md-button: md-raised's "hover" status should not raise higher ("pressed" should)

[albertboada]

Right now (https://material.angularjs.org/#/demo/material.components.button), raised _md-button_s raise higher when hovered.
However, according to the public Material Design guidelines, raising only happens when you press the button (or when it is focused), not when you hover it:

http://material-design.storage.googleapis.com/publish/v_2/material_ext_publish/0B08MbvYZK1iNelZlNW13UVRzUnc/components-buttons-mainbuttons-buttons-motionraised_large_xhdpi.mp4

Sorry if this has been already informed or already scheduled for development, could not find anything about it.

[marcysutton]

I don't see a hover state at all in that video. I think we should get clarification from the UX team on this one, as I have seen internal design docs that show additional raising on focus to differentiate from hover. cc @ThomasBurleson

[albertboada]

Exactly, hover state has no special style at all anywhere in the spec. Not sure this is intended, so you better internally confirm this!

[marcysutton]

Actually it turns out there is no hover state for buttons per the design spec. Shadow raising should only occur on the focus and press actions, with the latter showing more of a shadow.

[albertboada]

So the video is trustworthy 100%, right? Because that focused state style would solve all the current confusion if implemented (#556, #142), even if it is always activated (not only through keyboard) (#1594).

In the meantime, being able to distinguish hover from focused status will help a lot, too.

[marcysutton]

That issue again....it's a really tough one to solve unfortunately, as the "fix" is pretty hacky. It's a larger issue in browser focus support, IMO. That PR should make it better, but it's not perfect.

There is work to be done on focus/pressed states, so I'll work that in as part of this issue.

[albertboada]

Yeah, but I meant... even if #1594 never landed, with these new (and very distinguishable) hover/focused/pressed styles there will be no confusion anymore, so it will not be an issue anymore if the button stays "focused" when pressed :)