Class Group

The OCG::Group object represents an optional-content group. This corresponds to a PDF OCG dictionary representing a collection of graphic objects that can be made visible or invisible (Section 4.10.1 'Optional Content Groups' in PDF Reference). Any graphic content of the PDF can be made optional, including page contents, XObjects, and annotations. The specific content objects in the group have an OC entry in the PDF as part of the surrounding marked content or in the XObject dictionary. The group itself is a named object that can be typically manipulated through a Layers panel in a PDF viewer.

In the simplest case, the group's ON-OFF state makes the associated content visible or hidden. The ON-OFF state of a group can be toggled for a particular context (OCG::Context), and a set of states is kept in a configuration (OCG::Config). The visibility can depend on more than one group in an optional-content membership dictionary (OCG::OCMD), and can also be affected by the context's draw mode (OCGContext::OCDrawMode).

A group has an Intent entry, broadly describing the intended use. A group's content is considered to be optional (that is, the group's state is considered in its visibility) if any intent in its list matches an intent of the context. The intent list of the context is usually set from the intent list of the document configuration.

A Usage dictionary entry provides more specific intended usage information than an intent entry. Possible key values are: CreatorInfo, Language, Export, Zoom, Print, View, User, PageElement. The usage value can act as a kind of metadata, describing the sort of things that belong to the group, such as text in French, fine detail on a map, or a watermark. The usage values can also be used by the AutoState mechanism to make decisions about what groups should be on and what groups should be off. The AutoState mechanism considers the usage information in the OCGs, the AS array of the configuration, and external factors; for example, the language the application is running in, the current zoom level on the page, or whether the page is being printed.

Inheritance

object

Group

Inherited Members

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

Namespace: pdftron.PDF.OCG

Assembly: PDFNet.dll

Syntax

public class Group

Constructors

Group(Obj)

Creates a new optional-content group (OCG) object from an existing SDF/Cos object.

Declaration

public Group(Obj ocg)

Parameters

Type	Name	Description
Obj	ocg	the ocg

Methods

Create(PDFDoc, string)

Creates a new optional-content group (OCG) object in the document.

Declaration

public static Group Create(PDFDoc doc, string name)

Parameters

Type	Name	Description
PDFDoc	doc	The document in which the new OCG will be created.
string	name	The name of the optional-content group.

Returns

Type	Description
Group	The newly created OCG::Group object.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

GetCurrentState(Context)

Declaration

public bool GetCurrentState(Context context)

Parameters

Type	Name	Description
Context	context

Returns

Type	Description
bool

GetInitialState(Config)

Gets the initial state.

Declaration

public bool GetInitialState(Config config)

Parameters

Type	Name	Description
Config	config	The configuration for which to get the group's initial state.

Returns

Type	Description
bool	The initial state (ON or OFF) of the optional-content group (OCG) object in a given configuration.

Remarks

If the configuration has a BaseState of Unchanged, and the OCG is not listed explicitly in its ON list or OFF list, then the initial state is taken from the OCG's current state in the document's default context.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

GetIntent()

Gets the intent.

Declaration

public Obj GetIntent()

Returns

Type

Description

Obj

OCG intent. An intent is a name object (or an array of name objects) broadly describing the intended use, which can be either "View" or "Design". A group's content is considered to be optional (that is, the group's state is considered in its visibility) if any intent in its list matches an intent of the context. The intent list of the context is usually set from the intent list of the document configuration.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

GetName()

Gets the name.

Declaration

public string GetName()

Returns

Type	Description
string	the name of this optional-content group (OCG).

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

GetSDFObj()

Gets the SDFObj.

Declaration

public Obj GetSDFObj()

Returns

Type	Description
Obj	Pointer to the underlying SDF/Cos object.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

GetUsage(string)

Gets the usage.

Declaration

public Obj GetUsage(string key)

Parameters

Type	Name	Description
string	key	The usage key in the usage dictionary entry. The possible key values are: CreatorInfo, Language, Export, Zoom, Print, View, User, PageElement.

Returns

Type	Description
Obj	The usage information associated with the given key in the Usage dictionary for the group, or a NULL if the entry is not present. A Usage dictionary entry provides more specific intended usage information than an intent entry.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

HasUsage()

Checks for usage.

Declaration

public bool HasUsage()

Returns

Type	Description
bool	true if this group is associated with a Usage dictionary, false otherwise.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

IsLocked(Config)

Checks if is locked.

Declaration

public bool IsLocked(Config config)

Parameters

Type	Name	Description
Config	config	The OC configuration.

Returns

Type	Description
bool	true if this OCG is locked in a given configuration, false otherwise. The on/off state of a locked OCG cannot be toggled by the user through the user interface.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

IsValid()

Checks if is valid.

Declaration

public bool IsValid()

Returns

Type	Description
bool	True if this is a valid (non-null) OCG, false otherwise.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

SetCurrentState(Context, bool)

Declaration

public void SetCurrentState(Context context, bool state)

Parameters

Type	Name	Description
Context	context
bool	state

SetInitialState(Config, bool)

Sets the initial state (ON or OFF) of the optional-content group (OCG) object in a given configuration.

Declaration

public void SetInitialState(Config config, bool state)

Parameters

Type	Name	Description
Config	config	The configuration for which to set the group's initial state.
bool	state	The new initial state, true if the state is ON, false if it is OFF.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

SetIntent(Obj)

Sets the Intent entry in an optional-content group's SDF/Cos dictionary. For more information, see GetIntent().

Declaration

public void SetIntent(Obj intent)

Parameters

Type	Name	Description
Obj	intent	The new Intent entry value (a name object or an array of name objects).

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

SetLocked(Config, bool)

Sets the locked state of an OCG in a given configuration. The on/off state of a locked OCG cannot be toggled by the user through the user interface.

Declaration

public void SetLocked(Config config, bool locked)

Parameters

Type	Name	Description
Config	config	IN/OUT The optional-content configuration.
bool	locked	true if the OCG should be locked, false otherwise.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception

SetName(string)

Sets the name of this optional-content group (OCG).

Declaration

public void SetName(string name)

Parameters

Type	Name	Description
string	name	The new name.

Exceptions

Type	Condition
PDFNetException	PDFNetException the PDFNet exception