default MINMAXINFO values?

Question

I am currently working on a piece of code to circumvent the modal loops for moving and resizing Windows by effectively re-implementing DefWindowProc for the process.

The first snag I've hit is with MINMAXINFO. It seems that Windows fills this in with default values before sending the message along to the WindowProc, so simply sending the message to a window that doesn't override the values wouldn't do any good. Figuring that this wouldn't be as simple as giving it the desktop window size for the max and zeroes for the min, I checked how ReactOS does it in their source and.... well, I don't understand why they do the things they do in calculating it.

In particular, they choose to negate the WS_BORDER style when calling AdjustWindowRectEx. Their use of variables named "xinc" and "yinc" also seems unusual to me.

Basically, I'm hoping someone who has worked with the code (or MINMAXINFO more generally) can explain what I'm missing.ReactOS: WinPosGetMinMaxInfo

Answer 1

The ptMaxSize values in the MINMAXINFO structure are not the maximum size you can drag size to, but what the size will be if the window is actually maximized. When a window is maximized, the thick border is removed (since you no longer want the user to grab the border and try to resize it).

Make sure you read all the details in the explanation of the values for MINMAXINFO.