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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
#include "default_extensionfactory.h"
#include "qextensionmanager.h"
#include <qpointer.h>
#include <QtCore/qdebug.h>
QT_BEGIN_NAMESPACE
/*!
\class QExtensionFactory
\brief The QExtensionFactory class allows you to create a factory
that is able to make instances of custom extensions in Qt
Designer.
\inmodule QtDesigner
In \QD the extensions are not created until they are required. For
that reason, when implementing a custom extension, you must also
create a QExtensionFactory, i.e. a class that is able to make an
instance of your extension, and register it using \QD's \l
{QExtensionManager}{extension manager}.
The QExtensionManager class provides extension management
facilities for \QD. When an extension is required, Qt
Designer's \l {QExtensionManager}{extension manager} will run
through all its registered factories calling
QExtensionFactory::createExtension() for each until the first one
that is able to create a requested extension for the selected
object, is found. This factory will then make an instance of the
extension.
There are four available types of extensions in \QD:
QDesignerContainerExtension , QDesignerMemberSheetExtension,
QDesignerPropertySheetExtension and QDesignerTaskMenuExtension. Qt
Designer's behavior is the same whether the requested extension is
associated with a multi page container, a member sheet, a property
sheet or a task menu.
You can either create a new QExtensionFactory and reimplement the
QExtensionFactory::createExtension() function. For example:
\snippet lib/tools_designer_src_lib_extension_default_extensionfactory.cpp 0
Or you can use an existing factory, expanding the
QExtensionFactory::createExtension() function to make the factory
able to create your extension as well. For example:
\snippet lib/tools_designer_src_lib_extension_default_extensionfactory.cpp 1
For a complete example using the QExtensionFactory class, see the
\l {taskmenuextension}{Task Menu Extension example}. The
example shows how to create a custom widget plugin for Qt
Designer, and how to use the QDesignerTaskMenuExtension class
to add custom items to \QD's task menu.
\sa QExtensionManager, QAbstractExtensionFactory
*/
/*!
Constructs an extension factory with the given \a parent.
*/
QExtensionFactory::QExtensionFactory(QExtensionManager *parent)
: QObject(parent)
{
}
/*!
Returns the extension specified by \a iid for the given \a object.
\sa createExtension()
*/
QObject *QExtensionFactory::extension(QObject *object, const QString &iid) const
{
if (!object)
return nullptr;
const auto key = std::make_pair(iid, object);
auto it = m_extensions.find(key);
if (it == m_extensions.end()) {
if (QObject *ext = createExtension(object, iid, const_cast<QExtensionFactory*>(this))) {
connect(ext, &QObject::destroyed, this, &QExtensionFactory::objectDestroyed);
it = m_extensions.insert(key, ext);
}
}
if (!m_extended.contains(object)) {
connect(object, &QObject::destroyed, this, &QExtensionFactory::objectDestroyed);
m_extended.insert(object, true);
}
if (it == m_extensions.end())
return nullptr;
return it.value();
}
void QExtensionFactory::objectDestroyed(QObject *object)
{
for (auto it = m_extensions.begin(); it != m_extensions.end(); ) {
if (it.key().second == object || object == it.value())
it = m_extensions.erase(it);
else
++it;
}
m_extended.remove(object);
}
/*!
Creates an extension specified by \a iid for the given \a object.
The extension object is created as a child of the specified \a
parent.
\sa extension()
*/
QObject *QExtensionFactory::createExtension(QObject *object, const QString &iid, QObject *parent) const
{
Q_UNUSED(object);
Q_UNUSED(iid);
Q_UNUSED(parent);
return nullptr;
}
/*!
Returns the extension manager for the extension factory.
*/
QExtensionManager *QExtensionFactory::extensionManager() const
{
return static_cast<QExtensionManager *>(parent());
}
QT_END_NAMESPACE
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