Sencha Touch 2 - Android Performance
We are developing a Sencha Touch 2 application which makes use of Phonegap to be able to install it as an application and access the storage of a device. This works really well on the iPad 2 and the iPad 3. However when we tried to run the application on an android device, the performance was very slow. The main elements which slowed down the system were lists and carousels. When we tried to test the same application through the chrome browser, the performance was on-par with that of the iPad.
Do you have any suggestions on what we can do to improve the performance on android, maybe even ditching Phonegap for something which works better. Or if we can force phonegap to run as a chrome browser.
Thank you for your time & help.
Answer
The problem you have here is that the Android browser does not use graphics hardware acceleration. This means that the standard tricks that Sencha (and other HTML5 libraries such as jQueryMobile, iScroll etc...) use to provide good scrolling performance, such as CSS 3D transforms to cause a your list to be rendered in a separate layer, which can then be translated in hardware, will not work on Android. Instead, list scroll will be performed entirely in software, which is going to be slow!
The Chrome browser, does however provide GPU acceleration. The Android device is more than capable of delivering a good HTML5 experience, it is simply that the standard browser does not take advantage of GPU hardware yet.
Unless you can force your end users to use Chrome (which I doubt), the only option is to degrade user experience, and deliver a slightly simpler UI for Android users.
For further details, see "IMPROVING THE PERFORMANCE OF YOUR HTML5 APP"