aboutsummaryrefslogtreecommitdiffstats
path: root/src/qml/jsapi/qjsvalueiterator.cpp
blob: 1ee4121f5c1c1152eb35e73f6ba163d909f9ba11 (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
/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the QtQml module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL21$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see http://www.qt.io/terms-conditions. For further
** information use the contact form at http://www.qt.io/contact-us.
**
** 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 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** As a special exception, The Qt Company gives you certain additional
** rights. These rights are described in The Qt Company LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qjsvalueiterator.h"
#include "qjsvalueiterator_p.h"
#include "qjsvalue_p.h"
#include "private/qv4string_p.h"
#include "private/qv4object_p.h"
#include "private/qv4context_p.h"

QT_BEGIN_NAMESPACE

QJSValueIteratorPrivate::QJSValueIteratorPrivate(const QJSValue &v)
    : value(v)
    , currentIndex(UINT_MAX)
    , nextIndex(UINT_MAX)
{
    QV4::ExecutionEngine *e = QJSValuePrivate::engine(&v);
    if (!e)
        return;

    QV4::Scope scope(e);
    QV4::ScopedObject o(scope, QJSValuePrivate::getValue(&v));
    iterator.set(e, e->newForEachIteratorObject(o));

    currentName = (QV4::String *)0;
    nextName = (QV4::String *)0;
}


/*!
    \class QJSValueIterator

    \brief The QJSValueIterator class provides a Java-style iterator for QJSValue.

    \ingroup qtjavascript
    \inmodule QtQml


    The QJSValueIterator constructor takes a QJSValue as
    argument.  After construction, the iterator is located at the very
    beginning of the sequence of properties. Here's how to iterate over
    all the properties of a QJSValue:

    \snippet code/src_script_qjsvalueiterator.cpp 0

    The next() advances the iterator. The name() and value()
    functions return the name and value of the last item that was
    jumped over.

    Note that QJSValueIterator only iterates over the QJSValue's
    own properties; i.e. it does not follow the prototype chain. You can
    use a loop like this to follow the prototype chain:

    \snippet code/src_script_qjsvalueiterator.cpp 1

    \sa QJSValue::property()
*/

/*!
    Constructs an iterator for traversing \a object. The iterator is
    set to be at the front of the sequence of properties (before the
    first property).
*/
QJSValueIterator::QJSValueIterator(const QJSValue& object)
    : d_ptr(new QJSValueIteratorPrivate(object))
{
    QV4::ExecutionEngine *v4 = d_ptr->iterator.engine();
    if (!v4)
        return;
    QV4::Scope scope(v4);
    QV4::Scoped<QV4::ForEachIteratorObject> it(scope, d_ptr->iterator.value());
    it->d()->it.flags =  QV4::ObjectIterator::NoFlags;
    QV4::ScopedString nm(scope);
    it->d()->it.next(nm.getRef(), &d_ptr->nextIndex, &d_ptr->nextProperty, &d_ptr->nextAttributes);
    d_ptr->nextName = nm;
}

/*!
    Destroys the iterator.
*/
QJSValueIterator::~QJSValueIterator()
{
}

/*!
    Returns true if there is at least one item ahead of the iterator
    (i.e. the iterator is \e not at the back of the property sequence);
    otherwise returns false.

    \sa next()
*/
bool QJSValueIterator::hasNext() const
{
    QV4::Value *val = QJSValuePrivate::getValue(&d_ptr->value);
    if (!val || !val->isObject())
        return false;
    return !!d_ptr->nextName || d_ptr->nextIndex != UINT_MAX;
}

/*!
    Advances the iterator by one position.
    Returns true if there was at least one item ahead of the iterator
    (i.e. the iterator was \e not already at the back of the property sequence);
    otherwise returns false.

    \sa hasNext(), name()
*/
bool QJSValueIterator::next()
{
    QV4::Value *val = QJSValuePrivate::getValue(&d_ptr->value);
    if (!val || !val->isObject())
        return false;
    d_ptr->currentName = d_ptr->nextName;
    d_ptr->currentIndex = d_ptr->nextIndex;
    d_ptr->currentProperty.copy(&d_ptr->nextProperty, d_ptr->nextAttributes);
    d_ptr->currentAttributes = d_ptr->nextAttributes;

    QV4::ExecutionEngine *v4 = d_ptr->iterator.engine();
    if (!v4)
        return false;
    QV4::Scope scope(v4);
    QV4::Scoped<QV4::ForEachIteratorObject> it(scope, d_ptr->iterator.value());
    QV4::ScopedString nm(scope);
    it->d()->it.next(nm.getRef(), &d_ptr->nextIndex, &d_ptr->nextProperty, &d_ptr->nextAttributes);
    d_ptr->nextName = nm;
    return !!d_ptr->currentName || d_ptr->currentIndex != UINT_MAX;
}

/*!
    Returns the name of the last property that was jumped over using
    next().

    \sa value()
*/
QString QJSValueIterator::name() const
{
    QV4::Value *val = QJSValuePrivate::getValue(&d_ptr->value);
    if (!val || !val->isObject())
        return QString();
    if (!!d_ptr->currentName)
        return d_ptr->currentName->toQString();
    if (d_ptr->currentIndex < UINT_MAX)
        return QString::number(d_ptr->currentIndex);
    return QString();
}


/*!
    Returns the value of the last property that was jumped over using
    next().

    \sa name()
*/
QJSValue QJSValueIterator::value() const
{
    QV4::ExecutionEngine *engine = d_ptr->iterator.engine();
    if (!engine)
        return QJSValue();
    QV4::Scope scope(engine);
    QV4::ScopedObject obj(scope, QJSValuePrivate::getValue(&d_ptr->value));
    if (!obj)
        return QJSValue();

    if (!d_ptr->currentName && d_ptr->currentIndex == UINT_MAX)
        return QJSValue();

    QV4::ScopedValue v(scope, obj->getValue(*obj, &d_ptr->currentProperty, d_ptr->currentAttributes));
    if (scope.hasException()) {
        engine->catchException();
        return QJSValue();
    }
    return QJSValue(engine, v->asReturnedValue());
}


/*!
    Makes the iterator operate on \a object. The iterator is set to be
    at the front of the sequence of properties (before the first
    property).
*/
QJSValueIterator& QJSValueIterator::operator=(QJSValue& object)
{
    d_ptr->value = object;
    d_ptr->currentIndex = UINT_MAX;
    d_ptr->nextIndex = UINT_MAX;
    d_ptr->currentName = (QV4::String *)0;
    d_ptr->nextName = (QV4::String *)0;
    QV4::ExecutionEngine *v4 = d_ptr->iterator.engine();
    if (!v4) {
        d_ptr->iterator.clear();
        return *this;
    }

    QV4::Scope scope(v4);
    QV4::ScopedObject o(scope, QJSValuePrivate::getValue(&object));
    d_ptr->iterator.set(v4, v4->newForEachIteratorObject(o));
    QV4::Scoped<QV4::ForEachIteratorObject> it(scope, d_ptr->iterator.value());
    it->d()->it.flags =  QV4::ObjectIterator::NoFlags;
    QV4::ScopedString nm(scope);
    it->d()->it.next(nm.getRef(), &d_ptr->nextIndex, &d_ptr->nextProperty, &d_ptr->nextAttributes);
    d_ptr->nextName = nm;
    return *this;
}

QT_END_NAMESPACE