1017383 - Guess KeyboardEvent.code value from virtual keycode when scancode is 0 (e.g., inputting from VKB)

Status: NEW

(Core :: DOM: Events, defect)

Description

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

When scancode is 0, we should guess KeyboardEvent.code values from virtual keycode as far as possible. This is necessary to support VKB input. Key events from VKB may not have proper scancode value. But we need to emulate it.
https://dvcs.w3.org/hg/dom3events/raw-file/tip/html/DOM3-Events.html#code-virtual-keyboards

Comment 1

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

Attachment: Patch

This patch adds a mapping table from virtual keycode of Android to .code value.

This patch does NOT map any printable keys in standard position because the mapping depends on selected keyboard layout. Therefore, I think that it's impossible to emulate printable key' code value with a lot of keyboard layouts.
# Android doesn't have an API to compute scancode from virtual keycode like Windows.

FYI: The spec is here:
https://dvcs.w3.org/hg/dom3events/raw-file/tip/html/DOM3-Events.html#code-virtual-keyboards

I'll ask this printable key issue to WG tomorrow if we have much time. Otherwise, I'll file a spec bug for it.

Anyway, at least for now, emulating non-printable key's code values is important because it makes I fix bug 936313 easier.

Comment 2

[Olli Pettay [:smaug][[e-mail]]]

Need to wait for some resolution for the printable keys, since it would be odd to
support only non-printables, IMO.

Comment 3

[Olli Pettay [:smaug][[e-mail]]]

Btw, could you add the spec bug url here, if there is such.

Comment 4

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

Spec bug:
https://www.w3.org/Bugs/Public/show_bug.cgi?id=25968

Comment 5

[Olli Pettay [:smaug][[e-mail]]]

Comment on attachment 8433400 [details] [diff] [review]
Patch

Clearing the review request until we have some resolution to the spec bug.

Currently the spec says "code holds a string that identifies the physical key being pressed." so that at least should be changed somehow. There isn't 
anything physical in case of a vkb.

Comment 6

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

Sorry.

Garykac said that nobody should "guess" .code value. He will update the document. Let's wait the new explanation for confirming his exact intention.

Comment 7

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

Resetting assignee which I don't work on in this several months.