (Nokia OS), Java ME Not so smart phones

6 Smart phones

7 Developing for Android Get Eclipse Get Android SDK index.html Install and configure the Eclipse Android plugin

8 Android Programming Model Each screen is described by an Activity class. This class sets the display, possibly using XML. Events on the phone trigger certain methods.

9 Some Activity Methods oncreate When the window is first opened oncreateoptionsmenu When the menu button is pressed onoptionsitemselected When a menu item is selected.

10 Intents Intents are used to go from one Activity to another. Declare an Intent object with the name of the activity you want to start. Then start the new activity. And finish the current activity. See the example code.

11 Bundles Bundles let you pass primitive data types between Activities. Set the data with i.putextra( tag,value) Read the data with getintent().getextras().gettype See the example code.

12 Review Activities Extend the Activity class Override the oncreate method etc. Create TextViews Buttons, etc. and set OnClickListener Use intents and Bundles to move between Activities.

13 AndroidManifest.xml Every app has a manifest file. This file includes: Package name, App name Activitie names First Activities Intents etc

14 Permissions The manifest also lists what permissions the app has, e.g.: Access to the Internet: android.permission.internet Access the GPS: android.permission.access_fine_location Completely disable the device!!: android.permission.brick See: android/manifest.permission.html

15 Logging into the Emulator To emulate an events, telnet into the emulator. e.g. telent Commands include: help geo: set GPS location sms: receive an SMS message

16 The adb tool The android development bridge tool (adb), provides many admin commands: adb shell: opens a shell to the phone adb logcat: shows the log Can also install new apps, etc.

17 Log Messages To write your own message to the log use the Log object. Log.v( My App Tag, message ); Very useful for debugging your code (but not as useful as the Eclipse debugger).

18 Controlling the OS. Android is open source but that doesn t mean you get root. A phone company will normally deny users root access. You can get root access by replacing the OS on the phone.

19 Updating the Firmware Get the firmware as an update.zip file. Place the update on the SDcard Start the phone and hold back/home to enter the boot loader. Select update using update.zip

20 A more complex app Word dominoes app we developed with the English department. Define our own views to make tiles Use the ontouch methods to handle screen movements.

21 Some Student Projects Producing maps using GPS tracking, Prototype app for a local company, Better Security policies on Android, App to encrypt photos on lost phone via sms, Learn Japanese app, App to guide bham students to lecture rooms.

22 Conclusion Smart phones are the future of the Internet (maybe). Android is easy to program and mainly Java. Lots of good online docs: