Font.h   [plain text]

/*
 * This file is part of the html renderer for KDE.
 *
 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
 *           (C) 2000 Antti Koivisto (koivisto@kde.org)
 *           (C) 2000 Dirk Mueller (mueller@kde.org)
 * Copyright (C) 2003, 2006 Apple Computer, Inc.
 *
 * 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; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 */

#ifndef FONT_H
#define FONT_H

#include "Color.h"
#include "FontDescription.h"
#include "FontData.h"
#include "TextDirection.h"
#include "GlyphBuffer.h"

namespace WebCore {

class FontFallbackList;
class GraphicsContext;
class IntPoint;
class IntRect;
class FloatRect;
class FloatPoint;

class TextRun
{
public:
    TextRun(const UChar* c, int len)
    :m_characters(c), m_len(len), m_from(0), m_to(len)
    {}

    TextRun(const UChar* c, int len, int from, int to) // This constructor is only used in one place in Mac-specific code.
    :m_characters(c), m_len(len), m_from(from), m_to(to)
    {}

    TextRun(const StringImpl* s, int offset = 0, int length = -1, int from = -1, int to = -1)
    :m_characters(s->characters() + offset), m_len(length == -1 ? s->length() - offset : length), m_from(adjustFrom(from)), m_to(adjustTo(to))
    {}

    const UChar operator[](int i) const { return m_characters[i]; }
    const UChar* data(int i) const { return &m_characters[i]; }

    int adjustFrom(int from) const { return from == -1 ? 0 : from; }
    int adjustTo(int to) const { return to == -1 ? m_len : to; }
    void makeComplete() { m_from = 0; m_to = m_len; }

    const UChar* characters() const { return m_characters; }
    int length() const { return m_len; }
    int from() const { return m_from; }
    int to() const { return m_to; }

private:
    const UChar* m_characters;
    int m_len;
    int m_from;
    int m_to;
};

class TextStyle
{
public:
    TextStyle(int tabWidth = 0, int xpos = 0, int padding = 0, bool rtl = false, bool directionalOverride = false,
              bool applyRunRounding = true, bool applyWordRounding = true, bool attemptFontSubstitution = true)
    :m_tabWidth(tabWidth), m_xpos(xpos), m_padding(padding), m_rtl(rtl), m_directionalOverride(directionalOverride),
     m_applyRunRounding(applyRunRounding), m_applyWordRounding(applyWordRounding), m_attemptFontSubstitution(attemptFontSubstitution)
    , m_shouldSetColor(true)
    {}
    
    int tabWidth() const { return m_tabWidth; }
    int xPos() const { return m_xpos; }
    int padding() const { return m_padding; }
    bool rtl() const { return m_rtl; }
    bool ltr() const { return !m_rtl; }
    bool directionalOverride() const { return m_directionalOverride; }
    bool applyRunRounding() const { return m_applyRunRounding; }
    bool applyWordRounding() const { return m_applyWordRounding; }
    bool attemptFontSubstitution() const { return m_attemptFontSubstitution; }

    void disableRoundingHacks() { m_applyRunRounding = m_applyWordRounding = false; }
    void setRTL(bool b) { m_rtl = b; }

    void setAttemptFontSubstitution (bool f) { m_attemptFontSubstitution = f; }
    void setShouldSetColor (bool f) { m_shouldSetColor = f; }
    bool shouldSetColor () const { return m_shouldSetColor; }
    
private:
    int m_tabWidth;
    int m_xpos;
    int m_padding;
    bool m_rtl;
    bool m_directionalOverride;
    bool m_applyRunRounding;
    bool m_applyWordRounding;
    bool m_attemptFontSubstitution;
    bool m_shouldSetColor;
};

class Font {
public:
    Font();
    Font(const FontDescription&, float letterSpacing, float wordSpacing);
#if __APPLE__
    Font(const FontPlatformData& fontPlatformData); // This constructor is only used by Mac-specific code that already has a native font.
#endif
    ~Font();
    
    Font(const Font&);
    Font& operator=(const Font&);

    bool operator==(const Font& other) const {
        // Our FontData doesn't have to be checked, since
        // checking the font description will be fine.
        return (m_fontDescription == other.m_fontDescription &&
                m_letterSpacing == other.m_letterSpacing &&
                m_wordSpacing == other.m_wordSpacing);
    }

    bool operator!=(const Font& other) const {
        return !(*this == other);
    }

    const FontDescription& fontDescription() const { return m_fontDescription; }

    int pixelSize() const { return fontDescription().computedPixelSize(); }
    float size() const { return fontDescription().computedSize(); }
    
    void update() const;

    float drawText(GraphicsContext*, const TextRun&, const TextStyle&, const FloatPoint&) const;

    int width(const TextRun&, const TextStyle& = TextStyle()) const;
    float floatWidth(const TextRun&, const TextStyle& = TextStyle()) const;
    
    int offsetForPosition(const TextRun&, const TextStyle&, int position, bool includePartialGlyphs) const;
    FloatRect selectionRectForText(const TextRun&, const TextStyle&, const IntPoint&, int h) const;

    bool isSmallCaps() const { return m_fontDescription.smallCaps(); }

    float wordSpacing() const { return m_wordSpacing; }
    float letterSpacing() const { return m_letterSpacing; }
    void setWordSpacing(float s) { m_wordSpacing = s; }
    void setLetterSpacing(float s) { m_letterSpacing = s; }

    bool isFixedPitch() const;
    bool isPrinterFont() const { return m_fontDescription.usePrinterFont(); }

    FontFamily& firstFamily() { return m_fontDescription.firstFamily(); }
    const FontFamily& family() const { return m_fontDescription.family(); }

    bool italic() const { return m_fontDescription.italic(); }
    unsigned weight() const { return m_fontDescription.weight(); }
    bool bold() const { return m_fontDescription.bold(); }

#if __APPLE__
    GSFontRef getFont() const { return primaryFont()->getFont(); }
#endif

    // Metrics that we query the FontFallbackList for.
    int ascent() const;
    int descent() const;
    int height() const { return ascent() + descent(); }
    int lineSpacing() const;
    float xHeight() const;

    const FontData* primaryFont() const;
    const FontData* fontDataAt(unsigned) const;
    const FontData* fontDataForCharacters(const UChar*, int length) const;

private:
    // FIXME: This will eventually be cross-platform, but we want to keep Windows compiling for now.
    bool canUseGlyphCache(const TextRun&) const;
    float drawSimpleText(GraphicsContext*, const TextRun&, const TextStyle&, const FloatPoint&) const;
    void drawGlyphs(GraphicsContext*, const FontData*, const GlyphBuffer&, int from, int to, const FloatPoint&, bool setColor = true) const;

	float floatWidthForSimpleText(const TextRun&, const TextStyle&, const FontData* substituteFontData,
                                  float* startX, GlyphBuffer*) const;
    int offsetForPositionForSimpleText(const TextRun&, const TextStyle&, int position, bool includePartialGlyphs) const;
    FloatRect selectionRectForSimpleText(const TextRun&, const TextStyle&, const IntPoint&, int h) const;

    friend struct WidthIterator;
    
    // Useful for debugging the complex font rendering code path.
public:
    bool equalForTextAutoSizing (const Font &other) const {
        return (m_fontDescription.equalForTextAutoSizing(other.m_fontDescription) &&
                m_letterSpacing == other.m_letterSpacing &&
                m_wordSpacing == other.m_wordSpacing);
    }

    static void setAlwaysUseComplexPath(bool);
    static bool gAlwaysUseComplexPath;
    
    static const uint8_t gRoundingHackCharacterTable[256];
    static bool treatAsSpace(UChar c) { return c == ' ' || c == '\t' || c == '\n' || c == 0x00A0; }
    static bool isRoundingHackCharacter(UChar32 c)
    {
        return (((c & ~0xFF) == 0 && gRoundingHackCharacterTable[c])); 
    }

private:
    FontDescription m_fontDescription;
    mutable RefPtr<FontFallbackList> m_fontList;
    float m_letterSpacing;
    float m_wordSpacing;
};

}

#endif