Change Qucs-S workspace and tempfile paths

[wawuwo]

Hi!

This pull request addresses three issues described in #145.

1. Set root path for all temporary files produced by Qucs-S to QStandardPaths::CacheLocation (which is ~/.cache/qucs-s on GNU/Linux)
2. Set default Qucs-S workspace path to ~/QucsWorkspace
3. Fix a bug which led to recreation of default workspace dir on app start even if it was changed in app settings

I've tested all three changes, but testing of the first one was incomplete: I've tested only the ngspice simulation because I don't have a single clue how to run other types like VHDL, ASCO, etc. (I am complete noob in electrical engineering to be honest)

[ra3xdh]

Thanks. I will test this and share the feedback. It's need to use fresh installation to test this. To test VHDL/Verilog you should install ghdl and iverilog and make it available from $PATH. Then simulate schematic like in this thread: #97 (comment) Digital simulation starts automatically if the schematic contains Digigtal simulation type. I didn't use ASCO for a long time and I am not sure if it works 😄 ASCO works only with qucsator.

[wawuwo]

@ra3xdh I've found a bug: directory for simulator output (which is defined in "Simulator settings") is always set to ~/.cache/qucs-s/spice4qucs at app start. In other words custom path for simulator output is respected until app termination only.

I'll prepare a fix to respect user-defined setting after restart. But I'm in doubt: if simulator output is temporary data and temporary data should be stored in standard location, then shouldn't there be no way to set custom simulator output dir?

[ra3xdh]

But I'm in doubt: if simulator output is temporary data and temporary data should be stored in standard location

The user normally should not get access to raw SPICE simulator dataset. The output directory setting was implemented for example to redirect output to ramdisk mounted in /tmp. This would allow to achieve automatic clean caches. I think there is no need to set the simulator output directory by user after switching to standard paths. The cache cleaning could be done by means of global system tools.

[wawuwo]

I think there is no need to set the simulator output directory by user after switching to standard paths

I see; then I'll adjust simulator settings dialog and revert last fix 🤝

[ra3xdh]

I have tested this and found one major issue. The new Qucs-S always sets the project directory to $HOME/QucsWorkspace. The application shown an empty project tree and user libraries list after restart. Users need to move their data manually. This may lead to tons of false positive bugreports after releasing this feature. The following logic should be used here:

• Don't change projects tree location, if the old project directory QucsSetting.QucsHomeDir (usually points to $HOME/.qucs) contains some projects or user libraries. Probably need to check for _prj subdirectories (projects) and user_lib subdirectory.
• If there is no contents in $HOME/.qucs then migrate to $HOME/QucsWorkspace
• Ideally ask user if the data should be migrated and copy contents of $HOME/.qucs to $HOME/QucsWorkspace

Probably you can propose a better solution. I will merge this PR after this issue will be resolved.

[ra3xdh]

Also the solution may be to use new workspace location only on the fresh installation of the application. The QucsSettings.firstStart could be used.

[wawuwo]

@ra3xdh, oh, I see :(
That's because I decided to use another name for config property, "QucsHomeDir" property containing old path is ignored. I'll try to come with a fix today

[wawuwo]

@ra3xdh I implemented it the easy way: if it is a fresh install (no ~/.config/qucs/qucs_s.conf or no property in config), then set ~/QucsWorkspace, otherwise respect the value from config file.

[ra3xdh]

Thanks! Now everything works correct. Merging.