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Scroll bar, as designed, creates an undesired response lag.

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  • 2 have this problem
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  • Last reply by guigs

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Observation I'm unsure if accurate, but I've experienced firsthand:

    • It appears that the slider component of the scroll bar does not create/send "OnDrag" info until the cursor passes the midpoint of the slider. Thus, if I'm interested in scrolling down, for example, and I attempt to drag the control down, it won't respond until I'm half way down the component.**

This obviously means that my page won't start scrolling initially, and then it will jump, rather than smoothly scrolling.

In other tests I've done, I haven't seen the delay. For example, on a page that does not require a lot of scrolling, the slider is larger, and it seems responsive from the initial click point --- not just after the 50% point is hit. Because my tests are not displaying the same behavior, I may be off base... However...

I have produced an MP4 of me slowly dragging the slider up and down a longer page, and periodically I'll be able to have the mouse pointer leave the slider (even though I'm still in a MouseDown state), and later the slider will catch-up to the pointer. I can e-mail the file to you, if you want it.

There is additionally a lag in typing this post. As a test, I typed in the alphabet, and each character displayed instantaneously. But after a little while, about 10 characters buffered, and then all spilled out simultaneously. I wondered if it was my system, so I tried the test in Notepad, and it was fully responsive to each keystroke. (In typing the last sentence, the phrase "wondered if it was my system" all got buffered and sent to my textbox simultaneously.)

Clearly, if there's an issue with typing text, it'll likely spill over to the responsiveness of other controls. Maybe the scrollbar and textboxes are fine, but there's a bigger issue hitting FireFox internally?

Observation I'm unsure if accurate, but I've experienced firsthand: **It appears that the slider component of the scroll bar does not create/send "OnDrag" info until the cursor passes the midpoint of the slider. Thus, if I'm interested in scrolling down, for example, and I attempt to drag the control down, it won't respond until I'm half way down the component.** This obviously means that my page won't start scrolling initially, and then it will jump, rather than smoothly scrolling. In other tests I've done, I haven't seen the delay. For example, on a page that does not require a lot of scrolling, the slider is larger, and it seems responsive from the initial click point --- not just after the 50% point is hit. Because my tests are not displaying the same behavior, I may be off base... However... I have produced an MP4 of me slowly dragging the slider up and down a longer page, and periodically I'll be able to have the mouse pointer leave the slider (even though I'm still in a MouseDown state), and later the slider will catch-up to the pointer. I can e-mail the file to you, if you want it. There is additionally a lag in typing this post. As a test, I typed in the alphabet, and each character displayed instantaneously. But after a little while, about 10 characters buffered, and then all spilled out simultaneously. I wondered if it was my system, so I tried the test in Notepad, and it was fully responsive to each keystroke. (In typing the last sentence, the phrase "wondered if it was my system" all got buffered and sent to my textbox simultaneously.) Clearly, if there's an issue with typing text, it'll likely spill over to the responsiveness of other controls. Maybe the scrollbar and textboxes are fine, but there's a bigger issue hitting FireFox internally?

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A number of items from your profile can be affecting this.

Try Firefox Safe Mode to see if the problem goes away. Firefox Safe Mode is a troubleshooting mode that turns off some settings, disables most add-ons (extensions and themes).

If Firefox is open, you can restart in Firefox Safe Mode from the Help menu:

  • In Firefox 29.0 and above, click the menu button New Fx Menu, click Help Help-29 and select Restart with Add-ons Disabled.
  • In previous Firefox versions, click on the Firefox button at the top left of the Firefox window and click on Help (or click on Help in the Menu bar, if you don't have a Firefox button) then click on Restart with Add-ons Disabled.

If Firefox is not running, you can start Firefox in Safe Mode as follows:

  • On Windows: Hold the Shift key when you open the Firefox desktop or Start menu shortcut.
  • On Mac: Hold the option key while starting Firefox.
  • On Linux: Quit Firefox, go to your Terminal and run firefox -safe-mode
    (you may need to specify the Firefox installation path e.g. /usr/lib/firefox)

When the Firefox Safe Mode window appears, select "Start in Safe Mode".
Safe Mode Fx 15 - Win

If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, and you need to figure out which one. Please follow the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause.

To exit Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.

When you figure out what's causing your issues, please let us know. It might help others with the same problem.