How to resolve inheritance in WPF windows?

Question

I cant quite think of a good way to achieve the following:

• I have a base window class SlimWindow which inherits from some 3rd party window (Devexpress)
• I have a base dialog window SlimDialogWindow which inherits from SlimWindow
• I have a base window for certain class of windows ModuleWindow which inherits from SlimWindow
• I now need to have 2 sets of windows - one are that behave the same as SlimDialogWindow and another that behave like both - SlimDialogWindow and ModuleWindow. Lets say currently there are 10 windows inherit from SlimDialogWindow - I need to split them to 6 to behave like SlimDialogWindow + ModuleWindow and 4 to behave like SlimDialogWindow

SlimDialogWindow + ModuleWindow vs pure SlimDialogWindow - pure dialog is just a window with OK/Cancel buttons and some other functionality, ModuleWindow - sets some properties - e.g. remove it from task bar and alt-tab plus some other stuff.

How to make it work?

Answer 1

I think I would go with either of these approaches:

1. Create 2 versions of SlimDialogWindow. One that inherits SlimWindow, and another SlimModuleDialogWindow which inherits ModuleWindow.
   That'll give you the versatility to use either one according to the scenario. Of course I don't know how much code you have in SlimDialogWindow. If it's just xaml, it could be solved with a template to be used in both. For procedural code, maybe you could export it to a common class.

or use this approach:

2. Make ModuleWindow an optional extension of SlimWindow. You said it affects some properties. So maybe add a flag in the SlimWindow constructor - IsModule, to set the changed properties.
   If you want a single class for both scenarios, I don't think you have many options besides combining both.
   Thinking about it. Maybe you can have ModuleWindow as a single class, with a flag to disable its features. It would allow you to separate the classes, but it still amounts to the same thing.

Hope this helps