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.components;
016    
017    import org.apache.tapestry.IComponent;
018    import org.apache.tapestry.IMarkupWriter;
019    import org.apache.tapestry.IRequestCycle;
020    import org.apache.tapestry.engine.ILink;
021    
022    /**
023     *  A component that renders an HTML <a> element.  It exposes some
024     *  properties to the components it wraps.  This is basically to facilitate
025     *  the {@link org.apache.tapestry.html.Rollover} component.
026     *
027     *  @author Howard Lewis Ship
028     * 
029     **/
030    
031    public interface ILinkComponent extends IComponent
032    {
033    
034        /**
035         *  Returns whether this service link component is enabled or disabled.
036         *
037         *  @since 0.2.9
038         *
039         **/
040    
041        public boolean isDisabled();
042    
043        /**
044         *  Returns the anchor defined for this link, or null for no anchor.
045         * 
046         *  @since 3.0
047         * 
048         **/
049    
050        public String getAnchor();
051    
052        /**
053         * Returns the name of the target window or frame for this link,
054         * or null if current window or frame is to be used.
055         * 
056         * @since 4.0
057         */
058        public String getTarget();
059        
060        /**
061         *  Adds a new event handler.  When the event occurs, the JavaScript function
062         *  specified is executed.  Multiple functions can be specified, in which case
063         *  all of them are executed.
064         *
065         *  <p>This was created for use by
066         *  {@link org.apache.tapestry.html.Rollover} to set mouse over and mouse out handlers on
067         *  the {@link ILinkComponent} that wraps it, but can be used for
068         *  many other things as well.
069         *
070         *  @since 0.2.9
071         **/
072    
073        public void addEventHandler(LinkEventType type, String functionName);
074    
075        /**
076         *  Invoked by the {@link org.apache.tapestry.link.ILinkRenderer} (if
077         *  the link is not disabled) to provide a
078         *  {@link org.apache.tapestry.engine.EngineServiceLink} that the renderer can convert
079         *  into a URL.
080         * 
081         **/
082    
083        public ILink getLink(IRequestCycle cycle);
084    
085        /**
086         *  Invoked (by the {@link org.apache.tapestry.link.ILinkRenderer})
087         *  to make the link render any additional attributes.  These
088         *  are informal parameters, plus any attributes related to events.
089         *  This is only invoked for non-disabled links.
090         * 
091         *  @since 3.0
092         * 
093         **/
094    
095        public void renderAdditionalAttributes(IMarkupWriter writer, IRequestCycle cycle);
096    }