Mini Scrollbar with thumbnails on iphone

Question

Hello.

I was wondering, what would be the best way, to implement an 'extra' scrollbar, showing thumbnail versions of the pages, you are currently viewing.

In my case, I would like to have maybe around 20 images, which I would animate with Cover Flow Layers and while I 'scroll' up an down to view them, a scrollbar appears at the side, showing the smaller thumbnail versions of all the pages while the thumbnail currently visible is rendered slightly highlighted.

Is there anything specific I need to keep in mind? Thanks in advance for any ideas!

Answer 1

Hi

You are not giving much info to work with:)

Build a UIScrollView and a UIView, stick all the thumbnails into the UIView, stick the UIView into the UIScrollView.

If you have a lot of images, consider loading them in as "dummies/blank image" and have an NSOperation load them in the background. Consider releasing images that are outside of the screen, so that if 3-7 is on the screen then you only load in 2-8 and release everything else.

Regarding the logistics of it: Build a viewController for holding everything. Then build a thumbnail viewController "component" that has a delegate method for setting the "displayed" image and maybe one for scroll and click. Build a FullSize viewController component for handling the full size images. Have that also implement some delegate methods to communicate to the top most viewController. Add the two components to the top viewController, hook up the logic and you are done. Make sure there exists only one model array/dictionary in the top most viewController and "feed" that downwards to the thumbnail and fullsize viewController, when some one clicks or scrolls, inform the top most viewController and have that update the other viewController.

Was that the kind of answers you were looking for? :)