apps/tests/wm_paint/wm_paint.c

   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    MSG msg;
  28    WNDCLASS wc;
  29    memset(&wc, 0, sizeof(WNDCLASS));
  30
  31    wc.style = CS_VREDRAW | CS_HREDRAW | CS_DBLCLKS;
  32    wc.lpfnWndProc = MainWndProc;
  33    wc.hInstance = HInstance;
  34    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
  35    wc.hbrBackground = (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          while (GetMessage(&msg, NULL, 0, 0))
  52          {
  53              TranslateMessage(&msg);
  54              DispatchMessage(&msg);
  55          }
  56       }
  57     }
  58     return 0;
  59 }
  60 //------------------------------------------------------------------
  61
  62
  63 LRESULT CALLBACK MainWndProc(HWND HWnd, UINT Msg, WPARAM WParam,
  64    LPARAM LParam)
  65 {
  66   const char* text = "Persistent Text";
  67
  68    switch (Msg)
  69    {
  70       case WM_PAINT:
  71       {
  72          // determine the invalidated area of the window
  73          RECT RUpdate;
  74          HDC Hdc;
  75          GetUpdateRect(HWnd, &RUpdate, NULL);
  76
  77          // grab a handle to our window's
  78          // common display device context
  79          Hdc = GetDC(HWnd);
  80 #if 0
  81          try
  82 #endif
  83          {
  84             RECT RClient;
  85             GetClientRect(HWnd, &RClient);
  86
  87             // set the clipping region
  88             IntersectClipRect(Hdc, RUpdate.left, RUpdate.top,
  89                               RUpdate.right, RUpdate.bottom);
  90
  91             // fill the client area with the background brush
  92             //HBRUSH HBrush =
  93                //reinterpret_cast<HBRUSH>
  94                   (HBRUSH)(GetClassLong(HWnd, GCL_HBRBACKGROUND)
  95                   );
  96             FillRect(Hdc, &RClient, NULL);
  97
  98             // render the persistent text
  99             SetTextColor(Hdc, PALETTERGB(0, 0, 255));
 100             DrawText(Hdc, text, strlen(text), &RClient,
 101                      DT_CENTER | DT_VCENTER | DT_SINGLELINE);
 102          }
 103 #if 0
 104          catch (...)
 105 #endif
 106          {
 107             // release the device context
 108             ReleaseDC(HWnd, Hdc);
 109
 110             // validate the update area
 111             ValidateRect(HWnd, &RUpdate);
 112          }
 113          // release the device context
 114          ReleaseDC(HWnd, Hdc);
 115
 116          // validate the update area
 117          ValidateRect(HWnd, &RUpdate);
 118
 119          break;
 120       }
 121       case WM_DESTROY:
 122       {
 123          PostQuitMessage(0);
 124          return 0;
 125       }
 126    }
 127    return DefWindowProc(HWnd, Msg, WParam, LParam);
 128 }
 129 //------------------------------------------------------------------
 130