// Start.cpp : Defines the entry point for the DLL application.
//

#include "stdafx.h"
#include "start.h"
#include "resource.h"

HINSTANCE g_hInstance;
BOOL g_bInstalled = FALSE;
HBITMAP g_hbmStart = NULL;
BOOL g_bSubclassed = FALSE;
WNDPROC g_pfnStartProc = NULL;
HWND g_hwndTip = NULL;
TOOLINFO g_ti;
BOOL g_bAlreadyDrawn = FALSE;
BOOL g_bFirstTime = TRUE;

BOOL APIENTRY DllMain( HINSTANCE hInstance, 
                       DWORD  ul_reason_for_call, 
                       LPVOID lpReserved
					 )
{
   g_hInstance = hInstance;
   return TRUE;
}

/*---------------------------------------------------------------------------*/
// DllGetClassObject
// Main function for a COM in-proc object like this
/*---------------------------------------------------------------------------*/
STDAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, LPVOID* ppv)
{
   InstallHandler();
   return CLASS_E_CLASSNOTAVAILABLE;
}


/*---------------------------------------------------------------------------*/
// DllCanUnloadNow
// Confirm the unload for a COM library
/*---------------------------------------------------------------------------*/
STDAPI DllCanUnloadNow()
{
   return (g_bInstalled ? S_FALSE : S_OK);
}


STDAPI DllRegisterServer()
{
   TCHAR szSubKey[MAX_PATH] = {0};
   TCHAR szCLSID[MAX_PATH] = {0};
   TCHAR szModule[MAX_PATH] = {0};
   HKEY hKey;
   DWORD dwDisp;

   // Set the CLSID
   lstrcpy(szCLSID, __TEXT("{20051998-0019-0005-1998-000000000000}"));

   // Get the module name
   GetModuleFileName(g_hInstance, szModule, MAX_PATH);

   // HKCR: CLSID\{...}
   wsprintf(szSubKey, __TEXT("CLSID\\%s"), szCLSID);
   LRESULT lResult = RegCreateKeyEx(HKEY_CLASSES_ROOT, szSubKey, 0, NULL,
                 REG_OPTION_NON_VOLATILE, KEY_WRITE, NULL, &hKey, &dwDisp);
   if(lResult == NOERROR)
   {
      TCHAR szData[MAX_PATH] = {0};
      wsprintf(szData, __TEXT("Start Button"), szModule);
      lResult = RegSetValueEx(hKey, NULL, 0, REG_SZ,
                    reinterpret_cast<LPBYTE>(szData), lstrlen(szData) + 1);
      RegCloseKey(hKey);
   }

   // HKCR: CLSID\{...}\InProcServer32
   wsprintf(szSubKey, __TEXT("CLSID\\%s\\InProcServer32"), szCLSID);
   lResult = RegCreateKeyEx(HKEY_CLASSES_ROOT, szSubKey, 0, NULL,
                 REG_OPTION_NON_VOLATILE, KEY_WRITE, NULL, &hKey, &dwDisp);
   if(lResult == NOERROR)
   {
      lResult = RegSetValueEx(hKey, NULL, 0, REG_SZ,
                reinterpret_cast<LPBYTE>(szModule), lstrlen(szModule) + 1);
      TCHAR szData[MAX_PATH] = {0};
      lstrcpy(szData, __TEXT("Apartment"));
      lResult = RegSetValueEx(hKey, __TEXT("ThreadingModel"), 0, REG_SZ,
                    reinterpret_cast<LPBYTE>(szData), lstrlen(szData) + 1);
      RegCloseKey(hKey);
   }

   return S_OK;
}


STDAPI DllUnregisterServer()
{
   TCHAR szSubKey[MAX_PATH] = {0};
   TCHAR szCLSID[MAX_PATH] = {0};
   TCHAR szModule[MAX_PATH] = {0};
   HKEY hKey;
   DWORD dwDisp;

   // Set the CLSID
   lstrcpy(szCLSID, __TEXT("{20051998-0019-0005-1998-000000000000}"));

   // Open HKCR
   LRESULT lResult = RegCreateKeyEx(HKEY_CLASSES_ROOT, "", 0, NULL,
                 REG_OPTION_NON_VOLATILE, KEY_WRITE, NULL, &hKey, &dwDisp);
   if(lResult == NOERROR)
   {
      wsprintf(szSubKey, __TEXT("CLSID\\%s\\InProcServer32"), szCLSID);
      RegDeleteKey(hKey, szSubKey);
      wsprintf(szSubKey, __TEXT("CLSID\\%s"), szCLSID);
      RegDeleteKey(hKey, szSubKey);
      RegCloseKey(hKey);
   }

   return S_OK;
}


/*-------------------------------------------------------*/
// InstallHandler
// Replace the Start button and install the hooks
/*-------------------------------------------------------*/
void InstallHandler()
{
   if(g_bInstalled)
   {
      int irc = MessageBox(HWND_DESKTOP, 
          __TEXT("The extension is installed. Would you like to uninstall?"),
          __TEXT("Start"), MB_ICONQUESTION | MB_YESNO | MB_SETFOREGROUND);

      if(irc == IDYES)
         UninstallHandler();
      return;
   }

   // Remember whether the handler is installed
   g_bInstalled = TRUE;

   // Set a new Start button
   SetNewStartButton(TRUE);
}


void UninstallHandler()
{
   // Restore the Start settings
   SetNewStartButton(FALSE);

   // The handler is now uninstalled
   g_bInstalled = FALSE;

   // Restore the old tooltip text
   g_ti.lpszText = __TEXT("Click here to begin"); 
   SendMessage(g_hwndTip, TTM_UPDATETIPTEXT, 0, reinterpret_cast<LPARAM>(&g_ti));
}


HBITMAP NewStartBitmap(HWND hwndStart, BOOL fNew)
{
   if(!fNew)
   {
      if(g_hbmStart)
         SendMessage(hwndStart, BM_SETIMAGE, IMAGE_BITMAP, reinterpret_cast<LPARAM>(g_hbmStart));
  
      // Refresh the button to reflect the change
      SetWindowPos(hwndStart, NULL, 0, 0, 0, 0, SWP_NOSIZE | SWP_NOZORDER | SWP_NOMOVE | SWP_DRAWFRAME);
      return NULL;
   }
	
   // Save the current bitmap
   g_hbmStart = reinterpret_cast<HBITMAP>(SendMessage(hwndStart, BM_GETIMAGE, IMAGE_BITMAP, 0));

   // Load and set the new bitmap
   HBITMAP hbm = reinterpret_cast<HBITMAP>(LoadImage(g_hInstance, MAKEINTRESOURCE(IDB_NEWSTART), IMAGE_BITMAP, 0, 0, LR_DEFAULTSIZE));
   SendMessage(hwndStart, BM_SETIMAGE, IMAGE_BITMAP, reinterpret_cast<LPARAM>(hbm));

   // Refresh the button to reflect the change
   SetWindowPos(hwndStart, NULL, 0, 0, 0, 0, SWP_NOSIZE | SWP_NOZORDER | SWP_NOMOVE | SWP_DRAWFRAME);
   return g_hbmStart;
}

/*-------------------------------------------------------*/
// SetNewStartButton
// Replace/Restore the bitmap for the Start button
/*-------------------------------------------------------*/
void SetNewStartButton(BOOL fNew)
{
   // Get the handle to the Start button
   HWND hwndTray = FindWindowEx(NULL, NULL, "Shell_TrayWnd", NULL);
   HWND hwndStart = FindWindowEx(hwndTray, NULL, "Button", NULL); 

   // Change the bitmap
   g_hbmStart = NewStartBitmap(hwndStart, fNew);

   // Replace the tooltip text
   RemoveTooltip(hwndStart);

   // Subclass the button
   if(fNew)
   {
      if(!g_bSubclassed)
      {
         g_pfnStartProc = SubclassWindow(hwndStart, NewStartProc);
         g_bSubclassed = TRUE;
      }
   }
   else
   {
      if(g_pfnStartProc != NULL)
         SubclassWindow(hwndStart, g_pfnStartProc);
      g_bSubclassed = FALSE;
   }
}

LRESULT CALLBACK NewStartProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
   switch(uMsg)
   {
   case WM_SETCURSOR:
      SetCursor(LoadCursor(g_hInstance, MAKEINTRESOURCE(IDC_HANDY)));
      return 0;
   case WM_MEASUREITEM:
      MeasureItem(HWND_DESKTOP, reinterpret_cast<LPMEASUREITEMSTRUCT>(lParam));
      break;
   case WM_DRAWITEM:
      DrawItem(reinterpret_cast<LPDRAWITEMSTRUCT>(lParam));
      break;
   case WM_CONTEXTMENU:
      return 0; 
   case BM_SETSTATE:
   case WM_LBUTTONDOWN:
	  {
         WNDCLASS wc;
         GetClassInfo(NULL, "Button", &wc);
         CallWindowProc(wc.lpfnWndProc, hwnd, BM_SETSTATE, TRUE, 0);

         STARTMENUPOS smp;
         GetStartMenuPosition(&smp);
         HMENU hmnuPopup = GetMenuHandle("c:\\myStartMenu");
         int iCmd = TrackPopupMenu(hmnuPopup,
                                 smp.uFlags | TPM_RETURNCMD | TPM_NONOTIFY,
                                 smp.ix, smp.iy, 0, hwnd, NULL);

         // Handle the user's mouse clicks
         HandleResults(hmnuPopup, iCmd);

         // Free memory
         DestroyMenu(hmnuPopup);

         CallWindowProc(wc.lpfnWndProc, hwnd, BM_SETSTATE, FALSE, 0);
         return 0;
	  }
   }

   return CallWindowProc(g_pfnStartProc, hwnd, uMsg, wParam, lParam);
}


void RemoveTooltip(HWND hwndStart)
{
   EnumThreadWindows(GetCurrentThreadId(), EnumThreadWndProc, reinterpret_cast<LPARAM>(hwndStart));
}


// This thread created just one tooltip window. All the windows that belong
//  to the thread are enumerated in order to find the tooltip. This
//  callback receives the handle of all the windows the thread created. The
//  lParam is the handle (hwndStart) of the Start button.
BOOL CALLBACK EnumThreadWndProc(HWND hwnd, LPARAM lParam)
{
   TCHAR szClass[MAX_PATH] = {0};
   GetClassName(hwnd, szClass, MAX_PATH);
   if(0 == lstrcmpi(szClass, TOOLTIPS_CLASS))
   {
      // Tooltip window found, so try to locate the tool
      int iNumOfTools = SendMessage(hwnd, TTM_GETTOOLCOUNT, 0, 0);
      for(int i = 0 ; i < iNumOfTools ; i++)
      {
         // Get information about the ith tool
         TOOLINFO ti;
         g_hwndTip = hwnd;
         ti.cbSize = sizeof(TOOLINFO);
         SendMessage(hwnd, TTM_ENUMTOOLS, i, reinterpret_cast<LPARAM>(&ti));
         if(ti.uId == static_cast<UINT>(lParam))
         {
            // Tool for the Start button found.
            CopyMemory(&g_ti, &ti, sizeof(TOOLINFO));
            ti.lpszText = __TEXT("Buy this book!");
            SendMessage(hwnd, TTM_UPDATETIPTEXT, 0, reinterpret_cast<LPARAM>(&ti));
         }
      }
      return FALSE;
   }
   return TRUE;
}


void GetStartMenuPosition(LPSTARTMENUPOS lpsmp)
{
   // Get the taskbar's edge and position
   APPBARDATA abd;
   abd.cbSize = sizeof(APPBARDATA);
   SHAppBarMessage(ABM_GETTASKBARPOS, &abd);

   switch(abd.uEdge)
   {
   case ABE_BOTTOM:
      lpsmp->ix = 0;
      lpsmp->iy = abd.rc.top;
      lpsmp->uFlags = TPM_LEFTALIGN | TPM_BOTTOMALIGN;
      break;

   case ABE_TOP:
      lpsmp->ix = 0;
      lpsmp->iy = abd.rc.bottom;
      lpsmp->uFlags = TPM_LEFTALIGN | TPM_TOPALIGN;
      break;

   case ABE_LEFT:
      lpsmp->ix = abd.rc.right;
      lpsmp->iy = 0;
      lpsmp->uFlags = TPM_LEFTALIGN | TPM_TOPALIGN;
      break;

   case ABE_RIGHT:
      lpsmp->ix = abd.rc.left;
      lpsmp->iy = 0;
      lpsmp->uFlags = TPM_RIGHTALIGN | TPM_TOPALIGN;
      break;
   }
}


HMENU GetMenuHandle(LPTSTR szPath)