Not smooth animation for a list view with items of different height

[alexeyr15]

If items of a list view have different height, then animation to show/hide FAB when scrolling isn't smooth sometimes. I think it is due to assumption in getListViewScrollY method that all items have the same height.

[ViliusKraujutis]

True... I've fixed this in my project. Will try to contribute changes here this evening.

[alexeyr15]

Sorry, but I still have not smooth animation when showing/hiding FAB on scrolling a list view of items with diferent height. I think this issue should be reopened.

[makovkastar]

@alexey-rabets have you updated the library dependency to the version 1.0.4? I tested it on the list with different height items and an animation was smooth.

[alexeyr15]

Yes, I've updated to 1.0.4. I can create and share a demo which reproduces the issue.

[makovkastar]

Please, it will help.

[alexeyr15]

I have modified your sample to demonstrate the issue:
https://github.com/alexey-rabets/FloatingActionButton.git

[makovkastar]

Thanks, I'll check.

[sreichholf]

Hi,

the current approach is (fully) broken for lists with items of different heights.
I myself do have a list with headers that are about 1/8th of the size of a normal list item (wonder what happens to the height calculation).
The only proper approach i know of is where you check two conditions:

1. Did the first visibile change? Yes -> The index change show the direction, reset all "y pixels scrolled" values to firstVisibleitem's getTop() value.
2. No -> check how much firstVisibleItem.getTop() has changed and in which direction.

The downside is, raising the scroll events purely based on the minimum significant scroll value is not possible this way. But I honestly think that's worth the gain in reliability.

I couldn't finish that approach yesterday evening but i may find some time this weekend.

[sreichholf]

here's my version of a (as far as I've tested) reliable ScrollDirectionDetector which I am using with my slightly customized FloatingActionButton:

https://gist.github.com/anonymous/b3c82c1854da45b6ae57

[makovkastar]

@sreichholf Thanks! Could you send a pull request? I'll review and merge it.

[makovkastar]

@alexey-rabets The issue seems finally to be resolved. I'll push an update to the Maven Central soon. For now could you check with the latest code base from the repo if the FAB works now with list with different items height?

[alexeyr15]

Yes, it works now. Thanks!

[makovkastar]

Fine, I'll close the issue.