How to accurately detect if an application is theme-enabled?

Fig. 1 : System wide and app-specific themes enabled

Fig. 2 : System wide themes enabled, app-specific themes disabled

Fig. 3 : System wide themes disabled. (App-specific doesn't matter)

Overview

When you develop custom controls that work differently depending on whether the application has themes enabled or not, you need to detect whether the currently running application is using themes or not. MSDN lists two functions IsAppThemed and IsThemeActive and I list below snippets from their documentation :-

IsAppThemed Function - Reports whether the current application's user interface displays using visual styles.

IsThemeActive Function - Tests if a visual style for the current application is active.

You'd think that all you need to do is to use one or both of these functions, wouldn't you? Guess what? On XP (even SP2) both these functions return TRUE if your system wide themes setting is enabled. Thus any system that's using an XP styled theme will always have these two functions returning TRUE.

I googled around and didn't find anything worthwhile. I saw a posting from Jeff Partch (MVP) who suggested calling GetModuleHandle on comctl32.dll and comparing this module handle with the handle returned by calling GetClassLongPtr on a known control handle with the GCLP_HMODULE flag. While I didn't actually try that out, I thought it'd be easier to call DllGetVersion on comctl32.dll and check if the version is 6 or greater.

The IsThemed function

The code lavishly uses LoadLibrary/GetProcAddress to avoid a dependency on the PSDK (the code now compiles on the default installation of VC++ 6).

#pragma once

#include "stdafx.h"
#include <Shlwapi.h>

BOOL IsThemed()
{
    BOOL ret = FALSE;
    OSVERSIONINFO ovi = {0};
    ovi.dwOSVersionInfoSize = sizeof ovi;
    GetVersionEx(&ovi);
    if(ovi.dwMajorVersion==5 && ovi.dwMinorVersion==1)
    {
        //Windows XP detected
        typedef BOOL WINAPI ISAPPTHEMED();
        typedef BOOL WINAPI ISTHEMEACTIVE();
        ISAPPTHEMED* pISAPPTHEMED = NULL;
        ISTHEMEACTIVE* pISTHEMEACTIVE = NULL;
        HMODULE hMod = LoadLibrary(_T("uxtheme.dll"));
        if(hMod)
        {
            pISAPPTHEMED = reinterpret_cast<ISAPPTHEMED*>(
                GetProcAddress(hMod,_T("IsAppThemed")));
            pISTHEMEACTIVE = reinterpret_cast<ISTHEMEACTIVE*>(
                GetProcAddress(hMod,_T("IsThemeActive")));
            if(pISAPPTHEMED && pISTHEMEACTIVE)
            {
                if(pISAPPTHEMED() && pISTHEMEACTIVE())                
                {                
                    typedef HRESULT CALLBACK DLLGETVERSION(DLLVERSIONINFO*);
                    DLLGETVERSION* pDLLGETVERSION = NULL;

                    HMODULE hModComCtl = LoadLibrary(_T("comctl32.dll"));
                    if(hModComCtl)
                    {
                        pDLLGETVERSION = reinterpret_cast<DLLGETVERSION*>(
                            GetProcAddress(hModComCtl,_T("DllGetVersion")));
                        if(pDLLGETVERSION)
                        {
                            DLLVERSIONINFO dvi = {0};
                            dvi.cbSize = sizeof dvi;
                            if(pDLLGETVERSION(&dvi) == NOERROR )
                            {
                                ret = dvi.dwMajorVersion >= 6;
                            }
                        }
                        FreeLibrary(hModComCtl);                    
                    }
                }
            }
            FreeLibrary(hMod);
        }
    }    
    return ret;
}

Using the code

if(IsThemed())
    m_bThemed = true;
else
    m_bThemed = false;

History

• June 02, 2005 - Article first published