#include <tdefilemetainfo.h>
Inherits TQObject.
Public Member Functions | |
KFilePlugin (TQObject *parent, const char *name, const TQStringList &args) | |
virtual | ~KFilePlugin () |
virtual bool | readInfo (KFileMetaInfo &info, uint what=KFileMetaInfo::Fastest)=0 |
virtual bool | writeInfo (const KFileMetaInfo &info) const |
virtual TQValidator * | createValidator (const TQString &mimeType, const TQString &group, const TQString &key, TQObject *parent, const char *name) const |
Protected Member Functions | |
KFileMimeTypeInfo * | addMimeTypeInfo (const TQString &mimeType) |
KFileMimeTypeInfo::GroupInfo * | addGroupInfo (KFileMimeTypeInfo *info, const TQString &key, const TQString &translatedKey) const |
void | setAttributes (KFileMimeTypeInfo::GroupInfo *gi, uint attr) const |
void | addVariableInfo (KFileMimeTypeInfo::GroupInfo *gi, TQVariant::Type type, uint attr) const |
KFileMimeTypeInfo::ItemInfo * | addItemInfo (KFileMimeTypeInfo::GroupInfo *gi, const TQString &key, const TQString &translatedKey, TQVariant::Type type) |
void | setAttributes (KFileMimeTypeInfo::ItemInfo *item, uint attr) |
void | setHint (KFileMimeTypeInfo::ItemInfo *item, uint hint) |
void | setUnit (KFileMimeTypeInfo::ItemInfo *item, uint unit) |
void | setPrefix (KFileMimeTypeInfo::ItemInfo *item, const TQString &prefix) |
void | setSuffix (KFileMimeTypeInfo::ItemInfo *item, const TQString &suffix) |
KFileMetaInfoGroup | appendGroup (KFileMetaInfo &info, const TQString &key) |
void | appendItem (KFileMetaInfoGroup &group, const TQString &key, TQVariant value) |
virtual void | virtual_hook (int id, void *data) |
Protected Attributes | |
TQStringList | m_preferredKeys |
TQStringList | m_preferredGroups |
Detailed Description
Base class for a meta information plugin.
Meta information plugins are used to extract useful information from files of a given type. These plugins are used in Konqueror's file properties dialog, for example.
If you want to write your own plugin, you need to derive from this class.
In the constructor of your class, you need to call addMimeTypeInfo() to tell the KFile framework which mimetype(s) your plugin supports. For each mimetype, use the addGroupInfo() and addItemInfo() methods to declare the meta information items the plugin calculates and to group them accordingly. For groups, use setAttributes() to customize your group (see KFileMimeTypeInfo::Attributes). For items, use setAttributes() to define the behaviour of the item; use setHint() to define the meaning of the item; use setUnit() to define the Unit, such as KFileMimeTypeInfo::Seconds or KFileMimeTypeInfo::KiloBytes. In short, the constructor defines the data structure of the meta information supported by your plugin.
Example:
Some meta information items are likely to be available in several different file formats, such as "Author"
, "Title"
(for documents), and "Length"
(for multimedia files). Be sure to use the naming scheme from existing plugins for your meta information items if possible. If, for example, the meta information of a group of files is shown in a table view, this will allow two files to share the same column (say "Length") even if they are of a different file type.
You must overwrite the readInfo() method. In this method you need to extract the meta information of the given file. You can use a third-party library to achieve this task. This might be the best way for binary files, since a change in the file format is likely to be supported by subsequent releases of that library. Alternatively, for text-based file formats, you can use TQTextStream to parse the file. For simple file formats, TQRegExp can be of great help, too.
After you extracted the relevant information, use appendGroup() and appendItem() to fill the meta information data structure (as defined in the constructor) with values. Note that you can leave out groups or items which are not appropriate for a particular file.
Example:
If you want to define mutable meta information items, you need to overwrite the writeInfo() method. In this method, you can use third-party library (appropriate mostly for binary files, see above) or TQTextStream to write the information back to the file. If you use TQTextStream, be sure to write all file contents back.
For some items, it might be that not all possible values are allowed. You can overwrite the createValidator() method to define constraints for a meta information item. For example, the "Year"
field for an MP3 file could reject values outside the range 1500 - 2050 (at least for now). The validator is used to check values before the writeInfo() method is called so that writeInfo() is only provided correct values.
In your plugin, you need to create a factory for the KFilePlugin
Example:
To make your plugin available within KDE, you also need to provide a .desktop file which describes your plugin. The required fields in the file are:
Type:
must be"Service"
Name:
the name of the pluginServiceTypes:
must contain"KFilePlugin"
X-TDE-Library
: the name of the library containing the KFile pluginMimeType:
the mimetype(s) which are supported by the pluginPreferredGroups:
a comma-separated list of the most important groups. This list defines the order in which the meta information groups should be displayedPreferredItems:
a comma-separated list of the most important items. This list defines the order in which the meta information items should be displayed
Example:
Definition at line 1394 of file tdefilemetainfo.h.
Constructor & Destructor Documentation
◆ KFilePlugin()
KFilePlugin::KFilePlugin | ( | TQObject * | parent, |
const char * | name, | ||
const TQStringList & | args | ||
) |
Creates a new KFilePlugin instance.
You need to implement a constructor with the same argument list as this is required by KGenericFactory
- Parameters
-
parent the parent of the TQObject, can be 0
name the name of the TQObject, can be 0
args currently ignored
- See also
- addMimeTypeInfo()
- addGroupInfo()
- addItemInfo()
- TQObject()
Definition at line 781 of file tdefilemetainfo.cpp.
◆ ~KFilePlugin()
|
virtual |
Destructor.
Definition at line 788 of file tdefilemetainfo.cpp.
Member Function Documentation
◆ addGroupInfo()
|
protected |
Creates a meta information group for KFileMimeTypeInfo object returned by addMimeTypeInfo().
- Parameters
-
info the object returned by addMimeTypeInfo() key a unique string identifiing this group. For simplicity it is recommended to use the same string as for the translatedKey parameter translatedKey the translated version of the key string for displaying in user interfaces. Use i18n() to translate the string
- Returns
- a GroupInfo object. Pass this object to addItemInfo to add meta information attributed to this group.
- See also
- setAttributes()
- addItemInfo()
Definition at line 802 of file tdefilemetainfo.cpp.
◆ addItemInfo()
|
protected |
Adds a meta information item to a GroupInfo object as returned by addGroupInfo().
- Parameters
-
gi the GroupInfo object to add a new item to key a unique string to identify this item. For simplicity it is recommended to use the same string as for the translatedKey parameter translatedKey the translated version of the key string for displaying in user interfaces. Use i18n() to translate the string type the type of the meta information item, e.g. TQVariant::Int or TQVariant::String.
- Returns
- an ItemInfo object. Pass this object to setAttributes()
Definition at line 819 of file tdefilemetainfo.cpp.
◆ addMimeTypeInfo()
|
protected |
Call this from within your constructor to tell the KFile framework what mimetypes your plugin supports.
- Parameters
-
mimeType a string containing the mimetype, e.g. "text/html"
- Returns
- a KFileMimeTypeInfo object, to be used with addGroupInfo()
Definition at line 793 of file tdefilemetainfo.cpp.
◆ appendGroup()
|
protected |
Call this method from within readInfo() to indicate that you wish to fill meta information items of the group identified by key
with values.
- Parameters
-
info the KFileMetaInfo object. Use the parameter of the readInfo() method key the key string to identify the group. Use the string that you defined in your class' constructor
- Returns
- a KFileMetaInfoGroup object, to be used in appendItem()
Definition at line 894 of file tdefilemetainfo.cpp.
◆ appendItem()
|
protected |
Call this method from within readInfo() to fill the meta information item identified by key
with a value
.
- Parameters
-
group the KFileMetaInfoGroup object, as returned by appendGroup() key the key string to identify the item. value the value of the meta information item
Definition at line 899 of file tdefilemetainfo.cpp.
◆ createValidator()
|
inlinevirtual |
This method should create an appropriate validator for the specified item if it's editable or return a null pointer if not.
If you don't have any editable items, you don't need to implement this method.
If you you don't need any validation, e.g. you accept any input, you can simply return 0L
, or not reimplement this method at all.
- Parameters
-
mimeType the mime type group the group name of the validator item key the key name of the validator item parent the TQObject parent, can be 0
name the name of the TQObject, can be 0
Definition at line 1462 of file tdefilemetainfo.h.
◆ readInfo()
|
pure virtual |
Read the info from the file in this method and insert it into the provided KFileMetaInfo object.
You can get the path to the file with KFileMetaInfo::path(). Use appendGroup() and appendItem() to fill info
with the extracted values
- Parameters
-
info the information will be written here what defines what to read, see KFileMetaInfo::What
- Returns
true
if successful,false
if it failed
- See also
- writeInfo()
◆ setAttributes() [1/2]
|
protected |
Sets attributes of the GroupInfo object returned by addGroupInfo().
- Parameters
-
gi the object returned by addGroupInfo() attr the attributes for this group; these are values of type KFileMimeTypeInfo::Attributes, or'ed together
Definition at line 808 of file tdefilemetainfo.cpp.
◆ setAttributes() [2/2]
|
protected |
Sets some attributes for a meta information item.
The attributes describe if the item is mutable, how it should be computed for a list of files, and how it should be displayed
- Parameters
-
item the ItemInfo object as returned by addItemInfo() attr the attributes for this item; these are values of type KFileMimeTypeInfo::Attributes, or'ed together
Definition at line 827 of file tdefilemetainfo.cpp.
◆ setHint()
|
protected |
Defines the meaning of the meta information item.
Some applications make use of this information, so be sure to check KFileMimeTypeInfo::Hint to see if an item's meaning is in the list.
- Parameters
-
item the ItemInfo object as returned by addItemInfo() hint the item's meaning. See KFileMimeTypeInfo::Hint for a list of available meanings
Definition at line 832 of file tdefilemetainfo.cpp.
◆ setPrefix()
|
protected |
Sets a prefix string which is displayed before the item's value.
Use this string if no predefined unit fits the item's unit. Be sure to translate the string with i18n()
- Parameters
-
item the ItemInfo object as returned by addItemInfo() prefix the prefix string to display
Definition at line 884 of file tdefilemetainfo.cpp.
◆ setSuffix()
|
protected |
Sets a suffix string which is displayed before the item's value.
Use this string if no predefined unit fits the item's unit. Be sure to translate the string with i18n()
- Parameters
-
item the ItemInfo object as returned by addItemInfo() suffix the suffix string to display
Definition at line 889 of file tdefilemetainfo.cpp.
◆ setUnit()
|
protected |
Sets the unit used in the meta information item.
This unit is used to format the value and to make large values human-readable. For example, if the item's unit is KFileMimeTypeInfo::Seconds and the value is 276, it will be displayed as 4:36.
- Parameters
-
item the ItemInfo object as returned by addItemInfo() unit the item's unit. See KFileMimeTypeInfo::Unit for a list of available units
Definition at line 837 of file tdefilemetainfo.cpp.
◆ virtual_hook()
|
protectedvirtual |
Helper method to allow binary compatible extensions when needing "new virtual methods".
- Parameters
-
id the identifier of the new "virtual" method data any parameter data the new "virtual" method needs
Definition at line 798 of file tdefilemetainfo.cpp.
◆ writeInfo()
|
inlinevirtual |
Similar to the readInfo() but for writing the info back to the file.
If you don't have any writable keys, don't implement this method
- Parameters
-
info the information that will be written
- Returns
true
if successful,false
if it failed
Definition at line 1442 of file tdefilemetainfo.h.
The documentation for this class was generated from the following files: