javax.faces.render.RenderKit Maven / Gradle / Ivy
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/*
* Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package javax.faces.render;
import javax.faces.component.UIComponent;
import javax.faces.context.ResponseWriter;
import javax.faces.context.ResponseStream;
import java.io.Writer;
import java.io.OutputStream;
import java.util.Iterator;
import java.util.Collections;
import java.util.Set;
/**
* RenderKit
* represents a collection of {@link Renderer} instances that, together,
* know how to render JavaServer Faces {@link UIComponent} instances for
* a specific client. Typically, {@link RenderKit}s are specialized for
* some combination of client device type, markup language, and/or user
* Locale. A {@link RenderKit} also acts as a Factory for
* associated {@link Renderer} instances, which perform the actual
* rendering process for each component.
*
* A typical JavaServer Faces implementation will configure one or
* more {@link RenderKit} instances at web application startup. They
* are made available through calls to the getRenderKit()
* methods of {@link RenderKitFactory}. Because {@link RenderKit}
* instances are shared, they must be implemented in a thread-safe
* manner. Due to limitations in the current specification having
* multiple RenderKit instances at play in the same
* application requires a custom {@link
* javax.faces.application.ViewHandler} instance that is aware of how to
* deal with this case. This limitation will be lifted in a future
* version of the spec.
*
* The RenderKit instance must also vend a {@link
* ResponseStateManager} instance, which is used in the process of
* saving and restoring tree structure and state.
*/
public abstract class RenderKit {
/**
* Register the specified {@link Renderer} instance, associated with the
* specified component family and rendererType,
* to the set of {@link Renderer}s registered with this {@link RenderKit},
* replacing any previously registered {@link Renderer} for this
* combination of identifiers.
*
* @param family Component family of the {@link Renderer} to register
* @param rendererType Renderer type of the {@link Renderer} to register
* @param renderer {@link Renderer} instance we are registering
*
* @throws NullPointerException if family or
* rendererType or renderer is null
*/
public abstract void addRenderer(String family, String rendererType,
Renderer renderer);
/**
* Return the {@link Renderer} instance most recently registered for
* the specified component family and
* rendererType, if any; otherwise, return
* null.
*
* @param family Component family of the requested
* {@link Renderer} instance
* @param rendererType Renderer type of the requested
* {@link Renderer} instance
*
* @throws NullPointerException if family or
* rendererType is null
*
* @return the {@link Renderer} instance
*/
public abstract Renderer getRenderer(String family, String rendererType);
/**
* Return an instance of {@link ResponseStateManager} to handle
* rendering technology specific state management decisions.
*
* @return the {@link ResponseStateManager}
*/
public abstract ResponseStateManager getResponseStateManager();
/**
* Use the provided Writer to create a new {@link
* ResponseWriter} instance for the specified (optional) content
* type, and character encoding.
*
* Implementors are advised to consult the
* getCharacterEncoding() method of class {@link
* javax.servlet.ServletResponse} to get the required value for the
* characterEncoding for this method. Since the Writer
* for this response will already have been obtained (due to it
* ultimately being passed to this method), we know that the
* character encoding cannot change during the rendering of the
* response.
*
* @param writer the Writer around which this {@link ResponseWriter}
* must be built.
*
* @param contentTypeList an "Accept header style" list of content
* types for this response, or null if the RenderKit
* should choose the best fit. As of the current version, the
* values accepted by the Standard render-kit for this parameter
* include any valid "Accept header style" String that includes the
* String text/html,
* application/xhtml+xml, application/xml
* or text/xml. This may change in a future version.
* The RenderKit must support a value for this argument that comes
* straight from the Accept HTTP header, and therefore
* requires parsing according to the specification of the
* Accept header. Please see Section
* 14.1 of RFC 2616 for the specification of the
* Accept header.
*
* @param characterEncoding such as "ISO-8859-1" for this
* ResponseWriter, or null if the
* RenderKit should choose the best fit. Please see the
* IANA for a list of character encodings.
*
* @return a new {@link ResponseWriter}.
*
* @throws IllegalArgumentException if no matching content type
* can be found in contentTypeList, no appropriate
* content type can be found with the implementation dependent best
* fit algorithm, or no matching character encoding can be found for
* the argument characterEncoding.
*
*/
public abstract ResponseWriter createResponseWriter(Writer writer,
String contentTypeList,
String characterEncoding);
/**
* Use the provided OutputStream to create a new
* {@link ResponseStream} instance.
*
* @param out the {@code OutputStream} around which to create the
* {@link ResponseStream}
*
* @return the new {@link ResponseStream}
*
*/
public abstract ResponseStream createResponseStream(OutputStream out);
/**
* Return an Iterator over
* the component-family entries supported by this
* RenderKit instance.
*
*
* The default implementation of this method returns an empty
* Iterator
*
*
* @since 2.0
*
* @return Return an Iterator over
* the component-family entries
*
*/
public Iterator getComponentFamilies() {
Set empty = Collections.emptySet();
return empty.iterator();
}
/**
* Return an Iterator over
* the renderer-type entries for the given component-family.
*
* If the specified componentFamily
* is not known to this RenderKit implementation, return
* an empty Iterator
*
*
* The default implementation of this method returns an empty
* Iterator
*
*
* @param componentFamily one of the members of the
* Iterator returned by {@link #getComponentFamilies}.
*
* @since 2.0
*
* @return an Iterator over the renderer-type
*
*/
public Iterator getRendererTypes(String componentFamily) {
Set empty = Collections.emptySet();
return empty.iterator();
}
/**
* Register the specified {@link ClientBehaviorRenderer} instance,
* associated with the specified component type,
* to the set of {@link ClientBehaviorRenderer}s registered with this
* {@link RenderKit}, replacing any previously registered
* {@link ClientBehaviorRenderer} for this type.
*
* @param type type of the {@link ClientBehaviorRenderer} to register
* @param renderer {@link ClientBehaviorRenderer} instance we are registering
*
* @throws NullPointerException if type or
* renderer is null
*
* @since 2.0
*/
public void addClientBehaviorRenderer(String type, ClientBehaviorRenderer renderer) {
throw new UnsupportedOperationException("The default implementation must override this method");
}
/**
* Return the {@link ClientBehaviorRenderer} instance most recently
* registered for the specified type, if any;
* otherwise, return null.
*
* @param type type of the requested
* {@link ClientBehaviorRenderer} instance
*
* @throws NullPointerException if type
* is null
*
* @since 2.0
*
* @return the {@link ClientBehaviorRenderer} instance
*/
public ClientBehaviorRenderer getClientBehaviorRenderer(String type) {
throw new UnsupportedOperationException("The default implementation must override this method");
}
/**
* Return an Iterator over
* the {@link ClientBehaviorRenderer} types.
*
* @since 2.0
*
* @return an Iterator over
* the {@link ClientBehaviorRenderer}
*/
public Iterator getClientBehaviorRendererTypes() {
throw new UnsupportedOperationException("The default implementation must override this method");
}
}