History Graph Zoom unusable with many data points in Firefox

[bjoernmayer]

Checklist

• I have updated to the latest available Home Assistant version.
• I have cleared the cache of my browser.
• I have tried a different browser to see if it is related to my browser.
• I have tried reproducing the issue in safe mode to rule out problems with unsupported custom resources.

Describe the issue you are experiencing

With 2025.1 came the feature to zoom in history graphs.
Unfortunately, when using Firefox this feature is unsuable when the graph has many datapoints. The performance is extremly poor and freezes the whole tab with CPU at 100% constantly.

Describe the behavior you expected

Smooth zoom like in Google Chrome

Steps to reproduce the issue

1. Get Mozilla Firefox
2. Find a graph with many data points (mine was once per sec)
3. Try zooming into it
   ...

What version of Home Assistant Core has the issue?

core-2025.1.2

What was the last working version of Home Assistant Core?

core-2024.x

In which browser are you experiencing the issue?

Mozilla Firefox 134.0

Which operating system are you using to run this browser?

macOS 15.2

State of relevant entities

No response

Problem-relevant frontend configuration

No response

Javascript errors shown in your browser console/inspector

No response

Additional information

No response

[fallingcats]

I've also noticed there is a problem when zooming with my touchpad, it seems the "pixel perfect" zoom generates too many incremental zoom events and homeassistant needs to process them all in order.

Ideally it should instead combine all events that came in since the last "frame" started and combine them before calculating the next, instead of recalculating for each individual zoom event.