PDTask

A Pajdeg pipe task. More...

Files
file	PDTask.h

Typedefs
typedef struct PDTask *	PDTaskRef
typedef PDTaskResult(*	PDTaskFunc) (PDPipeRef pipe, PDTaskRef task, PDObjectRef object, void *info)

Enumerations
enum	PDFType {   PDFTypePage = 1, PDFTypePages, PDFTypeCatalog, PDFTypeAnnot,   PDFTypeFont, PDFTypeFontDescriptor, PDFTypeAction, _PDFTypeCount }
enum	PDPropertyType {   PDPropertyObjectId = 1, PDPropertyRootObject, PDPropertyInfoObject, PDPropertyPDFType,   PDPropertyPage }
enum	PDTaskResult { PDTaskFailure = -1, PDTaskDone = 0, PDTaskSkipRest = 1, PDTaskUnload = 2 }

Creating and manipulating filters
PDTaskRef	PDTaskCreateFilter (PDPropertyType propertyType)
PDTaskRef	PDTaskCreateFilterWithValue (PDPropertyType propertyType, PDInteger value)
PDTaskRef	PDTaskCreateMutator (PDTaskFunc mutatorFunc)
void	PDTaskAppendTask (PDTaskRef parentTask, PDTaskRef childTask)
void	PDTaskSetInfo (PDTaskRef task, void *info)
PDTaskResult	PDTaskExec (PDTaskRef task, PDPipeRef pipe, PDObjectRef object)

Convenience functions
PDTaskRef	PDTaskCreateMutatorForObject (long objectID, PDTaskFunc mutatorFunc)
PDTaskRef	PDTaskCreateMutatorForPropertyType (PDPropertyType propertyType, PDTaskFunc mutatorFunc)
PDTaskRef	PDTaskCreateMutatorForPropertyTypeWithValue (PDPropertyType propertyType, PDInteger value, PDTaskFunc mutatorFunc)

Detailed Description

A Pajdeg pipe task.

Typedef Documentation

typedef PDTaskResult(* PDTaskFunc) (PDPipeRef pipe, PDTaskRef task, PDObjectRef object, void *info)

Function signature for task callbacks.

typedef struct PDTask* PDTaskRef

A task.

Enumeration Type Documentation

enum PDFType

PDF object types.

Note

If this is modified, typeHash in PDPipe.c must be updated accordingly.

Enumerator
PDFTypePage	all page objects
PDFTypePages	all pages objects; pages objects are dictionaries with arrays of page objects (the "Kids")
PDFTypeCatalog	all catalog objects; normally, the Root object is the only catalog in a PDF
PDFTypeAnnot	all annotation objects, such as links
PDFTypeFont	font objects
PDFTypeFontDescriptor	font descriptor objects
PDFTypeAction	action objects; usually associated with a link annotation
_PDFTypeCount	enum item count

enum PDPropertyType

Task filter property type.

Enumerator
PDPropertyObjectId	value = object ID; only called for the live object, even if multiple copies exist
PDPropertyRootObject	triggered when root object is encountered
PDPropertyInfoObject	triggered when info object is encountered
PDPropertyPDFType	triggered for each object of the given PDFType value
PDPropertyPage	value = page number

enum PDTaskResult

Task result type.

Tasks are chained together. When triggered, the first task in the list of tasks for the specific state is executed. Before moving on to the next task in the list, each task has a number of options specified in the task result.

• A task has the option of canceling the entire PDF creation process due to some serious issue, via PDTaskFailure.
• It may also `filter' out its child tasks dynamically by returning PDTaskSkipRest for given conditions. This will stop the iterator, and any tasks remaining in the queue will be skipped.

Returning PDTaskDone means the task ended normally, and that the next task, if any, may execute. This is usually the preferred return value.

Enumerator
PDTaskFailure	the entire pipe operation is terminated and the destination file is left unfinished
PDTaskDone	the task ended as normal
PDTaskSkipRest	the task ended, and requires that remaining tasks in its pipeline are skipped
PDTaskUnload	the task ended as normal; additionally, it should never be called again

Function Documentation

void PDTaskAppendTask	(	PDTaskRef	parentTask,
		PDTaskRef	childTask
	)

Append a child task to a task. Child tasks are executed after their parent tasks, unless the parent decides to stop the chain. The child is appended to the end, as one would intuitively expect. Adding child A, followed by adding child B, to parent P, will result in the execution order

P -> A -> B

PDTaskRef PDTaskCreateFilter

(

PDPropertyType

propertyType

)

Create a filtering task. Filtering tasks find objects in a pipe based on given criteria and forward these to their child tasks.

PDTaskRef PDTaskCreateFilterWithValue	(	PDPropertyType	propertyType,
		PDInteger	value
	)

Create a filtering task with the given argument.

PDTaskRef PDTaskCreateMutator

(

PDTaskFunc

mutatorFunc

)

Create a mutator task. Mutator tasks receive objects from the pipe if their parent tasks pass them through. A mutator task can be a filter, if it uses PDTaskSkipRest to abort for objects that should be skipped.

PDTaskRef PDTaskCreateMutatorForObject	(	long	objectID,
		PDTaskFunc	mutatorFunc
	)

Create a mutator for the given object ID.

PDTaskRef PDTaskCreateMutatorForPropertyType	(	PDPropertyType	propertyType,
		PDTaskFunc	mutatorFunc
	)

Create a mutator for the given (value-less) property type.

PDTaskRef PDTaskCreateMutatorForPropertyTypeWithValue	(	PDPropertyType	propertyType,
		PDInteger	value,
		PDTaskFunc	mutatorFunc
	)

Create a mutator for the given property type with the given value.

PDTaskResult PDTaskExec	(	PDTaskRef	task,
		PDPipeRef	pipe,
		PDObjectRef	object
	)

Execute a task, possibly resulting in a chain of tasks executing if the task has children.

void PDTaskSetInfo	(	PDTaskRef	task,
		void *	info
	)

Set the info object for a task.

The info object is passed as is to the task upon execution.

Parameters

task	The task.
info	The info object.