Gui: Consolidate PythonWrapper

[3x380V]

This is just a draft as I'm unable to verify all configurations.
I'm still unhappy with PythonWrapper, there are way too many ifdeffed paths, making it error prone. An attempt to clean it up a bit is made. Disclaimer: a week ago I had zero knowledge about Shiboken and it does improve very slowly over time.

Issues:

• build system is unable to find pip installed QtWebEngineWidgets
• python claims value returned by toSecsSinceEpoch (into repo.updated_timestamp) is a float, therefore typecast.
• only Python loaded modules tested, not linked against shiboken.

Comments very welcome and appreciated.

[chennes]

I'm about to tear out QtWebEngineWidgets, so don't worry too much about that one 😄.

[3x380V]

@chennes, that was really fast, so I'm not worried any more. I would appreciate is someone could look at Addon Manager part. I works now, it is a bit ungly.

[chennes]

These AddonManager changes should be fine, all of those methods and constants existed in Qt 5.12.

[3x380V]

The problem with Addon Manager is that I do not know where that float comes from. It ends this way:

TypeError: 'float' object cannot be interpreted as an integer
/home/ladis/src/FreeCAD-build/Mod/AddonManager/package_details.py:137: RuntimeWarning: libshiboken: Overflow: Value 1695849953.710445 exceeds limits of type  [signed] "x" (8bytes).
  QtCore.QDateTime.fromSecsSinceEpoch(repo.updated_timestamp)
Traceback (most recent call last):
  File "/home/ladis/src/FreeCAD-build/Mod/AddonManager/AddonManager.py", line 748, in table_row_activated
    self.packageDetails.show_repo(selected_repo)
  File "/home/ladis/src/FreeCAD-build/Mod/AddonManager/package_details.py", line 124, in show_repo
    self.display_repo_status(self.repo.update_status)
  File "/home/ladis/src/FreeCAD-build/Mod/AddonManager/package_details.py", line 137, in display_repo_status
    QtCore.QDateTime.fromSecsSinceEpoch(repo.updated_timestamp)
OverflowError
TypeError: 'float' object cannot be interpreted as an integer
Traceback (most recent call last):
  File "/home/ladis/src/FreeCAD-build/Mod/AddonManager/package_details.py", line 137, in display_repo_status
    QtCore.QDateTime.fromSecsSinceEpoch(repo.updated_timestamp)
OverflowError

So that typecasing to int is needed, alhough documentation says it should be u64. And I do not like pushing things I do not understand.
I will create separate PR for Addon Manager once you merge #12097

@wwmayer, could you elaborate why is QPrinter special? (see XXX in the code)

[3x380V]

Ah, repo.updated_timestamp is updated also with os.path.getmtime() which returns a floating-point value of class ‘float’ that represents the time (in seconds) of last modification of the specified path.

[3x380V]

Addon Manager has its PR #12100 now. However I do not know how to remove label.

[chennes]

This is looking good now -- is it ready for review?

[3x380V]

Yes, however only shiboken/PySide access via C++ is working while via Python it still does not. This is the same as before. Of course, I would appreciate help with debugging. Just uncomment block mentioned in code, to see the problem

FreeCAD/src/Gui/PythonWrapper.cpp

Line 37 in 02c6a90

// Uncomment this block to remove PySide C++ support and switch to its Python interface

[3x380V]

So here it is:
PyObject* CommandPy::getAction(PyObject *args) is calling wrap.fromQObject(a) (there are some places where result of wrap.loadWidgetsModule() is not tested at all, btw) and because const char* className is set to nullptr, later in Py::Object PythonWrapper::fromQObject(QObject* object, const char* className) construction of std::string from nullptr fails.

I bet someone more familiar with codebase would find it way sooner (or perhaps I should try setting up a decent debugger)