001    /* IconView.java -- A view to render icons
002       Copyright (C) 2005  Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package javax.swing.text;
040    
041    import java.awt.Graphics;
042    import java.awt.Rectangle;
043    import java.awt.Shape;
044    
045    import javax.swing.Icon;
046    import 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     */
060    public 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    }