v131 · miscellaneous

Document picture-in-picture: copy document mode

This makes the document picture-in-picture Document's mode (quirks mode vs no-quirks-mode) match the mode of the opener Document. Currently, the empty document is quirks mode by default, so this allows websites that rely on non-quirks mode to still function properly within a document picture-in-picture window.

concepts

  1. DocPiP Copy Mode

    Document Picture-in-Picture's copyStyleSheets / requestWindow options let the PiP window inherit the host page's styling automatically.

  2. Music player popout

    The canonical use case: clone a music-player widget into a PiP window that inherits the host page's design system via copyStyleSheets.

  3. Quirks vs no-quirks probe

    Open a PiP window and probe compatMode, default box-sizing, and resolved line-height on both documents. See the v131 fix in action.

  4. Theme-aware popout

    Three themes (cyber, editorial, minimal). The PiP card inherits whichever theme the host has selected.

why it shipped

Currently, the empty document is quirks mode by default, so this allows websites that rely on non-quirks mode to still function properly within a document picture-in-picture window.

references