/*  This file is part of the KDE project.

Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

This library is free software: you can redistribute it and/or modify

it under the terms of the GNU Lesser General Public License as published by

the Free Software Foundation, either version 2.1 or 3 of the License.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License

along with this library.  If not, see <http://www.gnu.org/licenses/>.

*/

#ifndef PHONON_MMF_ANCESTORMOVEMONITOR_H

#define PHONON_MMF_ANCESTORMOVEMONITOR_H

#include <QObject>

#include <QHash>

#include <QList>

QT_BEGIN_NAMESPACE

namespace Phonon

{

namespace MMF

{

class AncestorMoveMonitor : public QObject

{

    Q_OBJECT

public:

    explicit AncestorMoveMonitor(QObject *parent);

    ~AncestorMoveMonitor();

    /**

     * Register target widget for notification.

     *

     * The widget receives an ancestorMoveEvent callback when a move event

     * is delivered to any of its ancestors:

     *

     * If the target is already registered, this function causes its

     * ancestor list to be updated - therefore it should be called when

     * the target receives a ParentChange event.

     */

    /**

     * Remove target from the monitor.

     *

     * The target will no longer receive notification when move events are

     * delivered to its ancestors.

     */

protected:

    /**

     * Function which receives events from the global event filter.

     */

    bool eventFilter(QObject *watched, QEvent *event);

    void dump();

private:

    /**

     * List of registered target widgets which descend from a given

     * ancestor.

     *

     * Note that the members of the list should be non-redundant; this

     * invariant is checked in debug builds.  Semantically, the value is

     * therefore a set, however we use QList rather than QSet for

     * efficiency of iteration.

     */

    /**

     * Map from widget on which the move event occurs, to widgets which

     * descend from it and therefore need to be notified.

     */

    typedef QHash<QObject *, TargetList> Hash;

    Hash m_hash;

};

}

}

QT_END_NAMESPACE