ownerdrw.c

Programming Windows 程序开发设计指南

/*----------------------------------------------
   OWNERDRW.C -- Owner-Draw Button Demo Program
                 (c) Charles Petzold, 1996
  ----------------------------------------------*/

#include <windows.h>

#define IDC_SMALLER      1
#define IDC_LARGER       2

#define BTN_WIDTH        (8 * cxChar)
#define BTN_HEIGHT       (4 * cyChar)

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

HINSTANCE hInst ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
		    PSTR szCmdLine, int iCmdShow)
     {
     static char szAppName[] = "OwnerDrw" ;
     MSG         msg ;
     HWND        hwnd ;
     WNDCLASSEX  wndclass ;

     hInst = hInstance ;

	 wndclass.cbSize        = sizeof (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  = szAppName ;
     wndclass.lpszClassName = szAppName ;
	 wndclass.hIconSm       = LoadIcon (NULL, IDI_APPLICATION) ;

     RegisterClassEx (&wndclass) ;

     hwnd = CreateWindow (szAppName, "Owner-Draw Button Demo",
                          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 ;
     }

void Triangle (HDC hdc, POINT pt[])
     {
     SelectObject (hdc, GetStockObject (BLACK_BRUSH)) ;
     Polygon (hdc, pt, 3) ;
     SelectObject (hdc, GetStockObject (WHITE_BRUSH)) ;
     }

LRESULT CALLBACK WndProc (HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
     {
     static HWND      hwndSmaller, hwndLarger ;
     static int       cxClient, cyClient, cxChar, cyChar ;
     int              cx, cy ;
     LPDRAWITEMSTRUCT pdis ;
     POINT            pt[3] ;
     RECT             rc ;

     switch (iMsg)
          {
          case WM_CREATE :
               cxChar = LOWORD (GetDialogBaseUnits ()) ;
               cyChar = HIWORD (GetDialogBaseUnits ()) ;

                         // Create the owner-draw pushbuttons

               hwndSmaller = CreateWindow ("button", "",
                                  WS_CHILD | WS_VISIBLE | BS_OWNERDRAW,
                                  0, 0, BTN_WIDTH, BTN_HEIGHT,
                                  hwnd, (HMENU) IDC_SMALLER, hInst, NULL) ;

               hwndLarger = CreateWindow ("button", "",
                                  WS_CHILD | WS_VISIBLE | BS_OWNERDRAW,
                                  0, 0, BTN_WIDTH, BTN_HEIGHT,
                                  hwnd, (HMENU) IDC_LARGER, hInst, NULL) ;
               return 0 ;

          case WM_SIZE :
               cxClient = LOWORD (lParam) ;
               cyClient = HIWORD (lParam) ;

                         // Move the buttons to the new center

               MoveWindow (hwndSmaller, cxClient / 2 - 3 * BTN_WIDTH  / 2,
                                        cyClient / 2 -     BTN_HEIGHT / 2,
                                        BTN_WIDTH, BTN_HEIGHT, TRUE) ;

               MoveWindow (hwndLarger,  cxClient / 2 +     BTN_WIDTH  / 2,
                                        cyClient / 2 -     BTN_HEIGHT / 2,
                                        BTN_WIDTH, BTN_HEIGHT, TRUE) ;
               return 0 ;

          case WM_COMMAND :
               GetWindowRect (hwnd, &rc) ;

                         // Make the window 10% smaller or larger

               switch (wParam)
                    {
                    case IDC_SMALLER :
                         rc.left   += cxClient / 20 ;
                         rc.right  -= cxClient / 20 ;
                         rc.top    += cyClient / 20 ;
                         rc.bottom -= cyClient / 20 ;

                         break ;

                    case IDC_LARGER :
                         rc.left   -= cxClient / 20 ;
                         rc.right  += cxClient / 20 ;
                         rc.top    -= cyClient / 20 ;
                         rc.bottom += cyClient / 20 ;

                         break ;
                    }

               MoveWindow (hwnd, rc.left, rc.top, rc.right  - rc.left,
                                                  rc.bottom - rc.top, TRUE) ;
               return 0 ;

          case WM_DRAWITEM :
               pdis = (LPDRAWITEMSTRUCT) lParam ;

                         // Fill area with white and frame it black

               FillRect (pdis->hDC, &pdis->rcItem,
                         (HBRUSH) GetStockObject (WHITE_BRUSH)) ;

               FrameRect (pdis->hDC, &pdis->rcItem,
                          (HBRUSH) GetStockObject (BLACK_BRUSH)) ;

                         // Draw inward and outward black triangles

               cx = pdis->rcItem.right  - pdis->rcItem.left ;
               cy = pdis->rcItem.bottom - pdis->rcItem.top  ;

               switch (pdis->CtlID)
                    {
                    case IDC_SMALLER :
                         pt[0].x = 3 * cx / 8 ;  pt[0].y = 1 * cy / 8 ;
                         pt[1].x = 5 * cx / 8 ;  pt[1].y = 1 * cy / 8 ;
                         pt[2].x = 4 * cx / 8 ;  pt[2].y = 3 * cy / 8 ;

                         Triangle (pdis->hDC, pt) ;

                         pt[0].x = 7 * cx / 8 ;  pt[0].y = 3 * cy / 8 ;
                         pt[1].x = 7 * cx / 8 ;  pt[1].y = 5 * cy / 8 ;
                         pt[2].x = 5 * cx / 8 ;  pt[2].y = 4 * cy / 8 ;

                         Triangle (pdis->hDC, pt) ;

                         pt[0].x = 5 * cx / 8 ;  pt[0].y = 7 * cy / 8 ;
                         pt[1].x = 3 * cx / 8 ;  pt[1].y = 7 * cy / 8 ;
                         pt[2].x = 4 * cx / 8 ;  pt[2].y = 5 * cy / 8 ;

                         Triangle (pdis->hDC, pt) ;

                         pt[0].x = 1 * cx / 8 ;  pt[0].y = 5 * cy / 8 ;
                         pt[1].x = 1 * cx / 8 ;  pt[1].y = 3 * cy / 8 ;
                         pt[2].x = 3 * cx / 8 ;  pt[2].y = 4 * cy / 8 ;

                         Triangle (pdis->hDC, pt) ;

                         break ;

                    case IDC_LARGER :

                         pt[0].x = 5 * cx / 8 ;  pt[0].y = 3 * cy / 8 ;
                         pt[1].x = 3 * cx / 8 ;  pt[1].y = 3 * cy / 8 ;
                         pt[2].x = 4 * cx / 8 ;  pt[2].y = 1 * cy / 8 ;

                         Triangle (pdis->hDC, pt) ;

                         pt[0].x = 5 * cx / 8 ;  pt[0].y = 5 * cy / 8 ;
                         pt[1].x = 5 * cx / 8 ;  pt[1].y = 3 * cy / 8 ;
                         pt[2].x = 7 * cx / 8 ;  pt[2].y = 4 * cy / 8 ;

                         Triangle (pdis->hDC, pt) ;

                         pt[0].x = 3 * cx / 8 ;  pt[0].y = 5 * cy / 8 ;
                         pt[1].x = 5 * cx / 8 ;  pt[1].y = 5 * cy / 8 ;
                         pt[2].x = 4 * cx / 8 ;  pt[2].y = 7 * cy / 8 ;

                         Triangle (pdis->hDC, pt) ;

                         pt[0].x = 3 * cx / 8 ;  pt[0].y = 3 * cy / 8 ;
                         pt[1].x = 3 * cx / 8 ;  pt[1].y = 5 * cy / 8 ;
                         pt[2].x = 1 * cx / 8 ;  pt[2].y = 4 * cy / 8 ;

                         Triangle (pdis->hDC, pt) ;

                         break ;
                    }

                         // Invert the rectangle if the button is selected

               if (pdis->itemState & ODS_SELECTED)
                    InvertRect (pdis->hDC, &pdis->rcItem) ;

                         // Draw a focus rectangle if the button has the focus

               if (pdis->itemState & ODS_FOCUS)
                    {
                    pdis->rcItem.left   += cx / 16 ;
                    pdis->rcItem.top    += cy / 16 ;
                    pdis->rcItem.right  -= cx / 16 ;
                    pdis->rcItem.bottom -= cy / 16 ;

                    DrawFocusRect (pdis->hDC, &pdis->rcItem) ;
                    }

               return 0 ;

          case WM_DESTROY :
               PostQuitMessage (0) ;
               return 0 ;
          }
     return DefWindowProc (hwnd, iMsg, wParam, lParam) ;
     }