130085 - Scrollbar stops scrolling when mouse is moved to far horizontally

Status: VERIFIED INVALID

(SeaMonkey :: UI Design, defect)

Description

[Jan D.]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X; en-US; rv:0.9.8) Gecko/20020204
BuildID:    2002020411

If I start scrolling and then move the mouse too far to the left or right (about
3-4 centimeters), the scrollbar and page jumps back to where scrolling started!

Reproducible: Always
Steps to Reproduce:
1. Load a page that is somewhat big, for example the Bug Template page.
2. Click on the scrollbar thumb and drag it down, say half the page.
3. While keeping the mouse button down, move the mouse to the left or right.


Actual Results:  When the mouse is moved about 3-4 centimeters from the
scrollbar, the scrollbar thumb suddnely jumps to the top of the page again,
displaying the top of the page.

Expected Results:  The vertical scrollbar thumb and vertical page position
should stay the same no matter how far the mouse is moved in the horizontal
direction.

I am using the modern theme if that matters.

Comment 1

[Boris Zbarsky [:bzbarsky]]

This is correct behavior on the mac.  See the Apple interface guidelines at:
http://developer.apple.com/techpubs/mac/HIGuidelines/HIGuidelines-121.html#HEADING121-40:

  If the user starts dragging the scroll box, then moves the pointer out of the
  scroll bar, the scroll box stops following the pointer and snaps back to
  its original position. The user can move the pointer out of the scroll bar
  region by a little more than the width of the scroll box before the scroll box
  snaps back. If the user then releases the mouse button, no scrolling occurs.
  But if the user, still holding down the mouse button, moves the pointer
  back into the scroll bar, the scroll box resumes its movement in the direction
  of the pointer. This type of tracking is standard behavior for controls in
  general, such as buttons, checkboxes, and radio buttons.

If you want, you can turn this off by setting:

user_pref("slider.snapMultiplier", 0);

in your prefs.js

Comment 2

[Peter Trudelle]

verified. This behavior also matches Windows IG, p112.

Comment 3

[Jan D.]

This is strange, why would anyone want this behaviour?  Anyway, thanks for the
prefs to turn it off.

Comment 4

[Peter Trudelle]

It is useful for getting back to where you were after dragging the thumb. About
95% of computer users have this in all their apps.