1/****************************************************************************
2**
3** Copyright (C) 2016 The Qt Company Ltd.
4** Contact: https://www.qt.io/licensing/
5**
6** This file is part of the QtQml module of the Qt Toolkit.
7**
8** $QT_BEGIN_LICENSE:LGPL$
9** Commercial License Usage
10** Licensees holding valid commercial Qt licenses may use this file in
11** accordance with the commercial license agreement provided with the
12** Software or, alternatively, in accordance with the terms contained in
13** a written agreement between you and The Qt Company. For licensing terms
14** and conditions see https://www.qt.io/terms-conditions. For further
15** information use the contact form at https://www.qt.io/contact-us.
16**
17** GNU Lesser General Public License Usage
18** Alternatively, this file may be used under the terms of the GNU Lesser
19** General Public License version 3 as published by the Free Software
20** Foundation and appearing in the file LICENSE.LGPL3 included in the
21** packaging of this file. Please review the following information to
22** ensure the GNU Lesser General Public License version 3 requirements
23** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
24**
25** GNU General Public License Usage
26** Alternatively, this file may be used under the terms of the GNU
27** General Public License version 2.0 or (at your option) the GNU General
28** Public license version 3 or any later version approved by the KDE Free
29** Qt Foundation. The licenses are as published by the Free Software
30** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
31** included in the packaging of this file. Please review the following
32** information to ensure the GNU General Public License requirements will
33** be met: https://www.gnu.org/licenses/gpl-2.0.html and
34** https://www.gnu.org/licenses/gpl-3.0.html.
35**
36** $QT_END_LICENSE$
37**
38****************************************************************************/
39
40#include "qqmlnotifier_p.h"
41#include "qqmlproperty_p.h"
42#include <QtCore/qdebug.h>
43#include <private/qthread_p.h>
44
45QT_BEGIN_NAMESPACE
46
47typedef void (*Callback)(QQmlNotifierEndpoint *, void **);
48
49void QQmlBoundSignal_callback(QQmlNotifierEndpoint *, void **);
50void QQmlJavaScriptExpressionGuard_callback(QQmlNotifierEndpoint *, void **);
51void QQmlVMEMetaObjectEndpoint_callback(QQmlNotifierEndpoint *, void **);
52
53static Callback QQmlNotifier_callbacks[] = {
54 nullptr,
55 QQmlBoundSignal_callback,
56 QQmlJavaScriptExpressionGuard_callback,
57 QQmlVMEMetaObjectEndpoint_callback
58};
59
60namespace {
61 struct NotifyListTraversalData {
62 NotifyListTraversalData(QQmlNotifierEndpoint *ep = nullptr)
63 : originalSenderPtr(0)
64 , disconnectWatch(nullptr)
65 , endpoint(ep)
66 {}
67
68 qintptr originalSenderPtr;
69 qintptr *disconnectWatch;
70 QQmlNotifierEndpoint *endpoint;
71 };
72}
73
74void QQmlNotifier::notify(QQmlData *ddata, int notifierIndex)
75{
76 if (QQmlNotifierEndpoint *ep = ddata->notify(index: notifierIndex))
77 emitNotify(ep, a: nullptr);
78}
79
80void QQmlNotifier::emitNotify(QQmlNotifierEndpoint *endpoint, void **a)
81{
82 QVarLengthArray<NotifyListTraversalData> stack;
83 while (endpoint) {
84 stack.append(t: NotifyListTraversalData(endpoint));
85 endpoint = endpoint->next;
86 }
87
88 int i = 0;
89 for (; i < stack.size(); ++i) {
90 NotifyListTraversalData &data = stack[i];
91
92 if (!data.endpoint->isNotifying()) {
93 data.endpoint->startNotifying(originalSenderPtr: &data.originalSenderPtr);
94 data.disconnectWatch = &data.originalSenderPtr;
95 } else {
96 data.disconnectWatch = (qintptr *)(data.endpoint->senderPtr & ~0x1);
97 }
98 }
99
100 while (--i >= 0) {
101 NotifyListTraversalData &data = stack[i];
102 if (*data.disconnectWatch) {
103 Q_ASSERT(QQmlNotifier_callbacks[data.endpoint->callback]);
104 QQmlNotifier_callbacks[data.endpoint->callback](data.endpoint, a);
105 if (data.disconnectWatch == &data.originalSenderPtr && data.originalSenderPtr) {
106 data.endpoint->stopNotifying(originalSenderPtr: &data.originalSenderPtr);
107 }
108 }
109 }
110}
111
112/*! \internal
113 \a sourceSignal MUST be in the signal index range (see QObjectPrivate::signalIndex()).
114 This is different from QMetaMethod::methodIndex().
115*/
116void QQmlNotifierEndpoint::connect(QObject *source, int sourceSignal, QQmlEngine *engine, bool doNotify)
117{
118 disconnect();
119
120 Q_ASSERT(engine);
121 if (QObjectPrivate::get(o: source)->threadData.loadRelaxed()->threadId.loadRelaxed() !=
122 QObjectPrivate::get(o: engine)->threadData.loadRelaxed()->threadId.loadRelaxed()) {
123
124 QString sourceName;
125 QDebug(&sourceName) << source;
126 sourceName = sourceName.left(n: sourceName.length() - 1);
127 QString engineName;
128 QDebug(&engineName).nospace() << engine;
129 engineName = engineName.left(n: engineName.length() - 1);
130
131 qFatal(msg: "QQmlEngine: Illegal attempt to connect to %s that is in"
132 " a different thread than the QML engine %s.", qPrintable(sourceName),
133 qPrintable(engineName));
134 }
135
136 setSender(qintptr(source));
137 this->sourceSignal = sourceSignal;
138 QQmlPropertyPrivate::flushSignal(sender: source, signal_index: sourceSignal);
139 QQmlData *ddata = QQmlData::get(object: source, create: true);
140 ddata->addNotify(index: sourceSignal, this);
141 if (doNotify) {
142 needsConnectNotify = doNotify;
143 QObjectPrivate * const priv = QObjectPrivate::get(o: source);
144 priv->connectNotify(signal: QMetaObjectPrivate::signal(m: source->metaObject(), signal_index: sourceSignal));
145 }
146}
147
148QT_END_NAMESPACE
149
150

source code of qtdeclarative/src/qml/qml/qqmlnotifier.cpp