Gegl.MetadataStore¶

Subclasses:: Gegl.MetadataHash

Methods¶

Inherited:: GObject.Object (37), Gegl.Metadata (9)
Structs:: GObject.ObjectClass (5)

	`declare` (pspec)
	`get_artist` ()
	`get_comment` ()
	`get_copyright` ()
	`get_description` ()
	`get_disclaimer` ()
	`get_file_module_name` ()
	`get_resolution_unit` ()
	`get_resolution_x` ()
	`get_resolution_y` ()
	`get_software` ()
	`get_source` ()
	`get_string` (name)
	`get_timestamp` ()
	`get_title` ()
	`get_value` (name, value)
	`get_warning` ()
	`has_value` (name)
	`notify` (pspec, shadow)
	`register` (local_name, name, transform)
	`set_artist` (artist)
	`set_comment` (comment)
	`set_copyright` (copyright)
	`set_description` (description)
	`set_disclaimer` (disclaimer)
	`set_resolution_unit` (unit)
	`set_resolution_x` (resolution_x)
	`set_resolution_y` (resolution_y)
	`set_software` (software)
	`set_source` (source)
	`set_string` (name, string)
	`set_timestamp` (timestamp)
	`set_title` (title)
	`set_value` (name, value)
	`set_warning` (warning)
	`typeof_value` (name)

Virtual Methods¶

Inherited:: GObject.Object (7), Gegl.Metadata (8)

	`do__declare` (pspec, shadow)
	`do__get_value` (name)
	`do_has_value` (name)
	`do_register_hook` (file_module_name, flags)
	`do_set_value` (name, value)

Properties¶

Name	Type	Flags	Short Description
`artist`	`str`	r/w/en	Name of image creator
`comment`	`str`	r/w/en	Miscellaneous comment
`copyright`	`str`	r/w/en	Copyright notice
`description`	`str`	r/w/en	Description of image (possibly long)
`disclaimer`	`str`	r/w/en	Legal disclaimer
`file-module-name`	`str`	r/en	Name of currently active file module or `None`
`resolution-unit`	`Gegl.ResolutionUnit`	r/w/en	Units for image resolution
`resolution-x`	`float`	r/w/en	X Resolution
`resolution-y`	`float`	r/w/en	X Resolution
`software`	`str`	r/w/en	Software used to create the image
`source`	`str`	r/w/en	Device used to create the image
`timestamp`	`GLib.DateTime`	r/w/en	Image creation time
`title`	`str`	r/w/en	Short title or caption
`warning`	`str`	r/w/en	Warning of nature of content

Signals¶

Inherited:: GObject.Object (1)

Name	Short Description
`changed`	`::changed` is emitted when a metadata value is changed.
`generate-value`	If a signal handler is connected to `::generate-value` a signal is emitted when the file module accesses a value using gegl_metadata_get_value().
`mapped`	`::mapped` is emitted after a file module registers a mapping and before other processing takes place.
`parse-value`	If a signal handler is connected to `::parse-value` a signal is emitted when the file module accesses a value using gegl_metadata_set_value().
`unmapped`	`::unmapped` is emitted when a file module tries to look up an unmapped metadata name.

Fields¶

Inherited:: GObject.Object (1)

Name	Type	Access	Description
parent_instance	`GObject.Object`	r

Class Details¶

class Gegl.MetadataStore(**kwargs)¶

Bases:: GObject.Object, Gegl.Metadata
Abstract:: Yes
Structure:: Gegl.MetadataStoreClass

declare(pspec)¶

Parameters:: pspec (GObject.ParamSpec) – A GObject.ParamSpec

Declare a metadata value using a GObject.ParamSpec.

get_artist()¶

Returns:: Artist or None if not set
Return type:: str

Get name of image creator.

get_comment()¶

Returns:: Comment or None if not set
Return type:: str

Get the comment.

get_copyright()¶

Returns:: Copyright or None if not set
Return type:: str

Get the copyright notice.

get_description()¶

Returns:: Description or None if not set
Return type:: str

Get description of image.

get_disclaimer()¶

Returns:: Disclaimer or None if not set
Return type:: str

Get the legal disclaimer.

get_file_module_name()¶

Returns:: Current file module name or None.
Return type:: str

Return the name registered by the current file module.

get_resolution_unit()¶

Returns:: a Gegl.ResolutionUnit.
Return type:: Gegl.ResolutionUnit

Get the units used for resolution.

get_resolution_x()¶

Returns:: X resolution
Return type:: float

Get the X resolution or density in dots per unit.

get_resolution_y()¶

Returns:: Y resolution
Return type:: float

Get the Y resolution or density in dots per unit.

get_software()¶

Returns:: Software or None if not set
Return type:: str

Get software used to create the image.

get_source()¶

Returns:: source or None if not set
Return type:: str

Get device used to create the image.

get_string(name)¶

Parameters:: name (str) – Metadata name
Returns:: String or None.
Return type:: str

A slightly more efficient version of Gegl.MetadataStore.get_value() for string values avoiding a duplication. Otherwise it behaves the same Gegl.MetadataStore.get_value().

get_timestamp()¶

Returns:: GLib.DateTime or None if not set. Free with GLib.DateTime.unref() when done.
Return type:: GLib.DateTime

Get time of original image creation.

get_title()¶

Returns:: Title or None if not set
Return type:: str

Get title or caption for image.

get_value(name, value)¶

Parameters:

name (str) – Metadata name
value (GObject.Value) – An initialised GObject.Value.

Returns:

An initialised GObject.Value.

Return type:

value: GObject.Value

Retrieve the metadata value. value must be initialised with a compatible type. If the value is unset or has not been previously declared value is unchanged and an error message is logged.

get_warning()¶

Returns:: Warning or None if not set
Return type:: str

Get warning.

has_value(name)¶

Parameters:: name (str) – Metadata name
Returns:: True if metadata is declared and contains a valid value.
Return type:: bool

Test whether the Gegl.MetadataStore contains a value for the specified name.

notify(pspec, shadow)¶

Parameters:

pspec (GObject.ParamSpec) – The GObject.ParamSpec used to declare the variable.
shadow (bool) – The metadata variable shadows a property.

Gegl.MetadataStore.notify() is called by subclasses when the value of a metadata variable changes. It emits the ::changed signal with the variable name as the detail parameter. Set shadow = True if variable is shadowed by a property so that a notify signal is emitted with the property name as the detail parameter.

register(local_name, name, transform)¶

Parameters:

local_name (str) – Metadata name known to file module
name (str) – Metadata name
transform (GObject.ValueTransform) – A GObject.ValueTransform function or None

set_artist(artist)¶

Parameters:: artist (str) – Artist string

Set name of image creator.

set_comment(comment)¶

Parameters:: comment (str) – Comment string

Set the miscellaneous comment; conversion from GIF comment.

set_copyright(copyright)¶

Parameters:: copyright (str) – Copyright string

Set the copyright notice.

set_description(description)¶

Parameters:: description (str) – Description string

Set description of image.

set_disclaimer(disclaimer)¶

Parameters:: disclaimer (str) – Disclaimer string

Set the legal disclaimer.

set_resolution_unit(unit)¶

Parameters:: unit (Gegl.ResolutionUnit) – Units as a Gegl.ResolutionUnit

Set the units used for the resolution (density) values.

set_resolution_x(resolution_x)¶

Parameters:: resolution_x (float) – X resolution or density

Set the X resolution or density in dots per unit.

set_resolution_y(resolution_y)¶

Parameters:: resolution_y (float) – Y resolution or density

Set the Y resolution or density in dots per unit.

set_software(software)¶

Parameters:: software (str) – Software string

Set software used to create the image.

set_source(source)¶

Parameters:: source (str) – Source string

Set device used to create the image.

set_string(name, string)¶

Parameters:

name (str) – Metadata name
string (str) – String value to set

A slightly more efficient version of Gegl.MetadataStore.set_value() for string values avoiding a duplication. Otherwise it behaves the same Gegl.MetadataStore.set_value().

set_timestamp(timestamp)¶

Parameters:: timestamp (GLib.DateTime) – A GLib.DateTime

Set time of original image creation.

set_title(title)¶

Parameters:: title (str) – Title string

Set title or caption for image.

set_value(name, value)¶

Parameters:

name (str) – Metadata name
value (GObject.Value) – (nullable): A valid GObject.Value or None

Set the specified metadata value. If value is None the default value from the associated GObject.ParamSpec is used. This operation will fail if the value has not been previously declared. A changed::name signal is emitted when the value is set. If the value is shadowed by a property a notify::name signal is also emitted.

set_warning(warning)¶

Parameters:: warning (str) – Warning string

Set the warning of nature of content.

typeof_value(name)¶

Parameters:: name (str) – Metadata name
Returns:: Declared GObject.GType of metadata value or GObject.TYPE_INVALID.
Return type:: GObject.GType

Get the declared type of the value in the Gegl.MetadataStore.

do__declare(pspec, shadow) virtual¶

Parameters:

pspec (GObject.ParamSpec) –
shadow (bool) –

The _declare virtual method creates a metadata variable in the underlying data store. It implements Gegl.MetadataStore.declare(). A GObject.ParamSpec is used to describe the variable. If the metadata shadows an object property, shadow should be True, otherwise False. It is acceptable for a subclass to provide additional variables which are implicitly declared, that is, they need not be declared using Gegl.MetadataStore.declare(), however the pspec method must still retrieve a GObject.ParamSpec describing such variables. This method MUST be provided by the subclass.

do__get_value(name) virtual¶

Parameters:: name (str) –
Return type:: GObject.Value

Return a pointer to a GObject.Value with the value of the metadata variable or None if not declared or the variable does not contain a valid value. Implements Gegl.MetadataStore.get_value(). This method MUST be provided by the subclass.

do_has_value(name) virtual¶

Parameters:: name (str) – Metadata name
Returns:: True if metadata is declared and contains a valid value.
Return type:: bool

Test whether the Gegl.MetadataStore contains a value for the specified name.

do_register_hook(file_module_name, flags) virtual¶

Parameters:

file_module_name (str) –
flags (int) –

This method is called after a file loader or saver registers a Gegl.MetadataMap and before any further processing takes place. It is intended to allow an application to create further application-specific mappings using Gegl.MetadataStore.register(). Gegl.MetadataStore provides a default method which emits the ::mapped signal.

do_set_value(name, value) virtual¶

Parameters:

name (str) – Metadata name
value (GObject.Value) – (nullable): A valid GObject.Value or None

Set the specified metadata value. If value is None the default value from the associated GObject.ParamSpec is used. This operation will fail if the value has not been previously declared. A changed::name signal is emitted when the value is set. If the value is shadowed by a property a notify::name signal is also emitted.

Signal Details¶

Gegl.MetadataStore.signals.changed(metadata_store, pspec)¶

Signal Name:

changed

Flags:

RUN_LAST, DETAILED

Parameters:

metadata_store (Gegl.MetadataStore) – The object which received the signal
pspec (GObject.ParamSpec) – A GObject.ParamSpec declaring the metadata value

::changed is emitted when a metadata value is changed. This is analogous to the GObject::notify signal.

Gegl.MetadataStore.signals.generate_value(metadata_store, pspec, value)¶

Signal Name:

generate-value

Flags:

RUN_LAST, DETAILED

Parameters:

metadata_store (Gegl.MetadataStore) – The object which received the signal
pspec (GObject.ParamSpec) – A GObject.ParamSpec declaring the metadata value
value (GObject.Value) – An initialised GObject.Value.

Returns:

True if a value is generated successfully.

value:: An initialised GObject.Value.

Return type:

(bool, value: GObject.Value)

If a signal handler is connected to ::generate-value a signal is emitted when the file module accesses a value using gegl_metadata_get_value(). The signal handler must generate a value of the type specified in the pspec argument. The signal handler’s return value indicates the success of the operation.

If no handler is connected the mapped metadata value is accessed normally,

Gegl.MetadataStore.signals.mapped(metadata_store, file_module, exclude_unmapped)¶

Signal Name:

mapped

Flags:

RUN_LAST

Parameters:

metadata_store (Gegl.MetadataStore) – The object which received the signal
file_module (str) – The file module name
exclude_unmapped (bool) – True if the file module cannot handle unmapped values

::mapped is emitted after a file module registers a mapping and before other processing takes place. An application may respond to the signal by registering additional mappings or overriding existing values, for example it might override the TIFF ImageDescription tag to format multiple metadata values into the description.

Gegl.MetadataStore.signals.parse_value(metadata_store, pspec, value)¶

Signal Name:

parse-value

Flags:

RUN_LAST, DETAILED

Parameters:

metadata_store (Gegl.MetadataStore) – The object which received the signal
pspec (GObject.ParamSpec) – A GObject.ParamSpec declaring the metadata value
value (GObject.Value) – A GObject.Value containing the value to parse.

Returns:

True if parsing is successful.

value:: A GObject.Value containing the value to parse.

Return type:

(bool, value: GObject.Value)

If a signal handler is connected to ::parse-value a signal is emitted when the file module accesses a value using gegl_metadata_set_value(). The signal handler should parse the value supplied in the GObject.Value and may set any number of metadata values using Gegl.MetadataStore.set_value().

If no handler is connected the mapped metadata value is set normally,

Gegl.MetadataStore.signals.unmapped(metadata_store, file_module, local_name)¶

Signal Name:

unmapped

Flags:

RUN_LAST

Parameters:

metadata_store (Gegl.MetadataStore) – The object which received the signal
file_module (str) – The file module name
local_name (str) – The unmapped metadata name as used by the file module

::unmapped is emitted when a file module tries to look up an unmapped metadata name. When the handler returns a second attempt is made to look up the metadata.

Property Details¶

Gegl.MetadataStore.props.artist¶

Name:: artist
Type:: str
Default Value:: None
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

Name of image creator.

Gegl.MetadataStore.props.comment¶

Name:: comment
Type:: str
Default Value:: None
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

Miscellaneous comment; conversion from GIF comment.

Gegl.MetadataStore.props.copyright¶

Name:: copyright
Type:: str
Default Value:: None
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

Copyright notice.

Gegl.MetadataStore.props.description¶

Name:: description
Type:: str
Default Value:: None
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

Description of image (possibly long).

Gegl.MetadataStore.props.disclaimer¶

Name:: disclaimer
Type:: str
Default Value:: None
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

Legal disclaimer.

Gegl.MetadataStore.props.file_module_name¶

Name:: file-module-name
Type:: str
Default Value:: None
Flags:: READABLE, EXPLICIT_NOTIFY

Current file loader/saver module name. Valid only while a Gegl.Metadata mapping is registered. This property is mainly provided for use in signal handlers.

Gegl.MetadataStore.props.resolution_unit¶

Name:: resolution-unit
Type:: Gegl.ResolutionUnit
Default Value:: Gegl.ResolutionUnit.DPI
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

A Gegl.ResolutionUnit specifying units for the image resolution (density).

Gegl.MetadataStore.props.resolution_x¶

Name:: resolution-x
Type:: float
Default Value:: 300.0
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

X resolution or density in dots per unit.

Gegl.MetadataStore.props.resolution_y¶

Name:: resolution-y
Type:: float
Default Value:: 300.0
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

Y resolution or density in dots per unit.

Gegl.MetadataStore.props.software¶

Name:: software
Type:: str
Default Value:: None
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

Software used to create the image.

Gegl.MetadataStore.props.source¶

Name:: source
Type:: str
Default Value:: None
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

Device used to create the image.

Gegl.MetadataStore.props.timestamp¶

Name:: timestamp
Type:: GLib.DateTime
Default Value:: None
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

Time of original image creation.

Gegl.MetadataStore.props.title¶

Name:: title
Type:: str
Default Value:: None
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

Short (one line) title or caption for image.

Gegl.MetadataStore.props.warning¶

Name:: warning
Type:: str
Default Value:: None
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

Warning of nature of content.