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.wml;
016    
017    import org.apache.hivemind.HiveMind;
018    import org.apache.tapestry.AbstractComponent;
019    import org.apache.tapestry.IMarkupWriter;
020    import org.apache.tapestry.IRequestCycle;
021    
022    /**
023     * The Timer element declares a card timer, which exposes a means of processing
024     * inactivity or idle time. The timer is initialised and started at card entry
025     * and is stopped when the card is exited.
026     * 
027     * @author David Solis
028     * @since 3.0
029     */
030    
031    public abstract class Timer extends AbstractComponent
032    {
033    
034        /**
035         * @see AbstractComponent#renderComponent(IMarkupWriter, IRequestCycle)
036         */
037    
038        protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
039        {
040            boolean render = !cycle.isRewinding();
041    
042            if (render)
043            {
044                writer.beginEmpty("timer");
045    
046                writer.attribute("name", getName());
047    
048                String value = getValue();
049                if (HiveMind.isNonBlank(value))
050                    writer.attribute("value", value);
051                else writer.attribute("value", "0");
052    
053                renderInformalParameters(writer, cycle);
054    
055                writer.closeTag();
056            }
057        }
058    
059        public abstract String getName();
060    
061        /** @since 4.0 */
062    
063        public abstract String getValue();
064    }