Weird bug regarding UIpanel visibility

I am encountering a weird bug regarding a UIpanel disappearing off the face of the earth.

the bug occurs in matlab 2022a but not in 2021b, although the application is the same one.

It occurs after I change the parent of the UIPanel from a tab in my application to a uifigure. afterwards the panel is invisible no matter what I do, even if I change the parent back to the original tab.

• the properties "Visible" and "Enable" are both set to "On".
• the position is correctly defined
• if I copy the panel (a=p.copy), and then set the copy's parent to be the same figure, the copy is not invisible.

would be thankfull for any assistance

Nathan

Answer 1

[Andreas Goser]

This issue was brought to attention of Technical Support by two users and confirmed as a bug. I recommend checking out the R2022b PreRelease that is soon to come out.

Answer 2

[Kevin Holly]

I made the following app in R2022a (see attached). I could not replicate the problem. There could have been a possible issue with position, but you said that you correctly defined the position. Did you place the uipanel on a uifigure in another window?

[Nathan Blanc]

Thank you for your answer Kevin.

the problem is a bit difficult to replicate. It doesn't always occur. I created a video showing exactly how to replicate it

https://drive.google.com/file/d/1PXosqhRQ9JvDPnuZBhtg6rsv-iNqWgqn/view?usp=sharing

here you can find both the app installation file and the video.

you can also see me investigating the panel using the debugger. i check there that the panel is visible, enabled, correctly positioned etc. I also create a copy of it and change the parent to the same figure, you can see the copied panel is visible

many thanks again

nathan

[Kevin Holly]

I messed around with the app you sent. It seems the error occurs when the component is created while being placed in the Sand Box. Sand Box -> New_system the uipanel disappears. New_system -> Sand Box, uipanel reappears. If created when first placed in New_system, the uipanel is present. Iteratively moving between New_system and Sand Box does not cause uipanel to disappear. Is the code different when creating the uipanel in Sand Box versus New_system?

[Nathan Blanc]

Thanks again kevin. Your description is largley accurate, although it is not always exactly like that. (see in the video, it sometimes behaves as you described and sometimes differently.)

regarding your question, A component created in the sandbox and moved to the system should be identical in every aspect to a component created directly in the system. I cannot be a hundrend percent sure that this is indeed the case but i did go over all the uipanel properties (including the hidden ones) and compare. I couldnt find a single difference.

Nathan