Hi, I have written a small C program using win32 functions. I want to basically enable the line buffering. For ex: when the text reaches to the end of the window, i want to scroll the text to one line above then then print the next line to the end of the window. Problem: I am able to scroll the text up when i reach to the end of the window but i m unable to see the next lines being printed to the end of the window. Can you please point out the flaw in my code. Collapse | Copy Code Code: // code for your reference // LRESULT CALLBACK WndProc( HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam ) { static cxChar, cyChar, cxClient, cyClient, iVertPos = 0, iCnt = 0; HDC hdc; PAINTSTRUCT ps; TEXTMETRIC tm; static RECT rect; static TCHAR cCh, cScrollFlag = 'N'; TCHAR szBuffer[30]; switch( message ) { case WM_CREATE: hdc = GetDC( hwnd ); GetTextMetrics( hdc, &tm ); cxChar = tm.tmAveCharWidth; cyChar = tm.tmHeight; ReleaseDC( hwnd, hdc ); break; case WM_SIZE: cxClient = LOWORD( lParam ); cyClient = HIWORD( lParam ); rect.left = cxChar; rect.right = cxClient; rect.top = cyChar; rect.bottom = cyClient; InvalidateRect( hwnd, &rect, TRUE ); break; case WM_CHAR: cCh = wParam; iVertPos = ++iCnt * cyChar; if( iVertPos >= cyClient ) // reached to the end of the window // { cScrollFlag = 'Y'; ScrollWindow( hwnd, 0, -cyChar, &rect, &rect ); } else // did not reach to the end of the window // { InvalidateRect( hwnd, &rect, FALSE ); cScrollFlag = 'N'; } break; case WM_PAINT: hdc = BeginPaint( hwnd, &ps ); wsprintf( szBuffer, TEXT("[%2d] Key pressed: %c, current pos: %d"), iCnt, cCh, iVertPos ); if( iVertPos ) { if( cScrollFlag == 'Y' ) // if scrolling required // { TextOut( hdc, cxChar, iVertPos, szBuffer, lstrlen( szBuffer ) ); } else // scroll not required // { TextOut( hdc, cxChar, iVertPos, szBuffer, lstrlen( szBuffer ) ); } } EndPaint( hwnd, &ps ); break; case WM_DESTROY: PostQuitMessage(0); break; } return DefWindowProc( hwnd, message, wParam, lParam ); } // Note: I wanted to achieve this using raw Win32 functions but not re-implementing the same using MFC or some other advanced concepts. Thanks
