001/* ImageGraphicAttribute.java
002   Copyright (C) 2003 Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package java.awt.font;
040
041import java.awt.Graphics2D;
042import java.awt.Image;
043import java.awt.geom.Rectangle2D;
044
045/**
046 * This is an implementation of GraphicAttribute which draws images in a
047 * TextLayout.
048 * 
049 * @author Lillian Angel
050 * @author Michael Koch
051 */
052public final class ImageGraphicAttribute
053    extends GraphicAttribute
054{
055  private Image image;
056  private float originX;
057  private float originY;
058
059  /**
060   * Constucts an instance from the specified Image. The origin is at (0, 0).
061   * 
062   * @param image - image to construct from.
063   * @param alignment - the alignment
064   */
065  public ImageGraphicAttribute(Image image, int alignment)
066  {
067    this(image, alignment, 0, 0);
068  }
069
070  /**
071   * Constucts an instance from the specified Image. The origin is at (originX,
072   * originY).
073   * 
074   * @param image - image to construct from
075   * @param alignment - the alignment
076   * @param originX - x point of origin
077   * @param originY - y point of origin
078   */
079  public ImageGraphicAttribute(Image image, int alignment, float originX,
080                               float originY)
081  {
082    super(alignment);
083    this.image = image;
084    this.originX = originX;
085    this.originY = originY;
086  }
087
088  /**
089   * Draws the image at the specified location, relative to the
090   * origin.
091   * 
092   * @param g - the graphics to use to render the image
093   * @param x - the x location
094   * @param y - the y location 
095   */
096  public void draw(Graphics2D g, float x, float y)
097  {
098    g.drawImage(image, (int) (x - originX), (int) (y - originY), null);
099  }
100
101  /**
102   * Compares this to the specified Object
103   * 
104   * @param obj - the object to compare
105   * @return true if the obj and this are equivalent
106   */
107  public boolean equals(Object obj)
108  {
109    if (! (obj instanceof ImageGraphicAttribute))
110      return false;
111
112    return equals((ImageGraphicAttribute) obj);
113  }
114
115  /**
116   * Compares this to the ImageGraphicAttribute given, by
117   * comparing all fields and values.
118   * 
119   * @param rhs - the ImageGraphicAttribute to compare
120   * @return true if the object given is equivalent to this
121   */
122  public boolean equals(ImageGraphicAttribute rhs)
123  {
124    return ((this == rhs) || ((this.getAscent() == rhs.getAscent())
125                              && (this.getAdvance() == rhs.getAdvance())
126                              && (this.getAlignment() == rhs.getAlignment())
127                              && (this.getBounds().equals(rhs.getBounds()))
128                              && (this.getDescent() == rhs.getDescent())
129                              && (this.hashCode() == rhs.hashCode())
130                              && (this.image.equals(rhs.image))
131                              && (this.originX == rhs.originX) 
132                              && (this.originY == rhs.originY)));
133  }
134
135  /**
136   * Returns distance from the origin to the right edge of the image of this.
137   * 
138   * @return the advance
139   */
140  public float getAdvance()
141  {
142    return Math.max(0, image.getWidth(null) - originX);
143  }
144
145  /**
146   * Returns the the distance from the top of the image to the origin of this.
147   * 
148   * @return the ascent.
149   */
150  public float getAscent()
151  {
152    return Math.max(0, originY);
153  }
154
155  /**
156   * Gets the bounds of the object rendered, relative to the position.
157   * 
158   * @return the bounds of the object rendered, relative to the position.
159   */
160  public Rectangle2D getBounds()
161  {
162    // This is equivalent to what Sun's JDK returns.
163    // I am not entirely sure why the origin is negative.
164    return new Rectangle2D.Float(- originX, - originY, image.getWidth(null),
165                                 image.getHeight(null));
166  }
167
168  /**
169   * Returns the distance from the origin to the bottom of the image.
170   * 
171   * @return the descent
172   */
173  public float getDescent()
174  {
175    return Math.max(0, image.getHeight(null) - originY);
176  }
177
178  /**
179   * Gets the hash code for this image.
180   * 
181   * @return the hash code
182   */
183  public int hashCode()
184  {
185    return image.hashCode();
186  }
187}