win32/examples/hello_win.c

   1 //+---------------------------------------------------------------------------
   2 //
   3 //  HELLO_WIN.C - Windows GUI 'Hello World!' Example
   4 //
   5 //+---------------------------------------------------------------------------
   6
   7 #include <windows.h>
   8
   9 #define APPNAME "HELLO_WIN"
  10
  11 char szAppName[] = APPNAME; // The name of this application
  12 char szTitle[]   = APPNAME; // The title bar text
  13 char *pWindowText;
  14
  15 HINSTANCE g_hInst;          // current instance
  16
  17 void CenterWindow(HWND hWnd);
  18
  19 //+---------------------------------------------------------------------------
  20 //
  21 //  Function:   WndProc
  22 //
  23 //  Synopsis:   very unusual type of function - gets called by system to
  24 //              process windows messages.
  25 //
  26 //  Arguments:  same as always.
  27 //----------------------------------------------------------------------------
  28
  29 LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
  30 {
  31         switch (message)
  32         {
  33                 // ----------------------- first and last
  34                 case WM_CREATE:
  35                         CenterWindow(hwnd);
  36                         break;
  37
  38                 case WM_DESTROY:
  39                         PostQuitMessage(0);
  40                         break;
  41
  42
  43                 // ----------------------- get out of it...
  44                 case WM_RBUTTONUP:
  45                         DestroyWindow(hwnd);
  46                         break;
  47
  48                 case WM_KEYDOWN:
  49                         if (VK_ESCAPE == wParam)
  50                                 DestroyWindow(hwnd);
  51                         break;
  52
  53
  54                 // ----------------------- display our minimal info
  55                 case WM_PAINT:
  56                 {
  57                         PAINTSTRUCT ps;
  58                         HDC         hdc;
  59                         RECT        rc;
  60                         hdc = BeginPaint(hwnd, &ps);
  61
  62                         GetClientRect(hwnd, &rc);
  63                         SetTextColor(hdc, RGB(240,240,96));
  64                         SetBkMode(hdc, TRANSPARENT);
  65                         DrawText(hdc, pWindowText, -1, &rc, DT_CENTER|DT_SINGLELINE|DT_VCENTER);
  66
  67                         EndPaint(hwnd, &ps);
  68                         break;
  69                 }
  70
  71                 // ----------------------- let windows do all other stuff
  72                 default:
  73                         return DefWindowProc(hwnd, message, wParam, lParam);
  74         }
  75         return 0;
  76 }
  77
  78 //+---------------------------------------------------------------------------
  79 //
  80 //  Function:   WinMain
  81 //
  82 //  Synopsis:   standard entrypoint for GUI Win32 apps
  83 //
  84 //----------------------------------------------------------------------------
  85 int APIENTRY WinMain(
  86                                 HINSTANCE hInstance,
  87                                 HINSTANCE hPrevInstance,
  88                                 LPSTR     lpCmdLine,
  89                                 int       nCmdShow)
  90 {
  91         MSG msg;
  92
  93         WNDCLASS wc;
  94
  95         HWND hwnd;
  96
  97         // Fill in window class structure with parameters that describe
  98         // the main window.
  99
 100         ZeroMemory(&wc, sizeof wc);
 101         wc.hInstance     = hInstance;
 102         wc.lpszClassName = szAppName;
 103         wc.lpfnWndProc   = (WNDPROC)WndProc;
 104         wc.style         = CS_DBLCLKS|CS_VREDRAW|CS_HREDRAW;
 105         wc.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
 106         wc.hIcon         = LoadIcon(NULL, IDI_APPLICATION);
 107         wc.hCursor       = LoadCursor(NULL, IDC_ARROW);
 108
 109         if (FALSE == RegisterClass(&wc)) return 0;
 110
 111         // create the browser
 112         hwnd = CreateWindow(
 113                 szAppName,
 114                 szTitle,
 115                 WS_OVERLAPPEDWINDOW|WS_VISIBLE,
 116                 CW_USEDEFAULT,
 117                 CW_USEDEFAULT,
 118                 360,//CW_USEDEFAULT,
 119                 240,//CW_USEDEFAULT,
 120                 0,
 121                 0,
 122                 g_hInst,
 123                 0);
 124
 125         if (NULL == hwnd) return 0;
 126
 127         pWindowText = lpCmdLine[0] ? lpCmdLine : "Hello Windows!";
 128
 129         // Main message loop:
 130         while (GetMessage(&msg, NULL, 0, 0) > 0)
 131         {
 132                 TranslateMessage(&msg);
 133                 DispatchMessage(&msg);
 134         }
 135
 136         return msg.wParam;
 137 }
 138
 139 //+---------------------------------------------------------------------------
 140
 141 //+---------------------------------------------------------------------------
 142
 143 void CenterWindow(HWND hwnd_self)
 144 {
 145         RECT rw_self, rc_parent, rw_parent; HWND hwnd_parent;
 146         hwnd_parent = GetParent(hwnd_self);
 147         if (NULL==hwnd_parent) hwnd_parent = GetDesktopWindow();
 148         GetWindowRect(hwnd_parent, &rw_parent);
 149         GetClientRect(hwnd_parent, &rc_parent);
 150         GetWindowRect(hwnd_self, &rw_self);
 151         SetWindowPos(hwnd_self, NULL,
 152                 rw_parent.left + (rc_parent.right + rw_self.left - rw_self.right) / 2,
 153                 rw_parent.top  + (rc_parent.bottom + rw_self.top - rw_self.bottom) / 2,
 154                 0, 0,
 155                 SWP_NOSIZE|SWP_NOZORDER|SWP_NOACTIVATE
 156                 );
 157 }
 158
 159 //+---------------------------------------------------------------------------