Explore possibilities of using System Theme 1.0 in Firefox 91.9.1esr and later.
After moving to Firefox 91.9.1esr I found problem with System theme 1.2. The color of tab add button was changed, and the button is not visible with my Windows 7 classic windows system theme. So, I'm trying to find a way to port System theme 1.0 color scheme to newer firefox versions.
Creation of a simple theme with firefox color extension works. But it is unable to recreate the effects related to active and inactive window color changes. As, I had to use bitmap to get the OS blue color transition pattern.
It seems the system theme is stored in omni.ja file. Modification of the omni.ja seems to be not a practical solution. So, it would be a better way to create an addon theme with the same code as the System Theme 1.0.
The first question is, if it will be possible to create a theme with the same code as a system theme has. Will it be able to perform the same way?
The next question is: Where the source code of the system theme is? I was unable to find it in the Firefox source. It seems, it is not stored in any obvious location.
Note Firefox 91.13.0 ESR (91.thirteen.0) was the last update for the old EOL Fx 91.0 ESR.
I obtained manifest.json from https://searchfox.org/mozilla-esr78/source/toolkit/mozapps/extensions/default-theme.
I loaded manifest.json to Firofox with no effect. It appears external theme should have a different id, so I replaced "id": "email@example.com" with something else. Now the theme is working, but it does not use system colors.
I suspect, a theme without firstname.lastname@example.org id can not use the system colors due to some restrictions.
I did repeat the test with the code found in https://searchfox.org/mozilla-esr91/source/toolkit/mozapps/extensions/default-theme/manifest.json.
This code does not work. I had to remove "theme_experiment" code fragment, then it started to work exactly the same way the esr78 did.
First, the code in the source/toolkit/mozapps/extensions/default-theme/ does not contain the system themes I found in installed Firefox. There is just the dark theme, but where are the definitions of the default, light and alpenglow? Second, the code is faulty with some garbage in it. So, it does not sufficienlty conclude, an external theme can not use system colors.