The findContainerStacks() will list all container stacks and lazily load them. However this lazy loading is done on the thread that's calling it. The lazy loading will create GlobalStack objects, which are QObjects. The QML code then can't access those QObjects because they are created on different threads. So now instead we'll do the find query on the main thread but all the rest on the background thread.
Contributes to issue CURA-6973.
Should be completely transparent. It'll fail the unit tests though because it now pretends that all printers have machine nodes.
Contributes to issue CURA-6793.
When switching printers, it would first emit the global container changed signal which connects to _onGlobalContainerChanged, then update stuff in the extruder manager, then manually call _onGlobalContainerChanged again to update some other stuff with the new data from the extruder manager. This was prohibitively expensive, so this prevents that.
Another double or triple emit of the activeExtruderChanged was removed in the extruder manager when creating the extruders for a printer: It would first set the extruder number to 0, possibly emitting the signal, then emit the signal just to be sure since the extruder itself changed (rather than just the number), and then change the extruder number to the preferred extruder, possibly again emitting a signal. Now it just sets the extruder number to the preferred extruder and always emits the signal once (either through setting the extruder number or manually afterwards).
Contributes to issue CURA-6793.
The extruders are added when changing printers anyway, and we call this change signal upon start-up. So one of them is going to do unnecessary work.
Contributes to issue CURA-6793.
Ultimaker's marketing department is not able to explain why users would want to print more accurately, apparently, so we need to remove these.
Contributes to issue CURA-6864.
Apart form it being way to agressive (and thus, slowing things down), it
also caused a re-slice to be done when a printer was connected with another printer.
If the diameter doesn't match up, then the print fails. If the preference is not held up, then it chooses some random material and the user will understand what it chose.
Done during Turbo Testing and Tooling because a test was failing.
