qabstractfontengine_qws.h

Go to the documentation of this file.

/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this module.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/

#ifndef QABSTRACTFONTENGINE_QWS_H
#define QABSTRACTFONTENGINE_QWS_H

#include <QtCore/qobject.h>
#include <QtCore/qhash.h>
#include <QtCore/qvariant.h>
#include <QtCore/qfactoryinterface.h>
#include <QtGui/qpaintengine.h>
#include <QtGui/qfontdatabase.h>

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

QT_MODULE(Gui)

class QFontEngineInfoPrivate;

class Q_GUI_EXPORT QFontEngineInfo
{
public:
    QDOC_PROPERTY(QString family READ family WRITE setFamily)
    QDOC_PROPERTY(qreal pixelSize READ pixelSize WRITE setPixelSize)
    QDOC_PROPERTY(int weight READ weight WRITE setWeight)
    QDOC_PROPERTY(QFont::Style style READ style WRITE setStyle)
    QDOC_PROPERTY(QList<QFontDatabase::WritingSystem> writingSystems READ writingSystems WRITE setWritingSystems)

    QFontEngineInfo();
    explicit QFontEngineInfo(const QString &family);
    QFontEngineInfo(const QFontEngineInfo &other);
    QFontEngineInfo &operator=(const QFontEngineInfo &other);
    ~QFontEngineInfo();

    void setFamily(const QString &name);
    QString family() const;

    void setPixelSize(qreal size);
    qreal pixelSize() const;

    void setWeight(int weight);
    int weight() const;

    void setStyle(QFont::Style style);
    QFont::Style style() const;

    QList<QFontDatabase::WritingSystem> writingSystems() const;
    void setWritingSystems(const QList<QFontDatabase::WritingSystem> &writingSystems);

private:
    QFontEngineInfoPrivate *d;
};

class QAbstractFontEngine;

struct Q_GUI_EXPORT QFontEngineFactoryInterface : public QFactoryInterface
{
     virtual QAbstractFontEngine *create(const QFontEngineInfo &info) = 0;
     virtual QList<QFontEngineInfo> availableFontEngines() const = 0;
};

#define QFontEngineFactoryInterface_iid "com.trolltech.Qt.QFontEngineFactoryInterface"
Q_DECLARE_INTERFACE(QFontEngineFactoryInterface, QFontEngineFactoryInterface_iid)

class QFontEnginePluginPrivate;

class Q_GUI_EXPORT QFontEnginePlugin : public QObject, public QFontEngineFactoryInterface
{
    Q_OBJECT
    Q_INTERFACES(QFontEngineFactoryInterface:QFactoryInterface)
public:
    QFontEnginePlugin(const QString &foundry, QObject *parent = 0);
    ~QFontEnginePlugin();

    virtual QStringList keys() const;

    virtual QAbstractFontEngine *create(const QFontEngineInfo &info) = 0;
    virtual QList<QFontEngineInfo> availableFontEngines() const = 0;

private:
    Q_DECLARE_PRIVATE(QFontEnginePlugin)
    Q_DISABLE_COPY(QFontEnginePlugin)
};

class QAbstractFontEnginePrivate;

class Q_GUI_EXPORT QAbstractFontEngine : public QObject
{
    Q_OBJECT
public:
    enum Capability {
        CanOutlineGlyphs = 1,
        CanRenderGlyphs_Mono = 2,
        CanRenderGlyphs_Gray = 4,
        CanRenderGlyphs = CanRenderGlyphs_Mono | CanRenderGlyphs_Gray
    };
    Q_DECLARE_FLAGS(Capabilities, Capability)

    explicit QAbstractFontEngine(QObject *parent = 0);
    ~QAbstractFontEngine();

    typedef int Fixed; // 26.6

    struct FixedPoint
    {
        Fixed x;
        Fixed y;
    };

    struct GlyphMetrics
    {
        inline GlyphMetrics()
            : x(0), y(0), width(0), height(0),
              advance(0) {}
        Fixed x;
        Fixed y;
        Fixed width;
        Fixed height;
        Fixed advance;
    };

    enum FontProperty {
        Ascent,
        Descent,
        Leading,
        XHeight,
        AverageCharWidth,
        LineThickness,
        UnderlinePosition,
        MaxCharWidth,
        MinLeftBearing,
        MinRightBearing,
        GlyphCount,

        // hints
        CacheGlyphsHint,
        OutlineGlyphsHint
    };

    // keep in sync with QTextEngine::ShaperFlag!!
    enum TextShapingFlag {
        RightToLeft         = 0x0001,
        ReturnDesignMetrics = 0x0002
    };
    Q_DECLARE_FLAGS(TextShapingFlags, TextShapingFlag)

    virtual Capabilities capabilities() const = 0;
    virtual QVariant fontProperty(FontProperty property) const = 0;

    virtual bool convertStringToGlyphIndices(const QChar *string, int length, uint *glyphs, int *numGlyphs, TextShapingFlags flags) const = 0;

    virtual void getGlyphAdvances(const uint *glyphs, int numGlyphs, Fixed *advances, TextShapingFlags flags) const = 0;

    virtual GlyphMetrics glyphMetrics(uint glyph) const = 0;

    virtual bool renderGlyph(uint glyph, int depth, int bytesPerLine, int height, uchar *buffer);

    virtual void addGlyphOutlinesToPath(uint *glyphs, int numGlyphs, FixedPoint *positions, QPainterPath *path);

    /*
    enum Extension {
        GetTrueTypeTable
    };

    virtual bool supportsExtension(Extension extension) const;
    virtual QVariant extension(Extension extension, const QVariant &argument = QVariant());
    */

private:
    Q_DECLARE_PRIVATE(QAbstractFontEngine)
    Q_DISABLE_COPY(QAbstractFontEngine)
};

Q_DECLARE_OPERATORS_FOR_FLAGS(QAbstractFontEngine::Capabilities)
Q_DECLARE_OPERATORS_FOR_FLAGS(QAbstractFontEngine::TextShapingFlags)

QT_END_NAMESPACE

QT_END_HEADER

#endif