Class

QCComposition

The QCComposition class represents a Quartz Composer composition that either:

Declaration

@interface QCComposition : NSObject

Overview

  • comes from the system-wide composition repository (/Library/Compositions and ~/Library/Compositions) where it can be accessed by any application through the methods of the QCCompositionRepository class

  • is created from an arbitrary source (typically a file on disk) using one of its methods

This class cannot be subclassed.

A QCComposition object has the following information associated with it and that you can obtain by using the appropriate method of the QCComposition class:

  • Attributes include the name and description of the composition, copyright information, and whether or not its provided by macOS (built-in).

  • The protocols that the composition conforms to. A composition protocol defines a set of required and optional input parameters and output results.

Many methods of the QCRenderer, QCCompositionLayer, and QCView classes take a QCComposition object as a parameter.

Topics

Creating a Composition

+ compositionWithFile:

Returns a composition object initialized with a Quartz Composer composition file.

+ compositionWithData:

Returns a composition object initialized with the contents of a Quartz Composer composition file.

Getting Information About a Composition

- attributes

Returns the attributes of the composition.

- protocols

Returns the list of protocols to which the composition conforms.

- identifier

Returns the unique and persistent identifier for the composition from the composition repository.

Getting Port Keys

- inputKeys

Returns an array listing the keys that identify the input ports of the root patch of the composition.

- outputKeys

Returns an array listing the keys that identify the output ports of the root patch of the composition.

Constants

Attribute Keys

Attributes of a composition.

Composition Categories

Categories for compositions.

Standard Protocol Input Keys

Input ports of a composition.

Standard Protocol Output Keys

Output ports of a composition.

Standard Protocols

Protocols for a composition.

Relationships

Inherits From

Conforms To