Bug 264158

Summary: Support devicePixelContentBoxSize with ResizeObserver
Product: WebKit Reporter: Gregg Tavares <gman>
Component: DOMAssignee: Nobody <webkit-unassigned>
Status: RESOLVED DUPLICATE    
Severity: Normal CC: karlcow, simon.fraser, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
example showing the need for devicePixelContentBoxSize
none
rendering in safari, firefox, chrome none

Gregg Tavares
Reported 2023-11-03 07:44:10 PDT
Created attachment 468470 [details] example showing the need for devicePixelContentBoxSize It's impossible to get the correct sizes for elements in Safari because it does not support devicePixelContentBoxSize with ResizeObserver See attached example: it makes 3 elements each 33% the size of their parent Asking the sizes via ResizeObserver or via getBoundingClientRect shows all 3 elements return the exact same size but take a screenshot measure and you'll see the center element is 200 device pixels where as the left and right elements are 199 device pixels This is one of the things that devicePixelContentBoxSize is for. Finding out the actual sizes of elements for pixel perfect rendering Try it in Firefox or Chrome and they'll tell you the sizes via devicePixelContentBoxSize
Attachments
example showing the need for devicePixelContentBoxSize (1.61 KB, text/html)
2023-11-03 07:44 PDT, Gregg Tavares 		no flags
Details
rendering in safari, firefox, chrome (300.96 KB, image/png)
2023-11-20 06:04 PST, Karl Dubost 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Radar WebKit Bug Importer
Comment 1 2023-11-10 06:45:14 PST
<rdar://problem/118233399>
Karl Dubost
Comment 2 2023-11-20 06:04:25 PST
Created attachment 468678 [details] rendering in safari, firefox, chrome devicePixelContentBoxSize.inlineSize is undefined in Safari.
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