An image descriptor is an object that knows how to create an SWT image. It does not hold onto images or cache them, but rather just creates them on demand. An image descriptor is intended to be a lightweight representation of an image that can be manipulated even when no SWT display exists.
This package defines a concrete image descriptor implementation which reads an image from a file (
FileImageDescriptor). It also provides abstract framework classes (this one and
CompositeImageDescriptor) which may be subclassed to define news kinds of image descriptors.
Using this abstract class involves defining a concrete subclass and providing an implementation for the
There are two ways to get an Image from an ImageDescriptor. The method createImage will always return a new Image which must be disposed by the caller. Alternatively, createResource() returns a shared Image. When the caller is done with an image obtained from createResource, they must call destroyResource() rather than disposing the Image directly. The result of createResource() can be safely cast to an Image.