Change definition of select element list box and drop-down box rendering

[josepharhar]

WebKittens

@annevk

Title of the proposal

Change definition of select element list box and drop-down box rendering

URL to the spec

whatwg/html#11460

URL to the spec's repository

https://github.com/whatwg/html

Issue Tracker URL

No response

Explainer URL

No response

TAG Design Review URL

No response

Mozilla standards-positions issue URL

mozilla/standards-positions#1274

WebKit Bugzilla URL

No response

Radar URL

No response

Description

This changes how the size and multiple attribute are used to choose between creating an in-page listbox or a drop-down popup select element across platforms so that mobile platforms can have an in-page listbox select and desktop can have a drop-down multi-select.

[josepharhar]

AppKit already supports multi-select with this API: https://developer.apple.com/documentation/appkit/nsmenu/selectionmode-swift.enum/selectany

[lukewarlow]

Worth noting that NSMenu doesn't seem to have an API that allows it to stay open when you select a menuitem so while selectionMode.selectAny lets you do multi selection the UX isn't ideal.