If you plan on completing examples in Defining lineups for multiple platforms, you can complete the other platform-specific class (ScreenPMCapture or ScreenWinCapture) simply by copying the methods to the other class. For example, if you implemented the methods in ScreenPMCapture but now want to add them to ScreenWinCapture, you can copy the methods to ScreenWinCapture as follows:
Now, if you want platform-specific BMPs captured, revise the method saveGraphicImage so it uses the class CgPMBMPFileFormat (or CgWinBMPFileFormat).
To test the changes, open an instance of ScreenWinCapture by evaluating ScreenWinCapture new open.
The examples in Defining lineups for multiple platforms describe how to configure DevelopScreenCapture and its two classes so a system automatically uses ScreenPMCapture for OS/2 and ScreenWinCapture for Windows.