Pressing esc in Widgets Editor closes panel in customizer

[gwwar]

When editing a widget in /wp-admin/customize.php?return=%2Fwp-admin%2Fwidgets.php using the widget block editor, try pressing "esc". The customizer panel is closed regardless of if the block editor has focus or not.

Fixes https://core.trac.wordpress.org/ticket/54030

When editing a widget in /wp-admin/customize.php?return=%2Fwp-admin%2Fwidgets.php using the widget block editor, try pressing "esc". The customizer panel is closed regardless of if the block editor has focus or not.

Instead of having the block editor stop propagation of key events, let's make the customizer aware of block editor instances and avoid firing keyboard shortcuts if an editor instance has focus.

#### Before

​https://user-images.githubusercontent.com/1270189/131191958-30bd5984-d5ba-4b61-a67d-a02534f3026a.mp4

#### After

​https://user-images.githubusercontent.com/1270189/131191962-cd5f54c1-04fe-4867-b810-c94e223733d6.mp4

### Testing Instructions

• Checkout this branch
• Activate the 2020 theme and enable the Gutenberg plugin
• Visit /wp-admin/customize.php?return=%2Fwp-admin%2Fwidgets.php
• Add a widget, and a block like a paragraph
• Press <kbd>esc</kbd>
• Verify that the block editor goes into navigator mode and that the customizer panel does not close

[dlh]

Thanks for the ticket and patch, @gwwar!

Both the Additional CSS code editor and the pre-block, TinyMCE-powered Text widget seem to also intercept the Escape key as described in the PR. So, while I don't have the background to comment on the specifics of the Pull Request, conceptually the idea makes sense to me at first glance.

[dlh]

I suppose this could also be eligible for 5.8.1 if there was interest in picking it up sooner.

[SergeyBiryukov]

In 51682:

Customize: Prevent collapsing expanded panel/section/control when Esc is pressed on a block editor instance.

This ensures that the current panel is not collapsed when hitting Esc with the focus on the widget block editor.

Follow-up to [37347], [39120].

Props gwwar, dlh.
Fixes #54030.

[SergeyBiryukov]

Reopening for 5.8.1 consideration.

[SergeyBiryukov]

In 51683:

Coding Standards: Fix WPCS issue in [51682].

This fixes a "Misleading line break before '||'; readers may interpret this as an expression boundary" error.

See #54030.

[peterwilsoncc]

In 51687:

Customize: Prevent collapsing expanded panel/section/control when Esc is pressed on a block editor instance.

This ensures that the current panel is not collapsed when hitting Esc with the focus on the widget block editor.

Follow-up to [37347], [39120].

Props gwwar, dlh, SergeyBiryukov.
Merges [51682,51683] to the 5.8 branch.
Fixes #54030.

[gwwar]

So speedy! Thanks y'all ✨

closing since the patch landed ✅