summaryrefslogtreecommitdiffstats
path: root/src/gui/accessible/qaccessiblecache.cpp
blob: 20376a54c4f02e21c4665f1223ef38d145893523 (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
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** 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 https://www.qt.io/terms-conditions. For further
** information use the contact form at https://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 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qaccessiblecache_p.h"
#include <QtCore/qdebug.h>
#include <QtCore/qloggingcategory.h>

#ifndef QT_NO_ACCESSIBILITY

QT_BEGIN_NAMESPACE

Q_LOGGING_CATEGORY(lcAccessibilityCache, "qt.accessibility.cache");

/*!
    \class QAccessibleCache
    \internal
    \brief Maintains a cache of accessible interfaces.
*/

static QAccessibleCache *accessibleCache = nullptr;

static void cleanupAccessibleCache()
{
    delete accessibleCache;
    accessibleCache = nullptr;
}

QAccessibleCache::~QAccessibleCache()
{
    for (QAccessible::Id id: idToInterface.keys())
        deleteInterface(id);
}

QAccessibleCache *QAccessibleCache::instance()
{
    if (!accessibleCache) {
        accessibleCache = new QAccessibleCache;
        qAddPostRoutine(cleanupAccessibleCache);
    }
    return accessibleCache;
}

/*
  The ID is always in the range [INT_MAX+1, UINT_MAX].
  This makes it easy on windows to reserve the positive integer range
  for the index of a child and not clash with the unique ids.
*/
QAccessible::Id QAccessibleCache::acquireId() const
{
    static const QAccessible::Id FirstId = QAccessible::Id(INT_MAX) + 1;
    static QAccessible::Id lastUsedId = FirstId;

    while (idToInterface.contains(lastUsedId)) {
        // (wrap back when when we reach UINT_MAX - 1)
        // -1 because on Android -1 is taken for the "View" so just avoid it completely for consistency
        if (lastUsedId == UINT_MAX - 1)
            lastUsedId = FirstId;
        else
            ++lastUsedId;
    }

    return lastUsedId;
}

QAccessibleInterface *QAccessibleCache::interfaceForId(QAccessible::Id id) const
{
    return idToInterface.value(id);
}

QAccessible::Id QAccessibleCache::idForInterface(QAccessibleInterface *iface) const
{
    return interfaceToId.value(iface);
}

QAccessible::Id QAccessibleCache::insert(QObject *object, QAccessibleInterface *iface) const
{
    Q_ASSERT(iface);
    Q_UNUSED(object)

    // object might be 0
    Q_ASSERT(!objectToId.contains(object));
    Q_ASSERT_X(!interfaceToId.contains(iface), "", "Accessible interface inserted into cache twice!");

    QAccessible::Id id = acquireId();
    QObject *obj = iface->object();
    Q_ASSERT(object == obj);
    if (obj) {
        objectToId.insert(obj, id);
        connect(obj, &QObject::destroyed, this, &QAccessibleCache::objectDestroyed);
    }
    idToInterface.insert(id, iface);
    interfaceToId.insert(iface, id);
    qCDebug(lcAccessibilityCache) << "insert - id:" << id << " iface:" << iface;
    return id;
}

void QAccessibleCache::objectDestroyed(QObject* obj)
{
    QAccessible::Id id = objectToId.value(obj);
    if (id) {
        Q_ASSERT_X(idToInterface.contains(id), "", "QObject with accessible interface deleted, where interface not in cache!");
        deleteInterface(id, obj);
    }
}

void QAccessibleCache::deleteInterface(QAccessible::Id id, QObject *obj)
{
    QAccessibleInterface *iface = idToInterface.take(id);
    qCDebug(lcAccessibilityCache) << "delete - id:" << id << " iface:" << iface;
    if (!iface) // the interface may be deleted already
        return;
    interfaceToId.take(iface);
    if (!obj)
        obj = iface->object();
    if (obj)
        objectToId.remove(obj);
    delete iface;

#ifdef Q_OS_MAC
    removeCocoaElement(id);
#endif
}

QT_END_NAMESPACE

#endif