D19542: [WIP] Make pop-up note text visible whatever background color is

[David Hurka]

davidhurka added a comment.


  After reading some Wikipedia, I can say:
  
  - Checkmarks use luma (NTSC)
  - Your approach uses luma (sRGB)
  - QColor::lightness() uses lightness (HSL-bi-hexcone)
  
  QColor::lightness() would not solve the problem, it would put white #ffffff text on yellow #00ffff background. Qt had to compute luma, but luma() would need to know the color space of the output device.  I can imagine that Qt developers decided to use value() as a better tradeoff than assuming sRGB or using the primary display’s color space.

REPOSITORY
  R223 Okular

REVISION DETAIL
  https://phabricator.kde.org/D19542

To: yurchor, #okular
Cc: davidhurka, aacid, okular-devel, tfella, ngraham, darcyshen
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.kde.org/pipermail/okular-devel/attachments/20190306/daca77f6/attachment.html>