dlls/comctl32/smoothscroll.c

   1 /*
   2  * Undocumented SmoothScrollWindow function from COMCTL32.DLL
   3  *
   4  * Copyright 2000 Marcus Meissner <marcus@jet.franken.de>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  * TODO
  21  *     - actually add smooth scrolling
  22  */
  23
  24 #include "winbase.h"
  25 #include "winreg.h"
  26 #include "winerror.h"
  27 #include "commctrl.h"
  28 #include "wine/debug.h"
  29
  30 WINE_DEFAULT_DEBUG_CHANNEL(commctrl);
  31
  32 static DWORD    smoothscroll = 2;
  33
  34 typedef BOOL (CALLBACK *SCROLLWINDOWEXPROC)(HWND,INT,INT,LPRECT,LPRECT,HRGN,LPRECT,DWORD);
  35 typedef struct tagSMOOTHSCROLLSTRUCT {
  36         DWORD                   dwSize;
  37         DWORD                   x2;
  38         HWND                    hwnd;
  39         DWORD                   dx;
  40
  41         DWORD                   dy;
  42         LPRECT                  lpscrollrect;
  43         LPRECT                  lpcliprect;
  44         HRGN                    hrgnupdate;
  45
  46         LPRECT                  lpupdaterect;
  47         DWORD                   flags;
  48         DWORD                   stepinterval;
  49         DWORD                   dx_step;
  50
  51         DWORD                   dy_step;
  52         SCROLLWINDOWEXPROC      scrollfun;      /* same parameters as ScrollWindowEx */
  53 } SMOOTHSCROLLSTRUCT;
  54
  55 /**************************************************************************
  56  * SmoothScrollWindow [COMCTL32.382]
  57  *
  58  * Lots of magic for smooth scrolling windows.
  59  *
  60  * Currently only scrolls ONCE. The comctl32 implementation uses GetTickCount
  61  * and what else to do smooth scrolling.
  62  */
  63
  64 BOOL WINAPI SmoothScrollWindow( SMOOTHSCROLLSTRUCT *smooth ) {
  65    LPRECT       lpupdaterect = smooth->lpupdaterect;
  66    HRGN         hrgnupdate = smooth->hrgnupdate;
  67    RECT         tmprect;
  68    BOOL         ret = TRUE;
  69    DWORD        flags = smooth->flags;
  70
  71    if (smooth->dwSize!=sizeof(SMOOTHSCROLLSTRUCT))
  72        return FALSE;
  73
  74    if (!lpupdaterect)
  75        lpupdaterect = &tmprect;
  76    SetRectEmpty(lpupdaterect);
  77
  78    if (!(flags & 0x40000)) { /* no override, use system wide defaults */
  79        if (smoothscroll == 2) {
  80            HKEY hkey;
  81
  82            smoothscroll = 0;
  83            if (!RegOpenKeyA(HKEY_CURRENT_USER,"Control Panel\\Desktop",&hkey)) {
  84                DWORD    len = 4;
  85
  86                RegQueryValueExA(hkey,"SmoothScroll",0,0,(LPBYTE)&smoothscroll,&len);
  87                RegCloseKey(hkey);
  88            }
  89        }
  90        if (!smoothscroll)
  91            flags |= 0x20000;
  92    }
  93
  94    if (flags & 0x20000) { /* are we doing jump scrolling? */
  95        if ((smooth->x2 & 1) && smooth->scrollfun)
  96            return smooth->scrollfun(
  97                smooth->hwnd,smooth->dx,smooth->dy,smooth->lpscrollrect,
  98                smooth->lpcliprect,hrgnupdate,lpupdaterect,
  99                flags & 0xffff
 100            );
 101        else
 102            return ScrollWindowEx(
 103                smooth->hwnd,smooth->dx,smooth->dy,smooth->lpscrollrect,
 104                smooth->lpcliprect,hrgnupdate,lpupdaterect,
 105                flags & 0xffff
 106            );
 107    }
 108
 109    FIXME("(hwnd=%p,flags=%lx,x2=%lx): should smooth scroll here.\n",
 110            smooth->hwnd,flags,smooth->x2
 111    );
 112    /* FIXME: do timer based smooth scrolling */
 113    if ((smooth->x2 & 1) && smooth->scrollfun)
 114        return smooth->scrollfun(
 115            smooth->hwnd,smooth->dx,smooth->dy,smooth->lpscrollrect,
 116            smooth->lpcliprect,hrgnupdate,lpupdaterect,
 117            flags & 0xffff
 118        );
 119    else
 120        return ScrollWindowEx(
 121            smooth->hwnd,smooth->dx,smooth->dy,smooth->lpscrollrect,
 122            smooth->lpcliprect,hrgnupdate,lpupdaterect,
 123            flags & 0xffff
 124        );
 125    return ret;
 126 }