1 /* ===========================================================
2  * JFreeChart : a free chart library for the Java(tm) platform
3  * ===========================================================
4  *
5  * (C) Copyright 2000-2013, by Object Refinery Limited and Contributors.
6  *
7  * Project Info:  http://www.jfree.org/jfreechart/index.html
8  *
9  * This library is free software; you can redistribute it and/or modify it
10  * under the terms of the GNU Lesser General Public License as published by
11  * the Free Software Foundation; either version 2.1 of the License, or
12  * (at your option) any later version.
13  *
14  * This library is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
16  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
17  * License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with this library; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
22  * USA.
23  *
24  * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
25  * Other names may be trademarks of their respective owners.]
26  *
27  * --------------
28  * DialLayer.java
29  * --------------
30  * (C) Copyright 2006-2008, by Object Refinery Limited.
31  *
32  * Original Author:  David Gilbert (for Object Refinery Limited);
33  * Contributor(s):   -;
34  *
35  * Changes
36  * -------
37  * 03-Nov-2006 : Version 1 (DG);
38  *
39  */
40 
41 package org.jfree.chart.plot.dial;
42 
43 import java.awt.Graphics2D;
44 import java.awt.geom.Rectangle2D;
45 import java.io.Serializable;
46 import java.util.EventListener;
47 
48 /**
49  * A dial layer draws itself within a reference frame.  The view frame is a
50  * subset of the reference frame, and defines the area that is actually
51  * visible.
52  * <br><br>
53  * Classes that implement this interface should be {@link Serializable},
54  * otherwise chart serialization may fail.
55  *
56  * @since 1.0.7
57  */
58 public interface DialLayer {
59 
60     /**
61      * Returns a flag that indicates whether or not the layer is visible.
62      *
63      * @return A boolean.
64      */
isVisible()65     public boolean isVisible();
66 
67     /**
68      * Registers a listener with this layer, so that it receives notification
69      * of changes to this layer.
70      *
71      * @param listener  the listener.
72      */
addChangeListener(DialLayerChangeListener listener)73     public void addChangeListener(DialLayerChangeListener listener);
74 
75     /**
76      * Deregisters a listener, so that it no longer receives notification of
77      * changes to this layer.
78      *
79      * @param listener  the listener.
80      */
removeChangeListener(DialLayerChangeListener listener)81     public void removeChangeListener(DialLayerChangeListener listener);
82 
83     /**
84      * Returns <code>true</code> if the specified listener is currently
85      * registered with the this layer.
86      *
87      * @param listener  the listener.
88      *
89      * @return A boolean.
90      */
hasListener(EventListener listener)91     public boolean hasListener(EventListener listener);
92 
93     /**
94      * Returns <code>true</code> if the drawing should be clipped to the
95      * dial window (which is defined by the {@link DialFrame}), and
96      * <code>false</code> otherwise.
97      *
98      * @return A boolean.
99      */
isClippedToWindow()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      */
draw(Graphics2D g2, DialPlot plot, Rectangle2D frame, Rectangle2D view)115     public void draw(Graphics2D g2, DialPlot plot, Rectangle2D frame,
116             Rectangle2D view);
117 
118 }
119