Avoid browser paint in the editor

[corentin-gautier]

Description

This issue tracks the various PR I have open around avoiding browser paint in the editor as requested by @ciampo in #45545 (review):

• Avoid paint on inserter animation #46185
• Popover: Avoid paint on popovers when scrolling #46187
• ListView: Avoid paint on list view item hover #46188
• Resizable Box: Avoid paint on resizable-box handles #46196
• CircularOption: Avoid paint on circular option hover #46197
• Avoid paint on popover when hovering content #46201
  • Popover: remove box shadow on quick inserter introduced in #46201 #46465

There are still paint issues that do not have a PR right now, they are related to the fact that the scroll areas are set to overflow: auto;, but setting overflow to scroll breaks the full site editor. Someone with a deeper knowledge of this area might find the solution.

• The whole page shifts when the sidebar gets a scrollbar #45386
• Editor: Interaction triggering drastic browser repaint #23427
• Typing block editor has significant lag, particularly on Chrome MacOS #22822

EDIT : This PR should fix the issue with the scrollbars :

• Performances: Avoid UI shifting when selecting blocks #47177

[ciampo]

Hey @corentin-gautier , thank you for opening those PRs!

Just wanted to let you know that I won't be around to continue reviewing those PRs in the next weeks, but I've made sure to add other folks as reviewers — so please feel free to ping them in case the reviews go stale without me

[corentin-gautier]

Hi @ciampo, I have open a new PR regarding the scroll areas issues :

• Performances: Avoid UI shifting when selecting blocks #47177

could you take a look at it or assign someone with knowledge of this area ? This would help close this issue 🙂

[corentin-gautier]

#46465 was fixed by #48794

[corentin-gautier]

Except for #22822 which might need further improvements, I think this issue can be closed @ciampo

[corentin-gautier]

I have also open this issue regarding js perfs #47619

[ciampo]

Agreed, we can close this issue since it was mostly around paint performance. We can treat input lag and overall bundle size separately.

Thank you for your great work so far!