001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
006 *
007 * Project Info: http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
022 * USA.
023 *
024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025 * in the United States and other countries.]
026 *
027 * --------------
028 * DialLayer.java
029 * --------------
030 * (C) Copyright 2006-2008, by Object Refinery Limited.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * Changes
036 * -------
037 * 03-Nov-2006 : Version 1 (DG);
038 *
039 */
040
041 package org.jfree.chart.plot.dial;
042
043 import java.awt.Graphics2D;
044 import java.awt.geom.Rectangle2D;
045 import java.io.Serializable;
046 import java.util.EventListener;
047
048 /**
049 * A dial layer draws itself within a reference frame. The view frame is a
050 * subset of the reference frame, and defines the area that is actually
051 * visible.
052 * <br><br>
053 * Classes that implement this interface should be {@link Serializable},
054 * otherwise chart serialization may fail.
055 *
056 * @since 1.0.7
057 */
058 public interface DialLayer {
059
060 /**
061 * Returns a flag that indicates whether or not the layer is visible.
062 *
063 * @return A boolean.
064 */
065 public boolean isVisible();
066
067 /**
068 * Registers a listener with this layer, so that it receives notification
069 * of changes to this layer.
070 *
071 * @param listener the listener.
072 */
073 public void addChangeListener(DialLayerChangeListener listener);
074
075 /**
076 * Deregisters a listener, so that it no longer receives notification of
077 * changes to this layer.
078 *
079 * @param listener the listener.
080 */
081 public void removeChangeListener(DialLayerChangeListener listener);
082
083 /**
084 * Returns <code>true</code> if the specified listener is currently
085 * registered with the this layer.
086 *
087 * @param listener the listener.
088 *
089 * @return A boolean.
090 */
091 public boolean hasListener(EventListener listener);
092
093 /**
094 * Returns <code>true</code> if the drawing should be clipped to the
095 * dial window (which is defined by the {@link DialFrame}), and
096 * <code>false</code> otherwise.
097 *
098 * @return A boolean.
099 */
100 public boolean isClippedToWindow();
101
102 /**
103 * Draws the content of this layer.
104 *
105 * @param g2 the graphics target (<code>null</code> not permitted).
106 * @param plot the plot (typically this should not be <code>null</code>,
107 * but for a layer that doesn't need to reference the plot, it may
108 * be permitted).
109 * @param frame the reference frame for the dial's geometry
110 * (<code>null</code> not permitted). This is typically larger than
111 * the visible area of the dial (see the next parameter).
112 * @param view the visible area for the dial (<code>null</code> not
113 * permitted).
114 */
115 public void draw(Graphics2D g2, DialPlot plot, Rectangle2D frame,
116 Rectangle2D view);
117
118 }