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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