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 <stdlib.h>
  23
  24 #include "windef.h"
  25 #include "wingdi.h"
  26 #include "wine/winuser16.h"
  27 #include "winuser.h"
  28 #include "user.h"
  29 #include "win.h"
  30 #include "wine/debug.h"
  31
  32 WINE_DEFAULT_DEBUG_CHANNEL(scroll);
  33
  34 /*************************************************************************
  35  *             fix_caret
  36  */
  37 static HWND fix_caret(HWND hWnd, LPRECT lprc, UINT flags)
  38 {
  39     GUITHREADINFO info;
  40
  41     if (!GetGUIThreadInfo( GetCurrentThreadId(), &info )) return 0;
  42     if (!info.hwndCaret) return 0;
  43     if (info.hwndCaret == hWnd ||
  44         ((flags & SW_SCROLLCHILDREN) && IsChild(hWnd, info.hwndCaret)))
  45     {
  46         POINT pt;
  47         pt.x = info.rcCaret.left;
  48         pt.y = info.rcCaret.top;
  49         MapWindowPoints( info.hwndCaret, hWnd, (LPPOINT)&info.rcCaret, 2 );
  50         if( IntersectRect(lprc, lprc, &info.rcCaret) )
  51         {
  52             HideCaret(0);
  53             lprc->left = pt.x;
  54             lprc->top = pt.y;
  55             return info.hwndCaret;
  56         }
  57     }
  58     return 0;
  59 }
  60
  61
  62 /*************************************************************************
  63  *              ScrollWindow (USER32.@)
  64  *
  65  */
  66 BOOL WINAPI ScrollWindow( HWND hwnd, INT dx, INT dy,
  67                               const RECT *rect, const RECT *clipRect )
  68 {
  69     return
  70         (ERROR != ScrollWindowEx( hwnd, dx, dy, rect, clipRect, 0, NULL,
  71                                     (rect ? 0 : SW_SCROLLCHILDREN) |
  72                                     SW_INVALIDATE ));
  73 }
  74
  75 /*************************************************************************
  76  *              ScrollDC (USER32.@)
  77  *
  78  *   Only the hrgnUpdate is return in device coordinate.
  79  *   rcUpdate must be returned in logical coordinate to comply with win API.
  80  *
  81  */
  82 BOOL WINAPI ScrollDC( HDC hdc, INT dx, INT dy, const RECT *rc,
  83                           const RECT *prLClip, HRGN hrgnUpdate,
  84                           LPRECT rcUpdate )
  85 {
  86     if (USER_Driver.pScrollDC)
  87         return USER_Driver.pScrollDC( hdc, dx, dy, rc, prLClip, hrgnUpdate, rcUpdate );
  88     return FALSE;
  89 }
  90
  91
  92 /*************************************************************************
  93  *              ScrollWindowEx (USER32.@)
  94  *
  95  * NOTE: Use this function instead of ScrollWindow32
  96  */
  97 INT WINAPI ScrollWindowEx( HWND hwnd, INT dx, INT dy,
  98                                const RECT *rect, const RECT *clipRect,
  99                                HRGN hrgnUpdate, LPRECT rcUpdate,
 100                                UINT flags )
 101 {
 102     RECT rc, cliprc;
 103     INT result;
 104
 105     if (!WIN_IsWindowDrawable( hwnd, TRUE )) return ERROR;
 106     hwnd = WIN_GetFullHandle( hwnd );
 107
 108     GetClientRect(hwnd, &rc);
 109     if (rect) IntersectRect(&rc, &rc, rect);
 110
 111     if (clipRect) IntersectRect(&cliprc,&rc,clipRect);
 112     else cliprc = rc;
 113
 114     if (!IsRectEmpty(&cliprc) && (dx || dy))
 115     {
 116         RECT caretrc = rc;
 117         HWND hwndCaret = fix_caret(hwnd, &caretrc, flags);
 118
 119         if (USER_Driver.pScrollWindowEx)
 120             result = USER_Driver.pScrollWindowEx( hwnd, dx, dy, rect, clipRect,
 121                                                   hrgnUpdate, rcUpdate, flags );
 122         else
 123             result = ERROR; /* FIXME: we should have a fallback implementation */
 124
 125         if( hwndCaret )
 126         {
 127             SetCaretPos( caretrc.left + dx, caretrc.top + dy );
 128             ShowCaret(hwndCaret);
 129         }
 130     }
 131     else
 132         result = NULLREGION;
 133
 134     return result;
 135 }