001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2007, 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 * DialBackground.java
029 * -------------------
030 * (C) Copyright 2006, 2007, 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 * 16-Oct-2007 : The equals() method needs to call super.equals() (DG);
039 * 
040 */
041
042package org.jfree.chart.plot.dial;
043
044import java.awt.Color;
045import java.awt.GradientPaint;
046import java.awt.Graphics2D;
047import java.awt.Paint;
048import java.awt.geom.Rectangle2D;
049import java.io.IOException;
050import java.io.ObjectInputStream;
051import java.io.ObjectOutputStream;
052import java.io.Serializable;
053
054import org.jfree.chart.HashUtilities;
055import org.jfree.io.SerialUtilities;
056import org.jfree.ui.GradientPaintTransformer;
057import org.jfree.ui.StandardGradientPaintTransformer;
058import org.jfree.util.PaintUtilities;
059import org.jfree.util.PublicCloneable;
060
061/**
062 * A regular dial layer that can be used to draw the background for a dial.
063 */
064public class DialBackground extends AbstractDialLayer implements DialLayer, 
065        Cloneable, PublicCloneable, Serializable {
066    
067    /** For serialization. */
068    static final long serialVersionUID = -9019069533317612375L;
069
070    /** 
071     * The background paint.  This field is transient because serialization
072     * requires special handling.
073     */
074    private transient Paint paint;
075    
076    /** 
077     * The transformer used when the background paint is an instance of
078     * <code>GradientPaint</code>. 
079     */
080    private GradientPaintTransformer gradientPaintTransformer;
081    
082    /** 
083     * Creates a new instance of <code>DialBackground</code>.  The 
084     * default background paint is <code>Color.white</code>.
085     */
086    public DialBackground() {
087        this(Color.white);
088    }
089    
090    /**
091     * Creates a new instance of <code>DialBackground</code>.  The 
092     *
093     * @param paint  the paint (<code>null</code> not permitted).
094     *
095     * @throws IllegalArgumentException if <code>paint</code> is 
096     *     <code>null</code>.
097     */
098    public DialBackground(Paint paint) {
099        if (paint == null) {
100            throw new IllegalArgumentException("Null 'paint' argument.");
101        }
102        this.paint = paint;
103        this.gradientPaintTransformer = new StandardGradientPaintTransformer();
104    }
105    
106    /**
107     * Returns the paint used to fill the background. 
108     *
109     * @return The paint (never <code>null</code>).
110     *
111     * @see #setPaint(Paint)
112     */
113    public Paint getPaint() {
114        return this.paint;
115    }
116    
117    /**
118     * Sets the paint for the dial background and sends a 
119     * {@link DialLayerChangeEvent} to all registered listeners.
120     *
121     * @param paint  the paint (<code>null</code> not permitted).
122     *
123     * @see #getPaint()
124     */
125    public void setPaint(Paint paint) {
126        if (paint == null) {
127            throw new IllegalArgumentException("Null 'paint' argument.");
128        }
129        this.paint = paint;
130        notifyListeners(new DialLayerChangeEvent(this));
131    }
132    
133    /**
134     * Returns the transformer used to adjust the coordinates of any 
135     * <code>GradientPaint</code> instance used for the background paint.
136     *
137     * @return The transformer (never <code>null</code>).
138     *
139     * @see #setGradientPaintTransformer(GradientPaintTransformer)
140     */
141    public GradientPaintTransformer getGradientPaintTransformer() {
142        return this.gradientPaintTransformer;
143    }
144    
145    /**
146     * Sets the transformer used to adjust the coordinates of any
147     * <code>GradientPaint</code> instance used for the background paint, and
148     * sends a {@link DialLayerChangeEvent} to all registered listeners.
149     *
150     * @param t  the transformer (<code>null</code> not permitted).
151     *
152     * @see #getGradientPaintTransformer()
153     */
154    public void setGradientPaintTransformer(GradientPaintTransformer t) {
155        if (t == null) {
156            throw new IllegalArgumentException("Null 't' argument.");
157        }
158        this.gradientPaintTransformer = t;
159        notifyListeners(new DialLayerChangeEvent(this));
160    }
161    
162    /**
163     * Returns <code>true</code> to indicate that this layer should be 
164     * clipped within the dial window. 
165     *
166     * @return <code>true</code>.
167     */
168    public boolean isClippedToWindow() {
169        return true;
170    }
171    
172    /**
173     * Draws the background to the specified graphics device.  If the dial
174     * frame specifies a window, the clipping region will already have been 
175     * set to this window before this method is called.
176     *
177     * @param g2  the graphics device (<code>null</code> not permitted).
178     * @param plot  the plot (ignored here).
179     * @param frame  the dial frame (ignored here).
180     * @param view  the view rectangle (<code>null</code> not permitted). 
181     */
182    public void draw(Graphics2D g2, DialPlot plot, Rectangle2D frame, 
183            Rectangle2D view) {
184
185        Paint p = this.paint;
186        if (p instanceof GradientPaint) {
187            p = this.gradientPaintTransformer.transform((GradientPaint) p, 
188                    view);
189        }
190        g2.setPaint(p);
191        g2.fill(view);
192    }
193    
194    /**
195     * Tests this instance for equality with an arbitrary object.
196     *
197     * @param obj  the object (<code>null</code> permitted).
198     *
199     * @return A boolean.
200     */
201    public boolean equals(Object obj) {
202        if (obj == this) {
203            return true;
204        }
205        if (!(obj instanceof DialBackground)) {
206            return false;
207        }
208        DialBackground that = (DialBackground) obj;
209        if (!PaintUtilities.equal(this.paint, that.paint)) {
210            return false;
211        }
212        if (!this.gradientPaintTransformer.equals(
213                that.gradientPaintTransformer)) {
214            return false;
215        }
216        return super.equals(obj);
217    }
218    
219    /**
220     * Returns a hash code for this instance.
221     * 
222     * @return The hash code.
223     */
224    public int hashCode() {
225        int result = 193;
226        result = 37 * result + HashUtilities.hashCodeForPaint(this.paint);
227        result = 37 * result + this.gradientPaintTransformer.hashCode();
228        return result;
229    }
230    
231    /**
232     * Returns a clone of this instance.
233     *
234     * @return The clone.
235     *
236     * @throws CloneNotSupportedException if some attribute of this instance
237     *     cannot be cloned.
238     */
239    public Object clone() throws CloneNotSupportedException {
240        return super.clone();
241    }
242    
243    /**
244     * Provides serialization support.
245     *
246     * @param stream  the output stream.
247     *
248     * @throws IOException  if there is an I/O error.
249     */
250    private void writeObject(ObjectOutputStream stream) throws IOException {
251        stream.defaultWriteObject();
252        SerialUtilities.writePaint(this.paint, stream);
253    }
254
255    /**
256     * Provides serialization support.
257     *
258     * @param stream  the input stream.
259     *
260     * @throws IOException  if there is an I/O error.
261     * @throws ClassNotFoundException  if there is a classpath problem.
262     */
263    private void readObject(ObjectInputStream stream) 
264            throws IOException, ClassNotFoundException {
265        stream.defaultReadObject();
266        this.paint = SerialUtilities.readPaint(stream);
267    }
268    
269}