2017167 - Using color picker after using Color vision simulation picks the wrong color

Status: NEW

(DevTools :: Inspector, defect, P2)

Description

[Julian Descottes [:jdescottes]]

STRs:

• open data:text/html,<div style="background:red; width:100px; height:100px">
• open devtools
• open accessibility panel
• Simulate Protanopia
• open inspector
• start the color picker
• try to pick the color in the square

The picked color will be "#ff0000", whereas the color actually rendered thanks to the color vision simulation is "#271d00".

Comment 1

[Nicolas Chevobbe [:nchevobbe]]

this should be fixed at the screenshot level. You get the same issue if you simulate color vision and take a screenshot (either using devtools tools or the main firefox screenshot one)

the simulation is set on the docShell in https://searchfox.org/firefox-main/rev/2477384eae35d0ee85d43dfdeba6f2ba51d9abfb/devtools/server/actors/accessibility/simulator.js#54

this.docShell.setColorMatrix(colorMatrix);

which ultimately calls https://searchfox.org/firefox-main/rev/2477384eae35d0ee85d43dfdeba6f2ba51d9abfb/docshell/base/nsDocShell.cpp#14607

nsDocShell::SetColorMatrix(const nsTArray<float>& aMatrix) {

so https://searchfox.org/firefox-main/rev/2477384eae35d0ee85d43dfdeba6f2ba51d9abfb/dom/ipc/WindowGlobalParent.cpp#1077

already_AddRefed<mozilla::dom::Promise> WindowGlobalParent::DrawSnapshot(

should somehow take this applied matrix into account

ahale, maybe you could help us here?

Comment 2

[Julian Descottes [:jdescottes]]

Also note that the devtools highlighters are impacted by the matrix, which can be an issue with the grid highlighters for instance which are color coded.

We might file a separate bug about this, but if we can make the matrix not apply to our highlighters, that would also solve this issue.

Comment 3

[Alexandre Poirot [:ochameau]]

Could it be that color matrix are only applied when using WebRender:
https://searchfox.org/firefox-main/rev/150ca809c7243bd6e994f28cc4a3750430783364/layout/painting/nsDisplayList.cpp#2406-2435

But the screenshots are using "software render", which may not be WebRender?
https://searchfox.org/firefox-main/rev/150ca809c7243bd6e994f28cc4a3750430783364/gfx/ipc/CrossProcessPaint.cpp#112-113