whatwg / whatwg/html

A signal for when an image (img) is decoded enough to paint

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addition/proposal needs implementer interest topic: img
Dominant language
HTML
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Description

See the discussion starting at https://github.com/whatwg/html/issues/1920#issuecomment-345400388 for context.

The idea is to extend the img element with an event, overload decode() somehow, or introduce a another signal not suggested thus far that indicates when it's ready to be displayed to users. While at the same time not making it a high priority relative to painting and hitting 60 FPS and such.

I hope I summarized that correctly.

cc @dbaron @smfr @othermaciej @vmpstr @aghassemi @cramforce @chrishtr

Contributor guide

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the discussion linked in the issue, then inspect the HTML Standard’s existing img element and decode() behavior. The work is complete only when the project agrees on a concrete signal for when an image is decoded enough to paint, including its interaction with painting and 60 FPS priorities.

Written by the indexing model from the issue text.

Assessment

Tech stack
html
Domain
frontend, web-dev
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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