001/* An attribute that specifies a color.
002
003 Copyright (c) 2003-2014 The Regents of the University of California.
004 All rights reserved.
005 Permission is hereby granted, without written agreement and without
006 license or royalty fees, to use, copy, modify, and distribute this
007 software and its documentation for any purpose, provided that the above
008 copyright notice and the following two paragraphs appear in all copies
009 of this software.
010
011 IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
012 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
013 ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
014 THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
015 SUCH DAMAGE.
016
017 THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
018 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
019 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
020 PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
021 CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
022 ENHANCEMENTS, OR MODIFICATIONS.
023
024 PT_COPYRIGHT_VERSION_2
025 COPYRIGHTENDKEY
026
027 */
028package ptolemy.actor.gui;
029
030import java.awt.Color;
031
032import ptolemy.data.ArrayToken;
033import ptolemy.data.DoubleToken;
034import ptolemy.data.expr.Parameter;
035import ptolemy.data.type.ArrayType;
036import ptolemy.data.type.BaseType;
037import ptolemy.kernel.util.IllegalActionException;
038import ptolemy.kernel.util.NameDuplicationException;
039import ptolemy.kernel.util.NamedObj;
040
041///////////////////////////////////////////////////////////////////
042//// ColorAttribute
043
044/**
045 This is an attribute that specifies a color.  The value of this
046 attribute is an array of four doubles in the form
047 {red, green, blue, alpha}, where each number is the range of 0.0
048 to 1.0.  The 'alpha' term represents opacity, where 1.0 is opaque,
049 and 0.0 is fully transparent (invisible).
050
051 @author Edward A. Lee
052 @version $Id$
053 @since Ptolemy II 4.0
054 @Pt.ProposedRating Yellow (eal)
055 @Pt.AcceptedRating Red (cxh)
056 */
057public class ColorAttribute extends Parameter {
058
059    /** Construct an attribute with the given name.
060     *  If the name argument is null, then the name is set to the empty
061     *  string. Increment the version of the workspace.
062     *  @param name The name of this attribute.
063     *  @exception IllegalActionException If the name contains a period.
064     *  @exception NameDuplicationException If the name coincides with
065     *   an attribute already in the container.
066     */
067    public ColorAttribute(String name)
068            throws IllegalActionException, NameDuplicationException {
069        super();
070        setTypeEquals(new ArrayType(BaseType.DOUBLE));
071    }
072
073    /** Construct an attribute with the given name contained by the
074     *  specified container. The container argument must not be null, or a
075     *  NullPointerException will be thrown.  This attribute will use the
076     *  workspace of the container for synchronization and version counts.
077     *  If the name argument is null, then the name is set to the empty
078     *  string. Increment the version of the workspace.
079     *  @param container The container.
080     *  @param name The name of this attribute.
081     *  @exception IllegalActionException If the attribute is not of an
082     *   acceptable class for the container, or if the name contains a period.
083     *  @exception NameDuplicationException If the name coincides with
084     *   an attribute already in the container.
085     */
086    public ColorAttribute(NamedObj container, String name)
087            throws IllegalActionException, NameDuplicationException {
088        super(container, name);
089        setTypeEquals(new ArrayType(BaseType.DOUBLE));
090    }
091
092    ///////////////////////////////////////////////////////////////////
093    ////                         public methods                    ////
094
095    /** Return the color as a Color object.
096     *  @return The color as a Color object.
097     */
098    public Color asColor() {
099        // NOTE: This also has to be handled by Query.java.
100        try {
101            ArrayToken spec = (ArrayToken) getToken();
102            int length = 0;
103
104            if (spec != null) {
105                length = spec.length();
106            }
107
108            // Default values allow us to tolerate incomplement specs.
109            float red = 0f;
110            float green = 0f;
111            float blue = 0f;
112            float alpha = 1.0f;
113
114            if (length > 0) {
115                red = (float) ((DoubleToken) spec.getElement(0)).doubleValue();
116            }
117
118            if (length > 1) {
119                green = (float) ((DoubleToken) spec.getElement(1))
120                        .doubleValue();
121            }
122
123            if (length > 2) {
124                blue = (float) ((DoubleToken) spec.getElement(2)).doubleValue();
125            }
126
127            if (length > 3) {
128                alpha = (float) ((DoubleToken) spec.getElement(3))
129                        .doubleValue();
130            }
131
132            return new Color(red, green, blue, alpha);
133        } catch (IllegalActionException ex) {
134            // getToken() failed for some reason.
135            return Color.black;
136        }
137    }
138}