Class DeviceResourceDescriptor

  • Direct Known Subclasses:
    ColorDescriptor, FontDescriptor, ImageDescriptor

    public abstract class DeviceResourceDescriptor
    extends Object
    Instances of this class can allocate and dispose SWT resources. Each instance describes a particular resource (such as a Color, Font, or Image) and can create and destroy that resource on demand. DeviceResourceDescriptors are managed by a ResourceRegistry.

    Note: It is recommended that subclasses implement #equals and #hashCode, so that clients, like decoration managers, can recognize when they have two equal descriptors at hand, e.g. decorating an identical object.

    Since:
    3.1
    See Also:
    ResourceManager
    • Constructor Detail

      • DeviceResourceDescriptor

        public DeviceResourceDescriptor()
    • Method Detail

      • createResource

        public abstract Object createResource​(Device device)
        Creates the resource described by this descriptor
        Parameters:
        device - the Device on which to allocate the resource
        Returns:
        the newly allocated resource (not null)
        Throws:
        DeviceResourceException - if unable to allocate the resource
        Since:
        3.1
      • destroyResource

        public abstract void destroyResource​(Object previouslyCreatedObject)
        Undoes everything that was done by a previous call to create(...), given the object that was returned by create(...).
        Parameters:
        previouslyCreatedObject - an object that was returned by an equal descriptor in a previous call to createResource(...).
        Since:
        3.1