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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  * TODO
  21  *     - actually add smooth scrolling
  22  */
  23
  24 #include <stdarg.h>
  25
  26 #include "windef.h"
  27 #include "winbase.h"
  28 #include "winreg.h"
  29 #include "winerror.h"
  30 #include "winuser.h"
  31 #include "wine/debug.h"
  32
  33 WINE_DEFAULT_DEBUG_CHANNEL(commctrl);
  34
  35 static DWORD    smoothscroll = 2;
  36
  37 typedef BOOL (CALLBACK *SCROLLWINDOWEXPROC)(HWND,INT,INT,LPRECT,LPRECT,HRGN,LPRECT,DWORD);
  38 typedef struct tagSMOOTHSCROLLSTRUCT {
  39         DWORD                   dwSize;
  40         DWORD                   x2;
  41         HWND                    hwnd;
  42         DWORD                   dx;
  43
  44         DWORD                   dy;
  45         LPRECT                  lpscrollrect;
  46         LPRECT                  lpcliprect;
  47         HRGN                    hrgnupdate;
  48
  49         LPRECT                  lpupdaterect;
  50         DWORD                   flags;
  51         DWORD                   stepinterval;
  52         DWORD                   dx_step;
  53
  54         DWORD                   dy_step;
  55         SCROLLWINDOWEXPROC      scrollfun;      /* same parameters as ScrollWindowEx */
  56 } SMOOTHSCROLLSTRUCT;
  57
  58 /**************************************************************************
  59  * SmoothScrollWindow [COMCTL32.382]
  60  *
  61  * Lots of magic for smooth scrolling windows.
  62  *
  63  * RETURNS
  64  *     Success: TRUE
  65  *     Failure: FALSE
  66  *
  67  * BUGS
  68  *     Currently only scrolls ONCE. The comctl32 implementation uses GetTickCount
  69  *     and what else to do smooth scrolling.
  70  */
  71 BOOL WINAPI SmoothScrollWindow( SMOOTHSCROLLSTRUCT *smooth ) {
  72    LPRECT       lpupdaterect = smooth->lpupdaterect;
  73    HRGN         hrgnupdate = smooth->hrgnupdate;
  74    RECT         tmprect;
  75    DWORD        flags = smooth->flags;
  76
  77    if (smooth->dwSize!=sizeof(SMOOTHSCROLLSTRUCT))
  78        return FALSE;
  79
  80    if (!lpupdaterect)
  81        lpupdaterect = &tmprect;
  82    SetRectEmpty(lpupdaterect);
  83
  84    if (!(flags & 0x40000)) { /* no override, use system wide defaults */
  85        if (smoothscroll == 2) {
  86            HKEY hkey;
  87
  88            smoothscroll = 0;
  89            if (!RegOpenKeyA(HKEY_CURRENT_USER,"Control Panel\\Desktop",&hkey)) {
  90                DWORD    len = 4;
  91
  92                RegQueryValueExA(hkey,"SmoothScroll",0,0,(LPBYTE)&smoothscroll,&len);
  93                RegCloseKey(hkey);
  94            }
  95        }
  96        if (!smoothscroll)
  97            flags |= 0x20000;
  98    }
  99
 100    if (flags & 0x20000) { /* are we doing jump scrolling? */
 101        if ((smooth->x2 & 1) && smooth->scrollfun)
 102            return smooth->scrollfun(
 103                smooth->hwnd,smooth->dx,smooth->dy,smooth->lpscrollrect,
 104                smooth->lpcliprect,hrgnupdate,lpupdaterect,
 105                flags & 0xffff
 106            );
 107        else
 108            return ScrollWindowEx(
 109                smooth->hwnd,smooth->dx,smooth->dy,smooth->lpscrollrect,
 110                smooth->lpcliprect,hrgnupdate,lpupdaterect,
 111                flags & 0xffff
 112            );
 113    }
 114
 115    FIXME("(hwnd=%p,flags=%lx,x2=%lx): should smooth scroll here.\n",
 116            smooth->hwnd,flags,smooth->x2
 117    );
 118    /* FIXME: do timer based smooth scrolling */
 119    if ((smooth->x2 & 1) && smooth->scrollfun)
 120        return smooth->scrollfun(
 121            smooth->hwnd,smooth->dx,smooth->dy,smooth->lpscrollrect,
 122            smooth->lpcliprect,hrgnupdate,lpupdaterect,
 123            flags & 0xffff
 124        );
 125    else
 126        return ScrollWindowEx(
 127            smooth->hwnd,smooth->dx,smooth->dy,smooth->lpscrollrect,
 128            smooth->lpcliprect,hrgnupdate,lpupdaterect,
 129            flags & 0xffff
 130        );
 131 }