Fix for slow file opening

[gtollini]

Description

• fixes Unable to open any .stl files at all. #16249
• fixes Very slow to startup as Cura tries to create lots of serial connections #18968
• fixes No model loading on Ubuntu 24.04 #19104
• fixes Really Very Slow import of .stl files #19139
• fixes "STL/OBJ file loading takes too long on Linux" Affected: 5.3.0 to 5.7.2 #19186

After looking at my logs (pretty much identical to this), I decided to take a deeper look into the code. As it turns out, 32 tty ports were being tested, 4 at a time, with 15s timeout, twice each. This would give me an expected wait of 32 * 15 * 2 / 4 = 240s of wait, or about 4 minutes. My logs actually match this expected time, so it took Cura 4 minutes between me selecting a file to open and it actually opening on Cura.

Ideally, this wouldn't be a hard-coded True. But I'm not that familiar with Qt - or the Cura project as a whole - so I wouldn't know the best way to handle this. Some suggestions are:

• Add a boolean to the configurations, something like "Auto Detect Serial Ports" or "Auto Detect Baud Rates". And please, make the default False.
• Instead of scanning for tty ports and trying every baud rate, have the user supply this data.

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

I had the same problem as listed on #16249. After building with the new source code, it opened files quickly - as expected.

Checklist:

• My code follows the style guidelines of this project as described in UltiMaker Meta and Cura QML best practices
• I have read the Contribution guide
• I have commented my code, particularly in hard-to-understand areas
• I have uploaded any files required to test this change

[kafufafu]

Could this have had any relation with the following? #19186

[gtollini]

Could this have had any relation with the following? #19186

Thanks for your comment, Kafufafu. I've added the two related issues to the list of issues this PR fixes.

[sneakythr0ws]

merge it pls!!!

[IT-Wizard]

I've tested the new 5.8 version, it is still not implemented.
The load of an STL file is still 4 minutes long. :o/