001: /*
002: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
003: *
004: * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
005: *
006: * The contents of this file are subject to the terms of either the GNU
007: * General Public License Version 2 only ("GPL") or the Common
008: * Development and Distribution License("CDDL") (collectively, the
009: * "License"). You may not use this file except in compliance with the
010: * License. You can obtain a copy of the License at
011: * http://www.netbeans.org/cddl-gplv2.html
012: * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
013: * specific language governing permissions and limitations under the
014: * License. When distributing the software, include this License Header
015: * Notice in each file and include the License file at
016: * nbbuild/licenses/CDDL-GPL-2-CP. Sun designates this
017: * particular file as subject to the "Classpath" exception as provided
018: * by Sun in the GPL Version 2 section of the License file that
019: * accompanied this code. If applicable, add the following below the
020: * License Header, with the fields enclosed by brackets [] replaced by
021: * your own identifying information:
022: * "Portions Copyrighted [year] [name of copyright owner]"
023: *
024: * Contributor(s):
025: *
026: * The Original Software is NetBeans. The Initial Developer of the Original
027: * Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
028: * Microsystems, Inc. All Rights Reserved.
029: *
030: * If you wish your version of this file to be governed by only the CDDL
031: * or only the GPL Version 2, indicate your decision by adding
032: * "[Contributor] elects to include this software in this distribution
033: * under the [CDDL or GPL Version 2] license." If you do not indicate a
034: * single choice of license, a recipient has the option to distribute
035: * your version of this file under either the CDDL, the GPL Version 2 or
036: * to extend the choice of license to its licensees as provided above.
037: * However, if you add GPL Version 2 code and therefore, elected the GPL
038: * Version 2 license, then the option applies only if the new code is
039: * made subject to such option by the copyright holder.
040: */
041:
042: package org.netbeans.spi.project.support.ant;
043:
044: import java.beans.PropertyChangeListener;
045: import java.util.Map;
046:
047: /**
048: * A way of mapping property names to values.
049: * <p>
050: * This interface defines no independent thread safety, but in typical usage
051: * it will be used with the project manager mutex. Changes should be fired
052: * synchronously.
053: * @author Jesse Glick
054: * @see PropertyUtils#sequentialPropertyEvaluator
055: * @see AntProjectHelper#getStandardPropertyEvaluator
056: */
057: public interface PropertyEvaluator {
058:
059: /**
060: * Evaluate a single property.
061: * @param prop the name of a property
062: * @return its value, or null if it is not defined or its value could not be
063: * retrieved for some reason (e.g. a circular definition)
064: */
065: String getProperty(String prop);
066:
067: /**
068: * Evaluate a block of text possibly containing property references.
069: * The syntax is the same as for Ant: <samp>${foo}</samp> means the value
070: * of the property <samp>foo</samp>; <samp>$$</samp> is an escape for
071: * <samp>$</samp>; references to undefined properties are left unsubstituted.
072: * @param text some text possibly containing one or more property references
073: * @return its value, or null if some problem (such a circular definition) made
074: * it impossible to retrieve the values of some properties
075: */
076: String evaluate(String text);
077:
078: /**
079: * Get a set of all current property definitions at once.
080: * This may be more efficient than evaluating individual properties,
081: * depending on the implementation.
082: * @return an immutable map from property names to values, or null if the
083: * mapping could not be computed (e.g. due to a circular definition)
084: */
085: Map<String, String> getProperties();
086:
087: /**
088: * Add a listener to changes in particular property values.
089: * As generally true with property change listeners, the old and new
090: * values may both be null in case the true values are not known or not
091: * easily computed; and the property name might be null to signal that any
092: * property might have changed.
093: * @param listener a listener to add
094: */
095: void addPropertyChangeListener(PropertyChangeListener listener);
096:
097: /**
098: * Remove a listener to changes in particular property values.
099: * @param listener a listener to remove
100: */
101: void removePropertyChangeListener(PropertyChangeListener listener);
102:
103: }
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