1 /*
2 * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package javax.swing.text;
26
27 import java.awt.*;
28 import javax.swing.event.*;
29
30 /**
31 * A <code>LabelView</code> is a styled chunk of text
32 * that represents a view mapped over an element in the
33 * text model. It caches the character level attributes
34 * used for rendering.
35 *
36 * @author Timothy Prinzing
37 */
38 public class LabelView extends GlyphView implements TabableView {
39
40 /**
41 * Constructs a new view wrapped on an element.
42 *
43 * @param elem the element
44 */
45 public LabelView(Element elem) {
46 super(elem);
47 }
48
49 /**
50 * Synchronize the view's cached values with the model.
51 * This causes the font, metrics, color, etc to be
52 * re-cached if the cache has been invalidated.
53 */
54 final void sync() {
55 if (font == null) {
56 setPropertiesFromAttributes();
57 }
58 }
59
60 /**
61 * Sets whether or not the view is underlined.
62 * Note that this setter is protected and is really
63 * only meant if you need to update some additional
64 * state when set.
65 *
66 * @param u true if the view is underlined, otherwise
67 * false
68 * @see #isUnderline
69 */
70 protected void setUnderline(boolean u) {
71 underline = u;
72 }
73
74 /**
75 * Sets whether or not the view has a strike/line
76 * through it.
77 * Note that this setter is protected and is really
78 * only meant if you need to update some additional
79 * state when set.
80 *
81 * @param s true if the view has a strike/line
82 * through it, otherwise false
83 * @see #isStrikeThrough
84 */
85 protected void setStrikeThrough(boolean s) {
86 strike = s;
87 }
88
89
90 /**
91 * Sets whether or not the view represents a
92 * superscript.
93 * Note that this setter is protected and is really
94 * only meant if you need to update some additional
95 * state when set.
96 *
97 * @param s true if the view represents a
98 * superscript, otherwise false
99 * @see #isSuperscript
100 */
101 protected void setSuperscript(boolean s) {
102 superscript = s;
103 }
104
105 /**
106 * Sets whether or not the view represents a
107 * subscript.
108 * Note that this setter is protected and is really
109 * only meant if you need to update some additional
110 * state when set.
111 *
112 * @param s true if the view represents a
113 * subscript, otherwise false
114 * @see #isSubscript
115 */
116 protected void setSubscript(boolean s) {
117 subscript = s;
118 }
119
120 /**
121 * Sets the background color for the view. This method is typically
122 * invoked as part of configuring this <code>View</code>. If you need
123 * to customize the background color you should override
124 * <code>setPropertiesFromAttributes</code> and invoke this method. A
125 * value of null indicates no background should be rendered, so that the
126 * background of the parent <code>View</code> will show through.
127 *
128 * @param bg background color, or null
129 * @see #setPropertiesFromAttributes
130 * @since 1.5
131 */
132 protected void setBackground(Color bg) {
133 this.bg = bg;
134 }
135
136 /**
137 * Sets the cached properties from the attributes.
138 */
139 protected void setPropertiesFromAttributes() {
140 AttributeSet attr = getAttributes();
141 if (attr != null) {
142 Document d = getDocument();
143 if (d instanceof StyledDocument) {
144 StyledDocument doc = (StyledDocument) d;
145 font = doc.getFont(attr);
146 fg = doc.getForeground(attr);
147 if (attr.isDefined(StyleConstants.Background)) {
148 bg = doc.getBackground(attr);
149 } else {
150 bg = null;
151 }
152 setUnderline(StyleConstants.isUnderline(attr));
153 setStrikeThrough(StyleConstants.isStrikeThrough(attr));
154 setSuperscript(StyleConstants.isSuperscript(attr));
155 setSubscript(StyleConstants.isSubscript(attr));
156 } else {
157 throw new StateInvariantError("LabelView needs StyledDocument");
158 }
159 }
160 }
161
162 /**
163 * Fetches the <code>FontMetrics</code> used for this view.
164 * @deprecated FontMetrics are not used for glyph rendering
165 * when running in the JDK.
166 */
167 @Deprecated
168 protected FontMetrics getFontMetrics() {
169 sync();
170 Container c = getContainer();
171 return (c != null) ? c.getFontMetrics(font) :
172 Toolkit.getDefaultToolkit().getFontMetrics(font);
173 }
174
175 /**
176 * Fetches the background color to use to render the glyphs.
177 * This is implemented to return a cached background color,
178 * which defaults to <code>null</code>.
179 *
180 * @return the cached background color
181 * @since 1.3
182 */
183 public Color getBackground() {
184 sync();
185 return bg;
186 }
187
188 /**
189 * Fetches the foreground color to use to render the glyphs.
190 * This is implemented to return a cached foreground color,
191 * which defaults to <code>null</code>.
192 *
193 * @return the cached foreground color
194 * @since 1.3
195 */
196 public Color getForeground() {
197 sync();
198 return fg;
199 }
200
201 /**
202 * Fetches the font that the glyphs should be based upon.
203 * This is implemented to return a cached font.
204 *
205 * @return the cached font
206 */
207 public Font getFont() {
208 sync();
209 return font;
210 }
211
212 /**
213 * Determines if the glyphs should be underlined. If true,
214 * an underline should be drawn through the baseline. This
215 * is implemented to return the cached underline property.
216 *
217 * <p>When you request this property, <code>LabelView</code>
218 * re-syncs its state with the properties of the
219 * <code>Element</code>'s <code>AttributeSet</code>.
220 * If <code>Element</code>'s <code>AttributeSet</code>
221 * does not have this property set, it will revert to false.
222 *
223 * @return the value of the cached
224 * <code>underline</code> property
225 * @since 1.3
226 */
227 public boolean isUnderline() {
228 sync();
229 return underline;
230 }
231
232 /**
233 * Determines if the glyphs should have a strikethrough
234 * line. If true, a line should be drawn through the center
235 * of the glyphs. This is implemented to return the
236 * cached <code>strikeThrough</code> property.
237 *
238 * <p>When you request this property, <code>LabelView</code>
239 * re-syncs its state with the properties of the
240 * <code>Element</code>'s <code>AttributeSet</code>.
241 * If <code>Element</code>'s <code>AttributeSet</code>
242 * does not have this property set, it will revert to false.
243 *
244 * @return the value of the cached
245 * <code>strikeThrough</code> property
246 * @since 1.3
247 */
248 public boolean isStrikeThrough() {
249 sync();
250 return strike;
251 }
252
253 /**
254 * Determines if the glyphs should be rendered as superscript.
255 * @return the value of the cached subscript property
256 *
257 * <p>When you request this property, <code>LabelView</code>
258 * re-syncs its state with the properties of the
259 * <code>Element</code>'s <code>AttributeSet</code>.
260 * If <code>Element</code>'s <code>AttributeSet</code>
261 * does not have this property set, it will revert to false.
262 *
263 * @return the value of the cached
264 * <code>subscript</code> property
265 * @since 1.3
266 */
267 public boolean isSubscript() {
268 sync();
269 return subscript;
270 }
271
272 /**
273 * Determines if the glyphs should be rendered as subscript.
274 *
275 * <p>When you request this property, <code>LabelView</code>
276 * re-syncs its state with the properties of the
277 * <code>Element</code>'s <code>AttributeSet</code>.
278 * If <code>Element</code>'s <code>AttributeSet</code>
279 * does not have this property set, it will revert to false.
280 *
281 * @return the value of the cached
282 * <code>superscript</code> property
283 * @since 1.3
284 */
285 public boolean isSuperscript() {
286 sync();
287 return superscript;
288 }
289
290 // --- View methods ---------------------------------------------
291
292 /**
293 * Gives notification from the document that attributes were changed
294 * in a location that this view is responsible for.
295 *
296 * @param e the change information from the associated document
297 * @param a the current allocation of the view
298 * @param f the factory to use to rebuild if the view has children
299 * @see View#changedUpdate
300 */
301 public void changedUpdate(DocumentEvent e, Shape a, ViewFactory f) {
302 font = null;
303 super.changedUpdate(e, a, f);
304 }
305
306 // --- variables ------------------------------------------------
307
308 private Font font;
309 private Color fg;
310 private Color bg;
311 private boolean underline;
312 private boolean strike;
313 private boolean superscript;
314 private boolean subscript;
315
316 }