1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
/*
* Copyright (C) 2004 Red Hat, Inc.
* Copyright (C) 2010 Brent Fulgham <bfulgham@webkit.org>
*
* Based on Pango sources (see pangocairo-render.c)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
*/
#if USE(CAIRO)
#ifndef DrawErrorUnderline_h
#define DrawErrorUnderline_h
#include <cairo.h>
//
// Draws an error underline that looks like one of:
//
// H E H
// /\ /\ /\ /\ /\ -
// A/ \ / \ / \ A/ \ / \ |
// \ \ / \ / /D \ \ / \ |
// \ \/ C \/ / \ \/ C \ | height = heightSquares * square
// \ /\ F / \ F /\ \ |
// \ / \ / \ / \ \G |
// \ / \ / \ / \ / |
// \/ \/ \/ \/ -
// B B
// |---|
// unitWidth = (heightSquares - 1) * square
//
// The x, y, width, height passed in give the desired bounding box;
// x/width are adjusted to make the underline a integer number of units
// wide.
//
static inline void drawErrorUnderline(cairo_t* cr, double x, double y, double width, double height)
{
static const double heightSquares = 2.5;
double square = height / heightSquares;
double halfSquare = 0.5 * square;
double unitWidth = (heightSquares - 1.0) * square;
int widthUnits = static_cast<int>((width + 0.5 * unitWidth) / unitWidth);
x += 0.5 * (width - widthUnits * unitWidth);
width = widthUnits * unitWidth;
double bottom = y + height;
double top = y;
// Bottom of squiggle
cairo_move_to(cr, x - halfSquare, top + halfSquare); // A
int i = 0;
for (i = 0; i < widthUnits; i += 2) {
double middle = x + (i + 1) * unitWidth;
double right = x + (i + 2) * unitWidth;
cairo_line_to(cr, middle, bottom); // B
if (i + 2 == widthUnits)
cairo_line_to(cr, right + halfSquare, top + halfSquare); // D
else if (i + 1 != widthUnits)
cairo_line_to(cr, right, top + square); // C
}
// Top of squiggle
for (i -= 2; i >= 0; i -= 2) {
double left = x + i * unitWidth;
double middle = x + (i + 1) * unitWidth;
double right = x + (i + 2) * unitWidth;
if (i + 1 == widthUnits)
cairo_line_to(cr, middle + halfSquare, bottom - halfSquare); // G
else {
if (i + 2 == widthUnits)
cairo_line_to(cr, right, top); // E
cairo_line_to(cr, middle, bottom - halfSquare); // F
}
cairo_line_to(cr, left, top); // H
}
cairo_fill(cr);
}
#endif // DrawErrorUnderline_h
#endif
|
