qsettings.cpp

奇趣公司比较新的qt/emd版本

                                                                      IniCaseSensitivity)]; \
        if (!sectionData.isEmpty()) \
            sectionData.append('\n'); \
        sectionData += data.mid(currentSectionStart, lineStart - currentSectionStart); \
    }

    QString currentSection;
    int currentSectionStart = 0;
    int dataPos = 0;
    int lineStart;
    int lineLen;
    int equalsPos;
    bool ok = true;

    while (readIniLine(data, dataPos, lineStart, lineLen, equalsPos)) {
        char ch = data.at(lineStart);
        if (ch == '[') {
            FLUSH_CURRENT_SECTION();

            // this is a section
            QByteArray iniSection;
            int idx = data.indexOf(']', lineStart);
            if (idx == -1 || idx >= lineStart + lineLen) {
                ok = false;
                iniSection = data.mid(lineStart + 1, lineLen - 1);
            } else {
                iniSection = data.mid(lineStart + 1, idx - lineStart - 1);
            }

            iniSection = iniSection.trimmed();

            if (qstricmp(iniSection, "general") == 0) {
                currentSection.clear();
            } else {
                if (qstricmp(iniSection, "%general") == 0) {
                    currentSection = QLatin1String(iniSection.constData() + 1);
                } else {
                    currentSection.clear();
                    iniUnescapedKey(iniSection, 0, iniSection.size(), currentSection);
                }
                currentSection += QLatin1Char('/');
            }
            currentSectionStart = dataPos;
        }
    }

    Q_ASSERT(lineStart == data.length());
    FLUSH_CURRENT_SECTION();

    return ok;

#undef FLUSH_CURRENT_SECTION
}

bool QConfFileSettingsPrivate::readIniSection(const QSettingsKey &section, const QByteArray &data,
                                              ParsedSettingsMap *settingsMap)
{
    QStringList strListValue;
    bool sectionIsLowercase = (section == section.originalCaseKey());
    int equalsPos;

    bool ok = true;
    int dataPos = 0;
    int lineStart;
    int lineLen;

    while (readIniLine(data, dataPos, lineStart, lineLen, equalsPos)) {
        char ch = data.at(lineStart);
        Q_ASSERT(ch != '[');

        if (equalsPos == -1) {
            if (ch != ';')
                ok = false;
            continue;
        }

        int keyEnd = equalsPos;
        while (keyEnd > lineStart && ((ch = data.at(keyEnd - 1)) == ' ' || ch == '\t'))
            --keyEnd;
        int valueStart = equalsPos + 1;

        QString key = section.originalCaseKey();
        bool keyIsLowercase = (iniUnescapedKey(data, lineStart, keyEnd, key) && sectionIsLowercase);

        QString strValue;
        strValue.reserve(lineLen - (valueStart - lineStart));
        bool isStringList = iniUnescapedStringList(data, valueStart, lineStart + lineLen,
                                                   strValue, strListValue);
        QVariant variant;
        if (isStringList) {
            variant = stringListToVariantList(strListValue);
        } else {
            variant = stringToVariant(strValue);
        }

        /*
            We try to avoid the expensive toLower() call in
            QSettingsKey by passing Qt::CaseSensitive when the
            key is already in lowercase.
        */
        settingsMap->insert(QSettingsKey(key, keyIsLowercase ? Qt::CaseSensitive
                                                             : IniCaseSensitivity),
                            variant);
    }

    return ok;
}

bool QConfFileSettingsPrivate::writeIniFile(QIODevice &device, const ParsedSettingsMap &map)
{
    typedef QMap<QString, QVariantMap> IniMap;
    IniMap iniMap;
    IniMap::const_iterator i;

#ifdef Q_OS_WIN
    const char * const eol = "\r\n";
#else
    const char eol = '\n';
#endif

    for (ParsedSettingsMap::const_iterator j = map.constBegin(); j != map.constEnd(); ++j) {
        QString section;
        QString key = j.key().originalCaseKey();
        int slashPos;

        if ((slashPos = key.indexOf(QLatin1Char('/'))) != -1) {
            section = key.left(slashPos);
            key.remove(0, slashPos + 1);
        }
        iniMap[section][key] = j.value();
    }

    bool writeError = false;
    for (i = iniMap.constBegin(); !writeError && i != iniMap.constEnd(); ++i) {
        QByteArray realSection;

        iniEscapedKey(i.key(), realSection);

        if (realSection.isEmpty()) {
            realSection = "[General]";
        } else if (qstricmp(realSection, "general") == 0) {
            realSection = "[%General]";
        } else {
            realSection.prepend('[');
            realSection.append(']');
        }

        if (i != iniMap.constBegin())
            realSection.prepend(eol);
        realSection += eol;

        device.write(realSection);

        const QVariantMap &ents = i.value();
        for (QVariantMap::const_iterator j = ents.constBegin(); j != ents.constEnd(); ++j) {
            QByteArray block;
            iniEscapedKey(j.key(), block);
            block += '=';

            const QVariant &value = j.value();

            /*
                The size() != 1 trick is necessary because
                QVariant(QString("foo")).toList() returns an empty
                list, not a list containing "foo".
            */
            if (value.type() == QVariant::StringList
                    || (value.type() == QVariant::List && value.toList().size() != 1)) {
                iniEscapedStringList(variantListToStringList(value.toList()), block);
            } else {
                iniEscapedString(variantToString(value), block);
            }
            block += eol;
            if (device.write(block) == -1) {
                writeError = true;
                break;
            }
        }
    }
    return !writeError;
}

void QConfFileSettingsPrivate::ensureAllSectionsParsed(QConfFile *confFile) const
{
    UnparsedSettingsMap::const_iterator i = confFile->unparsedIniSections.constBegin();
    const UnparsedSettingsMap::const_iterator end = confFile->unparsedIniSections.constEnd();

    for (; i != end; ++i) {
        if (!QConfFileSettingsPrivate::readIniSection(i.key(), i.value(), &confFile->originalKeys))
            setStatus(QSettings::FormatError);
    }
    confFile->unparsedIniSections.clear();
}

void QConfFileSettingsPrivate::ensureSectionParsed(QConfFile *confFile,
                                                   const QSettingsKey &key) const
{
    if (confFile->unparsedIniSections.isEmpty())
        return;

    UnparsedSettingsMap::iterator i;

    int indexOfSlash = key.indexOf(QLatin1Char('/'));
    if (indexOfSlash != -1) {
        i = confFile->unparsedIniSections.upperBound(key);
        if (i == confFile->unparsedIniSections.begin())
            return;
        --i;
        if (i.key().isEmpty() || !key.startsWith(i.key()))
            return;
    } else {
        i = confFile->unparsedIniSections.begin();
        if (i == confFile->unparsedIniSections.end() || !i.key().isEmpty())
            return;
    }

    if (!QConfFileSettingsPrivate::readIniSection(i.key(), i.value(), &confFile->originalKeys))
        setStatus(QSettings::FormatError);
    confFile->unparsedIniSections.erase(i);
}

/*!
    \class QSettings
    \brief The QSettings class provides persistent platform-independent application settings.

    \ingroup io
    \ingroup misc
    \mainclass
    \reentrant

    Users normally expect an application to remember its settings
    (window sizes and positions, options, etc.) across sessions. This
    information is often stored in the system registry on Windows,
    and in XML preferences files on Mac OS X. On Unix systems, in the
    absence of a standard, many applications (including the KDE
    applications) use INI text files.

    QSettings is an abstraction around these technologies, enabling
    you to save and restore application settings in a portable
    manner. It also supports \l{registerFormat()}{custom storage
    formats}.

    QSettings's API is based on QVariant, allowing you to save
    most value-based types, such as QString, QRect, and QImage,
    with the minimum of effort.

    If all you need is a non-persistent memory-based structure,
    consider using QMap<QString, QVariant> instead.

    \tableofcontents section1

    \section1 Basic Usage

    When creating a QSettings object, you must pass the name of your
    company or organization as well as the name of your application.
    For example, if your product is called Star Runner and your
    company is called MySoft, you would construct the QSettings
    object as follows:

    \quotefromfile snippets/settings/settings.cpp
    \skipuntil snippet_ctor1
    \skipline {
    \printline QSettings settings

    QSettings objects can be created either on the stack or on
    the heap (i.e. using \c new). Constructing and destroying a
    QSettings object is very fast.

    If you use QSettings from many places in your application, you
    might want to specify the organization name and the application
    name using QCoreApplication::setOrganizationName() and
    QCoreApplication::setApplicationName(), and then use the default
    QSettings constructor:

    \skipuntil snippet_ctor2
    \skipline {
    \printline setOrganizationName
    \printline setOrganizationDomain
    \printline setApplicationName
    \dots
    \skipto QSettings settings;
    \printuntil QSettings

    (Here, we also specify the organization's Internet domain. When
    the Internet domain is set, it is used on Mac OS X instead of the
    organization name, since Mac OS X applications conventionally use
    Internet domains to identify themselves. If no domain is set, a
    fake domain is derived from the organization name. See the
    \l{Platform-Specific Notes} below for details.)

    QSettings stores settings. Each setting consists of a QString
    that specifies the setting's name (the \e key) and a QVariant
    that stores the data associated with the key. To write a setting,
    use setValue(). For example:

    \skipto setValue(
    \printline setValue(

    If there already exists a setting with the same key, the existing
    value is overwritten by the new value. For efficiency, the
    changes may not be saved to permanent storage immediately. (You
    can always call sync() to commit your changes.)

    You can get a setting's value back using value():

    \printline settings.value(

    If there is no setting with the specified name, QSettings
    returns a null QVariant (which can be converted to the integer 0).
    You can specify another default value by passing a second
    argument to value():

    \skipline {
    \printline /settings.value\(.*,.*\)/
    \skipline }

    To test whether a given key exists, call contains(). To remove
    the setting associated with a key, call remove(). To obtain the
    list of all keys, call allKeys(). To remove all keys, call
    clear().

    \section1 QVariant and GUI Types

    Because QVariant is part of the \l QtCore library, it cannot provide
    conversion functions to data types such as QColor, QImage, and
    QPixmap, which are part of \l QtGui. In other words, there is no
    \c toColor(), \c toImage(), or \c toPixmap() functions in QVariant.

    Instead, you can use the QVariant::value() or the qVariantValue()
    template function. For example:

    \code
        QSettings settings("MySoft", "Star Runner");
        QColor color = settings.value("DataPump/bgcolor").value<QColor>();
    \endcode

    The inverse conversion (e.g., from QColor to QVariant) is
    automatic for all data types supported by QVariant, including
    GUI-related types:

    \code
        QSettings settings("MySoft", "Star Runner");
        QColor color = palette().background().color();
        settings.setValue("DataPump/bgcolor", color);
    \endcode

    Custom types registered using qRegisterMetaType() and
    qRegisterMetaTypeStreamOperators() can be stored using QSettings.

    \section1 Key Syntax

    Setting keys can contain any Unicode characters. The Windows
    registry and INI files use case-insensitive keys, whereas the
    Carbon Preferences API on Mac OS X uses case-sensitive keys. To
    avoid portability problems, follow these two simple rules:

    \list 1
    \o Always refer to the same key using the same case. For example,
       if you refer to a key as "text fonts" in one place in your
       code, don't refer to it as "Text Fonts" somewhere else.

    \o Avoid key names that are identical except for the case. For
       example, if you have a key called "MainWindow", don't try to
       save another key as "mainwindow".

    \o Do not use slashes  ('/' and '\\') in key names; the
       backslash character is used to separate sub keys (see below). On
       windows '\\' are converted by QSettings to '/', which makes
       them identical.
    \endlist

    You can form hierarchical keys using the '/' character as a
    separator, similar to Unix file paths. For example:

    \skipto settings.setValue("mainwindow/size", win->size());
    \printuntil settings.setValue(

    \skipto settings.setValue("mainwindow/fullScreen", win->isFullScreen());
    \printuntil settings.setValue(

    \skipto settings.setValue("outputpanel/visible", panel->isVisible());
    \printuntil settings.setValue(

    If you want to save or restore many settings with the same
    prefix, you can specify the prefix using beginGroup() and call
    endGroup() at the end. Here's the same example again, but this
    time using the group mechanism:

    \skipto settings.beginGroup("mainwindow");
    \printuntil endGroup

    \skipto settings.beginGroup("outputpanel");
    \printuntil endGroup

    If a group is set using beginGroup(), the behavior of most
    functions changes consequently. Groups can be set recursively.

    In addition to groups, QSettings also supports an "array"
    concept. See beginReadArray() and beginWriteArray() for details.

    \section1 Fallback Mechanism

    Let's assume that you have created a QSettings object with the
    organization name MySoft and the application name Star Runner.
    When you look up a value, up to four locations are searched in
    that order:

    \list 1
    \o a user-specific location for the Star Runner application
    \o a user-specific location for all applications by MySoft
    \o a system-wide location for the Star Runner application
    \o a system-wide location for all applications by MySoft
    \endlist

    (See \l{Platform-Specific Notes} below for information on wh