refactor: Improve accessibility of menus

[brenca]

Description of Change

There are a couple of accessibility problems related to menus that I've found:

• The Windows Narrator couldn't announce any menu items
• The menu bar on Windows (and I guess Linux too) was not accessible by keyboard
• Accessibility issue: Electron system tray context menu on Windows is not keyboard navigable #11587

The first fix was given to us by the Chromium 69 upgrade, which allowed the Windows Narrator to read the menus. This is because chromium's UIAutomation API implementation is not yet complete, and that's what the narrator uses on Windows (but the implementation progressed from 68 to 69 to allow the menus to be read).

The menu bar was not accessible because we basically didn't focus the View, which in turn didn't give it keyboard events. This was done because some commands in the menu (like copy) depend on the actual content being focused, instead of the bar. I fixed this by returning the focus before the command executes. Also, focusing the menu bar was not enough, since we used a plain View for the bar, which didn't implement any keyboard navigation of it's items. I changed the base class to AccessiblePaneView, which implements that navigation (should fix #2504).

#11587 was caused by the fact that the tray icon's context menu was spawned without a Widget, since it's not necessary to have a BrowserWindow to have an icon in the tray. The Widget is important because that's what actually captures keyboard events, and the menus leech off their parent Widgets for those events. I added a temporary non-visual Widget to the menu that gets destroyed when the menu closes, which fixed the issue.

Checklist

• PR description included and stakeholders cc'd
• npm test passes
• PR title follows semantic commit guidelines

Release Notes

Notes: improved tray icon context menu and menu bar accessibility

[ckerr]

Thanks for the changes!

[daviwil]

Thanks so much for addressing this issue! Atom users have been reporting it for at least 2 years: atom/atom#5998. Really excited to get this into a future release!

[codebytere]

🚀

[release-clerk]

Release Notes Persisted

Improved tray icon context menu and menu bar accessibility

[marisademeglio]

Thanks for these changes! Any idea which release they'll be in?

[deanwhillier]

Looks like it made it into v5. See Other Changes in release notes here: https://electronjs.org/releases/stable#release-notes-for-v500

[adamulrich]

@ckerr did this fix left/right arrow navigation between menus? It seems still broken.