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 QtGui 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 "qplatformprintplugin.h"
41#include "qplatformprintersupport.h"
42#include "qprinterinfo.h"
43#include "private/qfactoryloader_p.h"
44#include <qcoreapplication.h>
45#include <qdebug.h>
46
47#ifndef QT_NO_PRINTER
48
49QT_BEGIN_NAMESPACE
50
51Q_GLOBAL_STATIC_WITH_ARGS(QFactoryLoader, loader,
52 (QPlatformPrinterSupportFactoryInterface_iid, QLatin1String("/printsupport"), Qt::CaseInsensitive))
53
54QPlatformPrinterSupportPlugin::QPlatformPrinterSupportPlugin(QObject *parent)
55 : QObject(parent)
56{
57}
58
59QPlatformPrinterSupportPlugin::~QPlatformPrinterSupportPlugin()
60{
61}
62
63static QPlatformPrinterSupport *printerSupport = nullptr;
64
65static void cleanupPrinterSupport()
66{
67 delete printerSupport;
68 printerSupport = nullptr;
69}
70
71/*!
72 \internal
73
74 Returns a lazily-initialized singleton. Ownership is granted to the
75 QPlatformPrinterSupportPlugin, which is never unloaded or destroyed until
76 application exit, i.e. you can expect this pointer to always be valid and
77 multiple calls to this function will always return the same pointer.
78*/
79QPlatformPrinterSupport *QPlatformPrinterSupportPlugin::get()
80{
81 if (!printerSupport) {
82 const QMultiMap<int, QString> keyMap = loader()->keyMap();
83 QMultiMap<int, QString>::const_iterator it = keyMap.cbegin();
84 if (!qEnvironmentVariableIsEmpty(varName: "QT_PRINTER_MODULE")) {
85 QString module = QString::fromLocal8Bit(str: qgetenv(varName: "QT_PRINTER_MODULE"));
86 QMultiMap<int, QString>::const_iterator it2 = std::find_if(first: keyMap.cbegin(), last: keyMap.cend(), pred: [module](const QString &value){ return value == module; });
87 if (it2 == keyMap.cend())
88 qWarning() << "Unable to load printer plugin" << module;
89 else
90 it = it2;
91 }
92 if (it != keyMap.cend())
93 printerSupport = qLoadPlugin<QPlatformPrinterSupport, QPlatformPrinterSupportPlugin>(loader: loader(), key: it.value());
94 if (printerSupport)
95 qAddPostRoutine(cleanupPrinterSupport);
96 }
97 return printerSupport;
98}
99
100QT_END_NAMESPACE
101
102#endif
103

source code of qtbase/src/printsupport/kernel/qplatformprintplugin.cpp