1 /*
2 * Copyright (C) 2006 Apple Computer, Inc. All rights reserved.
3 * Copyright (C) 2006 Michael Emmel mike.emmel@gmail.com
4 * Copyright (C) 2007, 2008 Alp Toker <alp@atoker.com>
5 * Copyright (C) 2007 Holger Hans Peter Freyther
6 * Copyright (C) 2007 Pioneer Research Center USA, Inc.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
19 * its contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
23 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
24 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
26 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
27 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
29 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include "config.h"
35 #include "SimpleFontData.h"
36
37 #include "FloatRect.h"
38 #include "Font.h"
39 #include "FontCache.h"
40 #include "FontDescription.h"
41 #include "GlyphBuffer.h"
42 #include <cairo.h>
43 #include <wtf/MathExtras.h>
44
45 namespace WebCore {
46
platformInit()47 void SimpleFontData::platformInit()
48 {
49 cairo_font_extents_t font_extents;
50 cairo_text_extents_t text_extents;
51 cairo_scaled_font_extents(m_platformData.m_scaledFont, &font_extents);
52
53 m_fontMetrics.setAscent(font_extents.ascent);
54 m_fontMetrics.setDescent(font_extents.descent);
55
56 // There seems to be some rounding error in cairo (or in how we
57 // use cairo) with some fonts, like DejaVu Sans Mono, which makes
58 // cairo report a height smaller than ascent + descent, which is
59 // wrong and confuses WebCore's layout system. Workaround this
60 // while we figure out what's going on.
61 float lineSpacing = font_extents.height;
62 if (lineSpacing < font_extents.ascent + font_extents.descent)
63 lineSpacing = font_extents.ascent + font_extents.descent;
64 m_fontMetrics.setLineSpacing(lroundf(lineSpacing));
65 m_fontMetrics.setLineGap(lineSpacing - font_extents.ascent - font_extents.descent);
66
67 cairo_scaled_font_text_extents(m_platformData.m_scaledFont, "x", &text_extents);
68 m_fontMetrics.setXHeight(text_extents.height);
69
70 cairo_scaled_font_text_extents(m_platformData.m_scaledFont, " ", &text_extents);
71 m_spaceWidth = static_cast<float>(text_extents.x_advance);
72
73 m_syntheticBoldOffset = m_platformData.syntheticBold() ? 1.0f : 0.f;
74 }
75
platformCharWidthInit()76 void SimpleFontData::platformCharWidthInit()
77 {
78 m_avgCharWidth = 0.f;
79 m_maxCharWidth = 0.f;
80 initCharWidths();
81 }
82
platformDestroy()83 void SimpleFontData::platformDestroy()
84 {
85 }
86
scaledFontData(const FontDescription & fontDescription,float scaleFactor) const87 SimpleFontData* SimpleFontData::scaledFontData(const FontDescription& fontDescription, float scaleFactor) const
88 {
89 FontDescription desc = FontDescription(fontDescription);
90 desc.setSpecifiedSize(scaleFactor * fontDescription.computedSize());
91 FontPlatformData platformData(desc, desc.family().family());
92 return new SimpleFontData(platformData);
93 }
94
smallCapsFontData(const FontDescription & fontDescription) const95 SimpleFontData* SimpleFontData::smallCapsFontData(const FontDescription& fontDescription) const
96 {
97 if (!m_derivedFontData)
98 m_derivedFontData = DerivedFontData::create(isCustomFont());
99 if (!m_derivedFontData->smallCaps)
100 m_derivedFontData->smallCaps = scaledFontData(fontDescription, .7);
101
102 return m_derivedFontData->smallCaps.get();
103 }
104
emphasisMarkFontData(const FontDescription & fontDescription) const105 SimpleFontData* SimpleFontData::emphasisMarkFontData(const FontDescription& fontDescription) const
106 {
107 if (!m_derivedFontData)
108 m_derivedFontData = DerivedFontData::create(isCustomFont());
109 if (!m_derivedFontData->emphasisMark)
110 m_derivedFontData->emphasisMark = scaledFontData(fontDescription, .5);
111
112 return m_derivedFontData->emphasisMark.get();
113 }
114
containsCharacters(const UChar * characters,int length) const115 bool SimpleFontData::containsCharacters(const UChar* characters, int length) const
116 {
117 bool result = true;
118
119 PangoCoverage* coverage = pango_font_get_coverage(m_platformData.m_font, pango_language_get_default());
120
121 for (int i = 0; i < length; i++) {
122 if (PANGO_COVERAGE_NONE == pango_coverage_get(coverage, characters[i])) {
123 result = false;
124 break;
125 }
126 }
127
128 pango_coverage_unref(coverage);
129
130 return result;
131 }
132
determinePitch()133 void SimpleFontData::determinePitch()
134 {
135 if (isCustomFont()) {
136 m_treatAsFixedPitch = false;
137 return;
138 }
139
140 m_treatAsFixedPitch = m_platformData.isFixedPitch();
141 }
142
platformBoundsForGlyph(Glyph) const143 FloatRect SimpleFontData::platformBoundsForGlyph(Glyph) const
144 {
145 return FloatRect();
146 }
147
platformWidthForGlyph(Glyph glyph) const148 float SimpleFontData::platformWidthForGlyph(Glyph glyph) const
149 {
150 ASSERT(m_platformData.m_scaledFont);
151
152 cairo_glyph_t cglyph = { glyph, 0, 0 };
153 cairo_text_extents_t extents;
154 cairo_scaled_font_glyph_extents(m_platformData.m_scaledFont, &cglyph, 1, &extents);
155
156 float width = (float)m_spaceWidth;
157 if (cairo_scaled_font_status(m_platformData.m_scaledFont) == CAIRO_STATUS_SUCCESS && extents.x_advance != 0)
158 width = (float)extents.x_advance;
159
160 return width;
161 }
162
163 }
164