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#include <QtDesigner/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 Qt Designer. 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 Qt Designer:

    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 doc/src/snippets/code/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 doc/src/snippets/code/tools_designer_src_lib_extension_default_extensionfactory.cpp 1

    For a complete example using the QExtensionFactory 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 Qt Designer'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 0;

    const IdObjectKey key = qMakePair(iid, object);

    ExtensionMap::iterator it = m_extensions.find(key);

    if (it == m_extensions.end()) {

        if (QObject *ext = createExtension(object, iid, const_cast<QExtensionFactory*>(this))) {

            connect(ext, SIGNAL(destroyed(QObject*)), this, SLOT(objectDestroyed(QObject*)));

            it = m_extensions.insert(key, ext);

        }

    }

    if (!m_extended.contains(object)) {

        connect(object, SIGNAL(destroyed(QObject*)), this, SLOT(objectDestroyed(QObject*)));

        m_extended.insert(object, true);

    }

    if (it == m_extensions.end())

        return 0;

    return it.value();

}

void QExtensionFactory::objectDestroyed(QObject *object)

{

    QMutableMapIterator< IdObjectKey, QObject*> it(m_extensions);

    while (it.hasNext()) {

        it.next();

        QObject *o = it.key().second;

        if (o == object || object == it.value()) {

            it.remove();

        }

    }

    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 0;

}

/*!

    Returns the extension manager for the extension factory.

*/

QExtensionManager *QExtensionFactory::extensionManager() const

{

    return static_cast<QExtensionManager *>(parent());

}

QT_END_NAMESPACE