001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.link;
016    
017    import org.apache.tapestry.IMarkupWriter;
018    import org.apache.tapestry.IRequestCycle;
019    import org.apache.tapestry.components.ILinkComponent;
020    
021    /**
022     *  Used by various instances of {@link org.apache.tapestry.components.ILinkComponent} to
023     *  actually renderer a link.  Implementations of the interface can manipulate
024     *  some of the details of how the link is written.
025     * 
026     *  <p>
027     *  A link rendered may be used in many threads, and must be threadsafe.
028     *
029     *  @author Howard Lewis Ship
030     *  @since 3.0
031     * 
032     **/
033    
034    public interface ILinkRenderer
035    {
036        /**
037         *  Renders the link, taking into account whether the link is
038         *  {@link org.apache.tapestry.components.ILinkComponent#isDisabled() disabled}.
039         *  This is complicated by the fact that the rendering of the body must be done
040         *  within a nested writer, since the Link component will not render its tag
041         *  until after its body renders (to allow for any wrapped components that need
042         *  to write event handlers for the link).
043         * 
044         *  <p>
045         *  The renderer is expected to call back into the link component to handle
046         *  any informal parameters, and to handle events output.
047         * 
048         * 
049         **/
050    
051        void renderLink(IMarkupWriter writer, IRequestCycle cycle, ILinkComponent linkComponent);
052    
053    }