libjava/classpath/javax/swing/text/IconView.java

   1 /* IconView.java -- A view to render icons
   2    Copyright (C) 2005  Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package javax.swing.text;
  40
  41 import java.awt.Graphics;
  42 import java.awt.Rectangle;
  43 import java.awt.Shape;
  44
  45 import javax.swing.Icon;
  46 import javax.swing.JTextPane;
  47 import javax.swing.SwingConstants;
  48
  49 /**
  50  * A View that can render an icon. This view is created by the
  51  * {@link StyledEditorKit}'s view factory for all elements that have name
  52  * {@link StyleConstants#IconElementName}. This is usually created by
  53  * inserting an icon into <code>JTextPane</code> using
  54  * {@link JTextPane#insertIcon(Icon)}
  55  *
  56  * The icon is determined using the attribute
  57  * {@link StyleConstants#IconAttribute}, which's value must be an {@link Icon}.
  58  *
  59  * @author Roman Kennke (kennke@aicas.com)
  60  */
  61 public class IconView
  62   extends View
  63 {
  64
  65   /**
  66    * Creates a new <code>IconView</code> for the given <code>Element</code>.
  67    *
  68    * @param element the element that is rendered by this IconView
  69    */
  70   public IconView(Element element)
  71   {
  72     super(element);
  73   }
  74
  75   /**
  76    * Renders the <code>Element</code> that is associated with this
  77    * <code>View</code>.
  78    *
  79    * @param g the <code>Graphics</code> context to render to
  80    * @param a the allocated region for the <code>Element</code>
  81    */
  82   public void paint(Graphics g, Shape a)
  83   {
  84     Icon icon = StyleConstants.getIcon(getElement().getAttributes());
  85     Rectangle b = a.getBounds();
  86     icon.paintIcon(getContainer(), g, b.x, b.y);
  87   }
  88
  89   /**
  90    * Returns the preferred span of the content managed by this
  91    * <code>View</code> along the specified <code>axis</code>.
  92    *
  93    * @param axis the axis
  94    *
  95    * @return the preferred span of this <code>View</code>.
  96    */
  97   public float getPreferredSpan(int axis)
  98   {
  99     Icon icon = StyleConstants.getIcon(getElement().getAttributes());
 100     float span;
 101     if (axis == X_AXIS)
 102       span = icon.getIconWidth();
 103     else if (axis == Y_AXIS)
 104       span = icon.getIconHeight();
 105     else
 106       throw new IllegalArgumentException();
 107     return span;
 108   }
 109
 110   /**
 111    * Maps a position in the document into the coordinate space of the View.
 112    * The output rectangle usually reflects the font height but has a width
 113    * of zero.
 114    *
 115    * @param pos the position of the character in the model
 116    * @param a the area that is occupied by the view
 117    * @param b either {@link Position.Bias#Forward} or
 118    *        {@link Position.Bias#Backward} depending on the preferred
 119    *        direction bias. If <code>null</code> this defaults to
 120    *        <code>Position.Bias.Forward</code>
 121    *
 122    * @return a rectangle that gives the location of the document position
 123    *         inside the view coordinate space
 124    *
 125    * @throws BadLocationException if <code>pos</code> is invalid
 126    * @throws IllegalArgumentException if b is not one of the above listed
 127    *         valid values
 128    */
 129   public Shape modelToView(int pos, Shape a, Position.Bias b)
 130     throws BadLocationException
 131   {
 132     Element el = getElement();
 133     if (pos < el.getStartOffset() || pos >= el.getEndOffset())
 134       throw new BadLocationException("Illegal offset for this view", pos);
 135     Rectangle r = a.getBounds();
 136     Icon icon = StyleConstants.getIcon(el.getAttributes());
 137     return new Rectangle(r.x, r.y, icon.getIconWidth(), icon.getIconHeight());
 138   }
 139
 140   /**
 141    * Maps coordinates from the <code>View</code>'s space into a position
 142    * in the document model.
 143    *
 144    * @param x the x coordinate in the view space
 145    * @param y the y coordinate in the view space
 146    * @param a the allocation of this <code>View</code>
 147    * @param b the bias to use
 148    *
 149    * @return the position in the document that corresponds to the screen
 150    *         coordinates <code>x, y</code>
 151    */
 152   public int viewToModel(float x, float y, Shape a, Position.Bias[] b)
 153   {
 154     // The element should only have one character position and it is clear
 155     // that this position is the position that best matches the given screen
 156     // coordinates, simply because this view has only this one position.
 157     Element el = getElement();
 158     return el.getStartOffset();
 159   }
 160
 161 }