com.communote.server.core.image

Class ImageProviderManager

java.lang.Object

com.communote.server.core.image.ImageProviderManager

public class ImageProviderManager
extends Object

Manages image types and image providers for these types. Some built-in types and providers are added automatically during initialization.

Author:

Communote GmbH - http://www.communote.com/

Constructor Summary

Constructors

Constructor and Description
ImageProviderManager() Constructor

Method Summary

Modifier and Type	Method and Description
ImageProvider	getBuiltInProvider(String imageTypeName) Return a built-in provider for the given image type.
List<ImageProvider>	getProviders(String imageTypeName) Return the image providers that can handle the given image type
ImageTypeDescriptor	getTypeDescriptor(String imageTypeName)
void	registerProvider(String imageTypeName, ImageProvider provider) Register a provider which can load images for the given image type.
boolean	registerTypeDescriptor(ImageTypeDescriptor imageType) Register an image type.
void	unregisterProvider(String imageTypeName, ImageProvider provider) Remove a provider that was added for a given image type.
boolean	unregisterTypeDescriptor(ImageTypeDescriptor imageType) Remove a previously registered image type.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ImageProviderManager

public ImageProviderManager()

Constructor

Method Detail

getBuiltInProvider

public ImageProvider getBuiltInProvider(String imageTypeName)

Return a built-in provider for the given image type.

Parameters:

imageTypeName - the name of the image type

Returns:

the provider or null if there is no built-in provider for that type

getProviders

public List<ImageProvider> getProviders(String imageTypeName)

Return the image providers that can handle the given image type

Parameters:

imageTypeName - the name of the image type

Returns:

the providers or null if the type does not exist

getTypeDescriptor

public ImageTypeDescriptor getTypeDescriptor(String imageTypeName)

registerProvider

public void registerProvider(String imageTypeName,
                             ImageProvider provider)
                      throws ImageProviderManagerException,
                             ImageTypeNotFoundException

Register a provider which can load images for the given image type. There can be several providers for a type.

Parameters:

imageTypeName - the name of the type which must have been registered before.

provider - the provider to add

Throws:

ImageProviderManagerException - in case there is already a provider with the same identifier

ImageTypeNotFoundException - in case the image type does not exist

registerTypeDescriptor

public boolean registerTypeDescriptor(ImageTypeDescriptor imageType)
                               throws IllegalArgumentException

Register an image type. If there is already a type with the same name the new one will be an overlay for the existing, that is, it will become the active descriptor for that type. The existing descriptor will become the active one as soon as the overlay is unregistered. Such an overlay is for instance useful for changing the supported image sizes. After adding a type, providers for that type can be registered.

Parameters:

imageType - the descriptor of the type

Returns:

true if there was already a descriptor with the same name and the new type was added as an overlay

Throws:

IllegalArgumentException - in case the type has no name

unregisterProvider

public void unregisterProvider(String imageTypeName,
                               ImageProvider provider)
                        throws ImageProviderManagerException

Remove a provider that was added for a given image type. If the type or the provider do not exist the call is ignored.

Parameters:

imageTypeName - the name of the type

provider - the provider to remove

Throws:

ImageProviderManagerException - in case the provider to remove is built-in provider

unregisterTypeDescriptor

public boolean unregisterTypeDescriptor(ImageTypeDescriptor imageType)

Remove a previously registered image type. If there are several types with the same name and the type to remove is the active one the next type which was registered before this type will become the active one.
Providers will not be removed by this method, even if there are no more types with the same name. However, a call to getProviders(String) with the name of the removed type will return null.
If the type to remove does not exist the call is ignored.

Parameters:

imageType - the type to remove

Returns:

true if an active overlay was removed, false otherwise