1/*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.  Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26/*
27 *
28 *
29 * (C) Copyright IBM Corp. 1998-2010 - All Rights Reserved
30 *
31 */
32
33#include "LETypes.h"
34#include "OpenTypeTables.h"
35#include "OpenTypeUtilities.h"
36#include "ScriptAndLanguage.h"
37#include "LESwaps.h"
38
39U_NAMESPACE_BEGIN
40
41LEReferenceTo<LangSysTable> ScriptTable::findLanguage(const LETableReference& base, LETag languageTag, LEErrorCode &success, le_bool exactMatch) const
42{
43    le_uint16 count = SWAPW(langSysCount);
44    Offset langSysTableOffset = exactMatch? 0 : SWAPW(defaultLangSysTableOffset);
45
46    if (count > 0) {
47      LEReferenceToArrayOf<TagAndOffsetRecord> langSysRecords(base, success, langSysRecordArray, count);
48      Offset foundOffset =
49        OpenTypeUtilities::getTagOffset(languageTag, langSysRecords, success);
50
51      if (foundOffset != 0 && LE_SUCCESS(success)) {
52        langSysTableOffset = foundOffset;
53      }
54    }
55
56    if (langSysTableOffset != 0) {
57      return LEReferenceTo<LangSysTable>(base, success, langSysTableOffset);
58    }
59
60    return LEReferenceTo<LangSysTable>();
61}
62
63LEReferenceTo<ScriptTable> ScriptListTable::findScript(const LETableReference &base, LETag scriptTag, LEErrorCode &success) const
64{
65    if (LE_FAILURE(success) ) {
66      return LEReferenceTo<ScriptTable>(); // get out
67    }
68    /*
69     * There are some fonts that have a large, bogus value for scriptCount. To try
70     * and protect against this, we use the offset in the first scriptRecord,
71     * which we know has to be past the end of the scriptRecordArray, to compute
72     * a value which is greater than or equal to the actual script count.
73     *
74     * Note: normally, the first offset will point to just after the scriptRecordArray,
75     * but there's no guarantee of this, only that it's *after* the scriptRecordArray.
76     * Because of this, a binary serach isn't safe, because the new count may include
77     * data that's not actually in the scriptRecordArray and hence the array will appear
78     * to be unsorted.
79     */
80    le_uint16 count = SWAPW(scriptCount);
81
82    if (count == 0) {
83      return LEReferenceTo<ScriptTable>(); // no items, no search
84    }
85
86    // attempt to construct a ref with at least one element
87    LEReferenceToArrayOf<ScriptRecord> oneElementTable(base, success, &scriptRecordArray[0], 1);
88
89    if( LE_FAILURE(success) ) {
90      return LEReferenceTo<ScriptTable>(); // couldn't even read the first record - bad font.
91    }
92
93    le_uint16 limit = ((SWAPW(scriptRecordArray[0].offset) - sizeof(ScriptListTable)) / sizeof(scriptRecordArray)) + ANY_NUMBER;
94    Offset scriptTableOffset = 0;
95
96
97    if (count > limit) {
98        // the scriptCount value is bogus; do a linear search
99        // because limit may still be too large.
100        LEReferenceToArrayOf<ScriptRecord> scriptRecordArrayRef(base, success, &scriptRecordArray[0], limit);
101        for(le_int32 s = 0; (s < limit)&&LE_SUCCESS(success); s += 1) {
102          if (SWAPT(scriptRecordArrayRef(s,success).tag) == scriptTag) {
103            scriptTableOffset = SWAPW(scriptRecordArrayRef(s,success).offset);
104            break;
105          }
106        }
107    } else {
108      LEReferenceToArrayOf<ScriptRecord> scriptRecordArrayRef(base, success, &scriptRecordArray[0], count);
109
110      scriptTableOffset = OpenTypeUtilities::getTagOffset(scriptTag, scriptRecordArrayRef, success);
111    }
112
113    if (scriptTableOffset != 0) {
114      return LEReferenceTo<ScriptTable>(base, success, scriptTableOffset);
115    }
116
117  return LEReferenceTo<ScriptTable>();
118}
119
120LEReferenceTo<LangSysTable>  ScriptListTable::findLanguage(const LETableReference &base, LETag scriptTag, LETag languageTag, LEErrorCode &success, le_bool exactMatch) const
121{
122  const LEReferenceTo<ScriptTable> scriptTable = findScript(base, scriptTag, success);
123
124  if (scriptTable.isEmpty()) {
125    return LEReferenceTo<LangSysTable>();
126  }
127
128  return scriptTable->findLanguage(scriptTable, languageTag, success, exactMatch).reparent(base);
129}
130
131U_NAMESPACE_END
132