Standardize a way to scroll into view within text controls

[saschanaz]

While several selection setter APIs including setSelectionRange() allows selection inside text controls ( and <textarea>), there is no straightforward way to scroll to the selected range without hacks.

Gecko has a nonstandard behavior where those APIs always scroll to the internal focus offset, and I'd like to standardize this behavior:

• Specify what Gecko does (always scroll to the internal focus offset)
• Or, add a parameter to setSelectionRange: setSelectionRange(start, end, { scroll: true, direction })
• Or, add a method scrollToFocus()

[domenic]

What is "internal focus offset"?

[saschanaz]

Ah, the cursor/head part of a text selection.

[annevk]

cc @zcorpan

[zcorpan]

Related: #5099

cc @josepharhar