summaryrefslogtreecommitdiffstats
path: root/src/xmlpatterns/data/qitem_p.h
blob: 588f040300049dccc95d72eca645d9549f1d6c59 (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
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtXmlPatterns module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at http://qt.nokia.com/contact.
** $QT_END_LICENSE$
**
****************************************************************************/

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.

#ifndef Patternist_Item_H
#define Patternist_Item_H

#include <QtXmlPatterns/private/qcppcastinghelper_p.h>
#include <QtXmlPatterns/private/qitemtype_p.h>
#include <QtXmlPatterns/private/qsingletoniterator_p.h>
#include <QtXmlPatterns/QAbstractXmlNodeModel>

#include <QUrl>
#include <QVariant>

/**
 * @file
 * @short Due to strong interdependencies, this file contains the definitions for
 * the classes Item, QXmlNodeModelIndex, QAbstractXmlNodeModel and AtomicValue. The implementations are
 * in their respective source files.
 */

/**
 * @class QSharedData
 * @short Qt's base class for reference counting.
 * @author Trolltech
 */

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

template<typename T> class QList;
template<typename T> class QVector;
template<typename T> class QAbstractXmlForwardIterator;

class QSourceLocation;
class QAbstractXmlReceiver;

namespace QPatternist
{
    class DynamicContext;
    class Item;
    class ItemType;
    class QObjectNodeModel;
    template<typename T> class EmptyIterator;
    template<typename T, typename ListType> class ListIterator;

    /**
     * @short Base class for all classes representing atomic values.
     *
     * Instantiating AtomicValues sub classes from a value of somekind,
     * for a certain type is done in three different ways:
     *
     * - The static factory fromLexical which available in most classes. This
     * function attempts to create a value from a QString that is considered
     * a lexical representation of the value. Thus, this function performs validation, takes
     * care of whitespace facets, and everything else related to instantiating a value from
     * a lexical representation.
     * - The static factory function fromValue. This function exists for
     * values where a C++ type exists which corresponds to the type's value space.
     * - By using instances available in CommonValues. This is the preferred method
     * since it uses existing singleton instances and thus saves memory. CommonValues
     * should be used whenever possible, it can be thought as a collection of constant values.
     *
     * For types that does not distinguish the value space and lexical space, such as <tt>xs:string</tt>,
     * only the fromValue() function exist, and fromLexical() is omitted.
     *
     * @ingroup Patternist_xdm
     * @author Frans Englich <fenglich@trolltech.com>
     */
    class AtomicValue : public QSharedData
                      , public CppCastingHelper<AtomicValue>
    {
    public:
        virtual ~AtomicValue();

        /**
         * A smart pointer wrapping AtomicValue instances.
         */
        typedef QExplicitlySharedDataPointer<AtomicValue> Ptr;

        /**
         * A list if smart pointers wrapping AtomicValue instances.
         */
        typedef QList<AtomicValue::Ptr> List;

        /**
         * Determines whether this atomic value has an error. This is used
         * for implementing casting.
         *
         * @returns always @c false
         */
        virtual bool hasError() const;

        /**
         * Always fails by issuing the type error ReportContext::FORG0006. Sub-classes
         * whose represented type do allow EBV to be extracted from, must thus
         * re-implement this function.
         */
        virtual bool evaluateEBV(const QExplicitlySharedDataPointer<DynamicContext> &context) const;

        virtual QString stringValue() const = 0;
        virtual ItemType::Ptr type() const = 0;

        /**
         * Converts @p value to a QVariant.
         */
        static QVariant toQt(const AtomicValue *const value);

        static inline QVariant toQt(const AtomicValue::Ptr &value)
        {
            return toQt(value.data());
        }

        static Item toXDM(const QVariant &value);

        static ItemType::Ptr qtToXDMType(const QXmlItem &item);
    protected:
        inline AtomicValue()
        {
        }
    };

    /**
     * @short Represents an item in the XPath 2.0 Data Model.
     *
     * There exists two types of items: nodes and atomic values.
     *
     * The XQuery 1.0 and XPath 2.0 Data Model and XML Path Language (XPath) 2.0 specification
     * makes a very strong distinction between a sequence of items and an atomized sequence.
     *
     * @ingroup Patternist_xdm
     * @author Frans Englich <fenglich@trolltech.com>
     */
    class Item
    {
        friend class QT_PREPEND_NAMESPACE(QXmlItem);

    public:
        /**
         * A smart pointer wrapping an Item instance.
         */
        typedef QAbstractXmlForwardIterator<Item> Iterator;

        /**
         * A list of Item instances, each wrapped in a smart pointer.
         */
        typedef QList<Item> List;

        /**
         * A vector of Item instances, each wrapped in a smart pointer.
         */
        typedef QVector<Item> Vector;

        typedef QPatternist::SingletonIterator<Item> SingletonIterator;
        typedef QPatternist::EmptyIterator<Item> EmptyIterator;

        /**
         * Default constructor.
         */
        inline Item()
        {
            /* Note that this function should be equal to reset(). */

            /* This is the area which atomicValue uses. Becauase we want as()
             * to return null on null-constructed objects, we initialize it. */
            node.data = 0;

            /* This signals that we're not an atomic value. */
            node.model = 0;
        }

        inline Item(const QXmlNodeModelIndex &n) : node(n.m_storage)
        {
        }

        inline Item(const Item &other) : node(other.node)
        {
            Q_ASSERT_X(sizeof(QXmlNodeModelIndex) >= sizeof(AtomicValue), Q_FUNC_INFO,
                       "Since we're only copying the node member, it must be the largest.");
            if(isAtomicValue())
                atomicValue->ref.ref();
        }

        inline Item(const AtomicValue::Ptr &a)
        {
            if(a)
            {
                atomicValue = a.data();
                atomicValue->ref.ref();

                /* Signal that we're housing an atomic value. */
                node.model = reinterpret_cast<const QAbstractXmlNodeModel *>(~0);
            }
            else
                node.model = 0; /* Like the default constructor. */
        }

        inline Item(const AtomicValue *const a)
        {
            /* Note, the implementation is a copy of the constructor above. */

            if(a)
            {
                atomicValue = a;
                atomicValue->ref.ref();

                /* Signal that we're housing an atomic value. */
                node.model = reinterpret_cast<const QAbstractXmlNodeModel *>(~0);
            }
            else
                node.model = 0; /* Like the default constructor. */
        }

        inline ~Item()
        {
            if(isAtomicValue() && !atomicValue->ref.deref())
                delete atomicValue;
        }

        inline Item &operator=(const Item &other)
        {
            Q_ASSERT_X(sizeof(QXmlNodeModelIndex) >= sizeof(AtomicValue *), Q_FUNC_INFO,
                       "If this doesn't hold, we won't copy all data.");

            if(other.isAtomicValue())
                other.atomicValue->ref.ref();

            if(isAtomicValue())
            {
                if(!atomicValue->ref.deref())
                    delete atomicValue;
            }

            node = other.node;

            return *this;
        }

        template<typename TCastTarget>
        inline TCastTarget *as() const
        {
#if defined(Patternist_DEBUG) && !defined(Q_CC_XLC)
/* At least on aix-xlc-64, the compiler cries when it sees dynamic_cast. */
            Q_ASSERT_X(atomicValue == 0 || dynamic_cast<const TCastTarget *>(atomicValue),
                       Q_FUNC_INFO,
                       "The cast is invalid. This class does not inherit the cast target.");
#endif
            return const_cast<TCastTarget *>(static_cast<const TCastTarget *>(atomicValue));
        }

        /**
         * @short Returns the string value of this Item.
         *
         * In the case of a node, it is the node value corresponding to
         * the particular node type. For atomic values, it is equivalent
         * to the value cast as <tt>xs:string</tt>.
         *
         * Conceptually, this functions corresponds to the <tt>dm:string-value</tt> accessor.
         *
         * @see <a href="http://www.w3.org/TR/xpath-datamodel/#dm-string-value">XQuery 1.0 and
         * XPath 2.0 Data Model, 5.13 string-value Accessor</a>
         * @returns the string value.
         */
        inline QString stringValue() const
        {
            if(isAtomicValue())
                return atomicValue->stringValue();
            else
                return asNode().stringValue();
        }

        /**
         * @short Returns the typed value of this item.
         *
         * Conceptually, this functions corresponds to the <tt>dm:typed-value</tt> accessor. Here are
         * examples of what the typed value of an Item is:
         *
         * - The typed value of an atomic value is always the atomic value itself.
         * - A comment node has always a typed value of type @c xs:string
         * - For attribute and element nodes, the typed value can be arbitrary. For example, an
         *   element can have a sequence of @c xs:dateTime instances.
         *
         * @returns the typed value of this item
         * @see <a href="http://www.w3.org/TR/xpath-datamodel/#dm-typed-value">XQuery 1.0 and
         * XPath 2.0 Data Model, 5.15 typed-value Accessor</a>
         */
        Item::Iterator::Ptr sequencedTypedValue() const;

        /**
         * @short Determines whether this item is an atomic value, or a node.
         *
         * If this Item is @c null, @c false is returned.
         *
         * @see isNode()
         * @returns @c true if it is an atomic value, otherwise @c false.
         */
        inline bool isAtomicValue() const
        {
            /* Setting node.model to ~0, signals that it's an atomic value. */
            return node.model == reinterpret_cast<QAbstractXmlNodeModel *>(~0);
        }

        /**
         * @short Determines whether this item is an atomic value, or a node.
         *
         * If this Item is @c null, false is returned.
         *
         * @see isAtomicValue()
         * @returns @c true if this item is a node, otherwise @c false.
         */
        inline bool isNode() const
        {
            //return !isAtomicValue();
            return node.model && node.model != reinterpret_cast<QAbstractXmlNodeModel *>(~0);
        }

        /**
         * @short Returns the ItemType this Item is of.
         *
         * For example, if this Item is an XML node, more specifically a text node,
         * <tt>text()</tt> is returned. That is, BuiltinTypes::text. However, if this
         * Item is an atomic value of type <tt>xs:long</tt> that is what's returned,
         * BuiltinTypes::xsLong.
         *
         * @returns the type of this Item.
         */
        inline QExplicitlySharedDataPointer<ItemType> type() const
        {
            if(isAtomicValue())
                return atomicValue->type();
            else
                return asNode().type();
        }

        inline const AtomicValue *asAtomicValue() const
        {
            Q_ASSERT(isAtomicValue());
            return atomicValue;
        }

        inline const QXmlNodeModelIndex &asNode() const
        {
            Q_ASSERT_X(isNode() || isNull(), Q_FUNC_INFO,
                       "This item isn't a valid QXmlNodeModelIndex.");
            Q_ASSERT_X(sizeof(QXmlNodeModelIndex) == sizeof(QPatternist::NodeIndexStorage), Q_FUNC_INFO,
                       "If this doesn't hold, something is wrong.");

            return reinterpret_cast<const QXmlNodeModelIndex &>(node);
        }

        inline operator bool() const
        {
            return node.model;
        }

        inline bool isNull() const
        {
            return !node.model;
        }

        inline void reset()
        {
            /* Note that this function should be equal to the default
             * constructor. */
            node.model = 0;
            node.data = 0;
        }

        static inline Item fromPublic(const QXmlItem &i)
        {
            const Item it(i.m_node);
            if(it.isAtomicValue())
                it.asAtomicValue()->ref.ref();

            return it;
        }

        static inline QXmlItem toPublic(const Item &i)
        {
            return QXmlItem(i);
        }

    private:
        union
        {
            NodeIndexStorage node;
            const AtomicValue *atomicValue;
        };
    };

    template<typename T>
    inline Item toItem(const QExplicitlySharedDataPointer<T> atomicValue)
    {
        return Item(atomicValue.data());
    }

    /**
     * This is an overload, provided for convenience.
     * @relates QXmlNodeModelIndex
     */
    static inline QString formatData(const QXmlNodeModelIndex node)
    {
        return node.stringValue(); // This can be improved a lot.
    }
}

    inline QXmlName QXmlNodeModelIndex::name() const
    {
        return m_storage.model->name(*this);
    }

    inline QXmlNodeModelIndex QXmlNodeModelIndex::root() const
    {
        return m_storage.model->root(*this);
    }

    inline QXmlNodeModelIndex::Iterator::Ptr QXmlNodeModelIndex::iterate(const QXmlNodeModelIndex::Axis axis) const
    {
        return m_storage.model->iterate(*this, axis);
    }

    inline QUrl QXmlNodeModelIndex::documentUri() const
    {
        return m_storage.model->documentUri(*this);
    }

    inline QUrl QXmlNodeModelIndex::baseUri() const
    {
        return m_storage.model->baseUri(*this);
    }

    inline QXmlNodeModelIndex::NodeKind QXmlNodeModelIndex::kind() const
    {
        return m_storage.model->kind(*this);
    }

    inline bool QXmlNodeModelIndex::isDeepEqual(const QXmlNodeModelIndex &other) const
    {
        return m_storage.model->isDeepEqual(*this, other);
    }

    inline QXmlNodeModelIndex::DocumentOrder QXmlNodeModelIndex::compareOrder(const QXmlNodeModelIndex &other) const
    {
        Q_ASSERT_X(model() == other.model(), Q_FUNC_INFO, "The API docs guarantees the two nodes are from the same model");
        return m_storage.model->compareOrder(*this, other);
    }

    inline bool QXmlNodeModelIndex::is(const QXmlNodeModelIndex &other) const
    {
        return m_storage.model == other.m_storage.model &&
               m_storage.data == other.m_storage.data &&
               m_storage.additionalData == other.m_storage.additionalData;
    }

    inline void QXmlNodeModelIndex::sendNamespaces(QAbstractXmlReceiver *const receiver) const
    {
        m_storage.model->sendNamespaces(*this, receiver);
    }

    inline QVector<QXmlName> QXmlNodeModelIndex::namespaceBindings() const
    {
        return m_storage.model->namespaceBindings(*this);
    }

    inline QXmlName::NamespaceCode QXmlNodeModelIndex::namespaceForPrefix(const QXmlName::PrefixCode prefix) const
    {
        return m_storage.model->namespaceForPrefix(*this, prefix);
    }

    inline QString QXmlNodeModelIndex::stringValue() const
    {
        return m_storage.model->stringValue(*this);
    }

    inline QPatternist::ItemType::Ptr QXmlNodeModelIndex::type() const
    {
        return m_storage.model->type(*this);
    }

    inline QExplicitlySharedDataPointer<QAbstractXmlForwardIterator<QPatternist::Item> > QXmlNodeModelIndex::sequencedTypedValue() const
    {
        return m_storage.model->sequencedTypedValue(*this);
    }

    inline QXmlItem::QXmlItem(const QPatternist::Item &i) : m_node(i.node)
    {
        if(isAtomicValue())
            m_atomicValue->ref.ref();
    }

Q_DECLARE_TYPEINFO(QPatternist::Item::Iterator::Ptr, Q_MOVABLE_TYPE);
Q_DECLARE_TYPEINFO(QPatternist::AtomicValue, Q_MOVABLE_TYPE);

QT_END_NAMESPACE

QT_END_HEADER

#endif