Cut down accidentally opening Cura multiple times with a question dialog

Is your feature request related to a problem?

I'm always frustrated when opening a .stl file, as I know I have to sit through the entire startup process of Cura. What I think is a major waste is that in most cases I already have Cura open and with my 0 understanding of the software architecture and load process I assume there must be at least some corners that could be cut in that case?

Describe the solution you'd like

What if when you open a .stl file, it checks if there is already an instance of Cura running (and fully loaded). Then if that is the case; send that process a message with the new file to open. At that point Cura can offer to 1) add the model to the object list, or 2) replace the object list with just that model or 3) open the model in a new Cura.

This will cut out the waiting for Cura to load when the user accidentally opened Cura through the file association.

If at some point multiple app windows could be manage from a single application process, then the entire plugin loading across the processes could be unified into a single load phase. But adding this (which would functionally be identical to adding tabs like a browser or IDE has), would probably require changes to how plugins load.

That would be a more major modification, the dialog is simpler to implement and can cut out user frustration without having to overhaul the application architecture.

Describe alternatives you've considered

N/A

Affected users and/or printers

Users that prefer to open models through file-associations

Additional information & file uploads

N/A

There's an existing option about half-way down the preferences listed as Open a single instance of Cura. It's obviously not a dialogue box, but it does give the user an option as to whether they want more than one Cura to open automatically or to have everything contained within a single instance without necessarily getting in the way as much as a dialogue box would.

Historically there have been issues with dialogue boxes like that. Due to the potential intrusiveness there's a setting in all such current ones with wording along the lines of "Remember my choice" which then invariably leads to feature requests that a dialogue should be added by people who've long since forgotten that they've used that toggle.

Ultimaker / Cura