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FF/browser/Macbook has very low-freq mousemove events compared to FF/Android/Galaxy.S3 and Chrome/Safari/same 2012 Macbook Pro.

  • 10 replies
  • 1 has this problem
  • 9 views
  • Last reply by phobrain

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I have an app where the user draws on the screen, with mouse in the browser:

   document.addEventListener('mousemove', handleMouseMove, false);

However mousemove events seem to come in little bursts, so if I'm waving the mouse around, you can't see enough line to trace the path, just bits of line and dots all over the place. I see the same frequency when I just log the event, and when handling, the time is at worst 2 [Date()-Date()].

FF/Android draws nice lines of dots, as do Chrome and Safari on the Mac. FF is fine on Ubuntu 16.04 on desktop.

Seems like a bug? Should at least be configgable.

Also 'Upload images' just spins on uploading. I'm inclined to just list FF as unsupported on Mac.

I have an app where the user draws on the screen, with mouse in the browser: document.addEventListener('mousemove', handleMouseMove, false); However mousemove events seem to come in little bursts, so if I'm waving the mouse around, you can't see enough line to trace the path, just bits of line and dots all over the place. I see the same frequency when I just log the event, and when handling, the time is at worst 2 [Date()-Date()]. FF/Android draws nice lines of dots, as do Chrome and Safari on the Mac. FF is fine on Ubuntu 16.04 on desktop. Seems like a bug? Should at least be configgable. Also 'Upload images' just spins on uploading. I'm inclined to just list FF as unsupported on Mac.

Chosen solution

Go to about:config and set dom.event.coalesce_mouse_move = false.

Restart the browser.

Check if it helps.

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All Replies (10)

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This sounds more like mouse or security software caused problem and not Browser related. There is no AFAIK line tracing on the Browser in default installs.

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> Also 'Upload images' just spins on uploading.

That's 'Add images: Browse' in the Question/bug form.

Hah, it works here. Safari, then FF versions shown, same hand dynamics.

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WestEnd said

This sounds more like mouse or security software caused problem and not Browser related. There is no AFAIK line tracing on the Browser in default installs.

Mouse works fine with all other progs on machine. If security, personal-use Chrome with a bunch of security add-ons doesn't show it, and the FF install is vanilla for dev purposes, tried switching personal use once but never worked, tho it's my browser on Ubuntu.

What does line tracing have to do with it? Did you see the pics?

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I thought that surely FF, with the 7 threads I've granted it, must be very busy not to notice my puny actions, and found the Performance profiler. Turns out that Idle has 98%, see pic.

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On Android/Galaxy.S3, FF generates events like the others, tho the rendering lags.

In this case, maybe a single (priority?) number for mouse movement tracking isn't right for the MacOS mouse.

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Chosen Solution

Go to about:config and set dom.event.coalesce_mouse_move = false.

Restart the browser.

Check if it helps.

Modified by TyDraniu

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Solved, thanks! I think it needs to be more exposed, since searching didn't turn up anything. Maybe this issue will be enough.

> dom.event.coalesce_mouse_move = false

On the upload issue, best to convert .png screenshots to .jpg before unloading: worth mentioning next to the 'upload pic' button.

Photo: hidden fort of the mind to go with the config. :-)

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I also question whether the setting has any value. I'd be inclined to make it an adaptive behavior. The var and the touch equiv are true on my old Android OS, but doesn't cause unusable tracking.

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The problem recurs with 65.0 (64-bit). Setting remains, but original behavior is seen; also tried resetting/restarting.

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I have the app online now, so you can see it happen:

http://phobrain.com/pr/home/vvmeetup.html