Oh these are both super useful to know about! They didn't come up in my searches. Thanks. I could probably make either one work for my case. I'll probably try out pdcontrol in order to stay vanilla.

If anyone is curious, what I specifically want to do is to avoid writing to a table unless the window is open. I know the actual graphical table doesn't update if the subpatch is closed, but I want to save some cpu usage by actually not writing to it unless it's open.

I know you can send messages to a canvas to create objects, move things, make connections, etc.

Is there conversely a way to receive messages from a canvas? For example, can you get a message when an object is created or moved?

The use case I am specifically after right now is to create a conditional that checks if a subpatch is open or not. I can send vis 1 to the subpatch to open the window, but can I receive a vis 1 or vis 0 (or some other equivalent notification) when the window is opened or closed by other means?

Thanks for looking into that and clarifying @jancsika. And thank you @porres for pointing out the [list store] option.

@Jona Strange. I am using extended libraries, but in the list help-patch meta info, it says it's the version by Miller Puckette, so I assumed that it was the vanilla list.

However, I just went and checked the version in the vanilla git repo and it indeed does not accept a cat argument.

Apologies to @porres. I now realize you probably know what list is and you were just confused because I was using an argument that's not in vanilla.

I guess in the version I have, someone altered list and didn't update the meta info. I'll just avoid the cat argument I guess.

Also, if you could try making a [list cat] object, add a few elements, then clear it, then try to add more again, and let me know if it crashes, that would be helpful. I want to know if it's just me or if there's a bug.

@porres [list] is a fundamental data structure in PD for storing, well, lists. It's very useful for gathering and storing messages into a single message of various elements. "cat" is a creation argument that defines its behavior so that it accumulates messages that are sent to it. There are other creation arguments too that define different behavior.

If you haven't already, I suggest checking out the help-patch for list, it's really helpful. I didn't use it that much until recently but it's a game changer. It's also pretty indispensable for my current project.

When I send "clear" into the right inlet of [list cat], and then try to re-populate the list by sending something into the left inlet, pure data crashes.

Does this happen to anyone else?

@solipp Thanks for looking at this for me.

The fact that you're not getting drop outs helps narrow it down to something other than pd. It must be something else on my computer,

Good point about the envelope switching. That was just a quick thing I cobbled together by copying and pasting some stuff from another patch. I'll optimize that later.

I've now replaced arraycopy with a vanilla friendly array copier. It's better to do that anyway if I plan to give this to other people.

I've also added radio buttons in place of the dropdowns for vanilla compatibility.

Other than that I have no idea why things that are connected would not connect for you. If you could check if this works, I would appreciate it: pulsar.pd

@solipp I see what you mean. That's very strange. It doesn’t do that when I download it. Thank you for pointing this out. I'll figure out what's going on and re-upload a new patch.