Source code

001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-present, 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 java.util.Objects;
043import org.jfree.chart.HashUtils;
044import org.jfree.chart.ui.Size2D;
045import org.jfree.chart.ui.TextAnchor;
046import org.jfree.chart.util.PaintUtils;
047import org.jfree.chart.util.SerialUtils;
048
049/**
050 * A text item, with an associated font, that fits on a single line (see 
051 * {@link TextLine}).  Instances of the class are immutable.
052 */
053public class TextFragment implements Serializable {
054
055    /** For serialization. */
056    private static final long serialVersionUID = 4465945952903143262L;
057    
058    /** The default font. */
059    public static final Font DEFAULT_FONT = new Font("Serif", Font.PLAIN, 12);
060    
061    /** The default text color. */
062    public static final Paint DEFAULT_PAINT = Color.BLACK;
063    
064    /** The text. */
065    private String text;
066    
067    /** The font. */
068    private Font font;
069    
070    /** The text color. */
071    private transient Paint paint;
072    
073    /** 
074     * The baseline offset (can be used to simulate subscripts and 
075     * superscripts). 
076     */
077    private float baselineOffset;
078    
079    /**
080     * Creates a new text fragment.
081     * 
082     * @param text  the text ({@code null} not permitted).
083     */
084    public TextFragment(String text) {
085        this(text, DEFAULT_FONT, DEFAULT_PAINT);
086    }
087    
088    /**
089     * Creates a new text fragment.
090     * 
091     * @param text  the text ({@code null} not permitted).
092     * @param font  the font ({@code null} not permitted).
093     */
094    public TextFragment(String text, Font font) {
095        this(text, font, DEFAULT_PAINT);
096    }
097
098    /**
099     * Creates a new text fragment.
100     * 
101     * @param text  the text ({@code null} not permitted).
102     * @param font  the font ({@code null} not permitted).
103     * @param paint  the text color ({@code null} not permitted).
104     */
105    public TextFragment(String text, Font font, Paint paint) {
106        this(text, font, paint, 0.0f);
107    }
108
109    /**
110     * Creates a new text fragment.
111     * 
112     * @param text  the text ({@code null} not permitted).
113     * @param font  the font ({@code null} not permitted).
114     * @param paint  the text color ({@code null} not permitted).
115     * @param baselineOffset  the baseline offset.
116     */
117    public TextFragment(String text, Font font, Paint paint,
118            float baselineOffset) {
119        if (text == null) {
120            throw new IllegalArgumentException("Null 'text' argument.");  
121        }
122        if (font == null) {
123            throw new IllegalArgumentException("Null 'font' argument.");
124        }
125        if (paint == null) {
126            throw new IllegalArgumentException("Null 'paint' argument.");
127        }
128        this.text = text;
129        this.font = font;
130        this.paint = paint;
131        this.baselineOffset = baselineOffset;
132    }
133
134    /**
135     * Returns the text.
136     * 
137     * @return The text (possibly {@code null}).
138     */
139    public String getText() {
140        return this.text;
141    }
142    
143    /**
144     * Returns the font.
145     * 
146     * @return The font (never {@code null}).
147     */
148    public Font getFont() {
149        return this.font;
150    }
151    
152    /**
153     * Returns the text paint.
154     * 
155     * @return The text paint (never {@code null}).
156     */
157    public Paint getPaint() {
158        return this.paint;
159    }
160    
161    /**
162     * Returns the baseline offset.
163     * 
164     * @return The baseline offset.
165     */
166    public float getBaselineOffset() {
167        return this.baselineOffset;   
168    }
169    
170    /**
171     * Draws the text fragment.
172     * 
173     * @param g2  the graphics device.
174     * @param anchorX  the x-coordinate of the anchor point.
175     * @param anchorY  the y-coordinate of the anchor point.
176     * @param anchor  the location of the text that is aligned to the anchor 
177     *                point.
178     * @param rotateX  the x-coordinate of the rotation point.
179     * @param rotateY  the y-coordinate of the rotation point.
180     * @param angle  the angle.
181     */
182    public void draw(Graphics2D g2, float anchorX, float anchorY, 
183            TextAnchor anchor, float rotateX, float rotateY, double angle) {
184        g2.setFont(this.font);
185        g2.setPaint(this.paint);
186        TextUtils.drawRotatedString(this.text, g2, anchorX, anchorY 
187                + this.baselineOffset, anchor, angle, rotateX, rotateY);
188    }
189    
190    /**
191     * Calculates the dimensions of the text fragment.
192     * 
193     * @param g2  the graphics device.
194     * 
195     * @return The width and height of the text.
196     */
197    public Size2D calculateDimensions(Graphics2D g2) {
198        FontMetrics fm = g2.getFontMetrics(this.font);
199        Rectangle2D bounds = TextUtils.getTextBounds(this.text, g2, fm);
200        Size2D result = new Size2D(bounds.getWidth(), bounds.getHeight());
201        return result;
202    }
203    
204    /**
205     * Calculates the vertical offset between the baseline and the specified 
206     * text anchor.
207     * 
208     * @param g2  the graphics device.
209     * @param anchor  the anchor.
210     * 
211     * @return the offset.
212     */
213    public float calculateBaselineOffset(Graphics2D g2, TextAnchor anchor) {
214        float result = 0.0f;
215        FontMetrics fm = g2.getFontMetrics(this.font);
216        LineMetrics lm = fm.getLineMetrics("ABCxyz", g2);
217        if (anchor.isTop()) {
218            result = lm.getAscent();
219        }
220        else if (anchor.isHalfAscent()) {
221            result = lm.getAscent() / 2.0f;
222        }
223        else if (anchor.isVerticalCenter()) {
224            result = lm.getAscent() / 2.0f - lm.getDescent() / 2.0f;
225        }
226        else if (anchor.isBottom()) {
227            result = -lm.getDescent() - lm.getLeading();
228        }
229        return result;                                             
230    }
231    
232    /**
233     * Tests this instance for equality with an arbitrary object.
234     * 
235     * @param obj  the object to test against ({@code null} permitted).
236     * 
237     * @return A boolean.
238     */
239    @Override
240    public boolean equals(Object obj) {
241        if (obj == this)
242        {
243            return true;
244        }
245        if (!(obj instanceof TextFragment)) {
246            return false;
247        }
248        TextFragment tf = (TextFragment) obj;
249        if (!Objects.equals(this.text, tf.text)) {
250            return false;
251        }
252        if (!Objects.equals(this.font, tf.font)) {
253            return false;
254        }
255        if (!PaintUtils.equal(this.paint, tf.paint)) {
256            return false;
257        }
258        if (Float.floatToIntBits(this.baselineOffset) != 
259            Float.floatToIntBits(tf.baselineOffset)) {
260            return false;
261        }
262        return true;
263    }
264
265
266    /**
267     * Returns a hash code for this object.
268     * 
269     * @return A hash code.
270     */
271    @Override
272    public int hashCode() {
273        int hash = 7;
274        hash = 83 * hash + Objects.hashCode(this.text);
275        hash = 83 * hash + Objects.hashCode(this.font);
276        hash = 83 * hash + HashUtils.hashCodeForPaint(this.paint);
277        hash = 83 * hash + Float.floatToIntBits(this.baselineOffset);
278        return hash;
279    }
280
281    /**
282     * Provides serialization support.
283     *
284     * @param stream  the output stream.
285     *
286     * @throws IOException  if there is an I/O error.
287     */
288    private void writeObject(ObjectOutputStream stream) throws IOException {
289        stream.defaultWriteObject();
290        SerialUtils.writePaint(this.paint, stream);
291    }
292
293    /**
294     * Provides serialization support.
295     *
296     * @param stream  the input stream.
297     *
298     * @throws IOException  if there is an I/O error.
299     * @throws ClassNotFoundException  if there is a classpath problem.
300     */
301    private void readObject(ObjectInputStream stream) throws IOException, 
302            ClassNotFoundException {
303        stream.defaultReadObject();
304        this.paint = SerialUtils.readPaint(stream);
305    }
306   
307}
308