Add DetailedList to Windows

Expected Behavior

The detailed list example to render

Current Behavior

Unhandled Exception: Python.Runtime.PythonException: AttributeError : module 'toga_winforms.factory' has no attribute 'DetailedList'
   at Python.Runtime.Dispatcher.Dispatch(ArrayList args)
   at __System_Threading_ThreadStartDispatcher.Invoke()
   at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ThreadHelper.ThreadStart()

Process finished with exit code -532462766

Steps to reproduce

1. launch detailedlist example

Your Environment

• Python Version (list the specific version number) 3.6.5

• Operating System and Version (select from the following and list the specific version number; if your OS is not listed, list that as well)

  • macOS - version:
  • Linux - distro: - version:
  • [ x ] Windows - version: Win10 1607
  • Other - name: - version:

• Toga Target (the type of app you are trying to generate)

  • android
  • cocoa
  • django
  • gtk
  • iOS
  • tvOS
  • watchOS
  • [ x ] winforms
  • win32
  • Other (please specify)

[freakboy3742]

@obulat Agreed - that would be a nice improvement to the end-user experience.

The problem here is that what we’d need to catch is an attribute lookup on a module. This is something that is trivial to fix in Python 3.7 - we could add a module-level __getattr__ definition. However, on older Python versions, we’d need to completely change the way the factory is accessed (and prevent any other way of accessing the factory).

It may still be worth adding the module-level __getattr__, though - it won’t hurt having it on older Python versions, and the platform most likely to be affected by this (Windows) is also the one most likely to have a recent Python version (3.7+).

[saroad2]

I believe this was fixed in #1574 😄