android - PhoneGap 1.4 wrapping Sencha Touch 2.X - What about performance?

Question

I'm building a multiplatform tablet app wrapping it with Phonegap 1.4 using just its webview, then I work my magic with the Sencha Touch 2 framework. By multiplatform I mean iOS 5.X+ and Android 3.0+ (for now).

This app is working great so far, all its features work on both systems but... On the Android tablet (Samsung GalaxyTab) its really slow. What's happening? Can I do something about it, or its just android's limit?

Thanks

Ricardo Perre: http://edgecodetechology.blogspot.pt/

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****EDIT**** (I'm trying to make this post somewhat useful to sencha community)

Sencha Touch, like many other Javascript Frameworks are not the best example of performance due to javascript itself.

Then Why use Sencha Touch?

• In my case: Multiplatform (iOS, Android, Windows Phone, Blackberry, Windows, Mac OSX, Linux. Sharing 80-90% of the code)

Mitigating performance issues due to lack of visual pre-process in Android systems:

1. CSS3 heavy visual process:

   • Avoid Gradients
   • Avoid Shadows
   • Avoid Transformations and animations

2. Good MVC practices:

   • Don't use more views and you actually showing
   • Pre-render / Pre-datafetch when possible to avoid render and data process simultaneously

3. For any scrollviews, overscroll should be disabled on Android. I've tested many Sencha Touch 2 applications on Android devices and overscroll causes badly unpleasant experience because of delays and lags. (tested on Galaxy Tab, Nexus S, and some HTCs) by Thiem Nguyen (I've been mining your posts, sorry dude :P)

Answer 1

Same here. I've tested many of my Sencha Touch 2 applications on Samsung GalaxyTab and the performance is really terrible. There's a fact (which maybe a part of actual reason) that, iOS does many pre-process and calculation before rendering to make it seems smoother to user's look and feel, while Android tends to render & process simultaneously on the go.

In general, it could be say that, to every cross-platform mobile apps built on Javascript, like Sencha Touch, iOS performance is significantly better than Android. However, Sencha Touch dev team is trying their best to improve this, hopefully it would be better in next releases. You could see this article about iOS & Android devices performance comparison.

http://www.sencha.com/blog/sencha-touch-2-developer-preview/

PS: While it's much relevant to the OS's limit, you can also optimize your app to make it perform better on Android devices. To my experience, the best practice is:

• Do NOT use CSS3 too much.
• Keep your DOM as minimal as possible.

Hope it helps.