v149 · DOM · Popover
Hint in Nested Panel
A settings panel (auto) contains an Advanced panel (auto) whose rows each carry a hint tooltip. Opening a hint doesn't close the settings panels. Closing the Settings panel tears down the whole ancestor chain — Advanced and any open hints close with it.
Controls how aggressively responses are stored. "aggressive" may use more memory but reduces network calls for repeat loads.
Number of background workers to spawn. Setting above CPU count can cause scheduler thrashing.
Anonymous usage metrics. Opt-out at any time. No personally-identifiable information is collected.
Why hints don't close autos
Before Chrome 149, the popover stack was shared. Opening any new popover dismissed everything above it. This broke tooltip-on-menu patterns. Chrome 149 separates hint popovers into their own dismissal lane — they open alongside auto popovers without touching them.
Why closing the parent closes hints
A hint that's open inside a dismissed auto popover would be visually orphaned. The ancestor chain rule: when an ancestor auto closes, all descendant hints that were opened from inside it close too. The popover API tracks this via the invoker → popover relationship.
see also
- Hint Dismissal Audit — event-log verification of the four rules
- Nested Tooltip Menu — the original motivating pattern
- Tooltip Playground — open auto + hint independently
implementation reference
Need the exact API surface, compatibility boundaries, errors, lifecycle, and source links? Read the matching gendn reference ↗