This document discusses options for cross-platform mobile development and compares their pros and cons. It outlines that cross-platform frameworks allow developing for both iOS and Android at once but can limit capabilities and have differing UI implementations. Games may perform better than business apps on such frameworks. The document also introduces several specific cross-platform options like ngCore, JSX, and Arctic.js and notes tools like ExGame for porting Flash games to mobile.

1. CROSS-PLATFORM
DEVELOPMENT ON
MOBILE DEVICES
Takaaki Mizuno
DeNA

2. Takaaki Mizuno
• 15 years experience in Engineering.
• Works to DeNA Co., Ltd and Oceans Inc.

3. How to develop the app both for
iOS/Android ?
There are 2 options:
• Develop for both separately with different
languages ( Objective-C / Java )
• Use cross-platform development
environment and develop for both platform
at once

4. Cross-Platform development
environments

5. Are cross-platform dev denelopment
envivonments workable ?
Business • Not good at least now
Apps • It’s ok for simple apps
Games • Not so bad

6. Most important thing is…
To know the characteristics of each environment
Your code
Cross-platform Erase the difference
But limit the capability
Environment layer
sometimes
Native Layer

7. Business Apps
• Pros
• Write once, run on both devices
• No need to pass Apple’s review
• Cons
• UI of both environments are totally different
• Really slow

8. UI of both environments are different
• Android have “hardware back key” and “Menu”
• Positions of Tab Bar are different
• Android devices have so many aspect ratios and screen
sizes.
• You have to care about such differences in your code

9. Difficult to catch up with interface trends.
• Pull to refresh
• Side menu

10. UIWebView based application for iOS
Really Slow

11. Why ?
• Apple doesn’t allow to use JIT strategy

12. Chrome iOS version is SLOW

13. Facebook Application for iOS

14. Facebook will return to native

15. Game
• Pros
• Write once, run on both devices
• No need to pass Apple’s review
• Cons
• UI of both environments are totally different
• Really slow
• Use JavaScript

16. User Interface
• You don’t need to use native-like user interface

17. Speed
• Compiling code to native ( Unity )
• Preparing alternative Canvas ( appMobi )
• Use OpenGL directly ( ngCore )

18. JavaScript
• JavaScript for mobile application is totally different from
web app’s one ( such as using jQuery ).
• JavaScript is not suitable for large scale development.
• Because it is difficult to find a bug.

19. But if you want to use JavaScript still…

20. Closure Compiler
• Google’s answer for large scale JavaScript development
• It optimizes the code and finds error in code.

21. DeNA’s answer

22. ngCore
• JavaScript based Game development environment.
• Try ⇛ https://developer.mobage.com/

23. JSX
• a faster, safer, easier alternative to JavaScript
• JSX compilers compiles JSX code into JavaScript
interface Flyable {
abstract function fly() : void;
}
abstract class Animal {
function eat() : void {
log "An animal is eating!”;
}
}
class Bat extends Animal implements Flyable {
override function fly() : void {
log "A bat is flying!”;
}
}

24. JSX
we are observing 4% to 27% increase in performance

25. Try it
http://jsx.github.com/

26. Arctic.js
• Game engine for smartphone web browsers written in
JavaScript with HTML5 Canvas.
• It provides ActionScript3 friendly APIs which Flash
developers are familiar to.
var keyFrame = new arc.anim.KeyFrameAnimation(12, 5, [
new arc.anim.Timeline(this._yellowImg, {
1 : {visible:true},
3 : {visible:false}
}),
new arc.anim.Timeline(this._orangeImg, {
1 : {visible:true},
5 : {visible:false}
}),
new arc.anim.Timeline(this, {
1 : {scaleX:0.5, scaleY:0.5, transition:arc.anim.Transition.SINE_OUT},
5 : {scaleX:3, scaleY:3}
})
]);

27. Try it
http://denadev.github.com/Arctic.js/

28. ExGame
• Converts Flash Lite 1.1 SWF into JavaScript and make it
executable on iOS/Android devices.

29. How to use ExGame
• DeNA provides ExGame to the partner developers.
• Please access to our development sites:
http://developer.dena.jp/mbga/en/