Bug 226175 – Add modal dialog UA styles

• Component: CSS
• Status: RESOLVED FIXED

[Tim Nguyen (:ntim)]

Bug 226169 adds the non-modal dialog element UA styles, but the modal dialog styles are different:

https://html.spec.whatwg.org/#flow-content-3

"""
The dialog element, when its is modal flag is true, is expected to act as if it had a user-agent-level style sheet rule setting the following properties:

'position' property to 'fixed'
'overflow' property to 'auto'
'inset-block-start' property to '0'
'inset-block-end' property to '0'
'max-width' property to 'calc(100% - 6px - 2em)'
'max-height' property to 'calc(100% - 6px - 2em)'
"""

This needs an internal pseudo selector like ::-internal-modal-dialog to be able to apply those styles from the UA stylesheet.

[Radar WebKit Bug Importer]

<rdar://problem/78687090>

[Tim Nguyen (:ntim)]

Created attachment 432582 [details]
Patch

[Tim Nguyen (:ntim)]

Created attachment 432591 [details]
Patch

[Simon Fraser (smfr)]

Comment on attachment 432591 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=432591&action=review

> Source/WebCore/css/dialog.css:25
> +    max-width: calc(100% - 6px - 2em);
> +    max-height: calc(100% - 6px - 2em);

Where did these come from?

[Tim Nguyen (:ntim)]

Created attachment 432605 [details]
Patch

[Tim Nguyen (:ntim)]

(In reply to Simon Fraser (smfr) from comment #4)
> Comment on attachment 432591 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=432591&action=review
> 
> > Source/WebCore/css/dialog.css:25
> > +    max-width: calc(100% - 6px - 2em);
> > +    max-height: calc(100% - 6px - 2em);
> 
> Where did these come from?

As wonky as they are, they are actually from the spec, see comment 0.

[Tim Nguyen (:ntim)]

Committed r279414 (239279@main): <https://commits.webkit.org/239279@main>