source: trunk/src/user32/dcscroll.cpp

Last change on this file was 9662, checked in by sandervl, 23 years ago

must convert rectangle returned by GetClipBox to device coordinates
File size: 3.5 KB
Line 
1/* $Id: dcscroll.cpp,v 1.3 2003-01-10 17:11:18 sandervl 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 LPtoDP(hdc, (LPPOINT)&rSrc, 2);
57
58 IntersectRect( &rClip, &rSrc, &rClip );
59 IntersectRect( &rect, &rSrc, &rect );
60
61 POINT ptl[2] = { 0, 0, dx, dy };
62
63 LPtoDP( hdc, ptl, 2);
64
65 dx = (int)(ptl[1].x - ptl[0].x);
66 dy = (int)(ptl[1].y - ptl[0].y);
67
68 rSrc = rClip;
69 if (prLClip) {
70 OffsetRect( &rSrc, -dx, -dy );
71 IntersectRect( &rSrc, &rSrc, &rect );
72 }
73 if (!IsRectEmpty(&rSrc))
74 {
75 dest.x = (src.x = rSrc.left) + dx;
76 dest.y = (src.y = rSrc.top) + dy;
77
78 /* copy bits */
79
80 DPtoLP( hdc, (LPPOINT)&rSrc, 2 );
81 DPtoLP( hdc, &src, 1 );
82 DPtoLP( hdc, &dest, 1 );
83
84 if (!BitBlt( hdc, dest.x, dest.y,
85 rSrc.right - rSrc.left, rSrc.bottom - rSrc.top,
86 hdc, src.x, src.y, SRCCOPY))
87 {
88 return FALSE;
89 }
90 }
91
92 /* compute update areas */
93
94 if (hrgnUpdate || rcUpdate)
95 {
96 HRGN hrgn =
97 (hrgnUpdate) ? hrgnUpdate : CreateRectRgn( 0,0,0,0 );
98 HRGN hrgn2;
99
100 hrgn2 = CreateRectRgnIndirect( &rect );
101 SetRectRgn( hrgn, rClip.left, rClip.top,
102 rClip.right, rClip.bottom );
103 CombineRgn( hrgn, hrgn, hrgn2, RGN_AND );
104 OffsetRgn( hrgn2, dx, dy );
105 CombineRgn( hrgn, hrgn, hrgn2, RGN_DIFF );
106
107 if( rcUpdate )
108 {
109 GetRgnBox( hrgn, rcUpdate );
110
111 /* Put the rcUpdate in logical coordinate */
112 DPtoLP( hdc, (LPPOINT)rcUpdate, 2 );
113 }
114 if (!hrgnUpdate) DeleteObject( hrgn );
115 DeleteObject( hrgn2 );
116
117 }
118 return TRUE;
119}
120//******************************************************************************
121//******************************************************************************
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