/****************************************************************************

**

** Copyright (C) 2008-2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (developer.feedback@nokia.com)

**

** This file is part of the HbCore module of the UI Extensions for Mobile.

**

** GNU Lesser General Public License Usage

** This file may be used under the terms of the GNU Lesser General Public

** License version 2.1 as published by the Free Software Foundation and

** appearing in the file LICENSE.LGPL included in the packaging of this file.

** Please review the following information to ensure the GNU Lesser General

** Public License version 2.1 requirements will be met:

** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at developer.feedback@nokia.com.

**

****************************************************************************/

#include "hbwidgetsequentialshow_p.h"

#include <hbwidget.h>

HbWidgetSequentialShow::HbWidgetSequentialShow(ExternalSynchorization *externalSynchorization,

    void *funcArg)

{

    mWidgetShown = 0;

    mExternalSynchorization = externalSynchorization; // no ownership transfer

    mExternalSynchorizationArg = funcArg;

}

HbWidgetSequentialShow::~HbWidgetSequentialShow()

{

}

// Add widget into a show queue

void HbWidgetSequentialShow::add(HbWidget *widget)

{

    // Allow only single instance of a same widget in the queue

    if (mQueue.contains(widget)) {

        return;

    }

    mQueue.append(widget);

    connect(widget, SIGNAL(visibleChanged()), SLOT(widgetVisibleChanged()));

}

// Remove widget from a show queue

void HbWidgetSequentialShow::remove(HbWidget *widget)

{

    if (mWidgetShown == widget) {

        mWidgetShown = 0;

    }

    mQueue.removeOne(widget);

    widget->disconnect(this);

    showNext();

}

// Set currently showing widget

void HbWidgetSequentialShow::setShowing(HbWidget *widget)

{

    Q_ASSERT(mWidgetShown == 0);

    mWidgetShown = widget;

}

// Return a widget that is to be shown

HbWidget *HbWidgetSequentialShow::toShowNow()

{

    HbWidget *toShow = 0;

    if (mWidgetShown == 0 && !mQueue.empty() && externalAllows()){

        toShow = static_cast<HbWidget*>(mQueue.first());

    }

    return toShow;

}

// Show next widget if appropriate

void HbWidgetSequentialShow::showNext()

{

    HbWidget *toShow = toShowNow();

    if (toShow) {

        toShow->show();

    }

}

// Return true if external synchronization allows showing of widget

bool HbWidgetSequentialShow::externalAllows()

{

    bool allows = true;

    if (mExternalSynchorization) {

        allows = mExternalSynchorization(mExternalSynchorizationArg);

    }

    return allows;

}

// Widget visibility has changed

void HbWidgetSequentialShow::widgetVisibleChanged()

{

    // Added to the queue.

    HbWidget *widget = static_cast<HbWidget*>(sender());

    if (!widget->isVisible()) {

        // Hidden widget is removed from the queue

        remove(widget);

    }

    else {

        // Widget is visible, it should be the widget currently shown. If not, remove it from

        // the queue as sequence has been broken.

        if (mWidgetShown != widget) {

            remove(widget);

        }

    }

}

// External synchronization status has changed

void HbWidgetSequentialShow::externalStatusChanged()

{

    showNext();

}