onIdle fired immediately on window resize

[Retro-Bo]

I'm using onIdle to refetch map data. It works great! Except when resizing the browser window. As the user drags the window to change size onIdle constantly fires. There is no idle period where it will wait for the resizing to stop.

What is the typical approach used to address this? Manually debounce/timeout the handler? Or is this a bug with idle on the google side of things?

[usefulthink]

To me this sounds like it could be intended behaviour: the resize-event causes the tile-loader to check for tiles to load, it completes its work (or discovers there is nothing to do) and dispatches the idle event once there is nothing more to do. But you could certainly submit this as a question to the Google Maps Issue Tracker as well: https://issuetracker.google.com/issues?q=status:open%20componentid:188853&s=created_time:desc

I think in your situation I would recommend manually debouncing this or suspending loader logic until after the window resize ends.

[chama-x]

This is expected behavior from the Google Maps API perspective, but there are several patterns you can use to handle this effectively:

Root Cause

The onIdle event fires whenever the map transitions from a "busy" state (panning, zooming, etc.) to an "idle" state. During window resize, the internal map dimensions change multiple times rapidly, triggering re-renders and repositioning operations. Each resize triggers the idle event.

Recommended Solutions

1. Debounce with ResizeObserver (Most Reliable)

Use a ResizeObserver to track when the map container stops resizing, then allow onIdle to execute:

• Set a flag when resize starts
• Clear and reset a timeout on each resize event
• Only process onIdle when the flag is false
• Timeout of 200-300ms works well for most cases

2. Track Window Resize Events

Listen to window resize and suppress onIdle temporarily:

• Add a resize event listener
• Set isWindowResizing = true during resize
• Use setTimeout to reset the flag after resize completes
• Guard your onIdle handler with: if (!isWindowResizing) { /* process */ }

3. Use useCallback/useMemo for Stabilization

If your onIdle callback depends on frequently-changing props, memoize it to reduce unnecessary re-evaluations and re-triggers.

Why This Matters

The resize and idle events don't have a direct causation relationship you can suppress—the idle event genuinely fires because the map completes its internal repositioning. Debouncing ensures the resize operation finishes before your handler executes.

Performance Tips

• ResizeObserver is more precise than window resize events for individual elements
• 200-300ms debounce is typically sufficient for UX
• Consider your use case: data fetching vs. local state updates

The maintainer's suggestion is correct—debouncing is the right architectural pattern for this scenario.