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#include "qgenericunixthemes_p.h"
#include "../../services/genericunix/qgenericunixservices_p.h"

#include <QtGui/QPalette>
#include <QtGui/QGuiApplication>
#include <QtCore/QDir>
#include <QtCore/QFileInfo>
#include <QtCore/QFile>
#include <QtCore/QDebug>
#include <QtCore/QSettings>
#include <QtCore/QVariant>
#include <QtCore/QStringList>

QT_BEGIN_NAMESPACE

/*!
    \class QGenericX11ThemeQKdeTheme
    \brief QGenericX11Theme is a generic theme implementation for X11.
    \since 5.0
    \internal
    \ingroup qpa
*/

// Helper to return the icon theme paths from XDG.
QStringList QGenericUnixTheme::xdgIconThemePaths()
{
    QStringList paths;
    // Add home directory first in search path
    const QFileInfo homeIconDir(QDir::homePath() + QStringLiteral("/.icons"));
    if (homeIconDir.isDir())
        paths.prepend(homeIconDir.absoluteFilePath());

    QString xdgDirString = QFile::decodeName(qgetenv("XDG_DATA_DIRS"));
    if (xdgDirString.isEmpty())
        xdgDirString = QLatin1String("/usr/local/share/:/usr/share/");
    foreach (const QString &xdgDir, xdgDirString.split(QLatin1Char(':'))) {
        const QFileInfo xdgIconsDir(xdgDir + QStringLiteral("/icons"));
        if (xdgIconsDir.isDir())
            paths.append(xdgIconsDir.absoluteFilePath());
    }
    return paths;
}

QVariant QGenericUnixTheme::themeHint(ThemeHint hint) const
{
    switch (hint) {
    case QPlatformTheme::SystemIconFallbackThemeName:
        return QVariant(QString(QStringLiteral("hicolor")));
    case QPlatformTheme::IconThemeSearchPaths:
        return xdgIconThemePaths();
    case QPlatformTheme::DialogButtonBoxButtonsHaveIcons:
        return QVariant(true);
    case QPlatformTheme::StyleNames: {
        QStringList styleNames;
        styleNames << QStringLiteral("Plastique") << QStringLiteral("Windows");
        return QVariant(styleNames);
    }
    case QPlatformTheme::KeyboardScheme:
        return QVariant(int(X11KeyboardScheme));
    default:
        break;
    }
    return QPlatformTheme::themeHint(hint);
}

// Reads the color from the KDE configuration, and store it in the
// palette with the given color role if found.
static inline bool kdeColor(QPalette *pal, QPalette::ColorRole role,
                            const QSettings &kdeSettings, const QString &key)
{
    const QVariant value = kdeSettings.value(key);
    if (!value.isValid())
        return false;
    const QStringList values = value.toStringList();
    if (values.size() != 3)
        return false;
    pal->setBrush(role, QColor(values.at(0).toInt(), values.at(1).toInt(), values.at(2).toInt()));
    return true;
}

// Reads the KDE system palette
static inline bool readKdeSystemPalette(const QSettings &kdeSettings, QPalette *pal)
{
    // Setup KDE palette
    return kdeColor(pal, QPalette::Button, kdeSettings, QStringLiteral("Colors:Button/BackgroundNormal"))
        || kdeColor(pal, QPalette::Window, kdeSettings, QStringLiteral("Colors:Window/BackgroundNormal"))
        || kdeColor(pal, QPalette::Text, kdeSettings, QStringLiteral("Colors:View/ForegroundNormal"))
        || kdeColor(pal, QPalette::WindowText, kdeSettings, QStringLiteral("Colors:Window/ForegroundNormal"))
        || kdeColor(pal, QPalette::Base, kdeSettings, QStringLiteral("Colors:View/BackgroundNormal"))
        || kdeColor(pal, QPalette::Highlight, kdeSettings, QStringLiteral("Colors:Selection/BackgroundNormal"))
        || kdeColor(pal, QPalette::HighlightedText, kdeSettings, QStringLiteral("Colors:Selection/ForegroundNormal"))
        || kdeColor(pal, QPalette::AlternateBase, kdeSettings, QStringLiteral("Colors:View/BackgroundAlternate"))
        || kdeColor(pal, QPalette::ButtonText, kdeSettings, QStringLiteral("Colors:Button/ForegroundNormal"))
        || kdeColor(pal, QPalette::Link, kdeSettings, QStringLiteral("Colors:View/ForegroundLink"))
        || kdeColor(pal, QPalette::LinkVisited, kdeSettings, QStringLiteral("Colors:View/ForegroundVisited"));
}

/*!
    \class QKdeTheme
    \brief QKdeTheme is a theme implementation for the KDE desktop (version 4 or higher).
    \since 5.0
    \internal
    \ingroup qpa
*/

QKdeTheme::QKdeTheme(const QString &kdeHome, int kdeVersion) :
    m_kdeHome(kdeHome), m_kdeVersion(kdeVersion),
    m_toolButtonStyle(Qt::ToolButtonTextBesideIcon), m_toolBarIconSize(0)
{
    qFill(m_palettes, m_palettes + NPalettes, static_cast<QPalette *>(0));
    refresh();
}

void QKdeTheme::clearPalettes()
{
     qDeleteAll(m_palettes, m_palettes + NPalettes);
     qFill(m_palettes, m_palettes + NPalettes, static_cast<QPalette *>(0));
}

void QKdeTheme::refresh()
{
    clearPalettes();

    m_toolButtonStyle = Qt::ToolButtonTextBesideIcon;
    m_toolBarIconSize = 0;
    m_styleNames.clear();
    m_styleNames << QStringLiteral("Oxygen") << QStringLiteral("plastique") << QStringLiteral("windows");
    m_iconFallbackThemeName = m_iconThemeName = QStringLiteral("oxygen");

    // Read settings file.
    const QString settingsFile = globalSettingsFile();
    if (!QFileInfo(settingsFile).isReadable())
        return;

    const QSettings kdeSettings(settingsFile, QSettings::IniFormat);

    QPalette systemPalette;
    if (readKdeSystemPalette(kdeSettings, &systemPalette))
        m_palettes[SystemPalette] = new QPalette(systemPalette);
    //## TODO tooltip color

    const QVariant styleValue = kdeSettings.value(QStringLiteral("widgetStyle"));
    if (styleValue.isValid()) {
        const QString style = styleValue.toString();
        if (style != m_styleNames.front())
            m_styleNames.push_front(style);
    }

    const QVariant themeValue = kdeSettings.value(QStringLiteral("Icons/Theme"));
    if (themeValue.isValid())
        m_iconThemeName = themeValue.toString();

    const QVariant toolBarIconSizeValue = kdeSettings.value(QStringLiteral("ToolbarIcons/Size"));
    if (toolBarIconSizeValue.isValid())
        m_toolBarIconSize = toolBarIconSizeValue.toInt();

    const QVariant toolbarStyleValue = kdeSettings.value(QStringLiteral("ToolButtonStyle"));
    if (toolbarStyleValue.isValid()) {
        const QString toolBarStyle = toolbarStyleValue.toString();
        if (toolBarStyle == QStringLiteral("TextBesideIcon"))
            m_toolButtonStyle =  Qt::ToolButtonTextBesideIcon;
        else if (toolBarStyle == QStringLiteral("TextOnly"))
            m_toolButtonStyle = Qt::ToolButtonTextOnly;
        else if (toolBarStyle == QStringLiteral("TextUnderIcon"))
            m_toolButtonStyle = Qt::ToolButtonTextUnderIcon;
    }
}

QString QKdeTheme::globalSettingsFile() const
{
    return m_kdeHome + QStringLiteral("/share/config/kdeglobals");
}

static QStringList kdeIconThemeSearchPaths(const QString &kdeHome)
{
    QStringList candidates = QStringList(kdeHome);
    const QString kdeDirs = QFile::decodeName(qgetenv("KDEDIRS"));
    if (!kdeDirs.isEmpty())
        candidates.append(kdeDirs.split(QLatin1Char(':')));

    QStringList paths = QGenericUnixTheme::xdgIconThemePaths();
    const QString iconPath = QStringLiteral("/share/icons");
    foreach (const QString &candidate, candidates) {
        const QFileInfo fi(candidate + iconPath);
        if (fi.isDir())
            paths.append(fi.absoluteFilePath());
    }
    return paths;
}

QVariant QKdeTheme::themeHint(QPlatformTheme::ThemeHint hint) const
{
    switch (hint) {
    case QPlatformTheme::UseFullScreenForPopupMenu:
        return QVariant(true);
    case QPlatformTheme::DialogButtonBoxButtonsHaveIcons:
        return QVariant(true);
    case QPlatformTheme::DialogButtonBoxLayout:
        return QVariant(2); // QDialogButtonBox::KdeLayout
    case QPlatformTheme::ToolButtonStyle:
        return QVariant(m_toolButtonStyle);
    case QPlatformTheme::ToolBarIconSize:
        return QVariant(m_toolBarIconSize);
    case QPlatformTheme::SystemIconThemeName:
        return QVariant(m_iconThemeName);
    case QPlatformTheme::SystemIconFallbackThemeName:
        return QVariant(m_iconFallbackThemeName);
    case QPlatformTheme::IconThemeSearchPaths:
        return QVariant(kdeIconThemeSearchPaths(m_kdeHome));
    case QPlatformTheme::StyleNames:
        return QVariant(m_styleNames);
    case QPlatformTheme::KeyboardScheme:
        return QVariant(int(KdeKeyboardScheme));
    default:
        break;
    }
    return QPlatformTheme::themeHint(hint);
}

QPlatformTheme *QKdeTheme::createKdeTheme()
{
    // Check for version >= 4 and determine home folder from environment,
    // defaulting to ~/.kde<version>, ~/.kde
    const QByteArray kdeVersionBA = qgetenv("KDE_SESSION_VERSION");
    const int kdeVersion = kdeVersionBA.toInt();
    if (kdeVersion < 4)
        return 0;
    const QString kdeHomePathVar = QString::fromLocal8Bit(qgetenv("KDEHOME"));
    if (!kdeHomePathVar.isEmpty())
        return new QKdeTheme(kdeHomePathVar, kdeVersion);

     const QString kdeVersionHomePath = QDir::homePath() + QStringLiteral("/.kde") + QLatin1String(kdeVersionBA);
     if (QFileInfo(kdeVersionHomePath).isDir())
         return new QKdeTheme(kdeVersionHomePath, kdeVersion);

     const QString kdeHomePath = QDir::homePath() + QStringLiteral("/.kde");
     if (QFileInfo(kdeHomePath).isDir())
         return new QKdeTheme(kdeHomePath, kdeVersion);

     qWarning("%s: Unable to determine KDEHOME", Q_FUNC_INFO);
     return 0;
}

/*!
    \class QGnomeTheme
    \brief QGnomeTheme is a theme implementation for the Gnome desktop.
    \since 5.0
    \internal
    \ingroup qpa
*/

QVariant QGnomeTheme::themeHint(QPlatformTheme::ThemeHint hint) const
{
    switch (hint) {
    case QPlatformTheme::DialogButtonBoxButtonsHaveIcons:
        return QVariant(true);
    case QPlatformTheme::DialogButtonBoxLayout:
        return QVariant(3); // QDialogButtonBox::GnomeLayout
    case QPlatformTheme::SystemIconThemeName:
    case QPlatformTheme::SystemIconFallbackThemeName:
        return QVariant(QString(QStringLiteral("gnome")));
    case QPlatformTheme::IconThemeSearchPaths:
        return QVariant(QGenericUnixTheme::xdgIconThemePaths());
    case QPlatformTheme::StyleNames: {
        QStringList styleNames;
        styleNames << QStringLiteral("GTK+") << QStringLiteral("cleanlooks") << QStringLiteral("windows");
        return QVariant(styleNames);
    }
    case QPlatformTheme::KeyboardScheme:
        return QVariant(int(GnomeKeyboardScheme));
    default:
        break;
    }
    return QPlatformTheme::themeHint(hint);
}

/*!
    \brief Creates a UNIX theme according to the detected desktop environment.
*/

QPlatformTheme *QGenericUnixTheme::createUnixTheme()
{
    QPlatformTheme *result = 0;
    if (QGuiApplication::desktopSettingsAware()) {
        switch (QGenericUnixServices::desktopEnvironment()) {
        case QGenericUnixServices::DE_UNKNOWN:
            break;
        case QGenericUnixServices::DE_KDE:
            result = QKdeTheme::createKdeTheme();
            break;
        case QGenericUnixServices::DE_GNOME:
            result = new QGnomeTheme;
            break;
        }
    }
    if (!result)
        result = new QGenericUnixTheme;
    return result;
}

QT_END_NAMESPACE