001/* IconView.java -- A view to render icons
002   Copyright (C) 2005  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 javax.swing.text;
040
041import java.awt.Graphics;
042import java.awt.Rectangle;
043import java.awt.Shape;
044
045import javax.swing.Icon;
046import javax.swing.JTextPane;
047
048/**
049 * A View that can render an icon. This view is created by the
050 * {@link StyledEditorKit}'s view factory for all elements that have name
051 * {@link StyleConstants#IconElementName}. This is usually created by
052 * inserting an icon into <code>JTextPane</code> using
053 * {@link JTextPane#insertIcon(Icon)}
054 *
055 * The icon is determined using the attribute
056 * {@link StyleConstants#IconAttribute}, which's value must be an {@link Icon}.
057 *
058 * @author Roman Kennke (kennke@aicas.com)
059 */
060public class IconView
061  extends View
062{
063
064  /**
065   * Creates a new <code>IconView</code> for the given <code>Element</code>.
066   *
067   * @param element the element that is rendered by this IconView
068   */
069  public IconView(Element element)
070  {
071    super(element);
072  }
073
074  /**
075   * Renders the <code>Element</code> that is associated with this
076   * <code>View</code>.
077   *
078   * @param g the <code>Graphics</code> context to render to
079   * @param a the allocated region for the <code>Element</code>
080   */
081  public void paint(Graphics g, Shape a)
082  {
083    Icon icon = StyleConstants.getIcon(getElement().getAttributes());
084    Rectangle b = a.getBounds();
085    icon.paintIcon(getContainer(), g, b.x, b.y);
086  }
087
088  /**
089   * Returns the preferred span of the content managed by this
090   * <code>View</code> along the specified <code>axis</code>.
091   *
092   * @param axis the axis
093   *
094   * @return the preferred span of this <code>View</code>.
095   */
096  public float getPreferredSpan(int axis)
097  {
098    Icon icon = StyleConstants.getIcon(getElement().getAttributes());
099    float span;
100    if (axis == X_AXIS)
101      span = icon.getIconWidth();
102    else if (axis == Y_AXIS)
103      span = icon.getIconHeight();
104    else
105      throw new IllegalArgumentException();
106    return span;
107  }
108
109  /**
110   * Maps a position in the document into the coordinate space of the View.
111   * The output rectangle usually reflects the font height but has a width
112   * of zero.
113   *
114   * @param pos the position of the character in the model
115   * @param a the area that is occupied by the view
116   * @param b either {@link Position.Bias#Forward} or
117   *        {@link Position.Bias#Backward} depending on the preferred
118   *        direction bias. If <code>null</code> this defaults to
119   *        <code>Position.Bias.Forward</code>
120   *
121   * @return a rectangle that gives the location of the document position
122   *         inside the view coordinate space
123   *
124   * @throws BadLocationException if <code>pos</code> is invalid
125   * @throws IllegalArgumentException if b is not one of the above listed
126   *         valid values
127   */
128  public Shape modelToView(int pos, Shape a, Position.Bias b)
129    throws BadLocationException
130  {
131    Element el = getElement();
132    Rectangle r = a.getBounds();
133    Icon icon = StyleConstants.getIcon(el.getAttributes());
134    return new Rectangle(r.x, r.y, icon.getIconWidth(), icon.getIconHeight());
135  }
136
137  /**
138   * Maps coordinates from the <code>View</code>'s space into a position
139   * in the document model.
140   *
141   * @param x the x coordinate in the view space
142   * @param y the y coordinate in the view space
143   * @param a the allocation of this <code>View</code>
144   * @param b the bias to use
145   *
146   * @return the position in the document that corresponds to the screen
147   *         coordinates <code>x, y</code>
148   */
149  public int viewToModel(float x, float y, Shape a, Position.Bias[] b)
150  {
151    // The element should only have one character position and it is clear
152    // that this position is the position that best matches the given screen
153    // coordinates, simply because this view has only this one position.
154    Element el = getElement();
155    return el.getStartOffset();
156  }
157
158  /**
159   * Returns the alignment for this view. This will be 1.0 for the Y_AXIS,
160   * and the super behaviour for the X_AXIS.
161   *
162   * @param axis the axis for which to calculate the alignment
163   *
164   * @return the alignment
165   */
166  public float getAlignment(int axis)
167  {
168    float align;
169    if (axis == Y_AXIS)
170      align = 1.0F;
171    else
172      align = super.getAlignment(axis);
173    return align;
174  }
175}