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 * DialBackground.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 * 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 *
064 * @since 1.0.7
065 */
066public class DialBackground extends AbstractDialLayer implements DialLayer,
067        Cloneable, PublicCloneable, Serializable {
068
069    /** For serialization. */
070    static final long serialVersionUID = -9019069533317612375L;
071
072    /**
073     * The background paint.  This field is transient because serialization
074     * requires special handling.
075     */
076    private transient Paint paint;
077
078    /**
079     * The transformer used when the background paint is an instance of
080     * <code>GradientPaint</code>.
081     */
082    private GradientPaintTransformer gradientPaintTransformer;
083
084    /**
085     * Creates a new instance of <code>DialBackground</code>.  The
086     * default background paint is <code>Color.white</code>.
087     */
088    public DialBackground() {
089        this(Color.white);
090    }
091
092    /**
093     * Creates a new instance of <code>DialBackground</code>.  The
094     *
095     * @param paint  the paint (<code>null</code> not permitted).
096     *
097     * @throws IllegalArgumentException if <code>paint</code> is
098     *     <code>null</code>.
099     */
100    public DialBackground(Paint paint) {
101        if (paint == null) {
102            throw new IllegalArgumentException("Null 'paint' argument.");
103        }
104        this.paint = paint;
105        this.gradientPaintTransformer = new StandardGradientPaintTransformer();
106    }
107
108    /**
109     * Returns the paint used to fill the background.
110     *
111     * @return The paint (never <code>null</code>).
112     *
113     * @see #setPaint(Paint)
114     */
115    public Paint getPaint() {
116        return this.paint;
117    }
118
119    /**
120     * Sets the paint for the dial background and sends a
121     * {@link DialLayerChangeEvent} to all registered listeners.
122     *
123     * @param paint  the paint (<code>null</code> not permitted).
124     *
125     * @see #getPaint()
126     */
127    public void setPaint(Paint paint) {
128        if (paint == null) {
129            throw new IllegalArgumentException("Null 'paint' argument.");
130        }
131        this.paint = paint;
132        notifyListeners(new DialLayerChangeEvent(this));
133    }
134
135    /**
136     * Returns the transformer used to adjust the coordinates of any
137     * <code>GradientPaint</code> instance used for the background paint.
138     *
139     * @return The transformer (never <code>null</code>).
140     *
141     * @see #setGradientPaintTransformer(GradientPaintTransformer)
142     */
143    public GradientPaintTransformer getGradientPaintTransformer() {
144        return this.gradientPaintTransformer;
145    }
146
147    /**
148     * Sets the transformer used to adjust the coordinates of any
149     * <code>GradientPaint</code> instance used for the background paint, and
150     * sends a {@link DialLayerChangeEvent} to all registered listeners.
151     *
152     * @param t  the transformer (<code>null</code> not permitted).
153     *
154     * @see #getGradientPaintTransformer()
155     */
156    public void setGradientPaintTransformer(GradientPaintTransformer t) {
157        if (t == null) {
158            throw new IllegalArgumentException("Null 't' argument.");
159        }
160        this.gradientPaintTransformer = t;
161        notifyListeners(new DialLayerChangeEvent(this));
162    }
163
164    /**
165     * Returns <code>true</code> to indicate that this layer should be
166     * clipped within the dial window.
167     *
168     * @return <code>true</code>.
169     */
170    public boolean isClippedToWindow() {
171        return true;
172    }
173
174    /**
175     * Draws the background to the specified graphics device.  If the dial
176     * frame specifies a window, the clipping region will already have been
177     * set to this window before this method is called.
178     *
179     * @param g2  the graphics device (<code>null</code> not permitted).
180     * @param plot  the plot (ignored here).
181     * @param frame  the dial frame (ignored here).
182     * @param view  the view rectangle (<code>null</code> not permitted).
183     */
184    public void draw(Graphics2D g2, DialPlot plot, Rectangle2D frame,
185            Rectangle2D view) {
186
187        Paint p = this.paint;
188        if (p instanceof GradientPaint) {
189            p = this.gradientPaintTransformer.transform((GradientPaint) p,
190                    view);
191        }
192        g2.setPaint(p);
193        g2.fill(view);
194    }
195
196    /**
197     * Tests this instance for equality with an arbitrary object.
198     *
199     * @param obj  the object (<code>null</code> permitted).
200     *
201     * @return A boolean.
202     */
203    public boolean equals(Object obj) {
204        if (obj == this) {
205            return true;
206        }
207        if (!(obj instanceof DialBackground)) {
208            return false;
209        }
210        DialBackground that = (DialBackground) obj;
211        if (!PaintUtilities.equal(this.paint, that.paint)) {
212            return false;
213        }
214        if (!this.gradientPaintTransformer.equals(
215                that.gradientPaintTransformer)) {
216            return false;
217        }
218        return super.equals(obj);
219    }
220
221    /**
222     * Returns a hash code for this instance.
223     *
224     * @return The hash code.
225     */
226    public int hashCode() {
227        int result = 193;
228        result = 37 * result + HashUtilities.hashCodeForPaint(this.paint);
229        result = 37 * result + this.gradientPaintTransformer.hashCode();
230        return result;
231    }
232
233    /**
234     * Returns a clone of this instance.
235     *
236     * @return The clone.
237     *
238     * @throws CloneNotSupportedException if some attribute of this instance
239     *     cannot be cloned.
240     */
241    public Object clone() throws CloneNotSupportedException {
242        return super.clone();
243    }
244
245    /**
246     * Provides serialization support.
247     *
248     * @param stream  the output stream.
249     *
250     * @throws IOException  if there is an I/O error.
251     */
252    private void writeObject(ObjectOutputStream stream) throws IOException {
253        stream.defaultWriteObject();
254        SerialUtilities.writePaint(this.paint, stream);
255    }
256
257    /**
258     * Provides serialization support.
259     *
260     * @param stream  the input stream.
261     *
262     * @throws IOException  if there is an I/O error.
263     * @throws ClassNotFoundException  if there is a classpath problem.
264     */
265    private void readObject(ObjectInputStream stream)
266            throws IOException, ClassNotFoundException {
267        stream.defaultReadObject();
268        this.paint = SerialUtilities.readPaint(stream);
269    }
270
271}