tdelibs/khtml/rendering/font.h

/*
 * This file is part of the html renderer for KDE.
 *
 * Copyright (C) 2000-2003 Lars Knoll (knoll@kde.org)
 *           (C) 2000 Antti Koivisto (koivisto@kde.org)
 *           (C) 2000 Dirk Mueller (mueller@kde.org)
 *
 * 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., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#ifndef KHTMLFONT_H
#define KHTMLFONT_H

#include <qfont.h>
#include <qfontmetrics.h>
#include <qmap.h>
#include <qpainter.h>

class QFontDatabase;
class QPaintDeviceMetrics;

namespace khtml
{
class RenderStyle;
class CSSStyleSelector;

class FontDef
{
public:
    FontDef()
        : size( 0 ), italic( false ), smallCaps( false ), weight( 50 ) {}
    bool operator == ( const FontDef &other ) const {
        return ( family == other.family &&
                 size == other.size &&
                 italic == other.italic &&
                 smallCaps == other.smallCaps &&
                 weight == other.weight );
    }

    QString family;
    short int size;
    bool italic 		: 1;
    bool smallCaps 		: 1;
    unsigned int weight 		: 8;
};


class Font
{
    friend class RenderStyle;
    friend class CSSStyleSelector;

public:
    Font() : fontDef(), f(), fm( f ), scFont( 0 ), letterSpacing( 0 ), wordSpacing( 0 ) {}
    Font( const FontDef &fd )
        :  fontDef( fd ), f(), fm( f ), scFont( 0 ), letterSpacing( 0 ), wordSpacing( 0 )
        {}
    Font(const Font& o)
        : fontDef(o.fontDef), f(o.f), fm(o.fm), scFont(o.scFont), letterSpacing(o.letterSpacing), wordSpacing(o.wordSpacing) { if (o.scFont) scFont = new QFont(*o.scFont); }
    ~Font() { delete scFont; }

    bool operator == ( const Font &other ) const {
        return (fontDef == other.fontDef &&
                letterSpacing == other.letterSpacing &&
                wordSpacing == other.wordSpacing );
    }

    const FontDef& getFontDef() const { return fontDef; }

    void update( QPaintDeviceMetrics *devMetrics ) const;

    /**
     * Draws a piece from the given piece of text.
     * @param p painter
     * @param x x-coordinate to begin drawing, always denotes leftmost position
     * @param y y-coordinate of baseline of text
     * @param str string to draw a piece from
     * @param slen total length of string
     * @param pos zero-based offset of beginning of piece
     * @param len length of piece
     * @param width additional pixels to be distributed equally among all
     *		spaces
     * @param d text direction
     * @param from begin with this position relative to @p pos, -1 to start
     *		at @p pos
     * @param to stop before this position relative to @p pos, -1 to use full
     *		length of piece
     * @param bg if valid, fill the background of the drawn piece with this
     *		color
     * @param uy y-coordinate of top position, used for background and text
     *		decoration painting
     * @param h total height of line, only used for background and text
     *		decoration painting
     * @param deco combined text decoration (see Decoration)
     */
    void drawText( QPainter *p, int x, int y, QChar *str, int slen, int pos, int len, int width,
                   QPainter::TextDirection d, int from=-1, int to=-1, QColor bg=QColor(),
		   int uy=-1, int h=-1, int deco=0 ) const;

    /** returns the width of the given string chunk in pixels.
     *
     * The method also considers various styles like text-align and font-variant
     * @param str pointer to string
     * @param slen total length of string
     * @param pos zero-based position in string where to start measuring
     * @param len count of characters up to which the width should be determined
     * @param start starting position of inline text box within str, only
     * used when toAdd is specified.
     * @param end ending position of inline text box within str, only
     * used when toAdd is specified.
     * @param toAdd amount of pixels to distribute evenly among all spaces of
     * str. Note that toAdd applies to all spaces within str, but only those
     * within [pos, pos+len) are counted towards the width.
     */
    int width( QChar *str, int slen, int pos, int len, int start = 0, int end = 0, int toAdd = 0 ) const;
    /** return the width of the given char in pixels.
     *
     * The method also considers various styles like text-align and font-variant
     * @param str pointer to string
     * @param slen total length of string
     * @param pos zero-based position of char in string
     */
    int width( QChar *str, int slen, int pos) const;

    /** Text decoration constants.
     *
     * The enumeration constant values match those of ETextDecoration, but only
     * a subset is supported.
     */
    enum Decoration { UNDERLINE = 0x1, OVERLINE = 0x2, LINE_THROUGH= 0x4 };
    // Keep in sync with ETextDecoration

    /** draws text decoration
     * @param p painter
     * @param x x-coordinate
     * @param y top y-coordinate of line box
     * @param baseline baseline
     * @param width length of decoration in pixels
     * @param height height of line box
     * @param deco decoration to be drawn (see Decoration). The enumeration
     *		constants may be combined.
     */
    void drawDecoration(QPainter *p, int x, int y, int baseline, int width, int height, int deco) const;

    /** returns letter spacing
     */
    int getLetterSpacing() const { return letterSpacing; }
    /** returns word spacing
     */
    int getWordSpacing() const { return wordSpacing; }

private:
    mutable FontDef fontDef;
    mutable QFont f;
    mutable QFontMetrics fm;
    mutable QFont *scFont;
    short letterSpacing;
    short wordSpacing;

    struct ScalKey;
    enum   ScalInfo {
        Unknown,
        No,
        Yes
    };

    static QMap<ScalKey, ScalInfo>* scalCache;
    static QMap<ScalKey, QValueList<int> >* scalSizesCache;
    static bool isFontScalable(QFontDatabase& db, const QFont& font);
};

} // namespace

#endif