1/*
2 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
3 *           (C) 2000 Antti Koivisto (koivisto@kde.org)
4 *           (C) 2000 Dirk Mueller (mueller@kde.org)
5 * Copyright (C) 2003, 2006, 2007, 2010, 2011 Apple Inc. All rights reserved.
6 * Copyright (C) 2008 Holger Hans Peter Freyther
7 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Library General Public License for more details.
17 *
18 * You should have received a copy of the GNU Library General Public License
19 * along with this library; see the file COPYING.LIB.  If not, write to
20 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
22 *
23 */
24
25#ifndef Font_h
26#define Font_h
27
28#include "FontDescription.h"
29#include "FontFallbackList.h"
30#include "SimpleFontData.h"
31#include "TextDirection.h"
32#include "TypesettingFeatures.h"
33#include <wtf/HashMap.h>
34#include <wtf/HashSet.h>
35#include <wtf/MathExtras.h>
36#include <wtf/unicode/CharacterNames.h>
37
38#if PLATFORM(QT)
39#include <QFont>
40#endif
41
42namespace WebCore {
43
44class FloatPoint;
45class FloatRect;
46class FontData;
47class FontMetrics;
48class FontPlatformData;
49class FontSelector;
50class GlyphBuffer;
51class GlyphPageTreeNode;
52class GraphicsContext;
53class SVGFontElement;
54class TextRun;
55
56struct GlyphData;
57
58struct GlyphOverflow {
59    GlyphOverflow()
60        : left(0)
61        , right(0)
62        , top(0)
63        , bottom(0)
64        , computeBounds(false)
65    {
66    }
67
68    int left;
69    int right;
70    int top;
71    int bottom;
72    bool computeBounds;
73};
74
75
76class Font {
77public:
78    Font();
79    Font(const FontDescription&, short letterSpacing, short wordSpacing);
80    // This constructor is only used if the platform wants to start with a native font.
81    Font(const FontPlatformData&, bool isPrinting, FontSmoothingMode = AutoSmoothing);
82    ~Font();
83
84    Font(const Font&);
85    Font& operator=(const Font&);
86
87    bool operator==(const Font& other) const;
88    bool operator!=(const Font& other) const { return !(*this == other); }
89
90    const FontDescription& fontDescription() const { return m_fontDescription; }
91
92    int pixelSize() const { return fontDescription().computedPixelSize(); }
93    float size() const { return fontDescription().computedSize(); }
94
95    void update(PassRefPtr<FontSelector>) const;
96
97    void drawText(GraphicsContext*, const TextRun&, const FloatPoint&, int from = 0, int to = -1) const;
98    void drawEmphasisMarks(GraphicsContext*, const TextRun&, const AtomicString& mark, const FloatPoint&, int from = 0, int to = -1) const;
99
100    float width(const TextRun&, HashSet<const SimpleFontData*>* fallbackFonts = 0, GlyphOverflow* = 0) const;
101    float width(const TextRun&, int extraCharsAvailable, int& charsConsumed, String& glyphName) const;
102
103    int offsetForPosition(const TextRun&, float position, bool includePartialGlyphs) const;
104    FloatRect selectionRectForText(const TextRun&, const FloatPoint&, int h, int from = 0, int to = -1) const;
105
106    bool isSmallCaps() const { return m_fontDescription.smallCaps(); }
107
108    short wordSpacing() const { return m_wordSpacing; }
109    short letterSpacing() const { return m_letterSpacing; }
110    void setWordSpacing(short s) { m_wordSpacing = s; }
111    void setLetterSpacing(short s) { m_letterSpacing = s; }
112    bool isFixedPitch() const;
113    bool isPrinterFont() const { return m_fontDescription.usePrinterFont(); }
114
115    FontRenderingMode renderingMode() const { return m_fontDescription.renderingMode(); }
116
117    TypesettingFeatures typesettingFeatures() const
118    {
119        TextRenderingMode textRenderingMode = m_fontDescription.textRenderingMode();
120        return textRenderingMode == OptimizeLegibility || textRenderingMode == GeometricPrecision ? Kerning | Ligatures : 0;
121    }
122
123    FontFamily& firstFamily() { return m_fontDescription.firstFamily(); }
124    const FontFamily& family() const { return m_fontDescription.family(); }
125
126    bool italic() const { return m_fontDescription.italic(); }
127    FontWeight weight() const { return m_fontDescription.weight(); }
128    FontWidthVariant widthVariant() const { return m_fontDescription.widthVariant(); }
129
130    bool isPlatformFont() const { return m_isPlatformFont; }
131
132    // Metrics that we query the FontFallbackList for.
133    const FontMetrics& fontMetrics() const { return primaryFont()->fontMetrics(); }
134    float spaceWidth() const { return primaryFont()->spaceWidth() + m_letterSpacing; }
135    float tabWidth(const SimpleFontData& fontData) const { return 8 * fontData.spaceWidth() + letterSpacing(); }
136    int emphasisMarkAscent(const AtomicString&) const;
137    int emphasisMarkDescent(const AtomicString&) const;
138    int emphasisMarkHeight(const AtomicString&) const;
139
140    const SimpleFontData* primaryFont() const;
141    const FontData* fontDataAt(unsigned) const;
142    GlyphData glyphDataForCharacter(UChar32, bool mirror, FontDataVariant = AutoVariant) const;
143    bool primaryFontHasGlyphForCharacter(UChar32) const;
144
145    static bool isCJKIdeograph(UChar32);
146    static bool isCJKIdeographOrSymbol(UChar32);
147
148    static unsigned expansionOpportunityCount(const UChar*, size_t length, TextDirection, bool& isAfterExpansion);
149
150#if PLATFORM(QT)
151    QFont font() const;
152#endif
153
154    static void setShouldUseSmoothing(bool);
155    static bool shouldUseSmoothing();
156
157    enum CodePath { Auto, Simple, Complex, SimpleWithGlyphOverflow };
158
159private:
160#if ENABLE(SVG_FONTS)
161    void drawTextUsingSVGFont(GraphicsContext*, const TextRun&, const FloatPoint&, int from, int to) const;
162    float floatWidthUsingSVGFont(const TextRun&) const;
163    float floatWidthUsingSVGFont(const TextRun&, int extraCharsAvailable, int& charsConsumed, String& glyphName) const;
164    FloatRect selectionRectForTextUsingSVGFont(const TextRun&, const FloatPoint&, int h, int from, int to) const;
165    int offsetForPositionForTextUsingSVGFont(const TextRun&, float position, bool includePartialGlyphs) const;
166#endif
167
168    enum ForTextEmphasisOrNot { NotForTextEmphasis, ForTextEmphasis };
169
170    // Returns the initial in-stream advance.
171    float getGlyphsAndAdvancesForSimpleText(const TextRun&, int from, int to, GlyphBuffer&, ForTextEmphasisOrNot = NotForTextEmphasis) const;
172    void drawSimpleText(GraphicsContext*, const TextRun&, const FloatPoint&, int from, int to) const;
173    void drawEmphasisMarksForSimpleText(GraphicsContext*, const TextRun&, const AtomicString& mark, const FloatPoint&, int from, int to) const;
174#if PLATFORM(ANDROID)
175public:
176#endif
177    void drawGlyphs(GraphicsContext*, const SimpleFontData*, const GlyphBuffer&, int from, int to, const FloatPoint&) const;
178#if PLATFORM(ANDROID)
179private:
180#endif
181    void drawGlyphBuffer(GraphicsContext*, const GlyphBuffer&, const FloatPoint&) const;
182    void drawEmphasisMarks(GraphicsContext* context, const GlyphBuffer&, const AtomicString&, const FloatPoint&) const;
183    float floatWidthForSimpleText(const TextRun&, GlyphBuffer*, HashSet<const SimpleFontData*>* fallbackFonts = 0, GlyphOverflow* = 0) const;
184    int offsetForPositionForSimpleText(const TextRun&, float position, bool includePartialGlyphs) const;
185    FloatRect selectionRectForSimpleText(const TextRun&, const FloatPoint&, int h, int from, int to) const;
186
187    bool getEmphasisMarkGlyphData(const AtomicString&, GlyphData&) const;
188
189    static bool canReturnFallbackFontsForComplexText();
190    static bool canExpandAroundIdeographsInComplexText();
191
192    CodePath codePath(const TextRun&) const;
193
194    // Returns the initial in-stream advance.
195    float getGlyphsAndAdvancesForComplexText(const TextRun&, int from, int to, GlyphBuffer&, ForTextEmphasisOrNot = NotForTextEmphasis) const;
196    void drawComplexText(GraphicsContext*, const TextRun&, const FloatPoint&, int from, int to) const;
197    void drawEmphasisMarksForComplexText(GraphicsContext*, const TextRun&, const AtomicString& mark, const FloatPoint&, int from, int to) const;
198    float floatWidthForComplexText(const TextRun&, HashSet<const SimpleFontData*>* fallbackFonts = 0, GlyphOverflow* = 0) const;
199    int offsetForPositionForComplexText(const TextRun&, float position, bool includePartialGlyphs) const;
200    FloatRect selectionRectForComplexText(const TextRun&, const FloatPoint&, int h, int from, int to) const;
201
202    friend struct WidthIterator;
203
204public:
205    // Useful for debugging the different font rendering code paths.
206    static void setCodePath(CodePath);
207    static CodePath codePath();
208    static CodePath s_codePath;
209
210    FontSelector* fontSelector() const;
211    static bool treatAsSpace(UChar c) { return c == ' ' || c == '\t' || c == '\n' || c == noBreakSpace; }
212    static bool treatAsZeroWidthSpace(UChar c) { return treatAsZeroWidthSpaceInComplexScript(c) || c == 0x200c || c == 0x200d; }
213    static bool treatAsZeroWidthSpaceInComplexScript(UChar c) { return c < 0x20 || (c >= 0x7F && c < 0xA0) || c == softHyphen || (c >= 0x200e && c <= 0x200f) || (c >= 0x202a && c <= 0x202e) || c == zeroWidthNoBreakSpace || c == objectReplacementCharacter; }
214    static bool canReceiveTextEmphasis(UChar32 c);
215
216    static inline UChar normalizeSpaces(UChar character)
217    {
218        if (treatAsSpace(character))
219            return space;
220
221        if (treatAsZeroWidthSpace(character))
222            return zeroWidthSpace;
223
224        return character;
225    }
226
227    static String normalizeSpaces(const UChar*, unsigned length);
228
229#if ENABLE(SVG_FONTS)
230    bool isSVGFont() const;
231    SVGFontElement* svgFont() const;
232#endif
233
234    bool needsTranscoding() const { return m_needsTranscoding; }
235
236private:
237    bool loadingCustomFonts() const
238    {
239        return m_fontList && m_fontList->loadingCustomFonts();
240    }
241
242    FontDescription m_fontDescription;
243    mutable RefPtr<FontFallbackList> m_fontList;
244    short m_letterSpacing;
245    short m_wordSpacing;
246    bool m_isPlatformFont;
247    bool m_needsTranscoding;
248};
249
250inline Font::~Font()
251{
252}
253
254inline const SimpleFontData* Font::primaryFont() const
255{
256    ASSERT(m_fontList);
257    return m_fontList->primarySimpleFontData(this);
258}
259
260inline const FontData* Font::fontDataAt(unsigned index) const
261{
262    ASSERT(m_fontList);
263    return m_fontList->fontDataAt(this, index);
264}
265
266inline bool Font::isFixedPitch() const
267{
268    ASSERT(m_fontList);
269    return m_fontList->isFixedPitch(this);
270}
271
272inline FontSelector* Font::fontSelector() const
273{
274    return m_fontList ? m_fontList->fontSelector() : 0;
275}
276
277}
278
279#endif
280