/****************************************************************************

**

** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).

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** Contact: Nokia Corporation (qt-info@nokia.com)

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** This file is part of the QtGui module of the Qt Toolkit.

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** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

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** GNU Lesser General Public License Usage

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** 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

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**

** In addition, as a special exception, Nokia gives you certain additional

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** If you have questions regarding the use of this file, please contact

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** $QT_END_LICENSE$

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****************************************************************************/

#ifndef QT_NO_ICON

#include <private/qiconloader_p.h>

#include <private/qapplication_p.h>

#include <private/qicon_p.h>

#include <private/qguiplatformplugin_p.h>

#include <QtGui/QIconEnginePlugin>

#include <QtGui/QPixmapCache>

#include <QtGui/QIconEngine>

#include <QtGui/QStyleOption>

#include <QtCore/QList>

#include <QtCore/QHash>

#include <QtCore/QDir>

#include <QtCore/QSettings>

#include <QtGui/QPainter>

#ifdef Q_WS_MAC

#include <private/qt_cocoa_helpers_mac_p.h>

#endif

#ifdef Q_WS_X11

#include <private/qt_x11_p.h>

#endif

QT_BEGIN_NAMESPACE

Q_GLOBAL_STATIC(QIconLoader, iconLoaderInstance)

/* Theme to use in last resort, if the theme does not have the icon, neither the parents  */

static QString fallbackTheme()

{

#ifdef Q_WS_X11

    if (X11->desktopEnvironment == DE_GNOME) {

        return QLatin1String("gnome");

    } else if (X11->desktopEnvironment == DE_KDE) {

        return X11->desktopVersion >= 4

            ? QString::fromLatin1("oxygen")

            : QString::fromLatin1("crystalsvg");

    } else {

        return QLatin1String("hicolor");

    }

#endif

    return QString();

}

QIconLoader::QIconLoader() :

        m_themeKey(1), m_supportsSvg(false), m_initialized(false)

{

}

// We lazily initialize the loader to make static icons

// work. Though we do not officially support this.

void QIconLoader::ensureInitialized()

{

    if (!m_initialized) {

        m_initialized = true;

        Q_ASSERT(qApp);

        m_systemTheme = qt_guiPlatformPlugin()->systemIconThemeName();

        if (m_systemTheme.isEmpty())

            m_systemTheme = fallbackTheme();

#ifndef QT_NO_LIBRARY

        QFactoryLoader iconFactoryLoader(QIconEngineFactoryInterfaceV2_iid,

                                         QLatin1String("/iconengines"),

                                         Qt::CaseInsensitive);

        if (iconFactoryLoader.keys().contains(QLatin1String("svg")))

            m_supportsSvg = true;

#endif //QT_NO_LIBRARY

    }

}

QIconLoader *QIconLoader::instance()

{

   return iconLoaderInstance();

}

// Queries the system theme and invalidates existing

// icons if the theme has changed.

void QIconLoader::updateSystemTheme()

{

    // Only change if this is not explicitly set by the user

    if (m_userTheme.isEmpty()) {

        QString theme = qt_guiPlatformPlugin()->systemIconThemeName();

        if (theme.isEmpty())

            theme = fallbackTheme();

        if (theme != m_systemTheme) {

            m_systemTheme = theme;

            invalidateKey();

        }

    }

}

void QIconLoader::setThemeName(const QString &themeName)

{

    m_userTheme = themeName;

    invalidateKey();

}

void QIconLoader::setThemeSearchPath(const QStringList &searchPaths)

{

    m_iconDirs = searchPaths;

    themeList.clear();

    invalidateKey();

}

QStringList QIconLoader::themeSearchPaths() const

{

    if (m_iconDirs.isEmpty()) {

        m_iconDirs = qt_guiPlatformPlugin()->iconThemeSearchPaths();

        // Allways add resource directory as search path

        m_iconDirs.append(QLatin1String(":/icons"));

    }

    return m_iconDirs;

}

QIconTheme::QIconTheme(const QString &themeName)

        : m_valid(false)

{

    QFile themeIndex;

    QList <QIconDirInfo> keyList;

    QStringList iconDirs = QIcon::themeSearchPaths();

    for ( int i = 0 ; i < iconDirs.size() ; ++i) {

        QDir iconDir(iconDirs[i]);

        QString themeDir = iconDir.path() + QLatin1Char('/') + themeName;

        themeIndex.setFileName(themeDir + QLatin1String("/index.theme"));

        if (themeIndex.exists()) {

            m_contentDir = themeDir;

            m_valid = true;

            break;

        }

    }

#ifndef QT_NO_SETTINGS

    if (themeIndex.exists()) {

        const QSettings indexReader(themeIndex.fileName(), QSettings::IniFormat);

        QStringListIterator keyIterator(indexReader.allKeys());

        while (keyIterator.hasNext()) {

            const QString key = keyIterator.next();

            if (key.endsWith(QLatin1String("/Size"))) {

                // Note the QSettings ini-format does not accept

                // slashes in key names, hence we have to cheat

                if (int size = indexReader.value(key).toInt()) {

                    QString directoryKey = key.left(key.size() - 5);

                    QIconDirInfo dirInfo(directoryKey);

                    dirInfo.size = size;

                    QString type = indexReader.value(directoryKey +

                                                     QLatin1String("/Type")

                                                     ).toString();

                    if (type == QLatin1String("Fixed"))

                        dirInfo.type = QIconDirInfo::Fixed;

                    else if (type == QLatin1String("Scalable"))

                        dirInfo.type = QIconDirInfo::Scalable;

                    else

                        dirInfo.type = QIconDirInfo::Threshold;

                    dirInfo.threshold = indexReader.value(directoryKey +

                                                        QLatin1String("/Threshold"),

                                                        2).toInt();

                    dirInfo.minSize = indexReader.value(directoryKey +

                                                         QLatin1String("/MinSize"),

                                                         size).toInt();

                    dirInfo.maxSize = indexReader.value(directoryKey +

                                                        QLatin1String("/MaxSize"),

                                                        size).toInt();

                    m_keyList.append(dirInfo);

                }

            }

        }

        // Parent themes provide fallbacks for missing icons

        m_parents = indexReader.value(

                QLatin1String("Icon Theme/Inherits")).toStringList();

        // Ensure a default platform fallback for all themes

        if (m_parents.isEmpty())

            m_parents.append(fallbackTheme());

        // Ensure that all themes fall back to hicolor

        if (!m_parents.contains(QLatin1String("hicolor")))

            m_parents.append(QLatin1String("hicolor"));

    }

#endif //QT_NO_SETTINGS

}

QThemeIconEntries QIconLoader::findIconHelper(const QString &themeName,

                                 const QString &iconName,

                                 QStringList &visited) const

{

    QThemeIconEntries entries;

    Q_ASSERT(!themeName.isEmpty());

    QPixmap pixmap;

    // Used to protect against potential recursions

    visited << themeName;

    QIconTheme theme = themeList.value(themeName);

    if (!theme.isValid()) {

        theme = QIconTheme(themeName);

        if (!theme.isValid())

            theme = QIconTheme(fallbackTheme());

        themeList.insert(themeName, theme);

    }

    QString contentDir = theme.contentDir() + QLatin1Char('/');

    QList<QIconDirInfo> subDirs = theme.keyList();

    const QString svgext(QLatin1String(".svg"));

    const QString pngext(QLatin1String(".png"));

    // Add all relevant files

    for (int i = 0; i < subDirs.size() ; ++i) {

        const QIconDirInfo &dirInfo = subDirs.at(i);

        QString subdir = dirInfo.path;

        QDir currentDir(contentDir + subdir);

        if (currentDir.exists(iconName + pngext)) {

            PixmapEntry *iconEntry = new PixmapEntry;

            iconEntry->dir = dirInfo;

            iconEntry->filename = currentDir.filePath(iconName + pngext);

            // Notice we ensure that pixmap entries allways come before

            // scalable to preserve search order afterwards

            entries.prepend(iconEntry);

        } else if (m_supportsSvg &&

            currentDir.exists(iconName + svgext)) {

            ScalableEntry *iconEntry = new ScalableEntry;

            iconEntry->dir = dirInfo;

            iconEntry->filename = currentDir.filePath(iconName + svgext);

            entries.append(iconEntry);

        }

    }

    if (entries.isEmpty()) {

        const QStringList parents = theme.parents();

        // Search recursively through inherited themes

        for (int i = 0 ; i < parents.size() ; ++i) {

            const QString parentTheme = parents.at(i).trimmed();

            if (!visited.contains(parentTheme)) // guard against recursion

                entries = findIconHelper(parentTheme, iconName, visited);

            if (!entries.isEmpty()) // success

                break;

        }

    }

    return entries;

}

QThemeIconEntries QIconLoader::loadIcon(const QString &name) const

{

    if (!themeName().isEmpty()) {

        QStringList visited;

        return findIconHelper(themeName(), name, visited);

    }

    return QThemeIconEntries();

}

// -------- Icon Loader Engine -------- //

QIconLoaderEngine::QIconLoaderEngine(const QString& iconName)

        : m_iconName(iconName), m_key(0)

{

}

QIconLoaderEngine::~QIconLoaderEngine()

{

    while (!m_entries.isEmpty())

        delete m_entries.takeLast();

    Q_ASSERT(m_entries.size() == 0);

}

QIconLoaderEngine::QIconLoaderEngine(const QIconLoaderEngine &other)

        : QIconEngineV2(other),

        m_iconName(other.m_iconName),

        m_key(0)

{

}

QIconEngineV2 *QIconLoaderEngine::clone() const

{

    return new QIconLoaderEngine(*this);

}

bool QIconLoaderEngine::read(QDataStream &in) {

    in >> m_iconName;

    return true;

}

bool QIconLoaderEngine::write(QDataStream &out) const

{

    out << m_iconName;

    return true;

}

bool QIconLoaderEngine::hasIcon() const

{

    return !(m_entries.isEmpty());

}

// Lazily load the icon

void QIconLoaderEngine::ensureLoaded()

{

    iconLoaderInstance()->ensureInitialized();

    if (!(iconLoaderInstance()->themeKey() == m_key)) {

        while (!m_entries.isEmpty())

            delete m_entries.takeLast();

        Q_ASSERT(m_entries.size() == 0);

        m_entries = iconLoaderInstance()->loadIcon(m_iconName);

        m_key = iconLoaderInstance()->themeKey();

    }

}

void QIconLoaderEngine::paint(QPainter *painter, const QRect &rect,

                             QIcon::Mode mode, QIcon::State state)

{

    QSize pixmapSize = rect.size();

#if defined(Q_WS_MAC)

    pixmapSize *= qt_mac_get_scalefactor();

#endif

    painter->drawPixmap(rect, pixmap(pixmapSize, mode, state));

}

/*

 * This algorithm is defined by the freedesktop spec:

 * http://standards.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html

 */

static bool directoryMatchesSize(const QIconDirInfo &dir, int iconsize)

{

    if (dir.type == QIconDirInfo::Fixed) {

        return dir.size == iconsize;

    } else if (dir.type == QIconDirInfo::Scalable) {

        return dir.size <= dir.maxSize &&

                iconsize >= dir.minSize;

    } else if (dir.type == QIconDirInfo::Threshold) {

        return iconsize >= dir.size - dir.threshold &&

                iconsize <= dir.size + dir.threshold;

    }

    Q_ASSERT(1); // Not a valid value

    return false;

}

/*

 * This algorithm is defined by the freedesktop spec:

 * http://standards.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html

 */

static int directorySizeDistance(const QIconDirInfo &dir, int iconsize)

{

    if (dir.type == QIconDirInfo::Fixed) {

        return qAbs(dir.size - iconsize);

    } else if (dir.type == QIconDirInfo::Scalable) {

        if (iconsize < dir.minSize)

            return dir.minSize - iconsize;

        else if (iconsize > dir.maxSize)

            return iconsize - dir.maxSize;

        else

            return 0;

    } else if (dir.type == QIconDirInfo::Threshold) {

        if (iconsize < dir.size - dir.threshold)

            return dir.minSize - iconsize;

        else if (iconsize > dir.size + dir.threshold)

            return iconsize - dir.maxSize;

        else return 0;

    }

    Q_ASSERT(1); // Not a valid value

    return INT_MAX;

}

QIconLoaderEngineEntry *QIconLoaderEngine::entryForSize(const QSize &size)

{

    int iconsize = qMin(size.width(), size.height());

    // Note that m_entries are sorted so that png-files

    // come first

    // Search for exact matches first

    for (int i = 0; i < m_entries.count(); ++i) {

        QIconLoaderEngineEntry *entry = m_entries.at(i);

        if (directoryMatchesSize(entry->dir, iconsize)) {

            return entry;

        }

    }

    // Find the minimum distance icon

    int minimalSize = INT_MAX;

    QIconLoaderEngineEntry *closestMatch = 0;

    for (int i = 0; i < m_entries.count(); ++i) {

        QIconLoaderEngineEntry *entry = m_entries.at(i);

        int distance = directorySizeDistance(entry->dir, iconsize);

        if (distance < minimalSize) {

            minimalSize  = distance;

            closestMatch = entry;

        }

    }

    return closestMatch;

}

/*

 * Returns the actual icon size. For scalable svg's this is equivalent

 * to the requested size. Otherwise the closest match is returned but

 * we can never return a bigger size than the requested size.

 *

 */

QSize QIconLoaderEngine::actualSize(const QSize &size, QIcon::Mode mode,

                                   QIcon::State state)

{

    ensureLoaded();

    QIconLoaderEngineEntry *entry = entryForSize(size);

    if (entry) {

        const QIconDirInfo &dir = entry->dir;

        if (dir.type == QIconDirInfo::Scalable)

            return size;

        else {

            int result = qMin<int>(dir.size, qMin(size.width(), size.height()));

            return QSize(result, result);

        }

    }

    return QIconEngineV2::actualSize(size, mode, state);

}

QPixmap PixmapEntry::pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state)

{

    Q_UNUSED(state);

    // Ensure that basePixmap is lazily initialized before generating the

    // key, otherwise the cache key is not unique

    if (basePixmap.isNull())

        basePixmap.load(filename);

    int actualSize = qMin(size.width(), size.height());

    QString key = QLatin1String("$qt_theme_")

                  + QString::number(basePixmap.cacheKey(), 16)

                  + QLatin1Char('_')

                  + QString::number(mode)

                  + QLatin1Char('_')

                  + QString::number(qApp->palette().cacheKey(), 16)

                  + QLatin1Char('_')

                  + QString::number(actualSize);

    QPixmap cachedPixmap;

    if (QPixmapCache::find(key, &cachedPixmap)) {

        return cachedPixmap;

    } else {

        QStyleOption opt(0);

        opt.palette = qApp->palette();

        cachedPixmap = qApp->style()->generatedIconPixmap(mode, basePixmap, &opt);

        QPixmapCache::insert(key, cachedPixmap);

    }

    return cachedPixmap;

}

QPixmap ScalableEntry::pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state)

{

    if (svgIcon.isNull())

        svgIcon = QIcon(filename);

    // Simply reuse svg icon engine

    return svgIcon.pixmap(size, mode, state);

}

QPixmap QIconLoaderEngine::pixmap(const QSize &size, QIcon::Mode mode,

                                 QIcon::State state)

{

    ensureLoaded();

    QIconLoaderEngineEntry *entry = entryForSize(size);

    if (entry)

        return entry->pixmap(size, mode, state);

    return QPixmap();

}

QString QIconLoaderEngine::key() const

{

    return QLatin1String("QIconLoaderEngine");

}

void QIconLoaderEngine::virtual_hook(int id, void *data)

{

    ensureLoaded();

    switch (id) {

    case QIconEngineV2::AvailableSizesHook:

        {

            QIconEngineV2::AvailableSizesArgument &arg

                    = *reinterpret_cast<QIconEngineV2::AvailableSizesArgument*>(data);

            const QList<QIconDirInfo> directoryKey = iconLoaderInstance()->theme().keyList();

            arg.sizes.clear();

            // Gets all sizes from the DirectoryInfo entries

            for (int i = 0 ; i < m_entries.size() ; ++i) {

                int size = m_entries.at(i)->dir.size;

                arg.sizes.append(QSize(size, size));

            }

        }

        break;

    default:

        QIconEngineV2::virtual_hook(id, data);

    }

}

QT_END_NAMESPACE

#endif //QT_NO_ICON