Android Development...The 20,000-Foot View

Rich Web Experience 2010 Android Development... The 20,000Foot View

Welcome to Android! ● High Momentum – Today: smartphones – Tomorrow: tablets and televisions – Later: cars? toasters? cars that make toast?!?

Welcome to Android! ● Opportunities – Retail Distribution (Android Market, etc.) – OEM Distribution – Internal Distribution (enterprise, etc.) – Social Distribution

Welcome to Android ● Development Models – Standard Applications ● Java ● Web technologies – Games ● 2D (Canvas) ● 3D (OpenGL)

Basket of Components ● Activity – Primary unit of user interface – Think: screen, page, window – “User transaction” – Design model: lots of cheap activities

Basket of Components ● Service – Long-running task (download) – User-controlled background task (music player) – “Cron job” (check for unread email) – Integration point (third-party API)

Basket of Components ● Broadcast Receiver – System events (battery low) – Application messages ● Content Provider – Integration point (expose database) – Abstraction layer (expose Web service)

Activities and Widgets ● Activities Host Widgets – Widget = micro unit of UI – Organized via layout managers – Described using XML ● Activity as a whole ● Portions of an activity (rows in a selection list)

Activities and Widgets ● Multiple Layout Flavors – Portrait versus landscape – Normal versus large – Touchscreen versus pointer (trackball) ● Flow = Web-Like – Click to launch new activities – BACK button – HOME button

Java and Dalvik ● What You Write – Java – XML – C/C++ (optional)

Java and Dalvik ● What Android Runs: Dalvik – Virtual machine, like Perl or Java – Build tools translate your Java code to Dalvik bytecode – Usually invisible to you

Java and Dalvik ● Third-Party Code – Source or JARs – Possible Compatibility Issues ● Assumption of certain Java classes ● Assumption of certain platform ● Unsupported compiler (1.4.2)

Resources ● Non-Java Application Assets – Layouts – Images (PNG, JPEG, etc.) – Audio clips – Strings – Animations – Menus – Etc.

Resources ● Resource Sets – Language – Screen density – Screen size – Dozens of other criteria

Intents and Integration ● Intents as Message Bus – Start an activity – Start a service – Send a broadcast

Intents and Integration ● Use Intents Internally – Start your own activities – Start your own services – Send your own “narrowcasts” ● Service → activity or notification – Send your own “broadcasts” to third parties

Intents and Integration ● Use Intents Externally – Send a message with the users choice of “send” application (email? SMS? Twitter? Facebook?) – Offer to view a certain MIME type – Launch an OS-supplied activity (map) – Launch a third-party activity – Implement a plug-in system

Services and Multitasking ● The Download Scenario – User requests download of large file ● Should not need to keep activity going to accomplish this! – Use a service and a background thread – Service either updates activity or displays notification, then shuts down, when done

Services and Multitasking ● The Music Player Scenario – User presses “play” ● Should not need to keep player activity running! – Use a service, get control when song ends to change to next song in playlist – Stop the service only when user presses “stop” ● Use notification for ease of returning to player, plus to let OS know what is going on

Services and Multitasking ● The Email Client Scenario – Want to check for new messages every so often – Use AlarmManager to arrange for scheduled task ● Either only while phone is awake, or even if phone is asleep – Use background thread, download mail headers – Update activity or show notification – Service shuts down to await next alarm

App Widgets and Home Screens ● App Widget = You, on the Home Screen – Display key info at a glance – Light interactivity (launch an activity) – Update on demand or periodically – User control over roster, position

App Widgets and Home Screens ● Replacement Home Screen – You advertise that you implement one – User gets choice when presses HOME ● Or sets a default – You supply whatever experience you want!

Tools ● Eclipse... – Android Developer Tools plugin – GUI preview mode – MOTODEV Studio for Android ● Adds many more tools to standard Eclipse/ADT

Tools ● ...Or Not – IntelliJ IDEA – NetBeans – No particular IDE – No platform limitations

Production ● APK File – Android “executable” – Digitally signed (self-signed certificate) – Freely distributable ● Not limited to Android Market or any other single venue

Production ● Android Market – $25 setup fee – Upload and go ● Available on many devices within minutes of release ● Other Markets Available – Motorola SHOP4APPS – Verizon V-CAST

What If I Hate Java? ● Web Technologies – HTML5 – PhoneGap / Rhodes / Titanium Mobile – Adobe AIR ● Other Compiled JVM Languages (Scala) ● Scripting Languages (JRuby)

“Fragmentation” ● False Fragmentation = Choices – Consumer choices (screen size) – Manufacturer choices (hardware capabilities) – Carrier choices (device mix) – Developer choices ● Recognize that others choices matter ● Choose not to be chosen

“Fragmentation” ● True Fragmentation – Device manufacturers who break the SDK – Carriers who limit the devices – Developers who go beyond the SDK boundaries – Garden-variety bugs

Androids Future ● OS Releases – Gingerbread – Honeycomb – … – Expect 2-3 releases/year ● Good backwards compatibility

Androids Future ● Google TV – Powered by Android – Android Market and SDK/add-on in early 2011 ● Hardware Innovation and Experimentation – Desk phones for the enterprise – SonyEricsson LiveView – ???

Where Do We Go From Here? ● General Android Information – PlanetAndroid.com – Twitter: #androiddev – Social networks (Facebook, LinkedIn, etc.)

Where Do We Go From Here? ● Public Developer Support Resources – StackOverflow (#android) – Google Groups ● android-developers ● android-discuss – IRC – Other community support boards

Where Do We Go From Here? ● Rich Web Experience 2010 – Today ● Developing Android Apps Using Web Technologies ● The Future of Mobile: Learn to Build W3C Widgets and Device APIs with PhoneGap ● Choices in Mobile Application Development

Where Do We Go From Here? ● Rich Web Experience 2010 – Friday ● Ted Newards all-day Android-a-palooza (a.k.a., workshop) ● Easy Mobile Development Workshop: Mobile GUI Frameworks ● Easy Mobile Development Workshop: Appcelerator Titanium

Android Development...The 20,000-Foot View

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