MRG: Update time slider label

[GuillaumeFavelier]

This PR updates the slider time label instead of the default time actor. It improves consistency so now the size of the time label scales with the window size.

Known issue

• The time_actor doesn't come back when the interface is hidden

It's an item of #7162

[codecov]

Codecov Report

Merging #7263 into master will decrease coverage by <.01%.
The diff coverage is 84.37%.

@@            Coverage Diff             @@
##           master    #7263      +/-   ##
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- Coverage   89.79%   89.79%   -0.01%     
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  Files         447      447              
  Lines       80506    80518      +12     
  Branches    12873    12878       +5     
==========================================
+ Hits        72289    72299      +10     
- Misses       5390     5391       +1     
- Partials     2827     2828       +1

[agramfort]

works great except that now if I hide the controls I've lost the time information. It should appear as before.

[GuillaumeFavelier]

Good catch! I'll fix this one.

[GuillaumeFavelier]

Actually @agramfort I see 2 ways to solve this issue:

1. we bring back the standard time_actor but this one does not scale with the window size
2. we hide all the slider parts except the title. This will scale with the window but the slider is still active meaning the user can still click on it in hidden state

[larsoner]

We want a time label visible, it's useful.

Why not show the old actor when not in interactive mode, but hide it in interactive mode? It won't scale in non-interactive mode but I think that's okay. (Personally I think it would be better if none of the text actors scaled, it's how standard UI and plotters like mpl work.)

[GuillaumeFavelier]

Going for option 1 then

[agramfort]

works like a charm for me

[larsoner]

Works for me as well, thanks @GuillaumeFavelier