class KFileMetaInfo

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Definition#include <kfilemetainfo.h>
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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.

typedef KFileMimeTypeInfo::Hint Hint

Hint

typedef KFileMimeTypeInfo::Unit Unit

Unit

typedef KFileMimeTypeInfo::Attributes Attributes

Attributes

enum What { Fastest = 0x1, DontCare = 0x2, TechnicalInfo = 0x4, ContentInfo = 0x8, ExtenedAttr = 0x10, Thumbnail = 0x20, Preferred = 0x40, Everything = 0xffff }

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.

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

KFileMetaInfo

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:
pathThe file name. This must be the path to a local file.
mimeTypeThe name of the file's mimetype. If ommited, the mimetype is autodetected
whatone 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.

 KFileMetaInfo ()

KFileMetaInfo

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

 KFileMetaInfo ( const KFileMetaInfo& original)

KFileMetaInfo

Copy constructor

 ~KFileMetaInfo ()

~KFileMetaInfo

const KFileMetaInfo&  operator= (const KFileMetaInfo& info )

operator=

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

QStringList  groups ()

groups

[const]

Returns: all keys groups that the file has.

QStringList  supportedGroups ()

supportedGroups

[const]

QStringList  preferredGroups ()

preferredGroups

[const]

QStringList  preferredKeys ()

preferredKeys

[const]

QStringList  supportedKeys ()

supportedKeys

[const]

QStringList  editableGroups ()

editableGroups

[const]

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

KFileMetaInfoItem  item (const QString& key)

item

[const]

KFileMetaInfoItem  item (const KFileMetaInfoItem::Hint hint)

item

[const]

KFileMetaInfoItem  saveItem ( const QString& key, const QString& preferredGroup = QString::null, bool createGroup = true )

saveItem

KFileMetaInfoGroup  group (const QString& key)

group

[const]

KFileMetaInfoGroup  operator[] (const QString& key)

operator[]

[const]

bool  addGroup ( const QString& name )

addGroup

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.

bool  removeGroup ( const QString& name )

removeGroup

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!

QStringList  removedGroups ()

removedGroups

bool  applyChanges ()

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

bool  contains ( const QString& key )

contains

[const]

Returns: whether an item for this key exists.

bool  containsGroup ( const QString& key )

containsGroup

[const]

Returns: whether a group with this name exists.

const QVariant  value ( const QString& key )

value

[const]

bool  isValid ()

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

bool  isEmpty ()

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.

QString  mimeType ()

mimeType

[const]

QString  path ()

path

[const]

friend QDataStream&  operator >> (QDataStream& s, KFileMetaInfo& )

operator >>

friend QDataStream&  operator << (QDataStream& s, const KFileMetaInfo& )

operator <<

friend class KFilePlugin

KFilePlugin

KFileMetaInfoGroup  appendGroup (const QString& name)

appendGroup

[protected]

KFilePlugin * const  plugin ()

plugin

[protected const]

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

void  ref ()

ref

[protected]

void  deref ()

deref

[protected]

Data* d

d

[protected]


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