changing the color of MDI child windows under Windows 7

Question

I have an MDI application written in C++ that looks great under Windows XP. All of the MDI child windows end up looking like their parent window. Nice. However, under Windows 7 (and probably Vista), the parent windows have aero glass, and the child windows are this hideous unchangeable baby blue color (same as the Windows 7 Basic theme). So my application really looks very very bad.

You can see this same ugly behavior by launching Office 2003 and try looking at MDI child windows (perhaps in Excel). However, Office 2007 actually has three color themes - blue, silver, and black. These themes somehow carry through to the MDI child windows in Excel.

I don't know how Microsoft is doing this in Office 2007. I would love to know the trick. I need to hook and takeover the drawing of my MDI child windows and replicate what the Office 2007 team has pulled off. The problem is that I want to use all of the DrawTheme* calls so I get the gradients and rounded edges and buttons all drawn properly. And all of these system calls need a handle to a theme. But it doesn't seem to be possible to, for example, use SetWindowTheme to change to use the color scheme from another theme. At least as far as I can tell.

Anyone know how Microsoft accomplished this?

Answer 1

It's not a great solution, but poking around on the web, I found this article about how to place a WinXP rounded look into the squarish flat Win95/Win98/Win2k window style. It works by using BMP snapshots of the WinXP theme and than using bitblit functions to stretch them to appropriate sizes around the window frame border. I tried his demo software, and sure enough, it looks like WinXP Luna under Win7. I can use his example as a basis to hook and replace my MDI child window frame drawing.

The problem with this approach is that you either have to pick a titlebar width and stick with it and not respond to global theme adjustments that change the titlebar height, or you have to take many different BMP snapshots at different sizes. For my purposes, it is probably fine to just stick to one thickness and ignore user theme adjustments. Once in place, I can apply different themes just by BMP snapshotting them - so I could also apply the Office 2007 MDI child look as well.