QSettings Class Reference

The QSettings class provides persistent platform-independent application settings. More...

#include </home/clem/local/src/opie/noncore/apps/zsafe/extra/qsettings.h>

Collaboration diagram for QSettings:

[legend]List of all members.


Public Types
enum	Format { Native = 0, Ini }
enum	System { Unix = 0, Windows, Mac }
enum	Scope { User, Global }
enum	Format { Native = 0, Ini }
enum	System { Unix = 0, Windows, Mac }
enum	Scope { User, Global }
Public Member Functions
	QSettings (const QString &file=0)
	~QSettings ()
void	insertSearchPath (System, const QString &)
QString	readEntry (const QString &, const QString &def=QString::null)
int	readNumEntry (const QString &, int def=0)
bool	readBoolEntry (const QString &, bool def=0)
bool	writeEntry (const QString &, int)
bool	writeEntry (const QString &, bool)
bool	writeEntry (const QString &, const QString &)
bool	writeEntry (const QString &, const char *)
bool	removeEntry (const QString &)
QStringList	entryList (const QString &) const
	QSettings ()
	QSettings (Format format)
	~QSettings ()
bool	writeEntry (const QString &, bool)
bool	writeEntry (const QString &, double)
bool	writeEntry (const QString &, int)
bool	writeEntry (const QString &, const char *)
bool	writeEntry (const QString &, const QString &)
bool	writeEntry (const QString &, const QStringList &)
bool	writeEntry (const QString &, const QStringList &, const QChar &sep)
QStringList	entryList (const QString &) const
QStringList	subkeyList (const QString &) const
QStringList	readListEntry (const QString &, bool *=0)
QStringList	readListEntry (const QString &, const QChar &sep, bool *=0)
QString	readEntry (const QString &, const QString &def=QString::null, bool *=0)
int	readNumEntry (const QString &, int def=0, bool *=0)
double	readDoubleEntry (const QString &, double def=0, bool *=0)
bool	readBoolEntry (const QString &, bool def=FALSE, bool *=0)
QStringList	readListEntry (const QString &key, bool *ok=0) const
QStringList	readListEntry (const QString &key, const QChar &sep, bool *ok=0) const
QString	readEntry (const QString &key, const QString &def=QString::null, bool *ok=0) const
int	readNumEntry (const QString &key, int def=0, bool *ok=0) const
double	readDoubleEntry (const QString &key, double def=0, bool *ok=0) const
bool	readBoolEntry (const QString &key, bool def=FALSE, bool *ok=0) const
bool	removeEntry (const QString &)
void	insertSearchPath (System, const QString &)
void	removeSearchPath (System, const QString &)
void	setPath (const QString &domain, const QString &product, Scope=Global)
void	beginGroup (const QString &group)
void	endGroup ()
void	resetGroup ()
QString	group () const
bool	sync ()
Private Member Functions
	QSettings (const QSettings &)
QSettings &	operator= (const QSettings &)
QDateTime	lastModificationTime (const QString &)
Private Attributes
QAsciiDict< QString >	prefs
QString	fn
QSettingsPrivate *	d
Friends
class	QApplication

Detailed Description

The QSettings class provides persistent platform-independent application settings.

On Unix systems, QSettings uses text files to store settings. On Windows systems, QSettings uses the system registry. On Mac OS X, QSettings uses the Carbon preferences API.

Each setting comprises an identifying key and the data associated with the key. A key is a unicode string which consists of two or more subkeys. A subkey is a slash, '/', followed by one or more unicode characters (excluding slashes, newlines, carriage returns and equals, '=', signs). The associated data, called the entry or value, may be a boolean, an integer, a double, a string or a list of strings. Entry strings may contain any unicode characters.

If you want to save and restore the entire desktop's settings, i.e. which applications are running, use QSettings to save the settings for each individual application and QSessionManager to save the desktop's session.

Example settings:

    /MyCompany/MyApplication/background color
    /MyCompany/MyApplication/foreground color
    /MyCompany/MyApplication/geometry/x
    /MyCompany/MyApplication/geometry/y
    /MyCompany/MyApplication/geometry/width
    /MyCompany/MyApplication/geometry/height
    /MyCompany/MyApplication/recent files/1
    /MyCompany/MyApplication/recent files/2
    /MyCompany/MyApplication/recent files/3

Each line above is a complete key, made up of subkeys.

A typical usage pattern for reading settings at application startup:

    QSettings settings;
    settings.setPath( "MyCompany.com", "MyApplication" );

    QString bgColor = settings.readEntry( "/colors/background", "white" );
    int width = settings.readNumEntry( "/geometry/width", 640 );
    // ...

A typical usage pattern for saving settings at application exit or 'save preferences':

    QSettings settings;
    settings.setPath( "MyCompany.com", "MyApplication" );

    settings.writeEntry( "/colors/background", bgColor );
    settings.writeEntry( "/geometry/width", width );
    // ...

A key prefix can be prepended to all keys using beginGroup(). The application of the prefix is stopped using endGroup(). For example:

    QSettings settings;

    settings.beginGroup( "/MainWindow" );
        settings.beginGroup( "/Geometry" );
            int x = settings.readEntry( "/x" );
            // ...
        settings.endGroup();
        settings.beginGroup( "/Toolbars" );
            // ...
        settings.endGroup();
    settings.endGroup();

You can get a list of entry-holding keys by calling entryList(), and a list of key-holding keys using subkeyList().

    QStringList keys = entryList( "/MyApplication" );
    // keys contains 'background color' and 'foreground color'.

    QStringList keys = entryList( "/MyApplication/recent files" );
    // keys contains '1', '2' and '3'.

    QStringList subkeys = subkeyList( "/MyApplication" );
    // subkeys contains 'geometry' and 'recent files'

    QStringList subkeys = subkeyList( "/MyApplication/recent files" );
    // subkeys is empty.

Since settings for Windows are stored in the registry there are some size limitations as follows: A subkey may not exceed 255 characters. An entry's value may not exceed 16,300 characters. All the values of a key (for example, all the 'recent files' subkeys values), may not exceed 65,535 characters.

These limitations are not enforced on Unix or Mac OS X.

Warning:: Creating multiple, simultaneous instances of QSettings writing to a text file may lead to data loss! This is a known issue which will be fixed in a future release of Qt.

The location where settings are stored is not formally defined by the CFPreferences API. At the time of writing settings are stored (either on a global or user basis, preferring locally) into a plist file in \c $ROOT/System/Library/Preferences (in XML format). QSettings will create an appropriate plist file (\c{com.<first group name>.plist}) out of the full path to a key. For further information on CFPreferences see \link http://developer.apple.com/documentation/CoreFoundation/Conceptual/CFPreferences/index.html Apple's Specifications\endlink @section Notes for Unix Applications There is no universally accepted place for storing application settings under Unix. In the examples the settings file will be searched for in the following directories: \list 1 \i \c SYSCONF - the default value is \c INSTALL/etc/settings \i \c /opt/MyCompany/share/etc \i \c /opt/MyCompany/share/MyApplication/etc \i \c $HOME/.qt \endlist When reading settings the files are searched in the order shown above, with later settings overriding earlier settings. Files for which the user doesn't have read permission are ignored. When saving settings QSettings works in the order shown above, writing to the first settings file for which the user has write permission. (\c INSTALL is the directory where Qt was installed. This can be modified by using the configure script's -prefix argument ) If you want to put the settings in a particular place in the filesystem you could do this: @code settings.insertSearchPath( QSettings::Unix, "/opt/MyCompany/share" ); \endcode But in practice you may prefer not to use a search path for Unix. For example the following code: @code settings.writeEntry( "/MyApplication/geometry/width", width ); \endcode will end up writing the "geometry/width" setting to the file \c{$HOME/.qt/myapplicationrc} (assuming that the application is being run by an ordinary user, i.e. not by root). For cross-platform applications you should ensure that the \link #sizelimit Windows size limitations \endlink are not exceeded. Definition at line 14 of file qsettings.h.

Member Enumeration Documentation

enum QSettings::Format

Enumeration values:

Native

Ini

Definition at line 54 of file qsettings.h.

enum QSettings::Format

Native Store the settings in a platform dependent location Ini Store the settings in a text file
Enumeration values:

Native

Ini

Definition at line 17 of file qsettings.h.

enum QSettings::Scope

Enumeration values:

User

Global

Definition at line 63 of file qsettings.h.

enum QSettings::Scope

Global Save settings as global as possible User Save settings in user space
Enumeration values:

User

Global

Definition at line 26 of file qsettings.h.

enum QSettings::System

Enumeration values:

Unix

Windows

Mac

Definition at line 58 of file qsettings.h.

enum QSettings::System

Mac Macintosh execution environments Unix Mac OS X, Unix, Linux and Unix-like execution environments Windows Windows execution environments
Enumeration values:

Unix

Windows

Mac

Definition at line 21 of file qsettings.h.

Constructor & Destructor Documentation

QSettings::QSettings ( const QString & file = 0 )

Definition at line 11 of file qsettings.cpp.
References buf, QTextStream::eof(), f, fn, IO_ReadOnly, QFile::open(), pos, qWarning(), QTextStream::readLine(), s, t, val, and writeEntry().

QSettings::~QSettings ( )

Destroys the settings object. All modifications made to the settings will automatically be saved.
Definition at line 38 of file qsettings.cpp.
References buf, QAsciiDict< type >::clear(), QAsciiDictIterator< type >::current(), QAsciiDictIterator< type >::currentKey(), Opie::Core::endl(), f, fn, IO_WriteOnly, QFile::open(), prefs, and val.

QSettings::QSettings ( )

Creates a settings object.
Definition at line 873 of file qsettings.cpp.
References d, and Native.

QSettings::QSettings ( Format format )

Creates a settings object. If format is 'Ini' the settings will be stored in a text file, using the Unix strategy (see above). If format is 'Native', the settings will be stored in a platform specific way (ie. the Windows registry).
Definition at line 890 of file qsettings.cpp.
References d, and Native.

QSettings::~QSettings ( )

QSettings::QSettings ( const QSettings & ) [private]

Member Function Documentation

void QSettings::beginGroup ( const QString & group )

Appends group to the current key prefix.

QSettings settings; settings.beginGroup( "/MainWindow" ); // read values settings.endGroup();

Definition at line 2015 of file qsettings.cpp.
References d, QSettingsPrivate::groupDirty, QSettingsPrivate::groupStack, QValueStack< T >::push(), and TRUE.

void QSettings::endGroup ( )

Undo previous calls to beginGroup(). Note that a single beginGroup("a/b/c") is undone by a single call to endGroup().

QSettings settings; settings.beginGroup( "/MainWindow/Geometry" ); // read values settings.endGroup();

Definition at line 2032 of file qsettings.cpp.
References d, QSettingsPrivate::groupDirty, QSettingsPrivate::groupStack, QValueStack< T >::pop(), and TRUE.

QStringList QSettings::entryList ( const QString & ) const

QStringList QSettings::entryList ( const QString & key ) const

Returns a list of the keys which contain entries under key. Does not return any keys that contain keys.
Example settings:
/MyCompany/MyApplication/background color /MyCompany/MyApplication/foreground color /MyCompany/MyApplication/geometry/x /MyCompany/MyApplication/geometry/y /MyCompany/MyApplication/geometry/width /MyCompany/MyApplication/geometry/height

QStringList keys = entryList( "/MyCompany/MyApplication" );
keys contains 'background color' and 'foreground color'. It does not contain 'geometry' because this key contains keys not entries.
To access the geometry values could either use subkeyList() to read the keys and then read each entry, or simply read each entry directly by specifying its full key, e.g. "/MyCompany/MyApplication/geometry/y".

See also:
subkeyList()

Definition at line 134 of file qsettings.cpp.
References QValueList< T >::append(), buf, QString::contains(), QAsciiDictIterator< type >::current(), QAsciiDictIterator< type >::currentKey(), FALSE, QAsciiDict< type >::isEmpty(), list, prefs, qDebug(), qWarning(), and val.
Referenced by QMakeProperty::exec().

QString QSettings::group ( ) const

Returns the current key prefix, or a null string if there is no key prefix set.

See also:
beginGroup();

Definition at line 2053 of file qsettings.cpp.
References QValueList< T >::begin(), d, QValueList< T >::end(), FALSE, QSettingsPrivate::groupDirty, QSettingsPrivate::groupPrefix, QSettingsPrivate::groupStack, QString::null, and QString::prepend().
Referenced by lastModificationTime(), readBoolEntry(), readDoubleEntry(), readEntry(), readNumEntry(), subkeyList(), and writeEntry().

void QSettings::insertSearchPath ( System ,

const QString &

)

void QSettings::insertSearchPath ( System s,

const QString & path

)

Inserts path into the settings search path. The semantics of path depends on the system s. It is usually easier and better to use setPath() instead of this function.
When s is Windows and the execution environment is not Windows the function does nothing. Similarly when s is Unix and the execution environment is not Unix the function does nothing.
When s is Windows, and the execution environment is Windows, the search path list will be used as the first subfolder of the "Software" folder in the registry.
When reading settings the folders are searched forwards from the first folder (listed below) to the last, returning the first settings found, and ignoring any folders for which the user doesn't have read permission. 1 HKEY_CURRENT_USER/Software/MyCompany/MyApplication HKEY_LOCAL_MACHINE/Software/MyCompany/MyApplication HKEY_CURRENT_USER/Software/MyApplication HKEY_LOCAL_MACHINE/Software/MyApplication

QSettings settings; settings.insertSearchPath( QSettings::Windows, "/MyCompany" ); settings.writeEntry( "/MyApplication/Tip of the day", TRUE );
The code above will write the subkey "Tip of the day" into the first of the registry folders listed below that is found and for which the user has write permission. 1 HKEY_LOCAL_MACHINE/Software/MyCompany/MyApplication HKEY_CURRENT_USER/Software/MyCompany/MyApplication HKEY_LOCAL_MACHINE/Software/MyApplication HKEY_CURRENT_USER/Software/MyApplication If a setting is found in the HKEY_CURRENT_USER space, this setting is overwritten independently of write permissions in the HKEY_LOCAL_MACHINE space.
When s is Unix, and the execution environment is Unix, the search path list will be used when trying to determine a suitable filename for reading and writing settings files. By default, there are two entries in the search path:
1 SYSCONF - where SYSCONF is a directory specified when configuring Qt; by default it is INSTALL/etc/settings. $HOME/.qt/ - where $HOME is the user's home directory.
All insertions into the search path will go before $HOME/.qt/. For example:
QSettings settings; settings.insertSearchPath( QSettings::Unix, "/opt/MyCompany/share/etc" ); settings.insertSearchPath( QSettings::Unix, "/opt/MyCompany/share/MyApplication/etc" ); // ...
Will result in a search path of: 1 SYSCONF /opt/MyCompany/share/etc /opt/MyCompany/share/MyApplication/etc $HOME/.qt When reading settings the files are searched in the order shown above, with later settings overriding earlier settings. Files for which the user doesn't have read permission are ignored. When saving settings QSettings works in the order shown above, writing to the first settings file for which the user has write permission.
Note that paths in the file system are not created by this function, so they must already exist to be useful.
Settings under Unix are stored in files whose names are based on the first subkey of the key (not including the search path). The algorithm for creating names is essentially: lowercase the first subkey, replace spaces with underscores and add 'rc', e.g. /MyCompany/MyApplication/background color will be stored in myapplicationrc (assuming that /MyCompany is part of the search path).

See also:
removeSearchPath()

Definition at line 61 of file qsettings.cpp.
References fn.
Referenced by QComponentFactory::createInstance(), QComponentFactory::registerComponent(), setPath(), and QComponentFactory::unregisterComponent().

QDateTime QSettings::lastModificationTime ( const QString & key ) [private]

For internal use only.

This function returns the time of last modification for key.

Definition at line 1745 of file qsettings.cpp.
References QValueList< T >::count(), d, QSettingsPrivate::group, group(), groupKey(), QSettingsPrivate::heading, QString::isNull(), QString::latin1(), list, QSettingsPrivate::modificationTime(), qt_verify_key(), qWarning(), and QStringList::split().

QSettings& QSettings::operator= ( const QSettings & ) [private]

bool QSettings::readBoolEntry ( const QString & key,

bool def = FALSE,

bool * ok = 0

) const [inline]

Reads the entry specified by key, and returns a bool, or the default value, def, if the entry couldn't be read. If ok is non-null, *ok is set to TRUE if the key was read, FALSE otherwise.

See also:
readEntry(), readNumEntry(), readDoubleEntry(), writeEntry(), removeEntry()

Definition at line 122 of file qsettings.h.
References readBoolEntry().

bool QSettings::readBoolEntry ( const QString & key,

bool def = FALSE,

bool * ok = 0

)

For internal use only.

Definition at line 1082 of file qsettings.cpp.
References d, FALSE, group(), groupKey(), QString::isEmpty(), QString::isNull(), QString::latin1(), QString::lower(), qt_verify_key(), qWarning(), readEntry(), and TRUE.

bool QSettings::readBoolEntry ( const QString & ,

bool def = 0

)

Definition at line 84 of file qsettings.cpp.
References prefs, and s.
Referenced by readBoolEntry().

double QSettings::readDoubleEntry ( const QString & key,

double def = 0,

bool * ok = 0

) const [inline]

Reads the entry specified by key, and returns a double, or the default value, def, if the entry couldn't be read. If ok is non-null, *ok is set to TRUE if the key was read, FALSE otherwise.

See also:
readEntry(), readNumEntry(), readBoolEntry(), writeEntry(), removeEntry()

Definition at line 117 of file qsettings.h.
References readDoubleEntry().

double QSettings::readDoubleEntry ( const QString & key,

double def = 0,

bool * ok = 0

)

For internal use only.

Definition at line 1134 of file qsettings.cpp.
References d, FALSE, group(), groupKey(), QString::isEmpty(), QString::isNull(), QString::latin1(), QString::number(), qt_verify_key(), qWarning(), readEntry(), and QString::toDouble().
Referenced by readDoubleEntry().

QString QSettings::readEntry ( const QString & key,

const QString & def = QString::null,

bool * ok = 0

) const [inline]

Reads the entry specified by key, and returns a QString, or the default value, def, if the entry couldn't be read. If ok is non-null, *ok is set to TRUE if the key was read, FALSE otherwise.

See also:
readListEntry(), readNumEntry(), readDoubleEntry(), readBoolEntry(), writeEntry(), removeEntry()

Definition at line 105 of file qsettings.h.
References readEntry().

QString QSettings::readEntry ( const QString & key,

const QString & def = QString::null,

bool * ok = 0

)

For internal use only.

Definition at line 1225 of file qsettings.cpp.
References QValueList< T >::at(), QValueList< T >::count(), d, QMap< Key, T >::end(), end, FALSE, QMap< Key, T >::find(), QSettingsPrivate::group, group(), groupKey(), QSettingsPrivate::heading, QString::isNull(), QStringList::join(), QString::latin1(), list, qt_verify_key(), qWarning(), QSettingsPrivate::readGroup(), QValueList< T >::remove(), QStringList::split(), and TRUE.

QString QSettings::readEntry ( const QString & ,

const QString & def = QString::null

)

Definition at line 66 of file qsettings.cpp.
References QAsciiDict< type >::find(), prefs, and s.
Referenced by QComponentFactory::createInstance(), QMakeProperty::exec(), readBoolEntry(), readDoubleEntry(), readEntry(), readListEntry(), readNumEntry(), QComponentFactory::registerComponent(), QComponentFactory::unregisterComponent(), use_net2003_version(), and QMakeProperty::value().

QStringList QSettings::readListEntry ( const QString & key,

const QChar & separator,

bool * ok = 0

) const [inline]

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
Reads the entry specified by key as a string. The separator is used to create a QStringList by calling QStringList::split(separator, entry). If ok is not 0: *ok is set to TRUE if the key was read, otherwise *ok is set to FALSE.

Warning:
As the documentation states, QStringList::split() will omit empty strings from the list. Because of this, it is impossible to retrieve identical list data with this function. We recommend using the readListEntry() and writeEntry() overloads that do not take a separator argument.
Note that if you want to iterate over the list, you should iterate over a copy, e.g.
QStringList list = mySettings.readListEntry( "size", " " ); QStringList::Iterator it = list.begin(); while( it != list.end() ) { myProcessing( *it ); ++it; }

See also:
readEntry(), readDoubleEntry(), readBoolEntry(), writeEntry(), removeEntry(), QStringList::split()

Definition at line 100 of file qsettings.h.
References readListEntry().

QStringList QSettings::readListEntry ( const QString & key,

bool * ok = 0

) const [inline]

Reads the entry specified by key as a string. If ok is not 0, *ok is set to TRUE if the key was read, otherwise *ok is set to FALSE.
Note that if you want to iterate over the list, you should iterate over a copy, e.g.
QStringList list = mySettings.readListEntry( "recentfiles" ); QStringList::Iterator it = list.begin(); while( it != list.end() ) { myProcessing( *it ); ++it; }

See also:
readEntry(), readDoubleEntry(), readBoolEntry(), writeEntry(), removeEntry(), QStringList::split()

Definition at line 95 of file qsettings.h.
References readListEntry().

QStringList QSettings::readListEntry ( const QString & key,

const QChar & separator,

bool * ok = 0

)

For internal use only.

Definition at line 1878 of file qsettings.cpp.
References QString::null, readEntry(), and QStringList::split().

QStringList QSettings::readListEntry ( const QString & key,

bool * ok = 0

)

For internal use only.

Definition at line 1910 of file qsettings.cpp.
References QString::append(), QValueList< T >::append(), FALSE, i, l, QString::length(), QString::null, readEntry(), and TRUE.
Referenced by readListEntry().

int QSettings::readNumEntry ( const QString & key,

int def = 0,

bool * ok = 0

) const [inline]

Reads the entry specified by key, and returns an integer, or the default value, def, if the entry couldn't be read. If ok is non-null, *ok is set to TRUE if the key was read, FALSE otherwise.

See also:
readEntry(), readDoubleEntry(), readBoolEntry(), writeEntry(), removeEntry()

Definition at line 111 of file qsettings.h.
References readNumEntry().

int QSettings::readNumEntry ( const QString & key,

int def = 0,

bool * ok = 0

)

For internal use only.

Definition at line 1180 of file qsettings.cpp.
References d, FALSE, group(), groupKey(), QString::isEmpty(), QString::isNull(), QString::latin1(), QString::number(), qt_verify_key(), qWarning(), readEntry(), and QString::toInt().

int QSettings::readNumEntry ( const QString & ,

int def = 0

)

Definition at line 77 of file qsettings.cpp.
References prefs, s, and QString::toInt().
Referenced by ConfigMainWindow::ConfigMainWindow(), and readNumEntry().

bool QSettings::removeEntry ( const QString & )

bool QSettings::removeEntry ( const QString & key )

Removes the entry specified by key.
Returns TRUE if the entry existed and was removed; otherwise returns FALSE.

See also:
readEntry(), writeEntry()

Definition at line 128 of file qsettings.cpp.
References prefs, and QAsciiDict< type >::remove().
Referenced by QComponentFactory::unregisterComponent().

void QSettings::removeSearchPath ( System s,

const QString & path

)

Removes all occurrences of path (using exact matching) from the settings search path for system s. Note that the default search paths cannot be removed.

See also:
insertSearchPath()

Definition at line 837 of file qsettings.cpp.
References d, QValueList< T >::first(), QString::isNull(), QValueList< T >::last(), QString::latin1(), Mac, qt_verify_key(), qWarning(), QValueList< T >::remove(), QSettingsPrivate::searchPaths, and Unix.

void QSettings::resetGroup ( )

Set the current key prefix to the empty string.
Definition at line 2041 of file qsettings.cpp.
References QValueList< T >::clear(), d, FALSE, QSettingsPrivate::groupDirty, QSettingsPrivate::groupPrefix, QSettingsPrivate::groupStack, and QString::null.

void QSettings::setPath ( const QString & domain,

const QString & product,

Scope scope = Global

)

Insert platform-dependent paths from platform-independent information.
The domain should be an Internet domain name controlled by the producer of the software, eg. Trolltech products use "trolltech.com".
The product should be the official name of the product.
The scope should be QSettings::User for user-specific settings, or QSettings::Global for system-wide settings (generally these will be read-only to many users).
Not all information is relevant on all systems.
Definition at line 1961 of file qsettings.cpp.
References d, QString::findRev(), QSettingsPrivate::globalScope, QDir::homeDirPath(), insertSearchPath(), QString::isEmpty(), QString::left(), QString::length(), Mac, QString::mid(), qInstallPathSysconf(), QString::right(), Unix, User, and Windows.

QStringList QSettings::subkeyList ( const QString & key ) const

Returns a list of the keys which contain keys under key. Does not return any keys that contain entries.
Example settings:
/MyCompany/MyApplication/background color /MyCompany/MyApplication/foreground color /MyCompany/MyApplication/geometry/x /MyCompany/MyApplication/geometry/y /MyCompany/MyApplication/geometry/width /MyCompany/MyApplication/geometry/height /MyCompany/MyApplication/recent files/1 /MyCompany/MyApplication/recent files/2 /MyCompany/MyApplication/recent files/3

QStringList keys = subkeyList( "/MyCompany/MyApplication" );
keys contains 'geometry' and 'recent files'. It does not contain 'background color' or 'foreground color' because they are keys which contain entries not keys. To get a list of keys that have values rather than subkeys use entryList().

See also:
entryList()

Definition at line 1652 of file qsettings.cpp.
References QValueList< T >::at(), QMap< Key, T >::begin(), QValueList< T >::contains(), QValueList< T >::count(), d, QMap< Key, T >::end(), QString::find(), QSettingsPrivate::group, group(), groupKey(), QSettingsPrivate::heading, QSettingsPrivate::headings, QString::isNull(), QStringList::join(), QString::latin1(), QString::left(), QString::length(), list, qt_verify_key(), qWarning(), QSettingsPrivate::readGroup(), QString::remove(), QValueList< T >::remove(), QStringList::split(), and QString::truncate().
Referenced by QMakeProperty::exec(), and QMakeProperty::value().

bool QSettings::sync ( )

For internal use only.

Writes all modifications to the settings to disk. If any errors are encountered, this function returns FALSE, otherwise it will return TRUE.

Definition at line 926 of file qsettings.cpp.
References QValueList< T >::begin(), QMap< Key, T >::begin(), QFile::close(), d, data, QFile::encodeName(), QValueList< T >::end(), QMap< Key, T >::end(), Opie::Core::endl(), QDir::exists(), QFileInfo::exists(), FALSE, QFileInfo::filePath(), QSettingsPrivate::globalScope, QSettingsPrivate::headings, IO_Ok, IO_WriteOnly, QFileInfo::isDir(), QString::isEmpty(), QFileInfo::isFile(), QString::isNull(), QFileInfo::isWritable(), QDir::mkdir(), QSettingsPrivate::modified, QFile::name(), QFile::open(), qWarning(), QFile::remove(), QDir::remove(), QDir::rename(), QString::replace(), QSettingsPrivate::searchPaths, QTextStream::setEncoding(), QIODevice::status(), stream, TRUE, QTextStream::UnicodeUTF8, v, Qt::WV_2000, and Qt::WV_NT_based.

bool QSettings::writeEntry ( const QString & key,

const QStringList & value,

const QChar & separator

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
Writes the string list entry value into key key. The key is created if it doesn't exist. Any previous value is overwritten by value. The list is stored as a sequence of strings separated by separator (using QStringList::join()), so none of the strings in the list should contain the separator. If the list is empty or null the key's value will be an empty string.

Warning:
The list should not contain empty or null strings, as readListEntry() will use QStringList::split() to recreate the list. As the documentation states, QStringList::split() will omit empty strings from the list. Because of this, it is impossible to retrieve identical list data that is stored with this function. We recommend using the writeEntry() and readListEntry() overloads that do not take a separator argument.
If an error occurs the settings are left unchanged and FALSE is returned; otherwise returns TRUE.

See also:
readListEntry(), readNumEntry(), readDoubleEntry(), readBoolEntry(), removeEntry(), QStringList::join()

Definition at line 1810 of file qsettings.cpp.
References QStringList::join(), s, and writeEntry().

bool QSettings::writeEntry ( const QString & key,

const QStringList & value

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Writes the string list entry value into key key. The key is created if it doesn't exist. Any previous value is overwritten by value.
If an error occurs the settings are left unchanged and FALSE is returned; otherwise returns TRUE.

See also:
readListEntry(), readNumEntry(), readDoubleEntry(), readBoolEntry(), removeEntry()

Definition at line 1829 of file qsettings.cpp.
References QValueList< T >::begin(), QValueList< T >::end(), QString::isNull(), QString::replace(), and writeEntry().

bool QSettings::writeEntry ( const QString & ,

const QString &

)

bool QSettings::writeEntry ( const QString & ,

const char *

)

bool QSettings::writeEntry ( const QString & ,

int

)

bool QSettings::writeEntry ( const QString & key,

double value

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Writes the double entry value into key key. The key is created if it doesn't exist. Any previous value is overwritten by value.
If an error occurs the settings are left unchanged and FALSE is returned; otherwise TRUE is returned.

See also:
readListEntry(), readNumEntry(), readDoubleEntry(), readBoolEntry(), removeEntry()

Definition at line 1334 of file qsettings.cpp.
References d, FALSE, group(), groupKey(), QString::isNull(), QString::latin1(), QString::number(), qt_verify_key(), qWarning(), s, and writeEntry().

bool QSettings::writeEntry ( const QString & ,

bool

)

bool QSettings::writeEntry ( const QString & key,

const char * value

)

For internal use only.

Writes the entry specified by key with the string-literal value, replacing any previous setting. If value is zero-length or null, the entry is replaced by an empty setting.
NOTE: This function is provided because some compilers use the writeEntry (const QString &, bool) overload for this code: writeEntry ("/foo/bar", "baz")
If an error occurs, this functions returns FALSE and the object is left unchanged.

See also:
readEntry(), removeEntry()

Definition at line 121 of file qsettings.cpp.
References prefs, QAsciiDict< type >::replace(), and v.

bool QSettings::writeEntry ( const QString & key,

const QString & value

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Writes the string entry value into key key. The key is created if it doesn't exist. Any previous value is overwritten by value. If value is an empty string or a null string the key's value will be an empty string.
If an error occurs the settings are left unchanged and FALSE is returned; otherwise TRUE is returned.

See also:
readListEntry(), readNumEntry(), readDoubleEntry(), readBoolEntry(), removeEntry()

Definition at line 114 of file qsettings.cpp.
References prefs, QAsciiDict< type >::replace(), and v.

bool QSettings::writeEntry ( const QString & key,

bool value

)

Writes the boolean entry value into key key. The key is created if it doesn't exist. Any previous value is overwritten by value.
If an error occurs the settings are left unchanged and FALSE is returned; otherwise TRUE is returned.

See also:
readListEntry(), readNumEntry(), readDoubleEntry(), readBoolEntry(), removeEntry()

Definition at line 103 of file qsettings.cpp.
References prefs, QAsciiDict< type >::replace(), and v.

bool QSettings::writeEntry ( const QString & key,

int value

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Writes the integer entry value into key key. The key is created if it doesn't exist. Any previous value is overwritten by value.
If an error occurs the settings are left unchanged and FALSE is returned; otherwise TRUE is returned.

See also:
readListEntry(), readNumEntry(), readDoubleEntry(), readBoolEntry(), removeEntry()

Definition at line 94 of file qsettings.cpp.
References buf, prefs, QAsciiDict< type >::replace(), and v.
Referenced by main(), QSettings(), QComponentFactory::registerComponent(), QMakeProperty::setValue(), QComponentFactory::unregisterComponent(), and writeEntry().