001 /* InlineView.java -- Renders HTML content
002 Copyright (C) 2006 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.html;
040
041 import java.awt.FontMetrics;
042 import java.awt.Shape;
043 import java.text.BreakIterator;
044
045 import javax.swing.event.DocumentEvent;
046 import javax.swing.text.AttributeSet;
047 import javax.swing.text.BadLocationException;
048 import javax.swing.text.Document;
049 import javax.swing.text.Element;
050 import javax.swing.text.LabelView;
051 import javax.swing.text.Segment;
052 import javax.swing.text.View;
053 import javax.swing.text.ViewFactory;
054
055 /**
056 * Renders HTML content (identified by {@link HTML.Tag#CONTENT}). This is
057 * basically a {@link LabelView} that is adjusted to understand styles defined
058 * by stylesheets.
059 *
060 * @author Roman Kennke (kennke@aicas.com)
061 */
062 public class InlineView
063 extends LabelView
064 {
065
066 /**
067 * The attributes used by this view.
068 */
069 private AttributeSet attributes;
070
071 /**
072 * The span of the longest word in this view.
073 *
074 * @see #getLongestWord()
075 */
076 private float longestWord;
077
078 /**
079 * Indicates if we may wrap or not.
080 */
081 private boolean nowrap;
082
083 /**
084 * Creates a new <code>InlineView</code> that renders the specified element.
085 *
086 * @param element the element for this view
087 */
088 public InlineView(Element element)
089 {
090 super(element);
091 }
092
093 /**
094 * Receives notification that something was inserted into the document in
095 * a location that this view is responsible for.
096 *
097 * @param e the document event
098 * @param a the current allocation of this view
099 * @param f the view factory for creating new views
100 *
101 * @since 1.5
102 */
103 public void insertUpdate(DocumentEvent e, Shape a, ViewFactory f)
104 {
105 // FIXME: What to do here?
106 super.insertUpdate(e, a, f);
107 }
108
109 /**
110 * Receives notification that something was removed from the document in
111 * a location that this view is responsible for.
112 *
113 * @param e the document event
114 * @param a the current allocation of this view
115 * @param f the view factory for creating new views
116 *
117 * @since 1.5
118 */
119 public void removeUpdate(DocumentEvent e, Shape a, ViewFactory f)
120 {
121 // FIXME: What to do here?
122 super.removeUpdate(e, a, f);
123 }
124
125 /**
126 * Receives notification that attributes have changed in the document in
127 * a location that this view is responsible for. This calls
128 * {@link #setPropertiesFromAttributes}.
129 *
130 * @param e the document event
131 * @param a the current allocation of this view
132 * @param f the view factory for creating new views
133 *
134 * @since 1.5
135 */
136 public void changedUpdate(DocumentEvent e, Shape a, ViewFactory f)
137 {
138 super.changedUpdate(e, a, f);
139 StyleSheet ss = getStyleSheet();
140 attributes = ss.getViewAttributes(this);
141 preferenceChanged(null, true, true);
142 setPropertiesFromAttributes();
143 }
144
145 /**
146 * Returns the attributes that are used for rendering. This is implemented
147 * to multiplex the attributes specified in the model with a stylesheet.
148 *
149 * @return the attributes that are used for rendering
150 */
151 public AttributeSet getAttributes()
152 {
153 if (attributes == null)
154 {
155 StyleSheet ss = getStyleSheet();
156 attributes = ss.getViewAttributes(this);
157 }
158 return attributes;
159 }
160
161
162 public int getBreakWeight(int axis, float pos, float len)
163 {
164 int weight;
165 if (nowrap)
166 weight = BadBreakWeight;
167 else
168 weight = super.getBreakWeight(axis, pos, len);
169 return weight;
170 }
171
172 public View breakView(int axis, int offset, float pos, float len)
173 {
174 // FIXME: Implement this.
175 return super.breakView(axis, offset, pos, len);
176 }
177
178 /**
179 * Loads the character style properties from the stylesheet.
180 */
181 protected void setPropertiesFromAttributes()
182 {
183 super.setPropertiesFromAttributes();
184 AttributeSet atts = getAttributes();
185 Object o = atts.getAttribute(CSS.Attribute.TEXT_DECORATION);
186
187 // Check for underline.
188 boolean b = false;
189 if (o != null && o.toString().contains("underline"))
190 b = true;
191 setUnderline(b);
192
193 // Check for line-through.
194 b = false;
195 if (o != null && o.toString().contains("line-through"))
196 b = true;
197 setStrikeThrough(b);
198
199 // Check for vertical alignment (subscript/superscript).
200 o = atts.getAttribute(CSS.Attribute.VERTICAL_ALIGN);
201
202 // Subscript.
203 b = false;
204 if (o != null && o.toString().contains("sub"))
205 b = true;
206 setSubscript(b);
207
208 // Superscript.
209 b = false;
210 if (o != null && o.toString().contains("sup"))
211 b = true;
212 setSuperscript(b);
213
214 // Fetch nowrap setting.
215 o = atts.getAttribute(CSS.Attribute.WHITE_SPACE);
216 if (o != null && o.equals("nowrap"))
217 nowrap = true;
218 else
219 nowrap = false;
220 }
221
222 /**
223 * Returns the stylesheet used by this view. This returns the stylesheet
224 * of the <code>HTMLDocument</code> that is rendered by this view.
225 *
226 * @return the stylesheet used by this view
227 */
228 protected StyleSheet getStyleSheet()
229 {
230 Document doc = getDocument();
231 StyleSheet styleSheet = null;
232 if (doc instanceof HTMLDocument)
233 styleSheet = ((HTMLDocument) doc).getStyleSheet();
234 return styleSheet;
235 }
236
237 /**
238 * Returns the minimum span for the specified axis. This returns the
239 * width of the longest word for the X axis and the super behaviour for
240 * the Y axis. This is a slight deviation from the reference implementation.
241 * IMO this should improve rendering behaviour so that an InlineView never
242 * gets smaller than the longest word in it.
243 */
244 public float getMinimumSpan(int axis)
245 {
246 float min = super.getMinimumSpan(axis);
247 if (axis == X_AXIS)
248 min = Math.max(getLongestWord(), min);
249 return min;
250 }
251
252 /**
253 * Returns the span of the longest word in this view.
254 *
255 * @return the span of the longest word in this view
256 */
257 private float getLongestWord()
258 {
259 if (longestWord == -1)
260 longestWord = calculateLongestWord();
261 return longestWord;
262 }
263
264 /**
265 * Calculates the span of the longest word in this view.
266 *
267 * @return the span of the longest word in this view
268 */
269 private float calculateLongestWord()
270 {
271 float span = 0;
272 try
273 {
274 Document doc = getDocument();
275 int p0 = getStartOffset();
276 int p1 = getEndOffset();
277 Segment s = new Segment();
278 doc.getText(p0, p1 - p0, s);
279 BreakIterator iter = BreakIterator.getWordInstance();
280 iter.setText(s);
281 int wordStart = p0;
282 int wordEnd = p0;
283 int start = iter.first();
284 for (int end = iter.next(); end != BreakIterator.DONE;
285 start = end, end = iter.next())
286 {
287 if ((end - start) > (wordEnd - wordStart))
288 {
289 wordStart = start;
290 wordEnd = end;
291 }
292 }
293 if (wordEnd - wordStart > 0)
294 {
295 FontMetrics fm = getFontMetrics();
296 int offset = s.offset + wordStart - s.getBeginIndex();
297 span = fm.charsWidth(s.array, offset, wordEnd - wordStart);
298 }
299 }
300 catch (BadLocationException ex)
301 {
302 // Return 0.
303 }
304 return span;
305 }
306
307 }