Expected Behavior

The event loop created by gui_qt() should execute the QApplication if it is not already running.

Current Behavior

When running the code as a python module (python -m module_name), it seems to work fine in my Linux environment, but in Windows the program just finishes without launching the application window.

The problem lies here:

• In Linux app.applicationName() contains the name passed to the QApplication constructor app = QApplication([app_name]). This is what the code above is expecting.
• In Windows app.applicationName() contains the string python, therefore the if statement always evaluates to false.

On a side note, the code of the gui_qt() function seems to mask command line arguments instead of passing them on to the application.

Possible Solution

a. Manually set the application name with setApplicationName(). I've pushed #163 implementing this.
b. Alternatively, refactor the gui_qt function to receive the same parameters as QApplication. That is, receive argv and pass it on to QApplication, instead of only receiving a single string with the application_name. I believe this would also allow to pass command line arguments to the application, which is probably not the case at the moment.

Steps to Reproduce (for bugs)

1. python -m bluesky_widgets.examples.qt_run_tree_view
2. The program runs until completion without launching the application window.

Your Environment

Windows 10, python 3.9.7, conda 4.10.3, PyQt5 5.15.4