Handle to the PDF layer object which represents a named object whose state can be toggled in a User Interface to affect changes in visibility of content.
| IG_PDF_layer_create | Creates new layer (optional-content group) object in the document. |
| IG_PDF_layer_get_name | Gets the layer name. |
| IG_PDF_layer_set_name | Sets the new layer name. |
| IG_PDF_layer_get_current_state | Gets the current ON-OFF state of the layer object. |
| IG_PDF_layer_set_current_state | Sets the current ON-OFF state of the layer object. |
| IG_PDF_layer_get_initial_state | Gets the initial ON-OFF state of the layer object. |
| IG_PDF_layer_set_initial_state | Sets the initial ON-OFF state of the layer object. |
| IG_PDF_layer_has_usage_info | Tests whether a layer object is associated with a Usage dictionary. |
| IG_PDF_layer_get_usage_info | Gets usage information from a layer object. |
| IG_PDF_layer_set_usage_info | Sets a Usage dictionary entry in a layer object. |
| IG_PDF_layer_get_intent | Gets the intent list for a layer. |
| IG_PDF_layer_set_intent | Sets the Intent entry in a layer's dictionary. |
| IG_PDF_layer_get_unique_id | Sets a unique ID. |
| IG_PDF_layer_release | Releases a layer object. |
| IG_PDF_layer_remove | Destroys layer (optional-content group) object. |