Attempt to make buttons themed

[Jonathan Wilson]

ok, further to what I mentioned before about RegisterUserApiHooks (and 
poking around in uxtheme.dll), I see the following things being hooked by 
uxtheme (at least it seems to be the complete list)
GetScrollInfo
SetScrollInfo
EnableScrollBar
SetWindowRgn
DefWindowProcW
DefWindowProcA
PreWndProc (probobly stuff that happens internally before the window 
procedure gets called)
PostWndProc (probobly stuff that happens internally after the window 
procedure gets called)
PreDefDlgProc (probobly connected to dialog boxes)
PostDefDlgProc (probobly connected to dialog boxes)
GetSystemMetrics
SystemParametersInfoA
SystemParametersInfoW
DrawFrameControl
DrawCaption
MDIRedrawFrame (probobly related to MDI frame windows)

Best guess is that RegisterUserApiHook and UnregisterUserApiHook are 
specifically provided so that uxtheme can override/hook code in user32.dll 
but at the same time if the themes service is disabled, none of the theming 
code kicks in.
What probobly happens is that uxtheme.dll is loaded into every process 
(since even apps that know nothing about theming still get themed 
non-client areas etc AFAIK) which then hooks the user32 APIs to draw the 
themeing for the non-client areas.
Then, theme-aware apps provide a manifest and link to the comctl32.dll 6.0 
and from there get proper theming for all their standard (and common) controls.

Ordinal 34 (not given any external name by MS) in uxtheme.dll is what 
installs the user API hooks (what calls it I have no idea, probobly some 
system component, mabie the Theme service)