windows/scroll.c

   1 /*
   2  * Scroll windows and DCs
   3  *
   4  * Copyright  David W. Metcalfe, 1993
   5  *            Alex Korobka       1995,1996
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include <stdarg.h>
  23 #include <stdlib.h>
  24
  25 #include "windef.h"
  26 #include "winbase.h"
  27 #include "wingdi.h"
  28 #include "wine/winuser16.h"
  29 #include "winuser.h"
  30 #include "user.h"
  31 #include "win.h"
  32 #include "wine/debug.h"
  33
  34 WINE_DEFAULT_DEBUG_CHANNEL(scroll);
  35
  36 /*************************************************************************
  37  *             fix_caret
  38  */
  39 static HWND fix_caret(HWND hWnd, LPRECT lprc, UINT flags)
  40 {
  41     GUITHREADINFO info;
  42
  43     if (!GetGUIThreadInfo( GetCurrentThreadId(), &info )) return 0;
  44     if (!info.hwndCaret) return 0;
  45     if (info.hwndCaret == hWnd ||
  46         ((flags & SW_SCROLLCHILDREN) && IsChild(hWnd, info.hwndCaret)))
  47     {
  48         POINT pt;
  49         pt.x = info.rcCaret.left;
  50         pt.y = info.rcCaret.top;
  51         MapWindowPoints( info.hwndCaret, hWnd, (LPPOINT)&info.rcCaret, 2 );
  52         if( IntersectRect(lprc, lprc, &info.rcCaret) )
  53         {
  54             HideCaret(0);
  55             lprc->left = pt.x;
  56             lprc->top = pt.y;
  57             return info.hwndCaret;
  58         }
  59     }
  60     return 0;
  61 }
  62
  63
  64 /*************************************************************************
  65  *              ScrollWindow (USER32.@)
  66  *
  67  */
  68 BOOL WINAPI ScrollWindow( HWND hwnd, INT dx, INT dy,
  69                               const RECT *rect, const RECT *clipRect )
  70 {
  71     return
  72         (ERROR != ScrollWindowEx( hwnd, dx, dy, rect, clipRect, 0, NULL,
  73                                     (rect ? 0 : SW_SCROLLCHILDREN) |
  74                                     SW_INVALIDATE ));
  75 }
  76
  77 /*************************************************************************
  78  *              ScrollDC (USER32.@)
  79  *
  80  *   Only the hrgnUpdate is return in device coordinate.
  81  *   rcUpdate must be returned in logical coordinate to comply with win API.
  82  *
  83  */
  84 BOOL WINAPI ScrollDC( HDC hdc, INT dx, INT dy, const RECT *rc,
  85                           const RECT *prLClip, HRGN hrgnUpdate,
  86                           LPRECT rcUpdate )
  87 {
  88     if (USER_Driver.pScrollDC)
  89         return USER_Driver.pScrollDC( hdc, dx, dy, rc, prLClip, hrgnUpdate, rcUpdate );
  90     return FALSE;
  91 }
  92
  93
  94 /*************************************************************************
  95  *              ScrollWindowEx (USER32.@)
  96  *
  97  * NOTE: Use this function instead of ScrollWindow32
  98  */
  99 INT WINAPI ScrollWindowEx( HWND hwnd, INT dx, INT dy,
 100                                const RECT *rect, const RECT *clipRect,
 101                                HRGN hrgnUpdate, LPRECT rcUpdate,
 102                                UINT flags )
 103 {
 104     RECT rc, cliprc;
 105     INT result;
 106
 107     if (!WIN_IsWindowDrawable( hwnd, TRUE )) return ERROR;
 108     hwnd = WIN_GetFullHandle( hwnd );
 109
 110     GetClientRect(hwnd, &rc);
 111     if (rect) IntersectRect(&rc, &rc, rect);
 112
 113     if (clipRect) IntersectRect(&cliprc,&rc,clipRect);
 114     else cliprc = rc;
 115
 116     if (!IsRectEmpty(&cliprc) && (dx || dy))
 117     {
 118         RECT caretrc = rc;
 119         HWND hwndCaret = fix_caret(hwnd, &caretrc, flags);
 120
 121         if (USER_Driver.pScrollWindowEx)
 122             result = USER_Driver.pScrollWindowEx( hwnd, dx, dy, rect, clipRect,
 123                                                   hrgnUpdate, rcUpdate, flags );
 124         else
 125             result = ERROR; /* FIXME: we should have a fallback implementation */
 126
 127         if( hwndCaret )
 128         {
 129             SetCaretPos( caretrc.left + dx, caretrc.top + dy );
 130             ShowCaret(hwndCaret);
 131         }
 132     }
 133     else
 134         result = NULLREGION;
 135
 136     return result;
 137 }