source: trunk/src/user32/dcscroll.cpp@ 8765

Last change on this file since 8765 was 6650, checked in by bird, 24 years ago

Added $Id:$ keyword.
File size: 3.4 KB
Line 
1/* $Id: dcscroll.cpp,v 1.2 2001-09-05 13:53:50 bird Exp $ */
2/*
3 * ScrollDC implementation
4 *
5 * Ported from Wine (windows\scroll.c)
6 * Fixes for clip rectangles & adaption for Odin (SvL)
7 *
8 * Copyright David W. Metcalfe, 1993
9 * Alex Korobka 1995,1996
10 *
11 *
12 */
13
14#include <os2win.h>
15
16//******************************************************************************
17//TODO: Can be more efficient (update rect/rgn calc.)
18//******************************************************************************
19BOOL WINAPI ScrollDC( HDC hdc, INT dx, INT dy, const RECT *rc,
20 const RECT *prLClip, HRGN hrgnUpdate,
21 LPRECT rcUpdate )
22{
23 RECT rect, rClip, rSrc;
24 POINT src, dest;
25
26 dprintf(("USER32: ScrollDC %04x %d,%d hrgnUpdate=%04x rcUpdate = %p cliprc = (%d,%d-%d,%d), rc=(%d,%d-%d,%d)",
27 hdc, dx, dy, hrgnUpdate, rcUpdate,
28 prLClip ? prLClip->left : 0, prLClip ? prLClip->top : 0, prLClip ? prLClip->right : 0, prLClip ? prLClip->bottom : 0,
29 rc ? rc->left : 0, rc ? rc->top : 0, rc ? rc->right : 0, rc ? rc->bottom : 0 ));
30
31 if ( !hdc ) return FALSE;
32
33 /* compute device clipping region (in device coordinates) */
34
35 if ( rc )
36 rect = *rc;
37 else /* maybe we should just return FALSE? */
38 {
39 DebugInt3();
40 GetClipBox( hdc, &rect );
41 }
42
43 LPtoDP( hdc, (LPPOINT)&rect, 2 );
44
45 if (prLClip)
46 {
47 rClip = *prLClip;
48 LPtoDP( hdc, (LPPOINT)&rClip, 2 );
49 IntersectRect( &rClip, &rect, &rClip );
50 }
51 else
52 rClip = rect;
53
54 //limit scrolling to DC's clip rectangle
55 GetClipBox( hdc, &rSrc );
56 IntersectRect( &rClip, &rSrc, &rClip );
57 IntersectRect( &rect, &rSrc, &rect );
58
59 POINT ptl[2] = { 0, 0, dx, dy };
60
61 LPtoDP( hdc, ptl, 2);
62
63 dx = (int)(ptl[1].x - ptl[0].x);
64 dy = (int)(ptl[1].y - ptl[0].y);
65
66 rSrc = rClip;
67 if (prLClip) {
68 OffsetRect( &rSrc, -dx, -dy );
69 IntersectRect( &rSrc, &rSrc, &rect );
70 }
71 if (!IsRectEmpty(&rSrc))
72 {
73 dest.x = (src.x = rSrc.left) + dx;
74 dest.y = (src.y = rSrc.top) + dy;
75
76 /* copy bits */
77
78 DPtoLP( hdc, (LPPOINT)&rSrc, 2 );
79 DPtoLP( hdc, &src, 1 );
80 DPtoLP( hdc, &dest, 1 );
81
82 if (!BitBlt( hdc, dest.x, dest.y,
83 rSrc.right - rSrc.left, rSrc.bottom - rSrc.top,
84 hdc, src.x, src.y, SRCCOPY))
85 {
86 return FALSE;
87 }
88 }
89
90 /* compute update areas */
91
92 if (hrgnUpdate || rcUpdate)
93 {
94 HRGN hrgn =
95 (hrgnUpdate) ? hrgnUpdate : CreateRectRgn( 0,0,0,0 );
96 HRGN hrgn2;
97
98 hrgn2 = CreateRectRgnIndirect( &rect );
99 SetRectRgn( hrgn, rClip.left, rClip.top,
100 rClip.right, rClip.bottom );
101 CombineRgn( hrgn, hrgn, hrgn2, RGN_AND );
102 OffsetRgn( hrgn2, dx, dy );
103 CombineRgn( hrgn, hrgn, hrgn2, RGN_DIFF );
104
105 if( rcUpdate )
106 {
107 GetRgnBox( hrgn, rcUpdate );
108
109 /* Put the rcUpdate in logical coordinate */
110 DPtoLP( hdc, (LPPOINT)rcUpdate, 2 );
111 }
112 if (!hrgnUpdate) DeleteObject( hrgn );
113 DeleteObject( hrgn2 );
114
115 }
116
117 return TRUE;
118
119}
120//******************************************************************************
121//******************************************************************************
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