110995 - listboxes always generate onchange event

Status: RESOLVED FIXED

(Core :: Layout: Form Controls, defect, P1)

Description

[rods (gone)]

If you click on the same selected item it generates an onchange event OR if you 
are arrowing up or down in the list and hit the end it generates an obchange 
event each time you try to go off the end of the list.

Basically, if the index has changed you shouldn't generate the onchange event 
and you are.

Right now I have a simple patch for Comboboxes in Bug 110800, if you fix this in 
ListBoxFrame and that negates the fix for Bug 110800, let me know so I don't 
have to check it in.

Comment 1

[John Keiser (jkeiser)]

I thought it was odd, but I was copying existing behavior (at least with
clicking on the currently selected item).  The Oct. 29 build, for example
(pre-checkin), shows this behavior.

Are you sure this is how it should be?  I can easily change it.

Comment 2

[John Keiser (jkeiser)]

I'm not seeing the "scroll off the end of the list" problem you're describing,
on comboboxes at least--in fact, there is a separate problem there, the onChange
event is not firing at *all* when you (a) click on the combobox, (b) change the
selection with the arrow key, (c) click somewhere else (probably happens w/tab
too).  (This was happening pre-checkin also.)

Comment 3

[John Keiser (jkeiser)]

Ah, I am seeing it now--I was only looking at the listbox that was being dropped
down.  I will look at this issue tonight, it probably requires both our fixes
but I am not yet sure.  The other firing issue is not an issue now that I think
about it.  It's expected behavior.

Comment 4

[John Keiser (jkeiser)]

Attachment: Listbox Testcase

Comment 5

[John Keiser (jkeiser)]

I see the other one too, regressed on listbox.

Should comboboxes exhibit the same behavior? (i.e. if they don't change the
value onChange doesn't fire?)

Comment 6

[rods (gone)]

I have been doing my testing with 6.2 and the trunk. 

Let me summerize:

For the combobox once it is dropped down, if you arrow down and click off or tab 
it SHOULD do the onchange, this did work at one point (I spent a lot of time 
going thru all the cases) but I see it is broken in 6.2 for some reason.

Then for the listbox, if you click on the zero item and press the up arrow, you 
should not get an onchange and at the moment we do, this was working correctly 
in 6.2. The lisbox should be the easiest, basically if the index changes the 
onchange should fire.

The combobox is harder because it need to remember the selected index before it 
dropped down in case it is cancelled by the <esc> key etc.

I'll try to find my old bug that had all the cases to check it would be helpful.

Comment 7

[rods (gone)]

Comments from an old bug that covers most all the cases:
http://bugzilla.mozilla.org/show_bug.cgi?id=62753#c10

Comment 8

[John Keiser (jkeiser)]

Patch in bug 113866 fixes this and causes no known regressions.  Too big for
0.9.7.  Testers wanted.

Comment 9

[John Keiser (jkeiser)]

Fix in bug 112241, ready for review, fixes this too.

Comment 10

[John Keiser (jkeiser)]

Fixed with bug 112241.