PolymerElements
Why don't firstVisibleIndex and lastVisibleIndex bind or notify?
I have to actively read these properties with javascript, and there isn't a good way to get an event that would fire when these properties change, so I'm resorting to a timer to monitor them, which is pretty stupid.
If I could bind to these properties, I could have a declarative way of knowing what's visible.
Is this behavior intentional? Is there another way to get notified when they change?
Yes. Declarative properties are desirable from an API perspective although it might have a cost for users that don't care about these notifications. Depending on how it's implemented, the updates could be debounced to reduce stress. I'll keep the issue open.
Is it possible to use these values to tell me when the view is 'full', or when iron-list starts to fill the view? At the moment, I have a progress bar to tell the user when the data is loading, but assigning that data to the iron-list results in a pause while the UI does nothing. I would like an event to tell me when iron-list is starting to fill the view so I can stop my 'progress-bar' (it's not needed any more since the user can see the view filling up). Is there some other event I could use?
