aboutsummaryrefslogtreecommitdiffstats
path: root/src/java/org/apache/fop/accessibility/fo/StructureTreeEventTrigger.java
blob: b5cd0a5a4294f1ad81ee5d3b6bd792e6bd078757 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* $Id$ */

package org.apache.fop.accessibility.fo;

import java.util.Locale;

import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;

import org.apache.fop.accessibility.StructureTreeElement;
import org.apache.fop.accessibility.StructureTreeEventHandler;
import org.apache.fop.fo.FOEventHandler;
import org.apache.fop.fo.FONode;
import org.apache.fop.fo.FOText;
import org.apache.fop.fo.extensions.ExtensionElementMapping;
import org.apache.fop.fo.flow.AbstractGraphics;
import org.apache.fop.fo.flow.BasicLink;
import org.apache.fop.fo.flow.Block;
import org.apache.fop.fo.flow.BlockContainer;
import org.apache.fop.fo.flow.Character;
import org.apache.fop.fo.flow.ExternalGraphic;
import org.apache.fop.fo.flow.Footnote;
import org.apache.fop.fo.flow.FootnoteBody;
import org.apache.fop.fo.flow.Inline;
import org.apache.fop.fo.flow.InstreamForeignObject;
import org.apache.fop.fo.flow.ListBlock;
import org.apache.fop.fo.flow.ListItem;
import org.apache.fop.fo.flow.ListItemBody;
import org.apache.fop.fo.flow.ListItemLabel;
import org.apache.fop.fo.flow.PageNumber;
import org.apache.fop.fo.flow.PageNumberCitation;
import org.apache.fop.fo.flow.PageNumberCitationLast;
import org.apache.fop.fo.flow.Wrapper;
import org.apache.fop.fo.flow.table.Table;
import org.apache.fop.fo.flow.table.TableBody;
import org.apache.fop.fo.flow.table.TableCell;
import org.apache.fop.fo.flow.table.TableFooter;
import org.apache.fop.fo.flow.table.TableHeader;
import org.apache.fop.fo.flow.table.TableRow;
import org.apache.fop.fo.pagination.Flow;
import org.apache.fop.fo.pagination.PageSequence;
import org.apache.fop.fo.pagination.StaticContent;
import org.apache.fop.fo.properties.CommonAccessibilityHolder;
import org.apache.fop.util.XMLUtil;

/**
 * A bridge between {@link FOEventHandler} and {@link StructureTreeEventHandler}.
 */
class StructureTreeEventTrigger extends FOEventHandler {

    private StructureTreeEventHandler structureTreeEventHandler;

    public StructureTreeEventTrigger(StructureTreeEventHandler structureTreeEventHandler) {
        this.structureTreeEventHandler = structureTreeEventHandler;
    }

    @Override
    public void startDocument() throws SAXException {
    }

    @Override
    public void endDocument() throws SAXException {
    }

    @Override
    public void startPageSequence(PageSequence pageSeq) {
        Locale locale = null;
        if (pageSeq.getLanguage() != null) {
            if (pageSeq.getCountry() != null) {
                locale = new Locale(pageSeq.getLanguage(), pageSeq.getCountry());
            } else {
                locale = new Locale(pageSeq.getLanguage());
            }
        }
        structureTreeEventHandler.startPageSequence(locale);
    }

    @Override
    public void endPageSequence(PageSequence pageSeq) {
        structureTreeEventHandler.endPageSequence();
    }

    @Override
    public void startPageNumber(PageNumber pagenum) {
        startElementWithID(pagenum);
    }

    @Override
    public void endPageNumber(PageNumber pagenum) {
        endElement(pagenum);
    }

    @Override
    public void startPageNumberCitation(PageNumberCitation pageCite) {
        startElementWithID(pageCite);
    }

    @Override
    public void endPageNumberCitation(PageNumberCitation pageCite) {
        endElement(pageCite);
    }

    @Override
    public void startPageNumberCitationLast(PageNumberCitationLast pageLast) {
        startElementWithID(pageLast);
    }

    @Override
    public void endPageNumberCitationLast(PageNumberCitationLast pageLast) {
        endElement(pageLast);
    }

    @Override
    public void startFlow(Flow fl) {
        startElement(fl);
    }

    @Override
    public void endFlow(Flow fl) {
        endElement(fl);
    }

    @Override
    public void startBlock(Block bl) {
        startElement(bl);
    }

    @Override
    public void endBlock(Block bl) {
        endElement(bl);
    }

    @Override
    public void startBlockContainer(BlockContainer blc) {
        startElement(blc);
    }

    @Override
    public void endBlockContainer(BlockContainer blc) {
        endElement(blc);
    }

    @Override
    public void startInline(Inline inl) {
        startElement(inl);
    }

    @Override
    public void endInline(Inline inl) {
        endElement(inl);
    }

    @Override
    public void startTable(Table tbl) {
        startElement(tbl);
    }

    @Override
    public void endTable(Table tbl) {
        endElement(tbl);
    }

    @Override
    public void startHeader(TableHeader header) {
        startElement(header);
    }

    @Override
    public void endHeader(TableHeader header) {
        endElement(header);
    }

    @Override
    public void startFooter(TableFooter footer) {
        startElement(footer);
    }

    @Override
    public void endFooter(TableFooter footer) {
        endElement(footer);
    }

    @Override
    public void startBody(TableBody body) {
        startElement(body);
    }

    @Override
    public void endBody(TableBody body) {
        endElement(body);
    }

    @Override
    public void startRow(TableRow tr) {
        startElement(tr);
    }

    @Override
    public void endRow(TableRow tr) {
        endElement(tr);
    }

    @Override
    public void startCell(TableCell tc) {
        AttributesImpl attributes = new AttributesImpl();
        int colSpan = tc.getNumberColumnsSpanned();
        if (colSpan > 1) {
            addNoNamespaceAttribute(attributes, "number-columns-spanned",
                    Integer.toString(colSpan));
        }
        startElement(tc, attributes);
    }

    @Override
    public void endCell(TableCell tc) {
        endElement(tc);
    }

    @Override
    public void startList(ListBlock lb) {
        startElement(lb);
    }

    @Override
    public void endList(ListBlock lb) {
        endElement(lb);
    }

    @Override
    public void startListItem(ListItem li) {
        startElement(li);
    }

    @Override
    public void endListItem(ListItem li) {
        endElement(li);
    }

    @Override
    public void startListLabel(ListItemLabel listItemLabel) {
        startElement(listItemLabel);
    }

    @Override
    public void endListLabel(ListItemLabel listItemLabel) {
        endElement(listItemLabel);
    }

    @Override
    public void startListBody(ListItemBody listItemBody) {
        startElement(listItemBody);
    }

    @Override
    public void endListBody(ListItemBody listItemBody) {
        endElement(listItemBody);
    }

    @Override
    public void startStatic(StaticContent staticContent) {
        startElement(staticContent);
    }

    @Override
    public void endStatic(StaticContent statisContent) {
        endElement(statisContent);
    }

    @Override
    public void startLink(BasicLink basicLink) {
        startElementWithID(basicLink);
    }

    @Override
    public void endLink(BasicLink basicLink) {
        endElement(basicLink);
    }

    @Override
    public void image(ExternalGraphic eg) {
        startElementWithIDAndAltText(eg);
        endElement(eg);
    }

    @Override
    public void startInstreamForeignObject(InstreamForeignObject ifo) {
        startElementWithIDAndAltText(ifo);
    }

    @Override
    public void endInstreamForeignObject(InstreamForeignObject ifo) {
        endElement(ifo);
    }

    @Override
    public void startFootnote(Footnote footnote) {
        startElement(footnote);
    }

    @Override
    public void endFootnote(Footnote footnote) {
        endElement(footnote);
    }

    @Override
    public void startFootnoteBody(FootnoteBody body) {
        startElement(body);
    }

    @Override
    public void endFootnoteBody(FootnoteBody body) {
        endElement(body);
    }

    @Override
    public void startWrapper(Wrapper wrapper) {
        startElement(wrapper);
    }

    @Override
    public void endWrapper(Wrapper wrapper) {
        endElement(wrapper);
    }

    @Override
    public void character(Character c) {
        startElementWithID(c);
        endElement(c);
    }

    @Override
    public void characters(FOText foText) {
        startElementWithID(foText);
        endElement(foText);
    }


    private void startElement(FONode node) {
        startElement(node, new AttributesImpl());
    }

    private void startElementWithID(FONode node) {
        AttributesImpl attributes = new AttributesImpl();
        String localName = node.getLocalName();
        if (node instanceof CommonAccessibilityHolder) {
            addRole((CommonAccessibilityHolder) node, attributes);
        }
        node.setStructureTreeElement(structureTreeEventHandler.startReferencedNode(localName, attributes));
    }

    private void startElementWithIDAndAltText(AbstractGraphics node) {
        AttributesImpl attributes = new AttributesImpl();
        String localName = node.getLocalName();
        addRole(node, attributes);
        addAttribute(attributes, ExtensionElementMapping.URI, "alt-text",
                ExtensionElementMapping.STANDARD_PREFIX, node.getAltText());
        node.setStructureTreeElement(structureTreeEventHandler.startImageNode(localName, attributes));
    }

    private StructureTreeElement startElement(FONode node, AttributesImpl attributes) {
        String localName = node.getLocalName();
        if (node instanceof CommonAccessibilityHolder) {
            addRole((CommonAccessibilityHolder) node, attributes);
        }
        return structureTreeEventHandler.startNode(localName, attributes);
    }

    private void addNoNamespaceAttribute(AttributesImpl attributes, String name, String value) {
        attributes.addAttribute("", name, name, XMLUtil.CDATA, value);
    }

    private void addAttribute(AttributesImpl attributes,
            String namespace, String localName, String prefix, String value) {
        assert namespace.length() > 0 && prefix.length() > 0;
        String qualifiedName = prefix + ":" + localName;
        attributes.addAttribute(namespace, localName, qualifiedName, XMLUtil.CDATA, value);
    }

    private void addRole(CommonAccessibilityHolder node, AttributesImpl attributes) {
        String role = node.getCommonAccessibility().getRole();
        if (role != null) {
            addNoNamespaceAttribute(attributes, "role", role);
        }
    }

    private void endElement(FONode node) {
        String localName = node.getLocalName();
        structureTreeEventHandler.endNode(localName);
    }

}