clipview.c

Windows Programming source code

/*-----------------------------------------
   CLIPVIEW.C -- Simple Clipboard Viewer
                 (c) Charles Petzold, 1998
  -----------------------------------------*/

#include <windows.h>

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
     static TCHAR szAppName[] = TEXT ("ClipView") ;
     HWND         hwnd ;
     MSG          msg ;
     WNDCLASS     wndclass ;
     
     wndclass.style         = CS_HREDRAW | CS_VREDRAW ;
     wndclass.lpfnWndProc   = WndProc ;
     wndclass.cbClsExtra    = 0 ;
     wndclass.cbWndExtra    = 0 ;
     wndclass.hInstance     = hInstance ;
     wndclass.hIcon         = LoadIcon (NULL, IDI_APPLICATION) ;
     wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW) ;
     wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
     wndclass.lpszMenuName  = NULL ;
     wndclass.lpszClassName = szAppName ;
     
     if (!RegisterClass (&wndclass))
     {
          MessageBox (NULL, TEXT ("This program requires Windows NT!"),
                      szAppName, MB_ICONERROR) ;
          return 0 ;
     }
     
     hwnd = CreateWindow (szAppName, 
                          TEXT ("Simple Clipboard Viewer (Text Only)"),
                          WS_OVERLAPPEDWINDOW,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          NULL, NULL, hInstance, NULL) ;
     
     ShowWindow (hwnd, iCmdShow) ;
     UpdateWindow (hwnd) ;
     
     while (GetMessage (&msg, NULL, 0, 0))
     {
          TranslateMessage (&msg) ;
          DispatchMessage (&msg) ;
     }
     return msg.wParam ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
     static HWND hwndNextViewer ;
     HGLOBAL     hGlobal ;
     HDC         hdc ;
     PTSTR       pGlobal ;
     PAINTSTRUCT ps ;
     RECT        rect ;
     
     switch (message)
     {
     case WM_CREATE:
          hwndNextViewer = SetClipboardViewer (hwnd) ;
          return 0 ;
          
     case WM_CHANGECBCHAIN:
          if ((HWND) wParam == hwndNextViewer)
               hwndNextViewer = (HWND) lParam ;
          
          else if (hwndNextViewer)
               SendMessage (hwndNextViewer, message, wParam, lParam) ;
          
          return 0 ;
          
     case WM_DRAWCLIPBOARD:
          if (hwndNextViewer)
               SendMessage (hwndNextViewer, message, wParam, lParam) ;
          
          InvalidateRect (hwnd, NULL, TRUE) ;
          return 0 ;
          
     case WM_PAINT:
          hdc = BeginPaint (hwnd, &ps) ;
          GetClientRect (hwnd, &rect) ;
          OpenClipboard (hwnd) ;
          
#ifdef UNICODE
          hGlobal = GetClipboardData (CF_UNICODETEXT) ;
#else
          hGlobal = GetClipboardData (CF_TEXT) ;
#endif
          
          if (hGlobal != NULL)
          {
               pGlobal = (PTSTR) GlobalLock (hGlobal) ;
               DrawText (hdc, pGlobal, -1, &rect, DT_EXPANDTABS) ;
               GlobalUnlock (hGlobal) ;
          }
          
          CloseClipboard () ;
          EndPaint (hwnd, &ps) ;
          return 0 ;
          
     case WM_DESTROY:
          ChangeClipboardChain (hwnd, hwndNextViewer) ;
          PostQuitMessage (0) ;
          return 0 ;
     }
     return DefWindowProc (hwnd, message, wParam, lParam) ;
}