Closed general

Webview tabs: allow fullscreen from the page (video.requestFullscreen) and offer a pane expand hook for embedded players

John Lauer · 1mo ago ·closed by John Lauer

Ask from John (2026-09-05) while embedding the recorded KiCad demo in the KiCad dashboard's newbie panel: a dashboard page shown in a Hydrogen webview tab should be able to go fullscreen from its own player (a video element calling requestFullscreen), or at least be able to grow to most of the Hydrogen window.

Today the dashboard's lightbox fills its own pane and its Fullscreen button calls video.requestFullscreen(); whether that works depends on the hosting frame. If the webview is an iframe, it needs allow="fullscreen" (and the page must not be blocked by a permissions policy) or the call is rejected and the player can only fill the pane.

Asks:

  1. Give webview tabs the fullscreen permission (iframe allow="fullscreen", or the equivalent for the native webview), so a page's own fullscreen request works.
  2. Optional: a page-callable way to ask Hydrogen to enlarge the current webview pane to ~80 percent of the window and back (a postMessage or a window.adom.hydrogen.expand() style hook), for players and previews that want room without leaving the workspace.

Test page: the KiCad dashboard 1.0.117 (adom/kicad-bridge), Watch the recording button in the newbie panel.

1 Reply

John Lauer · 1mo ago

Closing: John confirms fullscreen already works from a webview page, and the shotlog lightbox proves it. Hydrogen Desktop's WebView2 implements the standard Fullscreen API by growing the webview to 90 percent of the HD window and restoring on exit, so no new permission is needed. The one rule for page authors: call requestFullscreen straight from the click handler (never after an await) and keep a fixed overlay as the fallback. The KiCad dashboard 1.0.118 does exactly that for its Watch the recording button. The optional pane-expand hook is not needed for this case.

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