Description of problem: If you are looking at a group like "programming", and are seeing both the available and installed package ... switching the filter to only show available shouldn't require another request/response. I'd also argue that switching back shouldn't either, just always get both but just display what the user wants ... but, meh. Version-Release number of selected component (if applicable): gnome-packagekit.x86_64 0.2.3-9.fc9 installed
This would be quite easy to do in gpk_application_menu_filter_installed_cb(), comparing the current filter against the new one. I'm not sure the frontend should second guess the backend tho, although the results -should- be exactly the same. I'm not sure if it makes sense to preserve the list and just toggle some invisible flag so you can switch between the states, but that just adds another layer of complexity. I'll stick it on the TODO, but can't make any promises about timescale.
Searching takes less than a second now, so I'm not sure it's worth the extra code.