[STOBJECT] Control sound muting from media buttons

Muting can be controlled explicitly by Mute button and implicitly unmute
by increasing volume.

Author: SigmaTel71

dll/shellext/stobject/csystray.cpp

@@ -359,6 +359,11 @@ BOOL CSysTray::ProcessWindowMessage(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM
         {
             MouseKeys_Update(this);
         }
+        else if (wParam == HSHELL_APPCOMMAND && ((GET_APPCOMMAND_LPARAM(lParam) >= APPCOMMAND_VOLUME_DOWN) || GET_APPCOMMAND_LPARAM(lParam) <= APPCOMMAND_VOLUME_UP))
+        {
+            lpVolCmd = GET_APPCOMMAND_LPARAM(lParam);
+            Volume_Update(this);
+        }
         lResult = 0L;
         return TRUE;
     }

dll/shellext/stobject/csystray.h

@@ -60,6 +60,8 @@ class CSysTray :
     static void RunDll(PCSTR Dll, PCSTR Parameters);
     static void RunAccessCpl(PCSTR Parameters);
 
+    LPARAM lpVolCmd;
+
 protected:
     BOOL ProcessWindowMessage(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam, LRESULT &lResult, DWORD dwMsgMapID = 0);
 

dll/shellext/stobject/volume.cpp

@@ -173,7 +173,32 @@ HRESULT STDMETHODCALLTYPE Volume_Update(_In_ CSysTray * pSysTray)
     PrevState = g_IsMute;
     Volume_IsMute();
 
-    if (PrevState != g_IsMute)
+    // Unmute if volume is increased or unmuted explicitly
+    if (pSysTray->lpVolCmd)
+    {
+        g_IsMute = pSysTray->lpVolCmd == APPCOMMAND_VOLUME_UP ? FALSE : !g_IsMute;
+
+        MIXERCONTROLDETAILS_BOOLEAN mxcdMute = {0};
+        mxcdMute.fValue = g_IsMute;
+
+        MIXERCONTROLDETAILS mxcd = {0};
+        mxcd.cbStruct = sizeof(mxcd);
+        mxcd.cChannels = 1;
+        mxcd.hwndOwner = NULL;
+        mxcd.dwControlID = g_muteControlID;
+        mxcd.paDetails = &mxcdMute;
+        mxcd.cbDetails = sizeof(mxcdMute);
+
+        MMRESULT mmres = mixerSetControlDetails((HMIXEROBJ)UlongToHandle(g_mixerId), &mxcd, MIXER_SETCONTROLDETAILSF_VALUE);
+
+        if (mmres)
+        {
+            ERR("Volume_Update failed at MMixer: %d\n", mmres);
+            return E_FAIL;
+        }
+    }
+
+    if (pSysTray->lpVolCmd == APPCOMMAND_VOLUME_MUTE || PrevState != g_IsMute)
     {
         WCHAR strTooltip[128];
         HICON icon;
@@ -188,6 +213,7 @@ HRESULT STDMETHODCALLTYPE Volume_Update(_In_ CSysTray * pSysTray)
             LoadStringW(g_hInstance, IDS_VOL_VOLUME, strTooltip, _countof(strTooltip));
         }
 
+        pSysTray->lpVolCmd = 0;        
         return pSysTray->NotifyIcon(NIM_MODIFY, ID_ICON_VOLUME, icon, strTooltip);
     }
     else