Windows Vista/7 glass completely broken?

Question

I'm trying to get the media player glass effect for an application, but I'm facing roadblocks all around. Is it me, or is it the API?

I started by calling:

MARGINS margins = { -1, -1, -1, -1 };
HRESULT result = ::DwmExtendFrameIntoClientArea(m_hWnd, &margins);

And erasing the background to black on:

OnEraseBkgnd

Everything was fine until I added an edit box. With EditBox, places where black text appears are replaced with glass. The problem is blown out of proportion with more advanced controls like ComboBoxEx and that like. Those start to look like mess.

The bright side with this approach is that the alpha blended images look alright. And are gradually blended into the glass.

The solution for edit boxes seems to be using WS_EX_LAYERED with LWA_COLORKEY and using some awful color for glass masking, and erasing the background to that color. Unfortunately this breaks other things. The alpha blending on icons looks super ugly with shadows blended to radioactive green, and the glass itself becomes click-throughable, even though I don't have a WS_EX_TRANSPARENT style on the window.

The third suggestion is sort of custom composition with GDI+, but that seems to be a bad approach, since GDI+ is a software fallback, and I can't find a way how to render EditBox or ComboBoxEx to an image that I could use for composition later.

Am I missing something?

The sources at SO also seem to face the same problems: link1 link2

Answer 1

The simple answer is, you cannot do this.

All the standard controls render themselves with normal GDI calls. Normal GDI calls are alpha unaware and mostly set the alpha channel to zero.

The more complicated answer is, you can: There are some samples on the net where standard controls are mixed with aero glass. They fall into two basic categories:

• WinForms (.NET) samples. WinForms don't actually use the native controls - the WinForms controls are all rewritten versions that, amongst other features, blit using alpha aware routines. This example is depressingly simple and makes me realize how much Microsoft hate native developers.

• Subclassed samples: The only way to get the regular/native controls to paint on aero glass is to sublclass the controls, catch WM_PAINT messages to create a DIBBitmap, call WM_PRINT to render the controls content onto it. Use the DWM functions to repair the alpha channel data. Paint the resulting alpha'd bitap yourself using AlphaBlend.

This article on CodeProject contains a reference implementation that subclasses most of the standard controls rather well.

Answer 2

Kenny Kerr wrote an excellent article on displaying controls on glass, using edit controls as an example:

http://weblogs.asp.net/kennykerr/archive/2007/01/23/controls-and-the-desktop-window-manager.aspx

Answer 3

Try changing your text/foreground color on controls like the edit box to something "almost black" (like #010101). Then you should be able to skip the other rendering issues except alpha transparency for images/icons.

Edit: Drawing other stuff - might be some weird approaches to handle compatibility, but then again classic apps aren't glass themed by default ... don't know. Just try to avoid drawing stuff yourself, if possible.