/*

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

* All rights reserved.

*

* This program 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, version 2.1 of the License.

*

* This program 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 program.  If not,

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

*

* Description:

*

*/

#include "SlidingWidget.h"

#include "ChromeSnippet.h"

#include <QDebug>

//NB: Note that the current implementation only supports one snippet child

namespace GVA {

  SlidingWidget::SlidingWidget(QGraphicsItem* parent)

    : QGraphicsWidget(parent),

      m_top(0),

      m_window(0),

      m_bottom(0),

      m_slideMax(0),

      m_slidePos(0),

      m_shrinked(0),

      m_shrinkMax(0),

      m_windowSize(QSizeF())

  {

    //Clip child item so that it can "slide" out of view

    setFlags(QGraphicsItem::ItemClipsChildrenToShape);

    //setSizePolicy(QSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred));

    m_layout = new QGraphicsAnchorLayout();

    m_layout->setContentsMargins(0,0,0,0);

    m_layout->setSpacing(0);

    setLayout(m_layout);

  }

  SlidingWidget:: ~SlidingWidget()

  {

    // delete m_layout;

  }

  void SlidingWidget::resizeEvent(QGraphicsSceneResizeEvent *ev)

  {

    if (m_window)

      m_window->resize(ev->newSize());

      m_windowSize = ev->newSize();

      m_shrinked = 0;

      //m_window->resize(ev->newSize().width(), m_window->size().height());

    QGraphicsWidget::resizeEvent(ev);

  }

  /* shrink the viewport at the bottom, to show content on top of toolbar */

  qreal SlidingWidget::shrink(qreal delta)

  {

      qreal newDelta = m_shrinked + delta;

      if (newDelta < -m_shrinkMax) {

          newDelta = -m_shrinkMax;

      }

      if (newDelta > 0) {

          newDelta = 0;

      }

      delta = newDelta - m_shrinked;

      if (delta != 0) {

          m_window->resize(m_window->size().width(), m_window->size().height() + delta);

          m_shrinked = newDelta;

      }

      return delta;

  }

  qreal SlidingWidget::slide(qreal delta)

  {

    qreal newPos = m_slidePos + delta;

    //qDebug() << "SlidingWidget::slide: delta: " << delta << " m_slidePos: " << m_slidePos << " newPos: " << newPos;

    if (newPos < 0) {

      if (m_slidePos == 0)

    return 0;

      delta = -m_slidePos;

      m_slidePos = 0;

    }

    else if (newPos > m_slideMax){

      if (m_slidePos == m_slideMax)

    return 0;

      delta = m_slideMax - m_slidePos;

      m_slidePos = m_slideMax;

    }

    else m_slidePos = newPos;

    //qDebug() << "calculated delta: " << delta << " new m_slidePos: " << m_slidePos;

    QTransform transform;

    transform.translate(0,delta);

    //m_window->setTransform(transform, true);

    //m_top->setTransform(transform, true);

    m_top->setPos(0, m_top->pos().y() + delta);

    m_window->setPos(0, m_window->pos().y() + delta);

    return delta;

  }

  void SlidingWidget::setWindow(QGraphicsWidget * window)

  {

    if (m_window)

      m_window->setParentItem(0);

    m_window = window;

    m_window->setParentItem(this);

    /* set the window size to saved value, before the viewport is shrinked */

    m_window->resize(m_windowSize);

    m_shrinked = 0;

    if (m_top) {

        slide(0);

        QGraphicsWidget* item=m_top;

        attachItem(item);

    }

    else

      m_window->setPos(0,0);

    //m_layout->addAnchors(m_window, m_layout, Qt::Horizontal);

  }

  void SlidingWidget::attachItem(QGraphicsWidget * item)

  {

    if (m_top)

      detachItem(m_top);

    m_top = item;

    m_top->setParentItem(this);

    m_top->setPos(0,0);

    m_slideMax =  m_top->size().height();

    m_slidePos = m_slideMax;

    if (m_window)

      m_window->setPos(0, m_top->size().height());

  }

  void SlidingWidget::detachItem(QGraphicsWidget * item)

  {

    if (m_top != item)

      return;

    m_top->setParentItem(0);

    m_top = 0;

    if (m_window)

      m_window->setPos(0,0);

  }

} // end of namespace GVA