147806 - Drop down part of popup menus displayed in the wrong place when in nested scrollable views

Status: NEW

(Core :: XUL, defect, P2)

Description

[Mark Kobine]

If you have a popup menu in nested (2 or more) scrollable views the drop down 
part will display in the wrong place if any of the outer most views are 
scrolled.

This problem does not occur if the popup menu is within a single scrollable 
view i.e. non-nested views. The problem does not occur if only the innermost 
view is scrolled and none of the outer ones are.

What appears to be happening is that if any of the outer views are scrolled 
then these are ignored when calculating the position of the drop down.

Comment 1

[Mark Kobine]

Attachment: XUL file that demonstrates the problem. Needs test.css

Use test.xul in conjunction with test.css to reproduce the problem.

Comment 2

[Mark Kobine]

Attachment: CSS file to accompany test.xul

Use this in conjunction with test.xul to reproduce the problem.

Comment 3

[Mark Kobine]

Attachment: Patch that fixes the problem.

This patch does appear to fix the problem but I'm unsure that it's 100% kosher
as I don't fully understand what's going on.

Comment 4

[GavinS]

Dup of one (or many) of:

bug#53318
bug#64902
bug#67661
bug#86909
bug#129782

??

Comment 5

[Chris Petersen]

Changing priority to P2.

Comment 6

[Kevin McCluskey (gone)]

-> XPTOOLKIT-XUL

Comment 7

[James Turner]

Attachment: Updated patch that applies against the trunk

Here's an updated version of the patch, could this get some r/sr love please?
If it's band-aid that shouldn't be applied or WONTFIX, could someone give us
some feedback as to why?

Comment 8

[Jan Varga [:janv]]

interesting

Comment 9

[Jan Varga [:janv]]

Comment on attachment 107012 [details] [diff] [review]
Updated patch that applies against the trunk

looks good too
r=varga

Comment 10

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

I think this should be folded into the equivalent loop in GetViewOffset, since
this is the only place GetViewOffset is called and GetViewOffset seems to be
logical place to do all this.

In fact I don't understand the comments in GetViewOffset. I think you should be
able to just run up the views and add in each view's position. I don't see why
we need to check bounds.y >= 0 etc etc. We should just add in the offset for
every view.

Also, instead of calling GetBounds you should call GetPosition. Bounds.x is not
always position.x (sometimes views have stuff spilling out to their left or top
of their actual position!!).

Comment 11

[Ian Nartowicz]

I see something similar to this very old bug.  With a scrollable PlacesToolbar element, bookmark folder dropdowns can appear where the unscrolled anchor button would have been, even though the button is actually scrolled to somewhere else.  The menupopup appears to be positioned using boxObject.x and boxObject,y of the button when screenx and screeny would be more correct.