[FR]: Reduce Side Panel Minimum Width

[chingweih]

Description

Reduce side panel minimum width so that extensions like "Vertical Tabs" can be more useful on laptop screens.

Who's implementing?

• I'm willing to implement this feature myself

The problem

I use many extensions that rely on chrome's Side Panel API, including this one called Vertical Tabs. However, the default minimum width of the side panel is fixed at 360px, which takes up almost 1/3 of the screen on smaller laptop displays, which is not ideal for the use case.

There is a ongoing discussion in the main Chromium repo about this behavior since 2024 but hasn't been implemented yet. I feel like Helium's tighter UI design is suitable for this patch.

Possible solutions

Change constant kSidePanelDefaultContentWidth in source code chrome/browser/ui/views/side_panel/side_panel_entry.h from 360 to a lower value (e.g. 260)

Additional context

[yinyu985]

Strong support for chingweih’s PR.

The fact that this fix involves modifying only the kSidePanelDefaultContentWidth constant makes the multi-year delay in the main Chromium project baffling. It undermines any justification based on "UI stability," especially since downstream browsers have managed this successfully.

This is a clear case where community initiative is correcting a long-standing oversight. Thank you for implementing this. I urge the maintainers to merge this patch without delay.