summaryrefslogtreecommitdiffstats
path: root/src/declarative/qml/qmlbindingoptimizations.cpp
blob: a10b1e39b124c63a809f25277386e8a653ef8b01 (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
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Qt Software Information (qt-info@nokia.com)
**
** This file is part of the QtDeclarative 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 qt-sales@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qmlbindingoptimizations_p.h"
#include <private/qmlcontext_p.h>

QT_BEGIN_NAMESPACE

/*
    The QmlBinding_Id optimization handles expressions of the type:

        property: id

    where id is a local context id, and property is an object property.  
    Coercian between id and property must be checked outside the QmlBinding_Id -
    it assumes that they coerce successfully.

    The QmlBinding_Id class avoids any signal slot connections, through the
    special "bindings" linked list maintained in the 
    QmlContextPrivate::ContextGuard instance for each id object.
*/
QmlBinding_Id::QmlBinding_Id(QObject *object, int propertyIdx,
                             QmlContext *context, int id)
: m_prev(0), m_next(0), m_object(object), m_propertyIdx(propertyIdx), m_id(id)
{
    QmlAbstractExpression::setContext(context);
}

void QmlBinding_Id::setEnabled(bool e)
{
    if (e) {
        addToObject(m_object);
        update();
    } else {
        removeFromObject();
    }
}

int QmlBinding_Id::propertyIndex()
{
    return m_propertyIdx;
}

void QmlBinding_Id::update()
{
    QmlContextPrivate *ctxtPriv = 
        static_cast<QmlContextPrivate *>(QObjectPrivate::get(context()));

    if (ctxtPriv) {

        if (!m_prev) {
            m_next = ctxtPriv->idValues[m_id].bindings;
            if (m_next) m_next->m_prev = &m_next;

            m_prev = &ctxtPriv->idValues[m_id].bindings;
            ctxtPriv->idValues[m_id].bindings = this;
        }

        QObject *o = ctxtPriv->idValues[m_id].data();
        void *a[] = { &o, 0 };
        QMetaObject::metacall(m_object, QMetaObject::WriteProperty, 
                              m_propertyIdx, a);
    } 
}

void QmlBinding_Id::reset()
{
    if (m_prev) {
        *m_prev = m_next;
        if (m_next) m_next->m_prev = m_prev;
        m_next = 0;
        m_prev = 0;
    }

    QObject *o = 0;
    void *a[] = { &o, 0 };
    QMetaObject::metacall(m_object, QMetaObject::WriteProperty, 
                          m_propertyIdx, a);
}

/*
    The QmlBinding_ObjectProperty optimization handles expressions of the type:

        property: objectProperty

    where both property and objectProperty are object properties on the target
    object.  Coercian between the two must be checked outside the 
    QmlBinding_ObjectProperty - it assumes that they coerce successfully.

    Due to dot properties, property does not have to be on the same object as 
    objectProperty.  For example:

        anchors.fill: parent
*/
QmlBinding_ObjProperty::QmlBinding_ObjProperty(QObject *object, int propertyIdx,
                                               QObject *context, int contextIdx,
                                               int notifyIdx)
: m_enabled(false), m_object(object), m_propertyIdx(propertyIdx), 
  m_context(context), m_contextIdx(contextIdx), m_notifyIdx(notifyIdx)
{
}

void QmlBinding_ObjProperty::setEnabled(bool e)
{
    m_enabled = e;
    if (e) {
        addToObject(m_object);
        update();
    } else {
        removeFromObject();
    }
}

int QmlBinding_ObjProperty::propertyIndex()
{
    return m_propertyIdx;
}

void QmlBinding_ObjProperty::update()
{
    if (!m_enabled)
        return;

    QObject *value = 0;
    void *a[] = { &value, 0 };

    // Read
    QMetaObject::metacall(m_context, QMetaObject::ReadProperty, 
                          m_contextIdx, a);

    // Write
    QMetaObject::metacall(m_object, QMetaObject::WriteProperty, 
                          m_propertyIdx, a);

    // Connect notify if needed.  Only need to connect once, so we set
    // m_notifyIdx back to -1 afterwards
    static int slotIdx = -1;
    if (m_notifyIdx != -1) {
        if (slotIdx == -1) 
            slotIdx = QmlBinding_ObjProperty::staticMetaObject.indexOfMethod("update()");

        QMetaObject::connect(m_context, m_notifyIdx, this, slotIdx);
        m_notifyIdx = -1;
    }
}

QT_END_NAMESPACE