180502 - By changing "zIndex" image is unvisible (..and "lost") - Only in Mozilla 1.2

Status: RESOLVED FIXED

(Core :: Web Painting, defect)

Description

[Peter Grabner]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.3a) Gecko/20021115
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.3a) Gecko/20021115

Until Mozila 1.2 the tabs were working fine.

2 Tabs are managed by changing the zIndex. The front tab got zIndex=1.
The background tab got the zIndex=0.

In Mozilla 1.2 the tab that got zIndex=0 is not visible any more ("lost").

I found out to fix it by using zIndex=1 and zIndex=2 (instead of 0 and 1).
But before Mozilla 1.2 it was working whitout that.
(Also in all other browsers  Mozill0.8-1.1, IE4-6, NS4-4.78)
On this site I have'nt done the possible "fix". - You can see the Problem.

(If you wonder, why the unvisible tab on the right side is clickable, - this is
another transparent gif to solve an IE4.0 Problem.)

Reproducible: Always

Steps to Reproduce:
1.http://www.mei-toys.de/psl/
2.click "Katalog"
3.There should be 2 tabs visible, and clickable (a little bit overlapping -
changing from back to frontside).
Actual Results:  
Only one tab is visible

Expected Results:  
There should be 2 tabs visible, and clickable (a little bit overlapping -
changing from back to frontside).

Comment 1

[Boris Zbarsky [:bzbarsky]]

Views.  Seeing this on Linux too.

Comment 2

[Jaffar]

Also on 1.3 nightly build 20021130 /win.

Comment 3

[Robert O'Callahan (:roc) (email my personal email if necessary)]

I really need a reduced testcase here, this page is really complicated.

Comment 4

[Peter Grabner]

I have build a showcase, you would like to have,
and it is getting clearer.

You can find it at:
http://www.pslx.de/testcase/index.html

Two tabs are defined over a picture.
Normally you should see both tabs.
But after clicking the one who gets "z-index:0" is lost/covered,
by an EARLIER defined picture with the same z-index.

If you use zindex 1 and 2 (in the javascript-file)(instead of 0 and 1) for
"reiter1" and "reiter2",
there will be no problem.
(Also, if you move the position of the picture)

**************************************************
But in earlier mozilla versions and other browsers,
the later defined object covers the earlier defined,
if they have the same z-index.

In the newer mozilla version (1.2) it is the same,
until you change z-index.
The visual order of objects with the same z-index is lost.
*****************************************************

Comment 5

[Robert O'Callahan (:roc) (email my personal email if necessary)]

That looks much better ... it would help a lot if you could get rid of the use
of frames, though.

Comment 6

[Peter Grabner]

I have now removed frames and further reduced some content and functions.
You get at:   http://www.pslx.de/testcase/index.html

index.html
(pslf-index.html before)

psljs_m.js
(Javascript-file)

3 Image-files

Comment 7

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Looks great! I will investigate.

Comment 8

[Peter Grabner]

I think that I had not transferred the last changes of the testfiles.
If you have downloaded, please do it again.

Comment 9

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Attachment: really reduced testcase

Comment 10

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Peter, see how I've reduced the testcase a lot more. Making it as simple as
possible is very important.

Comment 11

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Attachment: fix

The problem is that changing the z-index is causing us to lose the position of
the view in document order. Now that z-index is fully handled by sorting, we
don't really need to reorder the views. So let's stop doing that.

We probably should continue to try to reorder widgets, for maximum performance
and also correctness when plugins are present (although for plugins it's only
partial correctness because setting the widget z-index (which is what we do
today) is only approximately correct). So we unconditionally set the widget
z-index and hope.

Comment 12

[Kevin McCluskey (gone)]

Comment on attachment 112368 [details] [diff] [review]
fix

r=[e-mail]

Comment 13

[Robert O'Callahan (:roc) (email my personal email if necessary)]

*** Bug 183380 has been marked as a duplicate of this bug. ***

Comment 14

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Fix checked in.

Comment 15

[Robert O'Callahan (:roc) (email my personal email if necessary)]

I checked in a patch to nsContainerFrame saying it was for this bug, but it was
actually for bug 190193