lightweight css animations for new actions entering the log.

[threepointone]

while we ponder react-motion in #52, consider a simpler alternative for now :) this PR adds a css fadeIn animation to entries in the actions log.

[nicinabox]

Would be awesome if you could show a gif of it!

[threepointone]

it's quite subtle, doesn't show well (and seems longer) in this gif http://recordit.co/ss6t7FyU7H :|

[nicinabox]

Nice! What happens when you get down to the bottom and it starts scrolling?

[threepointone]

just adds it at the bottom as it already does now, along with the subtle fade. try it, it's really not much :)

[gaearon]

I'll defer any visual decisions to @nicinabox to approve

[nicinabox]

How do we feel about the flash? For reference:

[gaearon]

What if we do the opposite? Start off actions brighter than usual, then let them “cool down”. Like changing nodes in Chrome inspector.

[nicinabox]

That's a neat effect too. I think the biggest thing that's lacking with each of these is you don't really see the content move upwards (but these are still an improvement).

[dzannotti]

i like all 3

[nicinabox]

Oops, probably wasn't clear on the first one. It's @threepointone's. I just recorded at 30fps and showed scrolling.

[nicinabox]

Could we append it then animate scrolling to the bottom?

[gaearon]

Yeah. Let's replace naïve scrolling with something like https://github.com/alexkuz/additive-animation#usage-example?

[gaearon]

Closing, as I don't currently have time to make it better, and scrolling seems to be important for the desired effect. If someone would like to implement it, please do it in https://github.com/gaearon/redux-devtools-log-monitor instead (track #132 for discussion).