001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2022, by David Gilbert 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 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 */
028
029package org.jfree.chart.text;
030
031import java.awt.Color;
032import java.awt.Font;
033import java.awt.FontMetrics;
034import java.awt.Graphics2D;
035import java.awt.Paint;
036import java.awt.font.LineMetrics;
037import java.awt.geom.Rectangle2D;
038import java.io.IOException;
039import java.io.ObjectInputStream;
040import java.io.ObjectOutputStream;
041import java.io.Serializable;
042import org.jfree.chart.block.Size2D;
043import org.jfree.chart.internal.Args;
044import org.jfree.chart.internal.SerialUtils;
045
046/**
047 * A text item, with an associated font, that fits on a single line (see 
048 * {@link TextLine}).  Instances of the class are immutable.
049 */
050public class TextFragment implements Serializable {
051
052    /** For serialization. */
053    private static final long serialVersionUID = 4465945952903143262L;
054    
055    /** The default font. */
056    public static final Font DEFAULT_FONT = new Font("Serif", Font.PLAIN, 12);
057    
058    /** The default text color. */
059    public static final Paint DEFAULT_PAINT = Color.BLACK;
060    
061    /** The text. */
062    private String text;
063    
064    /** The font. */
065    private Font font;
066    
067    /** The text color. */
068    private transient Paint paint;
069    
070    /** 
071     * The baseline offset (can be used to simulate subscripts and 
072     * superscripts). 
073     */
074    private float baselineOffset;
075    
076    /**
077     * Creates a new text fragment.
078     * 
079     * @param text  the text ({@code null} not permitted).
080     */
081    public TextFragment(String text) {
082        this(text, DEFAULT_FONT, DEFAULT_PAINT);
083    }
084    
085    /**
086     * Creates a new text fragment.
087     * 
088     * @param text  the text ({@code null} not permitted).
089     * @param font  the font ({@code null} not permitted).
090     */
091    public TextFragment(String text, Font font) {
092        this(text, font, DEFAULT_PAINT);
093    }
094
095    /**
096     * Creates a new text fragment.
097     * 
098     * @param text  the text ({@code null} not permitted).
099     * @param font  the font ({@code null} not permitted).
100     * @param paint  the text color ({@code null} not permitted).
101     */
102    public TextFragment(String text, Font font, Paint paint) {
103        this(text, font, paint, 0.0f);
104    }
105
106    /**
107     * Creates a new text fragment.
108     * 
109     * @param text  the text ({@code null} not permitted).
110     * @param font  the font ({@code null} not permitted).
111     * @param paint  the text color ({@code null} not permitted).
112     * @param baselineOffset  the baseline offset.
113     */
114    public TextFragment(String text, Font font, Paint paint,
115            float baselineOffset) {
116        Args.nullNotPermitted(text, "text");
117        Args.nullNotPermitted(font, "font");
118        Args.nullNotPermitted(paint, "paint");
119        this.text = text;
120        this.font = font;
121        this.paint = paint;
122        this.baselineOffset = baselineOffset;
123    }
124
125    /**
126     * Returns the text.
127     * 
128     * @return The text (possibly {@code null}).
129     */
130    public String getText() {
131        return this.text;
132    }
133    
134    /**
135     * Returns the font.
136     * 
137     * @return The font (never {@code null}).
138     */
139    public Font getFont() {
140        return this.font;
141    }
142    
143    /**
144     * Returns the text paint.
145     * 
146     * @return The text paint (never {@code null}).
147     */
148    public Paint getPaint() {
149        return this.paint;
150    }
151    
152    /**
153     * Returns the baseline offset.
154     * 
155     * @return The baseline offset.
156     */
157    public float getBaselineOffset() {
158        return this.baselineOffset;   
159    }
160    
161    /**
162     * Draws the text fragment.
163     * 
164     * @param g2  the graphics device.
165     * @param anchorX  the x-coordinate of the anchor point.
166     * @param anchorY  the y-coordinate of the anchor point.
167     * @param anchor  the location of the text that is aligned to the anchor 
168     *                point.
169     * @param rotateX  the x-coordinate of the rotation point.
170     * @param rotateY  the y-coordinate of the rotation point.
171     * @param angle  the angle.
172     */
173    public void draw(Graphics2D g2, float anchorX, float anchorY, 
174            TextAnchor anchor, float rotateX, float rotateY, double angle) {
175        g2.setFont(this.font);
176        g2.setPaint(this.paint);
177        TextUtils.drawRotatedString(this.text, g2, anchorX, anchorY 
178                + this.baselineOffset, anchor, angle, rotateX, rotateY);
179    }
180    
181    /**
182     * Calculates the dimensions of the text fragment.
183     * 
184     * @param g2  the graphics device.
185     * 
186     * @return The width and height of the text.
187     */
188    public Size2D calculateDimensions(Graphics2D g2) {
189        FontMetrics fm = g2.getFontMetrics(this.font);
190        Rectangle2D bounds = TextUtils.getTextBounds(this.text, g2, fm);
191        Size2D result = new Size2D(bounds.getWidth(), bounds.getHeight());
192        return result;
193    }
194    
195    /**
196     * Calculates the vertical offset between the baseline and the specified 
197     * text anchor.
198     * 
199     * @param g2  the graphics device.
200     * @param anchor  the anchor.
201     * 
202     * @return the offset.
203     */
204    public float calculateBaselineOffset(Graphics2D g2, TextAnchor anchor) {
205        float result = 0.0f;
206        FontMetrics fm = g2.getFontMetrics(this.font);
207        LineMetrics lm = fm.getLineMetrics("ABCxyz", g2);
208        if (anchor.isTop()) {
209            result = lm.getAscent();
210        }
211        else if (anchor.isHalfAscent()) {
212            result = lm.getAscent() / 2.0f;
213        }
214        else if (anchor.isVerticalCenter()) {
215            result = lm.getAscent() / 2.0f - lm.getDescent() / 2.0f;
216        }
217        else if (anchor.isBottom()) {
218            result = -lm.getDescent() - lm.getLeading();
219        }
220        return result;                                             
221    }
222    
223    /**
224     * Tests this instance for equality with an arbitrary object.
225     * 
226     * @param obj  the object to test against ({@code null} permitted).
227     * 
228     * @return A boolean.
229     */
230    @Override
231    public boolean equals(Object obj) {
232        if (obj == null) {
233            return false;   
234        }
235        if (obj == this) {
236            return true;   
237        }
238        if (obj instanceof TextFragment) {
239            TextFragment tf = (TextFragment) obj;
240            if (!this.text.equals(tf.text)) {
241                return false;   
242            }
243            if (!this.font.equals(tf.font)) {
244                return false;   
245            }
246            if (!this.paint.equals(tf.paint)) {
247                return false;   
248            }
249            return true;
250        }
251        return false;
252    }
253
254    /**
255     * Returns a hash code for this object.
256     * 
257     * @return A hash code.
258     */
259    @Override
260    public int hashCode() {
261        int result;
262        result = (this.text != null ? this.text.hashCode() : 0);
263        result = 29 * result + (this.font != null ? this.font.hashCode() : 0);
264        result = 29 * result + (this.paint != null ? this.paint.hashCode() : 0);
265        return result;
266    }
267
268    /**
269     * Provides serialization support.
270     *
271     * @param stream  the output stream.
272     *
273     * @throws IOException  if there is an I/O error.
274     */
275    private void writeObject(ObjectOutputStream stream) throws IOException {
276        stream.defaultWriteObject();
277        SerialUtils.writePaint(this.paint, stream);
278    }
279
280    /**
281     * Provides serialization support.
282     *
283     * @param stream  the input stream.
284     *
285     * @throws IOException  if there is an I/O error.
286     * @throws ClassNotFoundException  if there is a classpath problem.
287     */
288    private void readObject(ObjectInputStream stream) throws IOException, 
289            ClassNotFoundException {
290        stream.defaultReadObject();
291        this.paint = SerialUtils.readPaint(stream);
292    }
293   
294}
295