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 the
025 * {@link org.apache.tapestry.html.Rollover} component.
026 *
027 * @author Howard Lewis Ship
028 */
029
030 public interface ILinkComponent extends IComponent
031 {
032
033 /**
034 * Returns the desired scheme (i.e., "http" or "https") for the link, or
035 * null to not output a specific scheme (in which case the URL will fall
036 * under the incoming request's scheme).
037 *
038 * @since 4.0
039 */
040
041 String getScheme();
042
043 /**
044 * Returns the desired port (i.e., "80" or "443") for the link, or null to
045 * not output a specific port (in which case the URL will fall under the
046 * incoming request's port).
047 *
048 * @since 4.1
049 */
050
051 Integer getPort();
052
053 /**
054 * Returns whether this service link component is enabled or disabled.
055 *
056 * @since 0.2.9
057 */
058
059 boolean isDisabled();
060
061 /**
062 * Returns the anchor defined for this link, or null for no anchor.
063 *
064 * @since 3.0
065 */
066
067 String getAnchor();
068
069 /**
070 * Returns the name of the target window or frame for this link, or null if
071 * current window or frame is to be used.
072 *
073 * @since 4.0
074 */
075 String getTarget();
076
077 /**
078 * Adds a new event handler. When the event occurs, the JavaScript function
079 * specified is executed. Multiple functions can be specified, in which case
080 * all of them are executed.
081 * <p>
082 * This was created for use by {@link org.apache.tapestry.html.Rollover} to
083 * set mouse over and mouse out handlers on the {@link ILinkComponent} that
084 * wraps it, but can be used for many other things as well.
085 *
086 * @since 0.2.9
087 */
088
089 void addEventHandler(LinkEventType type, String functionName);
090
091 /**
092 * Invoked by the {@link org.apache.tapestry.link.ILinkRenderer} (if the
093 * link is not disabled) to provide a
094 * {@link org.apache.tapestry.engine.EngineServiceLink} that the renderer
095 * can convert into a URL.
096 */
097
098 ILink getLink(IRequestCycle cycle);
099
100 /**
101 * Invoked (by the {@link org.apache.tapestry.link.ILinkRenderer}) to make
102 * the link render any additional attributes. These are informal parameters,
103 * plus any attributes related to events. This is only invoked for
104 * non-disabled links.
105 *
106 * @since 3.0
107 */
108
109 void renderAdditionalAttributes(IMarkupWriter writer,
110 IRequestCycle cycle);
111 }