qt_demoe/designer/lib/extension/qextensionmanager.cpp

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/****************************************************************************
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** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
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** Contact: Nokia Corporation (qt-info@nokia.com)
**
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#include "qextensionmanager.h"
QT_BEGIN_NAMESPACE
/*!
\class QExtensionManager
\brief The QExtensionManager class provides extension management
facilities for Qt Designer.
\inmodule QtDesigner
In \QD the extensions are not created until they are required. For
that reason, when implementing an 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 extension manager.
The registration of an extension factory is typically made in the
QDesignerCustomWidgetInterface::initialize() function:
\snippet doc/src/snippets/code/tools_designer_src_lib_extension_qextensionmanager.cpp 0
The QExtensionManager is not intended to be instantiated
directly. You can retrieve an interface to \QD's extension manager
using the QDesignerFormEditorInterface::extensionManager()
function. A pointer to \QD's current QDesignerFormEditorInterface
object (\c formEditor in the example above) is provided by the
QDesignerCustomWidgetInterface::initialize() function's
parameter. When implementing a custom widget plugin, you must
subclass the QDesignerCustomWidgetInterface to expose your plugin
to \QD.
Then, when an extension is required, \QD's extension manager will
run through all its registered factories calling
QExtensionFactory::createExtension() for each until the first one
that is able to create the 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. \QD's behavior is the same whether the
requested extension is associated with a container, a member
sheet, a property sheet or a task menu.
For a complete example using the QExtensionManager class, see the
\l {designer/taskmenuextension}{Task Menu Extension example}. The
example shows how to create a custom widget plugin for Qt
Designer, and how to to use the QDesignerTaskMenuExtension class
to add custom items to \QD's task menu.
\sa QExtensionFactory, QAbstractExtensionManager
*/
/*!
Constructs an extension manager with the given \a parent.
*/
QExtensionManager::QExtensionManager(QObject *parent)
: QObject(parent)
{
}
/*!
Destroys the extension manager
*/
QExtensionManager::~QExtensionManager()
{
}
/*!
Register the extension specified by the given \a factory and
extension identifier \a iid.
*/
void QExtensionManager::registerExtensions(QAbstractExtensionFactory *factory, const QString &iid)
{
if (iid.isEmpty()) {
m_globalExtension.prepend(factory);
return;
}
FactoryMap::iterator it = m_extensions.find(iid);
if (it == m_extensions.end())
it = m_extensions.insert(iid, FactoryList());
it.value().prepend(factory);
}
/*!
Unregister the extension specified by the given \a factory and
extension identifier \a iid.
*/
void QExtensionManager::unregisterExtensions(QAbstractExtensionFactory *factory, const QString &iid)
{
if (iid.isEmpty()) {
m_globalExtension.removeAll(factory);
return;
}
const FactoryMap::iterator it = m_extensions.find(iid);
if (it == m_extensions.end())
return;
FactoryList &factories = it.value();
factories.removeAll(factory);
if (factories.isEmpty())
m_extensions.erase(it);
}
/*!
Returns the extension specified by \a iid, for the given \a
object.
*/
QObject *QExtensionManager::extension(QObject *object, const QString &iid) const
{
const FactoryMap::const_iterator it = m_extensions.constFind(iid);
if (it != m_extensions.constEnd()) {
const FactoryList::const_iterator fcend = it.value().constEnd();
for (FactoryList::const_iterator fit = it.value().constBegin(); fit != fcend; ++fit)
if (QObject *ext = (*fit)->extension(object, iid))
return ext;
}
const FactoryList::const_iterator gfcend = m_globalExtension.constEnd();
for (FactoryList::const_iterator git = m_globalExtension.constBegin(); git != gfcend; ++git)
if (QObject *ext = (*git)->extension(object, iid))
return ext;
return 0;
}
QT_END_NAMESPACE