/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
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** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL21$
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** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
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** use the contact form at http://qt.digia.com/contact-us.
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** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
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**
** In addition, as a special exception, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
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****************************************************************************/

#pragma once

#include <QtCore/qglobal.h>

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

#include <QtGui/QIcon>
#include <QtGui/QIconEngine>
#include <QtGui/QPixmapCache>
#include <QtCore/QHash>
#include <QtCore/QVector>
#include <QtCore/QTypeInfo>


namespace QtXdg
{

class QIconLoader;

struct QIconDirInfo
{
    enum Type
    {
        Fixed,
        Scalable,
        Threshold
    };
    QIconDirInfo(const QString &_path = QString())
        : path(_path), size(0), maxSize(0), minSize(0), threshold(0), type(Threshold)
    {
    }
    QString path;
    short size;
    short maxSize;
    short minSize;
    short threshold;
    Type type : 4;
};

class QIconLoaderEngineEntry
{
public:
    virtual ~QIconLoaderEngineEntry()
    {
    }
    virtual QPixmap pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state) = 0;
    QString filename;
    QIconDirInfo dir;
    static int count;
};

struct ScalableEntry : public QIconLoaderEngineEntry
{
    QPixmap pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state) Q_DECL_OVERRIDE;
    QIcon svgIcon;
};

struct PixmapEntry : public QIconLoaderEngineEntry
{
    QPixmap pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state) Q_DECL_OVERRIDE;
    QPixmap basePixmap;
};

typedef QList<QIconLoaderEngineEntry *> QThemeIconEntries;

// class QIconLoaderEngine : public QIconEngine
class QIconLoaderEngineFixed : public QIconEngine
{
public:
    QIconLoaderEngineFixed(const QString &iconName = QString());
    ~QIconLoaderEngineFixed();

    void paint(QPainter *painter, const QRect &rect, QIcon::Mode mode, QIcon::State state);
    QPixmap pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state);
    QSize actualSize(const QSize &size, QIcon::Mode mode, QIcon::State state);
    QIconEngine *clone() const;
    bool read(QDataStream &in);
    bool write(QDataStream &out) const;

private:
    QString key() const;
    bool hasIcon() const;
    void ensureLoaded();
    void virtual_hook(int id, void *data);
    QIconLoaderEngineEntry *entryForSize(const QSize &size);
    QIconLoaderEngineFixed(const QIconLoaderEngineFixed &other);
    QThemeIconEntries m_entries;
    QString m_iconName;
    uint m_key;

    friend class QIconLoader;
};

class QIconTheme
{
public:
    QIconTheme(const QString &name);
    QIconTheme() : m_valid(false)
    {
    }
    QStringList parents()
    {
        return m_parents;
    }
    QVector<QIconDirInfo> keyList()
    {
        return m_keyList;
    }
    QString contentDir()
    {
        return m_contentDir;
    }
    QStringList contentDirs()
    {
        return m_contentDirs;
    }
    bool isValid()
    {
        return m_valid;
    }

private:
    QString m_contentDir;
    QStringList m_contentDirs;
    QVector<QIconDirInfo> m_keyList;
    QStringList m_parents;
    bool m_valid;
};

class QIconLoader
{
public:
    QIconLoader();
    QThemeIconEntries loadIcon(const QString &iconName) const;
    uint themeKey() const
    {
        return m_themeKey;
    }

    QString themeName() const
    {
        return m_userTheme.isEmpty() ? m_systemTheme : m_userTheme;
    }
    void setThemeName(const QString &themeName);
    QIconTheme theme()
    {
        return themeList.value(themeName());
    }
    void setThemeSearchPath(const QStringList &searchPaths);
    QStringList themeSearchPaths() const;
    QIconDirInfo dirInfo(int dirindex);
    static QIconLoader *instance();
    void updateSystemTheme();
    void invalidateKey()
    {
        m_themeKey++;
    }
    void ensureInitialized();

private:
    QThemeIconEntries findIconHelper(const QString &themeName, const QString &iconName,
                                     QStringList &visited) const;
    uint m_themeKey;
    bool m_supportsSvg;
    bool m_initialized;

    mutable QString m_userTheme;
    mutable QString m_systemTheme;
    mutable QStringList m_iconDirs;
    mutable QHash<QString, QIconTheme> themeList;
};

} // QtXdg

// Note: class template specialization of 'QTypeInfo' must occur at
//       global scope
Q_DECLARE_TYPEINFO(QtXdg::QIconDirInfo, Q_MOVABLE_TYPE);
