Custom QWidgets. How do I build/get the pyqt5 plugin for Qt Designer on Mac? - macos

Question

I want to be able to create my own custom widgets in Qt Designer using the pyqt5 plugin on my Mac!
On my windows system this is easy. I have/install pyqt5-tools, this contains pyqt5.dll and I copy this into the Qt Designers plugin directory (these packages were all installed via winPython).
I set PYQTDESIGNERPATH=.
In my current directory I have ledplugin.py and ledwidget.py
I start Qt Designer and I have my custom widget to drag and drop
( this tutorial was taken from https://www.ics.com/blog/integrating-python-based-custom-widget-qt-designer )
On my Mac, I can't figure out what the equivalent .dylib of pyqt5.dll is? What is it? Where do I get it? How do I build it?
I try: brew install Qt Creator, that doesn't have the pyqt plugin. I try: brew install pyqt5, that creates: libpyqt5qmlplugin.dylib. I copy that into the Qt Designer plugin dir and the plugin loads, but it doesn't seem to do anything with my .py plugin/widget files.
How do I get this working on a Mac? What is the actual .dylib plugin I'm looking for? I can't find anything googling around.
Thanks for any help

Answer 1

As my comment explained: the Qt designer plugin can be built via the reference link (SIP/PyQt5 via RiverBank and Qt src via Qt).
Make sure your Qt versions match, although Qt docs do say plugins of lower versions should work with Designers on higher versions, but I'm sure there's a limit.
Build inside a python venv, as suggested.
You'll need xtool dev pkg for building.
Everything built really easy for me.
This will place your pyqt5.dylib plugin right in your Qt/clang_64/plugins/designer folder (it will also build it in pyqt5 make folder)
At this point I expected things to work. The plugin shows that it loads fine inside Designer.
Some extra notes:
running from command line can help with debugging: Qt/clang_64/bin/Designer.app > show package > /MacOS/Designer (drag this to a terminal to execute from command line)
set an env variable (>>export QT_DEBUG_PLUGINS=1) will give debug info and show lots of stuff including that pyqt5.dylib loads fine
widget plugins are two files: widget.py and the widgetplugin.py file that exposes the widget to designer. This plugin file MUST end with "plugin.py"
widgetplugin.py files can reside in a number of places:
in /[Designer App]/plugins/designer/python/
in ~/user dir/.designer/plugins/python/
in a directory of you choosing using env var PYQTDESIGNERPATH
However, at this point still nothing showed in Designer and I had no errors to go by. Since I just built pyqt5.dylib, I figured I'd simply put a bunch of print statements in it, re-make it and debug to figure out why the pyqt5 plugin loaded fine, but my custom widgets were nowhere to be found...
first issue was trouble loading a python environment:
for this issue, I simply copied my (I use brew) /usr/local/Cellar/python/3.7.2/Frameworks/Python.framework to Qt/clang_64/lib (I'm sure there's a proper PATH/PYTHONPATH you can set for this, I'll figure that out later)
after that came, missing PyQt5.sip module
for this, I installed (pip install) pyqt5-sip and then put in in my PYTHONPATH
After that, everything finally worked and I could see my custom plugins inside Qt Designer.