001// Copyright 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 015package org.apache.tapestry.describe; 016 017import org.apache.tapestry.IMarkupWriter; 018import org.apache.tapestry.event.ReportStatusListener; 019 020/** 021 * Service for collecting together status information across the framework; service implementations 022 * implement the {@link org.apache.tapestry.event.ReportStatusListener} interface and register 023 * themselves as listeners here. When desired, the {@link #fireReportStatus(IMarkupWriter)} event 024 * will invoke the listener method on each registered object. 025 * 026 * @author Howard M. Lewis Ship 027 * @since 4.0 028 */ 029public interface ReportStatusHub 030{ 031 /** 032 * Adds the listener; listeners will be invoked in the order in which they are added. 033 * <strong>Note: only service implementation that are singletons should be report status 034 * listeners. Threaded or pooled implementations should not be added; or should be careful to 035 * add and remove themselves from the hub directly.</strong> 036 * 037 * @param listener 038 */ 039 public void addReportStatusListener(ReportStatusListener listener); 040 041 public void removeReportStatusListener(ReportStatusListener listener); 042 043 /** 044 * Generates an HTML status report by invoking 045 * {@link ReportStatusListener#reportStatus(ReportStatusEvent)} on each registered listener. 046 * 047 * @param writer 048 * a markup writer to send the report to. 049 */ 050 public void fireReportStatus(IMarkupWriter writer); 051}