control when listView removes nonvisible views?

Question

I find listView recycles its views too fast.

When my listView scrolls, views falls off the screen gets removed right away.

Each cell(row) has image loaded using universal-image-loader.
Views which fell off the screen has to reload the image when they comes back into visible area. (it shows the stub image for short time period and loads the correct image).

I definately need to keep the view recycling behavior, but can I modify the list view's behavior so that user won't notice constant reloading of images?(maybe I keep 2-3 times of # of views in a cache than a regular list view would)

Answer 1

Unfortunately the code for ListView and friends is horribly complicated by the fact that it's designed to scroll unevenly-sized items without knowing the height ahead of time. That makes it brutally difficult to run with anything but the default behavior. In addition, most of the methods you'd need access to, to easily customize the behavior are hidden or private. It would be a massive job to try and roll your own (across multiple platforms, subtleties of scrolling, flinging, dragging, scrolling, keyboard focus &c).

The best solution is probably to maintain an image cache that fills in lazily around the view positions that are active. Not neccesarily easy. But way easier that trying to mess with ListView.

A very useful API for this is ListView.setRecyclerListener(AbsListView.RecyclerListener listener), which gives you a hook to track which images are actively displayed.

Answer 2

I can suggest you to use a ScrollView instead of the list view. The ListView is designed to display a lot of data efficiently, that's why your off screen items are destroyed. In which concerns the scroll view, once loaded, you will be able to scroll up and down without recreating the off screen objects (because they ill not be destroyed).

See: http://developer.android.com/reference/android/widget/ScrollView.html

EDIT:

If it is mandatory for you to use the listView, you cluld take a look here: How do i prevent recycled ListView items from showing old content?

There is a posibility to override the listView getView method and keep more items not to be destroyed that the number the listView is keeping.