third_party/WebKit/Source/platform/fonts/FontDescription.h

   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, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
   6  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
   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.LIother.m_  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 FontDescription_h
  26 #define FontDescription_h
  27
  28 #include "platform/FontFamilyNames.h"
  29 #include "platform/fonts/FontCacheKey.h"
  30 #include "platform/fonts/FontFamily.h"
  31 #include "platform/fonts/FontFeatureSettings.h"
  32 #include "platform/fonts/FontOrientation.h"
  33 #include "platform/fonts/FontSmoothingMode.h"
  34 #include "platform/fonts/FontTraits.h"
  35 #include "platform/fonts/FontWidthVariant.h"
  36 #include "platform/fonts/TextRenderingMode.h"
  37 #include "platform/fonts/TypesettingFeatures.h"
  38 #include "wtf/MathExtras.h"
  39
  40 #include "wtf/RefPtr.h"
  41
  42 #include <unicode/uscript.h>
  43
  44 namespace blink {
  45
  46 const float FontSizeAdjustNone = -1;
  47
  48 class PLATFORM_EXPORT FontDescription {
  49 public:
  50     enum GenericFamilyType { NoFamily, StandardFamily, SerifFamily, SansSerifFamily,
  51                              MonospaceFamily, CursiveFamily, FantasyFamily, PictographFamily };
  52
  53     enum Kerning { AutoKerning, NormalKerning, NoneKerning };
  54
  55     enum LigaturesState { NormalLigaturesState, DisabledLigaturesState, EnabledLigaturesState };
  56
  57     FontDescription()
  58         : m_specifiedSize(0)
  59         , m_computedSize(0)
  60         , m_adjustedSize(0)
  61         , m_sizeAdjust(FontSizeAdjustNone)
  62         , m_letterSpacing(0)
  63         , m_wordSpacing(0)
  64         , m_orientation(static_cast<unsigned>(FontOrientation::Horizontal))
  65         , m_widthVariant(RegularWidth)
  66         , m_style(FontStyleNormal)
  67         , m_variant(FontVariantNormal)
  68         , m_isAbsoluteSize(false)
  69         , m_weight(FontWeightNormal)
  70         , m_stretch(FontStretchNormal)
  71         , m_genericFamily(NoFamily)
  72         , m_kerning(AutoKerning)
  73         , m_commonLigaturesState(NormalLigaturesState)
  74         , m_discretionaryLigaturesState(NormalLigaturesState)
  75         , m_historicalLigaturesState(NormalLigaturesState)
  76         , m_contextualLigaturesState(NormalLigaturesState)
  77         , m_keywordSize(0)
  78         , m_fontSmoothing(AutoSmoothing)
  79         , m_textRendering(AutoTextRendering)
  80         , m_script(USCRIPT_COMMON)
  81         , m_syntheticBold(false)
  82         , m_syntheticItalic(false)
  83         , m_subpixelTextPosition(s_useSubpixelTextPositioning)
  84         , m_typesettingFeatures(s_defaultTypesettingFeatures)
  85     {
  86     }
  87
  88     bool operator==(const FontDescription&) const;
  89     bool operator!=(const FontDescription& other) const { return !(*this == other); }
  90
  91     struct VariantLigatures {
  92         VariantLigatures(LigaturesState state = NormalLigaturesState)
  93             : common(state)
  94             , discretionary(state)
  95             , historical(state)
  96             , contextual(state)
  97         {
  98         }
  99
 100         unsigned common : 2;
 101         unsigned discretionary : 2;
 102         unsigned historical : 2;
 103         unsigned contextual : 2;
 104     };
 105
 106     struct Size {
 107         Size(unsigned keyword, float value, bool isAbsolute)
 108             : keyword(keyword)
 109             , isAbsolute(isAbsolute)
 110             , value(value)
 111         {
 112         }
 113         unsigned keyword : 4; // FontDescription::keywordSize
 114         unsigned isAbsolute : 1; // FontDescription::isAbsoluteSize
 115         float value;
 116     };
 117
 118     struct FamilyDescription {
 119         FamilyDescription(GenericFamilyType genericFamily) : genericFamily(genericFamily) { }
 120         FamilyDescription(GenericFamilyType genericFamily, const FontFamily& family)
 121             : genericFamily(genericFamily)
 122             , family(family)
 123         {
 124         }
 125         GenericFamilyType genericFamily;
 126         FontFamily family;
 127     };
 128
 129     const FontFamily& family() const { return m_familyList; }
 130     FamilyDescription familyDescription() const { return FamilyDescription(genericFamily(), family()); }
 131     FontFamily& firstFamily() { return m_familyList; }
 132     Size size() const { return Size(m_keywordSize, m_specifiedSize, m_isAbsoluteSize); }
 133     float specifiedSize() const { return m_specifiedSize; }
 134     float computedSize() const { return m_computedSize; }
 135     float adjustedSize() const { return m_adjustedSize; }
 136     float sizeAdjust() const { return m_sizeAdjust; }
 137     bool hasSizeAdjust() const { return m_sizeAdjust != FontSizeAdjustNone; }
 138     FontStyle style() const { return static_cast<FontStyle>(m_style); }
 139     int computedPixelSize() const { return int(m_computedSize + 0.5f); }
 140     FontVariant variant() const { return static_cast<FontVariant>(m_variant); }
 141     bool isAbsoluteSize() const { return m_isAbsoluteSize; }
 142     FontWeight weight() const { return static_cast<FontWeight>(m_weight); }
 143     FontStretch stretch() const { return static_cast<FontStretch>(m_stretch); }
 144     static FontWeight lighterWeight(FontWeight);
 145     static FontWeight bolderWeight(FontWeight);
 146     static Size largerSize(const Size&);
 147     static Size smallerSize(const Size&);
 148     GenericFamilyType genericFamily() const { return static_cast<GenericFamilyType>(m_genericFamily); }
 149
 150     // only use fixed default size when there is only one font family, and that family is "monospace"
 151     bool isMonospace() const
 152     {
 153         return genericFamily() == MonospaceFamily && !family().next() && family().family() == FontFamilyNames::webkit_monospace;
 154     }
 155     Kerning kerning() const { return static_cast<Kerning>(m_kerning); }
 156     VariantLigatures variantLigatures() const;
 157     LigaturesState commonLigaturesState() const { return static_cast<LigaturesState>(m_commonLigaturesState); }
 158     LigaturesState discretionaryLigaturesState() const { return static_cast<LigaturesState>(m_discretionaryLigaturesState); }
 159     LigaturesState historicalLigaturesState() const { return static_cast<LigaturesState>(m_historicalLigaturesState); }
 160     LigaturesState contextualLigaturesState() const { return static_cast<LigaturesState>(m_contextualLigaturesState); }
 161     unsigned keywordSize() const { return m_keywordSize; }
 162     FontSmoothingMode fontSmoothing() const { return static_cast<FontSmoothingMode>(m_fontSmoothing); }
 163     TextRenderingMode textRendering() const { return static_cast<TextRenderingMode>(m_textRendering); }
 164     UScriptCode script() const { return static_cast<UScriptCode>(m_script); }
 165     const AtomicString& locale(bool includeDefault = true) const;
 166     bool isSyntheticBold() const { return m_syntheticBold; }
 167     bool isSyntheticItalic() const { return m_syntheticItalic; }
 168     bool useSubpixelPositioning() const { return m_subpixelTextPosition; }
 169
 170     FontTraits traits() const;
 171     float wordSpacing() const { return m_wordSpacing; }
 172     float letterSpacing() const { return m_letterSpacing; }
 173     FontOrientation orientation() const { return static_cast<FontOrientation>(m_orientation); }
 174     bool isVerticalAnyUpright() const { return blink::isVerticalAnyUpright(orientation()); }
 175     bool isVerticalNonCJKUpright() const { return blink::isVerticalNonCJKUpright(orientation()); }
 176     bool isVerticalUpright(UChar32 character) const { return blink::isVerticalUpright(orientation(), character); }
 177     bool isVerticalBaseline() const { return blink::isVerticalBaseline(orientation()); }
 178     FontWidthVariant widthVariant() const { return static_cast<FontWidthVariant>(m_widthVariant); }
 179     FontFeatureSettings* featureSettings() const { return m_featureSettings.get(); }
 180
 181     float effectiveFontSize() const; // Returns either the computedSize or the computedPixelSize
 182     FontCacheKey cacheKey(const FontFaceCreationParams&, FontTraits desiredTraits = FontTraits(0)) const;
 183
 184     void setFamily(const FontFamily& family) { m_familyList = family; }
 185     void setComputedSize(float s) { m_computedSize = clampTo<float>(s); }
 186     void setSpecifiedSize(float s) { m_specifiedSize = clampTo<float>(s); }
 187     void setAdjustedSize(float s) { m_adjustedSize = clampTo<float>(s); }
 188     void setSizeAdjust(float aspect) { m_sizeAdjust = clampTo<float>(aspect); }
 189     void setStyle(FontStyle i) { m_style = i; }
 190     void setVariant(FontVariant c) { m_variant = c; }
 191     void setVariantLigatures(const VariantLigatures&);
 192     void setIsAbsoluteSize(bool s) { m_isAbsoluteSize = s; }
 193     void setWeight(FontWeight w) { m_weight = w; }
 194     void setStretch(FontStretch s) { m_stretch = s; }
 195     void setGenericFamily(GenericFamilyType genericFamily) { m_genericFamily = genericFamily; }
 196     void setKerning(Kerning kerning) { m_kerning = kerning; updateTypesettingFeatures(); }
 197     void setKeywordSize(unsigned s) { m_keywordSize = s; }
 198     void setFontSmoothing(FontSmoothingMode smoothing) { m_fontSmoothing = smoothing; }
 199     void setTextRendering(TextRenderingMode rendering) { m_textRendering = rendering; updateTypesettingFeatures(); }
 200     void setOrientation(FontOrientation orientation) { m_orientation = static_cast<unsigned>(orientation); }
 201     void setWidthVariant(FontWidthVariant widthVariant) { m_widthVariant = widthVariant; }
 202     void setScript(UScriptCode s) { m_script = s; }
 203     void setLocale(const AtomicString& locale) { m_locale = locale; }
 204     void setSyntheticBold(bool syntheticBold) { m_syntheticBold = syntheticBold; }
 205     void setSyntheticItalic(bool syntheticItalic) { m_syntheticItalic = syntheticItalic; }
 206     void setFeatureSettings(PassRefPtr<FontFeatureSettings> settings) { m_featureSettings = settings; }
 207     void setTraits(FontTraits);
 208     void setWordSpacing(float s) { m_wordSpacing = s; }
 209     void setLetterSpacing(float s) { m_letterSpacing = s; updateTypesettingFeatures(); }
 210
 211     TypesettingFeatures typesettingFeatures() const { return static_cast<TypesettingFeatures>(m_typesettingFeatures); }
 212
 213     static void setSubpixelPositioning(bool b) { s_useSubpixelTextPositioning = b; }
 214     static bool subpixelPositioning() { return s_useSubpixelTextPositioning; }
 215
 216     static void setDefaultTypesettingFeatures(TypesettingFeatures);
 217     static TypesettingFeatures defaultTypesettingFeatures();
 218
 219 private:
 220     FontFamily m_familyList; // The list of font families to be used.
 221     RefPtr<FontFeatureSettings> m_featureSettings;
 222     AtomicString m_locale;
 223
 224     void updateTypesettingFeatures() const;
 225
 226     float m_specifiedSize;   // Specified CSS value. Independent of rendering issues such as integer
 227                              // rounding, minimum font sizes, and zooming.
 228     float m_computedSize;    // Computed size adjusted for the minimum font size and the zoom factor.
 229
 230     // (Given aspect value / aspect value of a font family) * specifiedSize.
 231     // This value is adjusted for the minimum font size and the zoom factor
 232     // as well as a computed size is.
 233     float m_adjustedSize;
 234
 235     // Given aspect value, i.e. font-size-adjust.
 236     float m_sizeAdjust;
 237
 238     float m_letterSpacing;
 239     float m_wordSpacing;
 240
 241     unsigned m_orientation : static_cast<unsigned>(FontOrientation::BitCount);
 242
 243     unsigned m_widthVariant : 2; // FontWidthVariant
 244
 245     unsigned m_style : 2; // FontStyle
 246     unsigned m_variant : 1; // FontVariant
 247     unsigned m_isAbsoluteSize : 1; // Whether or not CSS specified an explicit size
 248                                   // (logical sizes like "medium" don't count).
 249     unsigned m_weight : 4; // FontWeight
 250     unsigned m_stretch : 4; // FontStretch
 251     unsigned m_genericFamily : 3; // GenericFamilyType
 252
 253     unsigned m_kerning : 2; // Kerning
 254
 255     unsigned m_commonLigaturesState : 2;
 256     unsigned m_discretionaryLigaturesState : 2;
 257     unsigned m_historicalLigaturesState : 2;
 258     unsigned m_contextualLigaturesState : 2;
 259
 260     unsigned m_keywordSize : 4; // We cache whether or not a font is currently represented by a CSS keyword (e.g., medium).  If so,
 261                            // then we can accurately translate across different generic families to adjust for different preference settings
 262                            // (e.g., 13px monospace vs. 16px everything else).  Sizes are 1-8 (like the HTML size values for <font>).
 263
 264     unsigned m_fontSmoothing : 2; // FontSmoothingMode
 265     unsigned m_textRendering : 2; // TextRenderingMode
 266     unsigned m_script : 7; // Used to help choose an appropriate font for generic font families.
 267     unsigned m_syntheticBold : 1;
 268     unsigned m_syntheticItalic : 1;
 269     unsigned m_subpixelTextPosition : 1;
 270
 271     mutable unsigned m_typesettingFeatures : 2; // TypesettingFeatures
 272
 273     static TypesettingFeatures s_defaultTypesettingFeatures;
 274
 275     static bool s_useSubpixelTextPositioning;
 276 };
 277
 278 inline bool FontDescription::operator==(const FontDescription& other) const
 279 {
 280     return m_familyList == other.m_familyList
 281         && m_specifiedSize == other.m_specifiedSize
 282         && m_computedSize == other.m_computedSize
 283         && m_adjustedSize == other.m_adjustedSize
 284         && m_sizeAdjust == other.m_sizeAdjust
 285         && m_letterSpacing == other.m_letterSpacing
 286         && m_wordSpacing == other.m_wordSpacing
 287         && m_style == other.m_style
 288         && m_variant == other.m_variant
 289         && m_isAbsoluteSize == other.m_isAbsoluteSize
 290         && m_weight == other.m_weight
 291         && m_stretch == other.m_stretch
 292         && m_genericFamily == other.m_genericFamily
 293         && m_kerning == other.m_kerning
 294         && m_commonLigaturesState == other.m_commonLigaturesState
 295         && m_discretionaryLigaturesState == other.m_discretionaryLigaturesState
 296         && m_historicalLigaturesState == other.m_historicalLigaturesState
 297         && m_contextualLigaturesState == other.m_contextualLigaturesState
 298         && m_keywordSize == other.m_keywordSize
 299         && m_fontSmoothing == other.m_fontSmoothing
 300         && m_textRendering == other.m_textRendering
 301         && m_orientation == other.m_orientation
 302         && m_widthVariant == other.m_widthVariant
 303         && m_script == other.m_script
 304         && m_syntheticBold == other.m_syntheticBold
 305         && m_syntheticItalic == other.m_syntheticItalic
 306         && m_featureSettings == other.m_featureSettings
 307         && m_subpixelTextPosition == other.m_subpixelTextPosition;
 308 }
 309
 310 } // namespace blink
 311
 312 #endif