Weird behavior for modal stacks and answer dialogs

Giovanni johnthejocker at
Mon Sep 9 11:16:05 EDT 2019

Hi everybody, 
thanks for feedback.
I think that the ones suggested cannot be considered as a solutions nor a workarounds.
If I am working on an application with thousands (literally) of answer/ask dialogs and modal called windows I cannot review all my code to find a way to do something that the engine is called to do on its own, don’t you think?
Anyway the “lock messages” can be used with answer/ask dialog but not with modal windows that are intended to be used by the user.
Moreover as the modal stack behavior is correct on Windows and seems to be correct on latest MacOS versions I found really strange to garbage my code to workaround an issue that, in my opinion, can be classified as a bug.

During my investigation I found an interesting thing: starting QuickTime to produce a screencast the app starts working properly even without closing/restarting it. Closing QuickTime immediately reintroduce the problem. This sounds like QuickTime uses a system library that LC should use but doesn’t. Can someone give an hint about this?!

> Il giorno 09/set/2019, alle ore 13:30, Paul Dupuis via use-livecode <use-livecode at> ha scritto:
> On 9/9/2019 6:50 AM, Giovanni via use-livecode wrote:
>> Hi everybody,
>> I’m writing here to report a very strange behavior of modal stacks and answer dialogs on MacOS Yosemite and Sierra.
>> Basically the modal windows or dialogs, in these OSes simply does not work and this seems to happen since LC 6.7.x!
>> When you open a modal stack the expected behavior is that the script execution is interrupted and you cannot interact with the calling or other opened windows. While the first thing seems to happen, the second one doesn’t work: you can click on buttons, fields or any other control in the calling stack or any other stack opened.
>> I think that this is a very big problem mainly in porting applications from older versions of LC to the newest one and it’s quite strange that nobody else noticed this before or consider this a problem.
>> I already filed a bug report at <> in which you can also find a demo stack to easily reproduce the behavior.
>> Anyone can comment on this? Are you experiencing this as a problem? Is there a workaround or a solution for this?
>> The problem seems not to be present on Mojave but I was not able to try on other versions on MacOS and it’s not present on Windows.
> This one has been around for a while, and I thought it had been previously reports (but still not fixed). I seem to recall there was a lengthy discussion of it on the list a long time ago.
> The work-around seems to be locking things down before calling an ask or answer dialog (lock messages, lock your menus and so on) so that no other user actions can start any other script.
> _______________________________________________
> use-livecode mailing list
> use-livecode at
> Please visit this url to subscribe, unsubscribe and manage your subscription preferences:

More information about the use-livecode mailing list