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 <stdarg.h>
  25
  26 #include "windef.h"
  27 #include "winbase.h"
  28 #include "winreg.h"
  29 #include "winerror.h"
  30 #include "wingdi.h"
  31 #include "winuser.h"
  32 #include "winnls.h"
  33 #include "commctrl.h"
  34 #include "wine/debug.h"
  35
  36 WINE_DEFAULT_DEBUG_CHANNEL(commctrl);
  37
  38 static DWORD    smoothscroll = 2;
  39
  40 typedef BOOL (CALLBACK *SCROLLWINDOWEXPROC)(HWND,INT,INT,LPRECT,LPRECT,HRGN,LPRECT,DWORD);
  41 typedef struct tagSMOOTHSCROLLSTRUCT {
  42         DWORD                   dwSize;
  43         DWORD                   x2;
  44         HWND                    hwnd;
  45         DWORD                   dx;
  46
  47         DWORD                   dy;
  48         LPRECT                  lpscrollrect;
  49         LPRECT                  lpcliprect;
  50         HRGN                    hrgnupdate;
  51
  52         LPRECT                  lpupdaterect;
  53         DWORD                   flags;
  54         DWORD                   stepinterval;
  55         DWORD                   dx_step;
  56
  57         DWORD                   dy_step;
  58         SCROLLWINDOWEXPROC      scrollfun;      /* same parameters as ScrollWindowEx */
  59 } SMOOTHSCROLLSTRUCT;
  60
  61 /**************************************************************************
  62  * SmoothScrollWindow [COMCTL32.382]
  63  *
  64  * Lots of magic for smooth scrolling windows.
  65  *
  66  * RETURNS
  67  *     Success: TRUE
  68  *     Failure: FALSE
  69  *
  70  * BUGS
  71  *     Currently only scrolls ONCE. The comctl32 implementation uses GetTickCount
  72  *     and what else to do smooth scrolling.
  73  */
  74 BOOL WINAPI SmoothScrollWindow( SMOOTHSCROLLSTRUCT *smooth ) {
  75    LPRECT       lpupdaterect = smooth->lpupdaterect;
  76    HRGN         hrgnupdate = smooth->hrgnupdate;
  77    RECT         tmprect;
  78    BOOL         ret = TRUE;
  79    DWORD        flags = smooth->flags;
  80
  81    if (smooth->dwSize!=sizeof(SMOOTHSCROLLSTRUCT))
  82        return FALSE;
  83
  84    if (!lpupdaterect)
  85        lpupdaterect = &tmprect;
  86    SetRectEmpty(lpupdaterect);
  87
  88    if (!(flags & 0x40000)) { /* no override, use system wide defaults */
  89        if (smoothscroll == 2) {
  90            HKEY hkey;
  91
  92            smoothscroll = 0;
  93            if (!RegOpenKeyA(HKEY_CURRENT_USER,"Control Panel\\Desktop",&hkey)) {
  94                DWORD    len = 4;
  95
  96                RegQueryValueExA(hkey,"SmoothScroll",0,0,(LPBYTE)&smoothscroll,&len);
  97                RegCloseKey(hkey);
  98            }
  99        }
 100        if (!smoothscroll)
 101            flags |= 0x20000;
 102    }
 103
 104    if (flags & 0x20000) { /* are we doing jump scrolling? */
 105        if ((smooth->x2 & 1) && smooth->scrollfun)
 106            return smooth->scrollfun(
 107                smooth->hwnd,smooth->dx,smooth->dy,smooth->lpscrollrect,
 108                smooth->lpcliprect,hrgnupdate,lpupdaterect,
 109                flags & 0xffff
 110            );
 111        else
 112            return ScrollWindowEx(
 113                smooth->hwnd,smooth->dx,smooth->dy,smooth->lpscrollrect,
 114                smooth->lpcliprect,hrgnupdate,lpupdaterect,
 115                flags & 0xffff
 116            );
 117    }
 118
 119    FIXME("(hwnd=%p,flags=%lx,x2=%lx): should smooth scroll here.\n",
 120            smooth->hwnd,flags,smooth->x2
 121    );
 122    /* FIXME: do timer based smooth scrolling */
 123    if ((smooth->x2 & 1) && smooth->scrollfun)
 124        return smooth->scrollfun(
 125            smooth->hwnd,smooth->dx,smooth->dy,smooth->lpscrollrect,
 126            smooth->lpcliprect,hrgnupdate,lpupdaterect,
 127            flags & 0xffff
 128        );
 129    else
 130        return ScrollWindowEx(
 131            smooth->hwnd,smooth->dx,smooth->dy,smooth->lpscrollrect,
 132            smooth->lpcliprect,hrgnupdate,lpupdaterect,
 133            flags & 0xffff
 134        );
 135    return ret;
 136 }