Grasshopper Behaviour when Hiden. Does it change?

Hi everyone,

I have been using for a while some scripts with HUMAN UI interface set to “always on top” that where used when GH canvas was hiden.

I have noticed that recently the human UI controls have been stop working when grasshopper panel is “hiden” not minimized, but “hiden” or closed (like when pushing the “x” button in the top right corner with the window)

I’m pretty sure this was not the behavior in the past. Is this by design? is it new? If so, is there any possibility to recover the old behavior (gh responsive even when “closed”). It was handy to me in some scenarios.

It is certainly not a big problem, but I liked more the old way (?)

Alternatively, how could I programmatically minimize the gh canvas? I was using the “-Grasshopper Window Hide _Enter”, to hide the GH canvas to the user, but as mentioned “hiding” is not viable anymore…


Hi @wim , my hipothesis is that this is not related to human UI but to a different GH behavior implemented in some recent version of Rhino. I would like to confirm from Rhino developers that this change does actually happen (or not) in recent WIP/BETA versions. Changing the topic to humanUI is probably taking apart the attention of Rhino developers… Would you be kind enough to restore the topic keywords to Serengeti? Thanks

This has always been the case as far as I know. If you “hide” Grasshopper by closing it with the X, it essentially makes all documents inactive and they will not execute. Now HumanUI will continue to be “operable”, in that you can slide sliders back and forth and such, but the Grasshopper script will not be responding to the changes in HumanUI while Grasshopper is closed. Has always been this way in my experience.


P.S. You can use this for programmatic minimize:

Grasshopper.Instances.DocumentEditor.WindowState = FormWindowState.Minimized;


uhm, that strange. I’m would say I have used my script in the past without problems “hidding” gh canvas. Well, maybe i’m forgetting something and i’m wrong in my assumption. thanks @marcsyp

Edit: maybe previously the macro “-Grasshopper Window Hide _Enter” was minimizing the canvas instead of closing it? boh… your miniminazation code will serve anyways. Thanks!

Hi -

Just to answer this one…
There have been a lot of changes between GH on Rhino 6 and GH on Rhino 7 and these changes have not been documented. It would be close to impossible for us to know what a 3rd party plug-in is using that has been changed. If something has changed, the author of that 3rd party plug-in would be in the best position to tell us about it.

of course @wim ! let me clarify that my hypothesis was that something changed between wip versions (from one week to the other), not between Rhino 6 and Rhino 7, and that the change was related to GH behavior (3rd party independent)

Anyway, my problem is solved (and certainly because you pointed it to Marc Syp) so thank you both!

Following Marc Syp idea, I found that instead of minimizing I can access to to visibility property and set it to False. This is has apparently the same effect of using the X button (no GH presence, even the minimized bar…) but still GH is responsive.

gh.Instances.DocumentEditor.Visible = False

to set it back to True, its enough to launch “Grasshopper” at commandline

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