001    /* ========================================================================
002     * JCommon : a free general purpose class 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/jcommon/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     * TextFragment.java
029     * -----------------
030     * (C) Copyright 2003-2007, by Object Refinery Limited and Contributors.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * $Id: TextFragment.java,v 1.13 2007/03/16 10:25:58 mungady Exp $
036     *
037     * Changes
038     * -------
039     * 07-Nov-2003 : Version 1 (DG);
040     * 25-Nov-2003 : Fixed bug in the dimension calculation (DG);
041     * 22-Dec-2003 : Added workaround for Java bug 4245442 (DG);
042     * 29-Jan-2004 : Added paint attribute (DG);
043     * 22-Mar-2004 : Added equals() method and implemented Serializable (DG);
044     * 01-Apr-2004 : Changed java.awt.geom.Dimension2D to org.jfree.ui.Size2D 
045     *               because of JDK bug 4976448 which persists on JDK 1.3.1 (DG);
046     * 30-Sep-2004 : Moved drawRotatedString() from RefineryUtilities 
047     *               --> TextUtilities (DG);
048     * 16-Mar-2007 : Fixed serialization for GradientPaint (DG);
049     *
050     */
051     
052    package org.jfree.text;
053    
054    import java.awt.Color;
055    import java.awt.Font;
056    import java.awt.FontMetrics;
057    import java.awt.Graphics2D;
058    import java.awt.Paint;
059    import java.awt.font.LineMetrics;
060    import java.awt.geom.Rectangle2D;
061    import java.io.IOException;
062    import java.io.ObjectInputStream;
063    import java.io.ObjectOutputStream;
064    import java.io.Serializable;
065    
066    import org.jfree.io.SerialUtilities;
067    import org.jfree.ui.Size2D;
068    import org.jfree.ui.TextAnchor;
069    import org.jfree.util.Log;
070    import org.jfree.util.LogContext;
071    
072    /**
073     * A text item, with an associated font, that fits on a single line (see 
074     * {@link TextLine}).  Instances of the class are immutable.
075     */
076    public class TextFragment implements Serializable {
077    
078        /** For serialization. */
079        private static final long serialVersionUID = 4465945952903143262L;
080        
081        /** The default font. */
082        public static final Font DEFAULT_FONT = new Font("Serif", Font.PLAIN, 12);
083        
084        /** The default text color. */
085        public static final Paint DEFAULT_PAINT = Color.black;
086        
087        /** The text. */
088        private String text;
089        
090        /** The font. */
091        private Font font;
092        
093        /** The text color. */
094        private transient Paint paint;
095        
096        /** 
097         * The baseline offset (can be used to simulate subscripts and 
098         * superscripts). 
099         */
100        private float baselineOffset;
101        
102        /** Access to logging facilities. */
103        protected static final LogContext logger = Log.createContext(
104                TextFragment.class);
105        
106        /**
107         * Creates a new text fragment.
108         * 
109         * @param text  the text (<code>null</code> not permitted).
110         */
111        public TextFragment(final String text) {
112            this(text, DEFAULT_FONT, DEFAULT_PAINT);
113        }
114        
115        /**
116         * Creates a new text fragment.
117         * 
118         * @param text  the text (<code>null</code> not permitted).
119         * @param font  the font (<code>null</code> not permitted).
120         */
121        public TextFragment(final String text, final Font font) {
122            this(text, font, DEFAULT_PAINT);
123        }
124    
125        /**
126         * Creates a new text fragment.
127         * 
128         * @param text  the text (<code>null</code> not permitted).
129         * @param font  the font (<code>null</code> not permitted).
130         * @param paint  the text color (<code>null</code> not permitted).
131         */
132        public TextFragment(final String text, final Font font, final Paint paint) {
133            this(text, font, paint, 0.0f);
134        }
135    
136        /**
137         * Creates a new text fragment.
138         * 
139         * @param text  the text (<code>null</code> not permitted).
140         * @param font  the font (<code>null</code> not permitted).
141         * @param paint  the text color (<code>null</code> not permitted).
142         * @param baselineOffset  the baseline offset.
143         */
144        public TextFragment(final String text, final Font font, final Paint paint,
145                            final float baselineOffset) {
146            if (text == null) {
147                throw new IllegalArgumentException("Null 'text' argument.");  
148            }
149            if (font == null) {
150                throw new IllegalArgumentException("Null 'font' argument.");
151            }
152            if (paint == null) {
153                throw new IllegalArgumentException("Null 'paint' argument.");
154            }
155            this.text = text;
156            this.font = font;
157            this.paint = paint;
158            this.baselineOffset = baselineOffset;
159        }
160    
161        /**
162         * Returns the text.
163         * 
164         * @return The text (possibly <code>null</code>).
165         */
166        public String getText() {
167            return this.text;
168        }
169        
170        /**
171         * Returns the font.
172         * 
173         * @return The font (never <code>null</code>).
174         */
175        public Font getFont() {
176            return this.font;
177        }
178        
179        /**
180         * Returns the text paint.
181         * 
182         * @return The text paint (never <code>null</code>).
183         */
184        public Paint getPaint() {
185            return this.paint;
186        }
187        
188        /**
189         * Returns the baseline offset.
190         * 
191         * @return The baseline offset.
192         */
193        public float getBaselineOffset() {
194            return this.baselineOffset;   
195        }
196        
197        /**
198         * Draws the text fragment.
199         * 
200         * @param g2  the graphics device.
201         * @param anchorX  the x-coordinate of the anchor point.
202         * @param anchorY  the y-coordinate of the anchor point.
203         * @param anchor  the location of the text that is aligned to the anchor 
204         *                point.
205         * @param rotateX  the x-coordinate of the rotation point.
206         * @param rotateY  the y-coordinate of the rotation point.
207         * @param angle  the angle.
208         */
209        public void draw(final Graphics2D g2, final float anchorX, 
210                         final float anchorY, final TextAnchor anchor,
211                         final float rotateX, final float rotateY, 
212                         final double angle) {
213        
214            g2.setFont(this.font);
215            g2.setPaint(this.paint);
216            TextUtilities.drawRotatedString(this.text, g2, anchorX, anchorY 
217                    + this.baselineOffset, anchor, angle, rotateX, rotateY);
218        
219        }
220        
221        /**
222         * Calculates the dimensions of the text fragment.
223         * 
224         * @param g2  the graphics device.
225         * 
226         * @return The width and height of the text.
227         */
228        public Size2D calculateDimensions(final Graphics2D g2) {
229            final FontMetrics fm = g2.getFontMetrics(this.font);
230            final Rectangle2D bounds = TextUtilities.getTextBounds(this.text, g2, 
231                    fm);
232            final Size2D result = new Size2D(bounds.getWidth(), bounds.getHeight());
233            return result;
234        }
235        
236        /**
237         * Calculates the vertical offset between the baseline and the specified 
238         * text anchor.
239         * 
240         * @param g2  the graphics device.
241         * @param anchor  the anchor.
242         * 
243         * @return the offset.
244         */
245        public float calculateBaselineOffset(final Graphics2D g2, 
246                                             final TextAnchor anchor) {
247            float result = 0.0f;
248            final FontMetrics fm = g2.getFontMetrics(this.font);
249            final LineMetrics lm = fm.getLineMetrics("ABCxyz", g2);
250            if (anchor == TextAnchor.TOP_LEFT || anchor == TextAnchor.TOP_CENTER
251                                              || anchor == TextAnchor.TOP_RIGHT) {
252                result = lm.getAscent();
253            }
254            else if (anchor == TextAnchor.BOTTOM_LEFT 
255                    || anchor == TextAnchor.BOTTOM_CENTER
256                    || anchor == TextAnchor.BOTTOM_RIGHT) {
257                result = -lm.getDescent() - lm.getLeading();
258            }
259            return result;                                             
260        }
261        
262        /**
263         * Tests this instance for equality with an arbitrary object.
264         * 
265         * @param obj  the object to test against (<code>null</code> permitted).
266         * 
267         * @return A boolean.
268         */
269        public boolean equals(final Object obj) {
270            if (obj == null) {
271                return false;   
272            }
273            if (obj == this) {
274                return true;   
275            }
276            if (obj instanceof TextFragment) {
277                final TextFragment tf = (TextFragment) obj;
278                if (!this.text.equals(tf.text)) {
279                    return false;   
280                }
281                if (!this.font.equals(tf.font)) {
282                    return false;   
283                }
284                if (!this.paint.equals(tf.paint)) {
285                    return false;   
286                }
287                return true;
288            }
289            return false;
290        }
291    
292        /**
293         * Returns a hash code for this object.
294         * 
295         * @return A hash code.
296         */
297        public int hashCode() {
298            int result;
299            result = (this.text != null ? this.text.hashCode() : 0);
300            result = 29 * result + (this.font != null ? this.font.hashCode() : 0);
301            result = 29 * result + (this.paint != null ? this.paint.hashCode() : 0);
302            return result;
303        }
304    
305        /**
306         * Provides serialization support.
307         *
308         * @param stream  the output stream.
309         *
310         * @throws IOException  if there is an I/O error.
311         */
312        private void writeObject(final ObjectOutputStream stream) 
313            throws IOException {
314            stream.defaultWriteObject();
315            SerialUtilities.writePaint(this.paint, stream);
316        }
317    
318        /**
319         * Provides serialization support.
320         *
321         * @param stream  the input stream.
322         *
323         * @throws IOException  if there is an I/O error.
324         * @throws ClassNotFoundException  if there is a classpath problem.
325         */
326        private void readObject(final ObjectInputStream stream) 
327            throws IOException, ClassNotFoundException {
328            stream.defaultReadObject();
329            this.paint = SerialUtilities.readPaint(stream);
330        }
331       
332    }