apps/tests/wm_paint/Listing1_1.cpp

   1
   2 // ------------------------------------------------------------------
   3 // Windows 2000 Graphics API Black Book
   4 // Chapter 1 - Listing 1.1 (WM_PAINT Demo)
   5 //
   6 // Created by Damon Chandler <dmc27@ee.cornell.edu>
   7 // Updates can be downloaded at: <www.coriolis.com>
   8 //
   9 // Please do not hesistate to e-mail me at dmc27@ee.cornell.edu
  10 // if you have any questions about this code.
  11 // ------------------------------------------------------------------
  12
  13
  14 //>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
  15 #include <windows.h>
  16 //<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
  17
  18
  19 const char* WndClassName = "GMainWnd";
  20 LRESULT CALLBACK MainWndProc(HWND HWnd, UINT Msg, WPARAM WParam,
  21    LPARAM LParam);
  22
  23
  24 int APIENTRY WinMain(HINSTANCE HInstance, HINSTANCE HPrevInstance,
  25     LPTSTR lpCmdLine, int nCmdShow)
  26 {
  27    WNDCLASS wc;
  28    memset(&wc, 0, sizeof(WNDCLASS));
  29
  30    wc.style = CS_VREDRAW | CS_HREDRAW | CS_DBLCLKS;
  31    wc.lpfnWndProc = MainWndProc;
  32    wc.hInstance = HInstance;
  33    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
  34    wc.hbrBackground =
  35       reinterpret_cast<HBRUSH>(COLOR_BTNFACE + 1);
  36    wc.lpszClassName = WndClassName;
  37
  38    if (RegisterClass(&wc))
  39    {
  40       HWND HWnd =
  41          CreateWindow(WndClassName, TEXT("WM_PAINT Demo"),
  42                       WS_OVERLAPPEDWINDOW | WS_CAPTION | WS_VISIBLE,
  43                       CW_USEDEFAULT, CW_USEDEFAULT, 200, 150,
  44                       NULL, NULL, HInstance, NULL);
  45
  46       if (HWnd)
  47       {
  48          ShowWindow(HWnd, nCmdShow);
  49          UpdateWindow(HWnd);
  50
  51          MSG msg;
  52          while (GetMessage(&msg, NULL, 0, 0))
  53          {
  54              TranslateMessage(&msg);
  55              DispatchMessage(&msg);
  56          }
  57       }
  58     }
  59     return 0;
  60 }
  61 //------------------------------------------------------------------
  62
  63
  64 LRESULT CALLBACK MainWndProc(HWND HWnd, UINT Msg, WPARAM WParam,
  65    LPARAM LParam)
  66 {
  67    switch (Msg)
  68    {
  69       case WM_PAINT:
  70       {
  71          // determine the invalidated area of the window
  72          RECT RUpdate;
  73          GetUpdateRect(HWnd, &RUpdate, false);
  74
  75          // grab a handle to our window's
  76          // common display device context
  77          HDC Hdc = GetDC(HWnd);
  78 #if 0
  79          try
  80 #endif
  81          {
  82             RECT RClient;
  83             GetClientRect(HWnd, &RClient);
  84
  85             // set the clipping region
  86             IntersectClipRect(Hdc, RUpdate.left, RUpdate.top,
  87                               RUpdate.right, RUpdate.bottom);
  88
  89             // fill the client area with the background brush
  90             HBRUSH HBrush =
  91                reinterpret_cast<HBRUSH>(
  92                   GetClassLong(HWnd, GCL_HBRBACKGROUND)
  93                   );
  94             FillRect(Hdc, &RClient, HBrush);
  95
  96             // render the persistent text
  97             const char* text = "Persistent Text";
  98             SetTextColor(Hdc, PALETTERGB(0, 0, 255));
  99             DrawText(Hdc, text, strlen(text), &RClient,
 100                      DT_CENTER | DT_VCENTER | DT_SINGLELINE);
 101          }
 102 #if 0
 103          catch (...)
 104 #endif
 105          {
 106             // release the device context
 107             ReleaseDC(HWnd, Hdc);
 108
 109             // validate the update area
 110             ValidateRect(HWnd, &RUpdate);
 111          }
 112          // release the device context
 113          ReleaseDC(HWnd, Hdc);
 114
 115          // validate the update area
 116          ValidateRect(HWnd, &RUpdate);
 117
 118          break;
 119       }
 120       case WM_DESTROY:
 121       {
 122          PostQuitMessage(0);
 123          return 0;
 124       }
 125    }
 126    return DefWindowProc(HWnd, Msg, WParam, LParam);
 127 }
 128 //------------------------------------------------------------------
 129