1 /* * This file is part of libgq *

     2  *

     3  * Copyright (C) 2009 Nokia Corporation.

     4  *

     5  * Contact: Marius Vollmer <marius.vollmer@nokia.com>

     6  *

     7  * This library is free software; you can redistribute it and/or

     8  * modify it under the terms of the GNU Lesser General Public License

     9  * version 2.1 as published by the Free Software Foundation.

    10  *

    11  * This library is distributed in the hope that it will be useful, but

    12  * WITHOUT ANY WARRANTY; without even the implied warranty of

    13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

    14  * Lesser General Public License for more details.

    15  *

    16  * You should have received a copy of the GNU Lesser General Public

    17  * License along with this library; if not, write to the Free Software

    18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA

    19  * 02110-1301 USA

    20  *

    21  */

    22 

    23 #ifndef GCONFITEM_H

    24 #define GCONFITEM_H

    25 

    26 #include <QVariant>

    27 #include <QStringList>

    28 #include <QObject>

    29 

    30 /*!

    31 

    32   \brief GConfItem is a simple C++ wrapper for GConf.

    33 

    34   Creating a GConfItem instance gives you access to a single GConf

    35   key.  You can get and set its value, and connect to its

    36   valueChanged() signal to be notified about changes.

    37 

    38   The value of a GConf key is returned to you as a QVariant, and you

    39   pass in a QVariant when setting the value.  GConfItem converts

    40   between a QVariant and GConf values as needed, and according to the

    41   following rules:

    42 

    43   - A QVariant of type QVariant::Invalid denotes an unset GConf key.

    44 

    45   - QVariant::Int, QVariant::Double, QVariant::Bool are converted to

    46     and from the obvious equivalents.

    47 

    48   - QVariant::String is converted to/from a GConf string and always

    49     uses the UTF-8 encoding.  No other encoding is supported.

    50 

    51   - QVariant::StringList is converted to a list of UTF-8 strings.

    52 

    53   - QVariant::List (which denotes a QList<QVariant>) is converted

    54     to/from a GConf list.  All elements of such a list must have the

    55     same type, and that type must be one of QVariant::Int,

    56     QVariant::Double, QVariant::Bool, or QVariant::String.  (A list of

    57     strings is returned as a QVariant::StringList, however, when you

    58     get it back.)

    59 

    60   - Any other QVariant or GConf value is essentially ignored.

    61 

    62   \warning GConfItem is as thread-safe as GConf.

    63 

    64 */

    65 

    66 class GConfItem : public QObject

    67 {

    68     Q_OBJECT

    69 

    70  public:

    71     /*! Initializes a GConfItem to access the GConf key denoted by

    72         \a key.  Key names should follow the normal GConf conventions

    73         like "/myapp/settings/first".

    74 

    75         \param key    The name of the key.

    76         \param parent Parent object

    77     */

    78     explicit GConfItem(const QString &key, QObject *parent = 0);

    79 

    80     /*! Finalizes a GConfItem.

    81      */

    82     virtual ~GConfItem();

    83 

    84     /*! Returns the key of this item, as given to the constructor.

    85      */

    86     QString key() const;

    87 

    88     /*! Returns the current value of this item, as a QVariant.

    89      */

    90     QVariant value() const;

    91 

    92     /*! Returns the current value of this item, as a QVariant.  If

    93      *  there is no value for this item, return \a def instead.

    94      */

    95     QVariant value(const QVariant &def) const;

    96 

    97     /*! Set the value of this item to \a val.  If \a val can not be

    98         represented in GConf or GConf refuses to accept it for other

    99         reasons, the current value is not changed and nothing happens.

   100 

   101         When the new value is different from the old value, the

   102         changedValue() signal is emitted on this GConfItem as part

   103         of calling set(), but other GConfItem:s for the same key do

   104         only receive a notification once the main loop runs.

   105 

   106         \param val  The new value.

   107     */

   108     void set(const QVariant &val);

   109 

   110     /*! Unset this item.  This is equivalent to

   111 

   112         \code

   113         item.set(QVariant(QVariant::Invalid));

   114         \endcode

   115      */

   116     void unset();

   117 

   118     /*! Return a list of the directories below this item.  The

   119         returned strings are absolute key names like

   120         "/myapp/settings".

   121 

   122         A directory is a key that has children.  The same key might

   123         also have a value, but that is confusing and best avoided.

   124     */

   125     QList<QString> listDirs() const;

   126 

   127     /*! Return a list of entries below this item.  The returned

   128         strings are absolute key names like "/myapp/settings/first".

   129 

   130         A entry is a key that has a value.  The same key might also

   131         have children, but that is confusing and is best avoided.

   132     */

   133     QList<QString> listEntries() const;

   134 

   135  signals:

   136     /*! Emitted when the value of this item has changed.

   137      */

   138     void valueChanged();

   139 

   140  private:

   141     friend struct GConfItemPrivate;

   142     struct GConfItemPrivate *priv;

   143 

   144     void update_value(bool emit_signal);

   145 };

   146 

   147 #endif // GCONFITEM_H