xref: /reactos/dll/win32/comctl32/smoothscroll.c (revision 1734f297)
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( const 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=%x,x2=%x): 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 }
132