the defaultStack changes on resume

Mark Waddingham mark at
Thu Aug 10 13:32:07 EDT 2017

On 2017-08-09 20:48, Trevor DeVore via use-livecode wrote:
> I think this bug report has a recipe for the issue you are seeing:
> This has been around for a long time. I don’t know of a workaround 
> other
> than fully qualifying all object references.

Unfortunately that is a separate issue.

The reason you get that error is because at present the popup button 
command requires there to be a mouseStack. So if you cmd-tab away from 
the app whilst your mouse is over some stack, and cmd-tab back in - it 
will work; if you do not have your mouse over any stack, and do the same 
you will get the error.

In fact, you get the same error if you press the shortcut combination 
without the mouse over a stack.

I guess the 'popup' command was always intended to be run in response to 
a mouse-click - both the ExecPopup function and the 'openmenu()' 
function in MCButton have a guard against doing anything if the 
mouseStack is empty.

The requirement for a mouseStack seems to be somewhat deeply tied into 
the menu code so this could be a little tricky to untangle. (It 
certainly seems to be part of the mouse tracking behavior menus need on 
Windows and Linux).

So a simple explanation, but not a clear or easy solution.

Warmest Regards,


Mark Waddingham ~ mark at ~
LiveCode: Everyone can create apps

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