1422711 - Autocomplete inline hint in jsterm can't handle wide character

Status: RESOLVED WORKSFORME

(DevTools :: Console, defect, P3)

Description

[nanaya]

Attachment: mstsc_2017-12-04_19-44-25.png

User Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0
Build ID: 20171128222554

Steps to reproduce:

- open dev tool
- type "テスト"
- type .l to show autocomplete list


Actual results:

- inline hint incorrectly aligned


Expected results:

- inline hint properly aligned

Comment 1

[nanaya]

Looking again the box is misaligned as well. Probably the box and inline hint both use same alignment?

Comment 2

[Brian Grinstead [:bgrins]]

I'm guessing this is due to a cached constant character width:

- https://dxr.mozilla.org/mozilla-central/rev/5be384bcf00191f97d32b4ac3ecd1b85ec7b18e1/devtools/client/webconsole/jsterm.js#1732-1750
- https://dxr.mozilla.org/mozilla-central/rev/5be384bcf00191f97d32b4ac3ecd1b85ec7b18e1//devtools/client/webconsole/jsterm.js#1626-1627

Comment 3

[Brian Grinstead [:bgrins]]

Rather than using (constant width * number of characters) we should look into measuring the exact text. I assume it was originally cached because of performance so we'll have to be mindful of that, but it doesn't seem like it should be too slow.

Comment 4

[nanaya]

Attachment: firefox_2017-12-06_02-24-05.png

That made me thinking how about the other way (0-width characters). And yeah, just as guessed.

String: "ȳ̳ TH̘Ë͖́̉ ͠P̯͍̭O̚​"

(taken from html regexp stackoverflow post)

I guess this applies to any characters that has different width even on "fixed width" font.

Comment 5

[Nicolas Chevobbe [:nchevobbe]]

This looks like it will be resolved by Bug 1473805.

Comment 6

[Nicolas Chevobbe [:nchevobbe]]

The STR from Comment 0 and Comment 4 looks fine to me on 64.