816383 - Unexpected redraw on favicon?

Status: NEW

(Core :: Graphics, defect)

Description

[Justin Dolske [:Dolske]]

Attachment: Video of comment 0

This is a subtle effect, but I've noticed it a few times now. I think I've seen it in content too, so I don't _think_ it's unique to my testcase.

In the attached video, my screen is zoomed in on an apptab favicon (Reddit, natch). I move the pointer to trigger a hover style, and then move it away. There should, I think, be exactly 2 states -- hovered or not.

[The favicon is normally styled with a small amount of opacity -- to blend in with the gray background -- and when hovered the opacity is removed. The visual effect is that hovered tabs get a "brighter" looking icon.]

I'm instead seeing 3 states when moving the mouse away:

1) normal hover (bright)
*mouse exit*
2) ??? (for like half a second)
3) normal unhovered (dim)

I don't understand what state 2 is. I do wonder if hidpi is involved here somehow (I am on a Retina MBP) -- it's hard to tell from the video, but whereas state 1 and 3 are the usual poor looking 16x16-to-32x32 upscaling, state 2 looks... smoother... like it's it's being blurred at native res.

Comment 1

[Justin Dolske [:Dolske]]

Original .MOV at https://people.mozilla.com/~dolske/bug816383.mov, it's a bit clearer.

Comment 2

[Justin Dolske [:Dolske]]

Attachment: Screenshot of state 2 from original video