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# 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