How to create a closed (circular) ListView ?

Question

Hi, I want to create a customized ListView (or similar) which will behave like a closed (circular) one:

1. scrolling down - after the last item was reached the first begins (.., n-1, n, 1, 2, ..)
2. scrolling upward - after the first item was reached the last begins (.., 2, 1, n, n-1, ..)

It sounds simple conceptually but, apparently, there is no straightforward approach to do this. Can anyone point me to the right solution ? Thank you !

I have already received an answer (from Streets Of Boston on Android-Developers google groups), but it sounds somehow ugly :) -

I did this by creating my own list-adapter (subclassed from BaseAdapter).

I coded my own list-adapter in such a way that its getCount() method returns a HUUUUGE number.

And if item 'x' is selected, then this item corresponds to adapter position='adapter.getCount()/2+x'

And for my adapter's method getItem(int position), i look in my array that backs up the adapter and fetch the item on index: (position-getCount()/2) % myDataItems.length

You need to do some more 'special' stuff to make it all work correctly, but you get the idea.

In principle, it is still possible to reach the end or the beginning of the list, but if you set getCount() to around a million or so, this is hard to do :-)

Answer 1

The solution you mention is the one I told other developers to use in the past. In getCount(), simply return Integer.MAX_VALUE, it will give you about 2 billion items, which should be enough.

Answer 2

any solutions ?