kio Library API Documentation

KFileMetaInfo Class Reference

This is the class for objects that hold meta information about a file. More...

#include <kfilemetainfo.h>

List of all members.

Public Types

typedef KFileMimeTypeInfo::Hint Hint
typedef KFileMimeTypeInfo::Unit Unit
typedef KFileMimeTypeInfo::Attributes Attributes
enum  What {
  Fastest = 0x1, DontCare = 0x2, TechnicalInfo = 0x4, ContentInfo = 0x8,
  ExtenedAttr = 0x10, Thumbnail = 0x20, Preferred = 0x40, Everything = 0xffff
}
 This is used to specify what a KFileMetaInfo object should read, so you can specify if you want to read "expensive" items or not. More...


Public Member Functions

 KFileMetaInfo (const QString &path, const QString &mimeType=QString::null, uint what=Fastest)
 The constructor.

 KFileMetaInfo ()
 Default constructor.

 KFileMetaInfo (const KFileMetaInfo &original)
 Copy constructor.

const KFileMetaInfooperator= (const KFileMetaInfo &info)
 The assignment operator, so you can do e.g.:.

QStringList groups () const
QStringList supportedGroups () const
QStringList preferredGroups () const
QStringList preferredKeys () const
QStringList supportedKeys () const
QStringList editableGroups () const
KFileMetaInfoItem item (const QString &key) const
KFileMetaInfoItem item (const KFileMetaInfoItem::Hint hint) const
KFileMetaInfoItem saveItem (const QString &key, const QString &preferredGroup=QString::null, bool createGroup=true)
KFileMetaInfoGroup group (const QString &key) const
KFileMetaInfoGroup operator[] (const QString &key) const
bool addGroup (const QString &name)
 Try to add the specified group.

bool removeGroup (const QString &name)
 remove the specified group.

QStringList removedGroups ()
bool applyChanges ()
 This method writes all pending changes of the meta info back to the file.

bool contains (const QString &key) const
bool containsGroup (const QString &key) const
const QVariant value (const QString &key) const
bool isValid () const
bool isEmpty () const
QString mimeType () const
QString path () const

Protected Member Functions

KFileMetaInfoGroup appendGroup (const QString &name)
KFilePlugin *const  plugin () const
void ref ()
void deref ()

Protected Attributes

Data * d

Friends

class KFilePlugin
QDataStreamoperator>> (QDataStream &s, KFileMetaInfo &)
QDataStreamoperator<< (QDataStream &s, const KFileMetaInfo &)


Detailed Description

This is the class for objects that hold meta information about a file.

The information is kept in form of a system of key/value pairs. See also KFileMetaInfoItem. This information is retrieved from the file through a plugin system, and this class is the main interface to it. If you want to write your own plugin, have a look at KFilePlugin. There are basically two different kinds of meta information: Fixed ones that the plugin knows about (e.g. an mp3 id3v1 tag has a well defined fixed list of fields), and variable keys that exist in mimetypes that support their own key/value system (comments in png files are of this type). Almost every file has fixed keys, but some also have variable keys.

The groups and the What enum are not yet supported, but already added to the interface so that adding support doesn't break compatibility.

Definition at line 853 of file kfilemetainfo.h.


Member Enumeration Documentation

enum KFileMetaInfo::What
 

This is used to specify what a KFileMetaInfo object should read, so you can specify if you want to read "expensive" items or not.

  • Fastest do the fastest possible read and omit all items that might need a significantly longer time than the others
  • Everything read everything, even if it might take a while
  • DontCare let the plugin decide what to read
  • TechnicalInfo extract technical details about the file, like e.g. play time, resolution or a compression type
  • ContentInfo read information about the content of the file, like comments or id3 tags
  • ExtendedAttr read filesystem based extended attributes if they are supported for the filesystem
  • Thumbnail only read the file's thumbnail, if it contains one
  • Preferred get at least the preferred items

Definition at line 880 of file kfilemetainfo.h.


Constructor & Destructor Documentation

KFileMetaInfo::KFileMetaInfo const QString path,
const QString mimeType = QString::null,
uint  what = Fastest
 

The constructor.

creating a KFileMetaInfo item through this will autoload the plugin belonging to the mimetype and try to get meta information about the specified file.

If no info is available, you'll get an empty (not invalid) object. You can test for it with the isEmpty() method.

Parameters:
path The file name. This must be the path to a local file.
mimeType The name of the file's mimetype. If ommited, the mimetype is autodetected
what one or more of the What enum values. It gives some hint to the plugin what information is desired. The plugin may still return more items.

Definition at line 288 of file kfilemetainfo.cpp.

References KMimeType::findByPath(), QString::isEmpty(), KFileMetaInfo(), plugin(), and KFilePlugin::readInfo().

KFileMetaInfo::KFileMetaInfo  ) 
 

Default constructor.

This will create an invalid object (see isValid().

Definition at line 325 of file kfilemetainfo.cpp.

Referenced by KFileMetaInfo().

KFileMetaInfo::KFileMetaInfo const KFileMetaInfo original  ) 
 

Copy constructor.

Definition at line 318 of file kfilemetainfo.cpp.


Member Function Documentation

const KFileMetaInfo & KFileMetaInfo::operator= const KFileMetaInfo info  ) 
 

The assignment operator, so you can do e.g.:.

KFileMetaInfo info; if (something) info = KFileMetaInfo("/the/file");

This will create a shared copy of the object. The actual data is automatically deleted if all copies go out of scope

Definition at line 470 of file kfilemetainfo.cpp.

References d.

QStringList KFileMetaInfo::groups  )  const
 

Returns:
all keys groups that the file has.

Definition at line 345 of file kfilemetainfo.cpp.

Referenced by contains(), and containsGroup().

QStringList KFileMetaInfo::editableGroups  )  const
 

Returns:
the list of groups that you can add or remove from the file.

Definition at line 355 of file kfilemetainfo.cpp.

References KFileMimeTypeInfo::GroupInfo::attributes().

bool KFileMetaInfo::addGroup const QString name  ) 
 

Try to add the specified group.

This will only succeed if it is in the list of editableGroups(). Note that all non-variable items that belong to this group are automatically added as empty item.

Definition at line 417 of file kfilemetainfo.cpp.

References KFileMetaInfoGroup::appendItem(), KFileMimeTypeInfo::ItemInfo::attributes(), KFileMimeTypeInfo::GroupInfo::itemInfo(), KFileMimeTypeInfo::ItemInfo::key(), KStdAccel::name(), KFileMetaInfoGroup::setAdded(), and KFileMimeTypeInfo::GroupInfo::supportedKeys().

bool KFileMetaInfo::removeGroup const QString name  ) 
 

remove the specified group.

This will only succeed if it is in the list of editableGroups(). Beware that this also removes all the items in that group, so always ask the user before removing it!

Definition at line 453 of file kfilemetainfo.cpp.

References KStdAccel::name().

bool KFileMetaInfo::applyChanges  ) 
 

This method writes all pending changes of the meta info back to the file.

If any items are marked as removed, they are really removed from the list. The info object as well as all items are updated.

Returns:
true if successful, false if not

Definition at line 498 of file kfilemetainfo.cpp.

References QMapConstIterator::data(), plugin(), and KFilePlugin::writeInfo().

bool KFileMetaInfo::contains const QString key  )  const
 

Returns:
whether an item for this key exists.

Definition at line 550 of file kfilemetainfo.cpp.

References KFileMetaInfoGroup::contains(), groups(), and KStdAccel::key().

bool KFileMetaInfo::containsGroup const QString key  )  const
 

Returns:
whether a group with this name exists.

Definition at line 561 of file kfilemetainfo.cpp.

References groups(), and KStdAccel::key().

bool KFileMetaInfo::isValid  )  const
 

Returns:
true if the item is valid, i.e. if actually represents the info about a file, false if the object is uninitialized

Definition at line 483 of file kfilemetainfo.cpp.

Referenced by KFileItem::getToolTipText(), and KFileItem::metaInfo().

bool KFileMetaInfo::isEmpty  )  const
 

Returns:
false if the object contains data, true if it's empty. You'll get an empty object if no plugin for the file could be found.

Definition at line 489 of file kfilemetainfo.cpp.

Referenced by KFileItem::getToolTipText().

KFilePlugin *const KFileMetaInfo::plugin  )  const [protected]
 

Returns:
a pointer to the plugin that belogs to this object's mimetype. It will be auto-loaded if it's currently not loaded

Definition at line 539 of file kfilemetainfo.cpp.

Referenced by applyChanges(), and KFileMetaInfo().


The documentation for this class was generated from the following files:
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This file is part of the documentation for kdelibs Version 3.1.4.
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Generated on Sun Feb 27 22:15:35 2005 by doxygen 1.3.4 written by Dimitri van Heesch, © 1997-2001