Re: Starting an alert sheet from an NSWindowController that owns a user-editable sheet

FROM : John Stiles
DATE : Fri Jan 18 20:15:10 2008

Seth Willits wrote:
> On Jan 17, 2008, at 9:56 AM, Jonathan Dann wrote:
>

>> ...but the HIG say that you shouldn't (and Cocoa can't) stack a sheet
>> on a sheet.

>
> Unfortunately Cocoa can.....
> http://www.sethwillits.com/temp/LeopardSheetBug.mov
>
> (I'm not sure whyyyy it does it here, but it does.)

I haven't watched your movie, but I've actually got an open bug on
NSSavePanel putting one sheet on top of another. It should not do that.
I am pretty sure that NSSavePanel has not changed, but instead the sheet
code in AppKit now allows two sheets at once. Previously, if you tried
it, the second sheet would simply not attach to the window at all; this
changed in Leopard and stacked sheets now function if you ask for them.
My suspicion is that the code always tried to stack sheets, but in 10.4
and before, the OS automatically converted the second sheet into a
regular dialog.
I honestly expect that they will update the HIG to allow stacked sheets.
(Though personally I think it is ugly and confusing.) At first they
rejected my bug as "behaves as expected" and only reopened it when I
pointed out the page and line of the HIG that says not to do it.