296446 - mousemove events on a position:fixed element causes bad screen/client/page-X/Y coordinates

Status: VERIFIED WORKSFORME

(Firefox :: Shell Integration, defect)

Description

[Percy]

User-Agent:       Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.7.8) Gecko/20050511 Firefox/1.0.4
Build Identifier: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.7.8) Gecko/20050511 Firefox/1.0.4

I am using a script to move a toolbar type thing around the page so that a user
can move it out of the way, etc.  Originally I was using position: absolute, and
everything worked fine.  However, I decided that position: fixed would be a
better alternative to absolute because then the toolbar would remain in the same
position during scrolling.  After changing this, the toolbar would still drag,
but on Mac, it would move around a little "floppy"-ish.  It still follows the
general movement of the mouse, but it will at times move around quite a bit
relative to the mouse...

Reproducible: Always

Steps to Reproduce:
1. Create a simple div or whatever that will have draggable content
2. Make sure that the div has position: fixed
3. Drag the div around
4. Change position to absolute
5. Drag div around

Actual Results:  
The div moves strangely when position = fixed but moves as expected when
position = absolute.

Expected Results:  
Both fixed and absolute would move in the same manner.

I will upload a small sample HTML file that reproduces this problem.  I did not
personally test this on Windows, but a coworker did and he said it works as
expected on Windows with both fixed and absolute.

Comment 1

[Percy]

Attachment: Sample HTML File

Comment 2

[Percy]

Attachment: Sample "Straight" line

This is a screen shot of one "straight" line that I dragged the div along. 
This is not nearly the worst I've seen, but it was the easiest one that I was
able to capture.  The actual line the mouse followed was down the center of
those dots, not in the random locations found around the general flow of the
line.  The same friend that tested this on his Windows Firefox machine also
tested it on his iMac G5 and he had the same problem as me.

Comment 3

[Percy]

Comment on attachment 185202 [details]
Sample HTML File

I forgot to write a comment about the attached HTML.  In the script I also made
it add some "tracking" ability so that you can see where the mouse coordinates
apparently were.  You should notice quite quickly that the red "tracking dots"
are often quite far off where the mouse actually ever was...

Comment 4

[José Jeria]

Please retest with deer park (firefox 1.1 alpha) and see if its still an issue
http://www.mozilla.org/projects/firefox/

Firefox 1.0.x uses gecko 1.7 which is more than one year old

Comment 5

[Percy]

Cool... Works like a charm!  I wasn't actually aware of Deer Park (silly me)...

Thanks a lot.