View Full Version : Carousel Swipe a little Jerky

16 Apr 2011, 11:55 AM
Hi All.

Just checking to see if anyone is having the same issue...

I have a simple carousel with full screen images (PNG). Entire experience will be on the iPad. When I play it, the swipe carousel transitions are not as smooth as I would like. There's a little hiccup in between each transition.

Is there something I can do to optimize the performance?

Any help would be greatly appreciated.

19 Apr 2011, 2:49 AM
I found adding any handlers to the carousel added a millisecond glitch. Do you have any listeners or handlers in the object?

19 Apr 2011, 8:29 AM
Hi isibbot.

I did have some Listeners... I removed them, but still performance issues. If there was any increased performance, it was negligible.

Full screen images could be too much for it to handle smoothly. I also a couple of nested carousels. I'm sure this is causing some of the performance issues, but when I remove those and have a single, full screen image carousel, It's still running a little laggy.

Thanks for the suggestion!

20 Apr 2011, 12:16 AM
Yeahm you forgot to mention the carousels!

I have used full screen rgb 72dpi jpegs for an ipad brochure app and as long as you refine the conpression for each file getting maxium quality to file size than a full screen image carousel works fine.

20 Apr 2011, 7:14 AM
Check out our app on iPad (mygazines.com/demo)
We spent a lot of time optimizing swipe performance, listeners slow down performance quite a lot. Image buffering seems to cause some performance issue as well as large images.

Any suggestions would be appreciated.

21 Apr 2011, 1:01 AM
tbh, simple trouble shooting points to a cause. Working on ipad and iphone (not simulators) you get the jerkyness when the contents of the cards has a high filesize e.g. 218kb-530kb png image.

Without having technical knowledge to explain it fully, I think this must be down to the Javascript engine the ipad runs for safari mobile. if the ipads processor and gfx chipset can handle 3d games, then the easing transition of 0.5mb image files between each other should be easy.

I have experimented with 3 js frameworks to produce a "brochure app", them being the only ones really available to my knowledge. JQTouch (where it was left before sencha), JQuery Mobile and Sencha Touch.

jQTouch was horrendous at animating. So much so that instead of using the native swipe animation, we replaced the transitions to use jquery cycle plugin.

JQuery mobile was ok, but young and ... simple.

Sencha is definately the best in performance and functionality. It seems professionally made in most areas and for this fact, I think that which ever means of mathmatical calculations the use for animation, it will be efficient. Which points me back again to the Javascript engine used in safari mobile.

21 Apr 2011, 1:07 AM
Oh, and Hitman01, May I commend your mygazine app. It looks very good. How has the uptake of this performed for your company?

21 Apr 2011, 6:09 AM

Thanks for your comment.

We had great success with our product but since we are competing against mostly native apps we are trying our best to tweak the performance and make it as smooth as possible at the same time not loosing the image quality.