testing/tools/screenshot/win32-screenshot.cpp

   1 /*
   2  * Copyright (c) 2009, The Mozilla Foundation
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are met:
   7  *     * Redistributions of source code must retain the above copyright
   8  *       notice, this list of conditions and the following disclaimer.
   9  *     * Redistributions in binary form must reproduce the above copyright
  10  *       notice, this list of conditions and the following disclaimer in the
  11  *       documentation and/or other materials provided with the distribution.
  12  *     * Neither the name of the Mozilla Foundation nor the
  13  *       names of its contributors may be used to endorse or promote products
  14  *       derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY The Mozilla Foundation ''AS IS'' AND ANY
  17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  19  * DISCLAIMED. IN NO EVENT SHALL The Mozilla Foundation BE LIABLE FOR ANY
  20  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  23  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  25  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  *
  27  * Contributors:
  28  *   Ted Mielczarek <ted.mielczarek@gmail.com>
  29  */
  30 /*
  31  * win32-screenshot.cpp: Save a screenshot of the Windows desktop in .png
  32  * format. If a filename is specified as the first argument on the commandline,
  33  *  then the image will be saved to that filename. Otherwise, the image will
  34  *  be saved as "screenshot.png" in the current working directory.
  35  */
  36
  37 // VS2015: Platform SDK 8.1's GdiplusTypes.h uses the min macro
  38 #undef NOMINMAX
  39 #undef WIN32_LEAN_AND_MEAN
  40 #include <windows.h>
  41 #include <gdiplus.h>
  42
  43 // Link w/ subsystem windows so we don't get a console when executing
  44 // this binary.
  45 #ifndef __MINGW32__
  46 #  pragma comment(linker, "/SUBSYSTEM:windows /ENTRY:wmainCRTStartup")
  47 #endif
  48
  49 using namespace Gdiplus;
  50
  51 // From http://msdn.microsoft.com/en-us/library/ms533843%28VS.85%29.aspx
  52 static int GetEncoderClsid(const WCHAR* format, CLSID* pClsid) {
  53   UINT num = 0;   // number of image encoders
  54   UINT size = 0;  // size of the image encoder array in bytes
  55
  56   ImageCodecInfo* pImageCodecInfo = nullptr;
  57
  58   GetImageEncodersSize(&num, &size);
  59   if (size == 0) return -1;  // Failure
  60
  61   pImageCodecInfo = (ImageCodecInfo*)(malloc(size));
  62   if (pImageCodecInfo == nullptr) return -1;  // Failure
  63
  64   GetImageEncoders(num, size, pImageCodecInfo);
  65
  66   for (UINT j = 0; j < num; ++j) {
  67     if (wcscmp(pImageCodecInfo[j].MimeType, format) == 0) {
  68       *pClsid = pImageCodecInfo[j].Clsid;
  69       free(pImageCodecInfo);
  70       return j;  // Success
  71     }
  72   }
  73
  74   free(pImageCodecInfo);
  75   return -1;  // Failure
  76 }
  77
  78 #ifdef __MINGW32__
  79 extern "C"
  80 #endif
  81     int
  82     wmain(int argc, wchar_t** argv) {
  83   GdiplusStartupInput gdiplusStartupInput;
  84   ULONG_PTR gdiplusToken;
  85   GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, nullptr);
  86
  87   HWND desktop = GetDesktopWindow();
  88   HDC desktopdc = GetDC(desktop);
  89   HDC mydc = CreateCompatibleDC(desktopdc);
  90   int width = GetSystemMetrics(SM_CXSCREEN);
  91   int height = GetSystemMetrics(SM_CYSCREEN);
  92   HBITMAP mybmp = CreateCompatibleBitmap(desktopdc, width, height);
  93   HBITMAP oldbmp = (HBITMAP)SelectObject(mydc, mybmp);
  94   BitBlt(mydc, 0, 0, width, height, desktopdc, 0, 0, SRCCOPY | CAPTUREBLT);
  95   SelectObject(mydc, oldbmp);
  96
  97   const wchar_t* filename = (argc > 1) ? argv[1] : L"screenshot.png";
  98   Bitmap* b = Bitmap::FromHBITMAP(mybmp, nullptr);
  99   CLSID encoderClsid;
 100   Status stat = GenericError;
 101   if (b && GetEncoderClsid(L"image/png", &encoderClsid) != -1) {
 102     stat = b->Save(filename, &encoderClsid, nullptr);
 103   }
 104   if (b) delete b;
 105
 106   // cleanup
 107   GdiplusShutdown(gdiplusToken);
 108   ReleaseDC(desktop, desktopdc);
 109   DeleteObject(mybmp);
 110   DeleteDC(mydc);
 111   return stat == Ok ? 0 : 1;
 112 }