sdk/samples/all in on code/Visual Studio 2008/CppSetDesktopWallpaper/Wallpaper.cpp

   1 /****************************** Module Header ******************************\
   2 Module Name:  Wallpaper.cpp
   3 Project:      CppSetDesktopWallpaper
   4 Copyright (c) Microsoft Corporation.
   5
   6 The file defines the wallpaper helper functions.
   7
   8     BOOL SupportJpgAsWallpaper();
   9     BOOL SupportFitFillWallpaperStyles();
  10     HRESULT SetDesktopWallpaper(PWSTR pszFile, WallpaperStyle style);
  11
  12 SetDesktopWallpaper is the key function that sets the desktop wallpaper. The
  13 function body is composed of configuring the wallpaper style in the registry
  14 and setting the wallpaper with SystemParametersInfo.
  15
  16 This source is subject to the Microsoft Public License.
  17 See http://www.microsoft.com/opensource/licenses.mspx#Ms-PL.
  18 All other rights reserved.
  19
  20 THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
  21 EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
  22 WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
  23 \***************************************************************************/
  24
  25 #include <stdio.h>
  26 #include <windows.h>
  27 #include "Wallpaper.h"
  28
  29
  30 //
  31 //   FUNCTION: SupportJpgAsWallpaper()
  32 //
  33 //   PURPOSE: Determine if .jpg files are supported as wallpaper in the
  34 //   current operating system. The .jpg wallpapers are not supported before
  35 //   Windows Vista.
  36 //
  37 BOOL SupportJpgAsWallpaper()
  38 {
  39     OSVERSIONINFOEX osVersionInfoToCompare = { sizeof(OSVERSIONINFOEX) };
  40     osVersionInfoToCompare.dwMajorVersion = 6;
  41     osVersionInfoToCompare.dwMinorVersion = 0;
  42
  43     ULONGLONG comparisonInfo = 0;
  44     BYTE conditionMask = VER_GREATER_EQUAL;
  45     VER_SET_CONDITION(comparisonInfo, VER_MAJORVERSION, conditionMask);
  46     VER_SET_CONDITION(comparisonInfo, VER_MINORVERSION, conditionMask);
  47
  48     return VerifyVersionInfo(&osVersionInfoToCompare,
  49         VER_MAJORVERSION | VER_MINORVERSION, comparisonInfo);
  50 }
  51
  52
  53 //
  54 //   FUNCTION: SupportFitFillWallpaperStyles()
  55 //
  56 //   PURPOSE: Determine if the fit and fill wallpaper styles are supported in
  57 //   the current operating system. The styles are not supported before
  58 //   Windows 7.
  59 //
  60 BOOL SupportFitFillWallpaperStyles()
  61 {
  62     OSVERSIONINFOEX osVersionInfoToCompare = { sizeof(OSVERSIONINFOEX) };
  63     osVersionInfoToCompare.dwMajorVersion = 6;
  64     osVersionInfoToCompare.dwMinorVersion = 1;
  65
  66     ULONGLONG comparisonInfo = 0;
  67     BYTE conditionMask = VER_GREATER_EQUAL;
  68     VER_SET_CONDITION(comparisonInfo, VER_MAJORVERSION, conditionMask);
  69     VER_SET_CONDITION(comparisonInfo, VER_MINORVERSION, conditionMask);
  70
  71     return VerifyVersionInfo(&osVersionInfoToCompare,
  72         VER_MAJORVERSION | VER_MINORVERSION, comparisonInfo);
  73 }
  74
  75
  76 //
  77 //   FUNCTION: SetDesktopWallpaper(PCWSTR, WallpaperStyle)
  78 //
  79 //   PURPOSE: Set the desktop wallpaper.
  80 //
  81 //   PARAMETERS:
  82 //   * pszFile - Path of the wallpaper
  83 //   * style - Wallpaper style
  84 //
  85 HRESULT SetDesktopWallpaper(PWSTR pszFile, WallpaperStyle style)
  86 {
  87     HRESULT hr = S_OK;
  88
  89     // Set the wallpaper style and tile.
  90     // Two registry values are set in the Control Panel\Desktop key.
  91     // TileWallpaper
  92     //  0: The wallpaper picture should not be tiled
  93     //  1: The wallpaper picture should be tiled
  94     // WallpaperStyle
  95     //  0:  The image is centered if TileWallpaper=0 or tiled if TileWallpaper=1
  96     //  2:  The image is stretched to fill the screen
  97     //  6:  The image is resized to fit the screen while maintaining the aspect
  98     //      ratio. (Windows 7 and later)
  99     //  10: The image is resized and cropped to fill the screen while
 100     //      maintaining the aspect ratio. (Windows 7 and later)
 101
 102     // Open the HKCU\Control Panel\Desktop registry key.
 103     HKEY hKey = NULL;
 104     hr = HRESULT_FROM_WIN32(RegOpenKeyEx(HKEY_CURRENT_USER,
 105         L"Control Panel\\Desktop", 0, KEY_READ | KEY_WRITE, &hKey));
 106     if (SUCCEEDED(hr))
 107     {
 108         PWSTR pszWallpaperStyle;
 109         PWSTR pszTileWallpaper;
 110
 111         switch (style)
 112         {
 113         case Tile:
 114             pszWallpaperStyle = L"0";
 115             pszTileWallpaper = L"1";
 116             break;
 117
 118         case Center:
 119             pszWallpaperStyle = L"0";
 120             pszTileWallpaper = L"0";
 121             break;
 122
 123         case Stretch:
 124             pszWallpaperStyle = L"2";
 125             pszTileWallpaper = L"0";
 126             break;
 127
 128         case Fit: // (Windows 7 and later)
 129             pszWallpaperStyle = L"6";
 130             pszTileWallpaper = L"0";
 131             break;
 132
 133         case Fill: // (Windows 7 and later)
 134             pszWallpaperStyle = L"10";
 135             pszTileWallpaper = L"0";
 136             break;
 137         }
 138
 139         // Set the WallpaperStyle and TileWallpaper registry values.
 140         DWORD cbData = lstrlen(pszWallpaperStyle) * sizeof(*pszWallpaperStyle);
 141         hr = HRESULT_FROM_WIN32(RegSetValueEx(hKey, L"WallpaperStyle", 0, REG_SZ,
 142             reinterpret_cast<const BYTE *>(pszWallpaperStyle), cbData));
 143         if (SUCCEEDED(hr))
 144         {
 145             cbData = lstrlen(pszTileWallpaper) * sizeof(*pszTileWallpaper);
 146             hr = HRESULT_FROM_WIN32(RegSetValueEx(hKey, L"TileWallpaper", 0, REG_SZ,
 147                 reinterpret_cast<const BYTE *>(pszTileWallpaper), cbData));
 148         }
 149
 150         RegCloseKey(hKey);
 151     }
 152
 153     // Set the desktop wallpapaer by calling the Win32 API SystemParametersInfo
 154     // with the SPI_SETDESKWALLPAPER desktop parameter. The changes should
 155     // persist, and also be immediately visible.
 156     if (SUCCEEDED(hr))
 157     {
 158         if (!SystemParametersInfo(SPI_SETDESKWALLPAPER, 0,
 159             static_cast<PVOID>(pszFile),
 160             SPIF_UPDATEINIFILE | SPIF_SENDWININICHANGE))
 161         {
 162             hr = HRESULT_FROM_WIN32(GetLastError());
 163         }
 164     }
 165
 166     return hr;
 167 }