1 /*

     2  * Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

     3  * All rights reserved.

     4  * This component and the accompanying materials are made available

     5  * under the terms of "Eclipse Public License v1.0"

     6  * which accompanies this distribution, and is available

     7  * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8  *

     9  * Initial Contributors:

    10  * Nokia Corporation - initial contribution.

    11  *

    12  * Contributors:

    13  *

    14  * Description: Customized scroll area which handles dynamic slide loading in

    15  *              unifiedviewer

    16  *

    17  */

    18 

    19 #include "uniscrollarea.h"

    20 

    21 #include <HbScrollBar>

    22 

    23 //---------------------------------------------------------------

    24 //UniScrollArea :: UniScrollArea

    25 // @see header file

    26 //---------------------------------------------------------------

    27 UniScrollArea::UniScrollArea(QGraphicsItem * parent) :

    28     HbScrollArea(parent), mCurrentSlide(0), mTotalSlides(0)

    29 {

    30     bool flag = connect(this, SIGNAL(scrollingEnded()),

    31     this, SLOT(handleScrollingEnded()));

    32     bool flag1 = connect(this, SIGNAL(scrollingStarted()),

    33     this, SLOT(handleScrollingStarted()));

    34 

    35 }

    36 

    37 //---------------------------------------------------------------

    38 //UniScrollArea :: ~UniScrollArea

    39 // @see header file

    40 //---------------------------------------------------------------

    41 UniScrollArea::~UniScrollArea()

    42 {

    43 

    44 }

    45 

    46 //---------------------------------------------------------------

    47 //UniScrollArea :: setTotalSlides

    48 // @see header file

    49 //---------------------------------------------------------------

    50 void UniScrollArea::setTotalSlides(int totalSlides)

    51 {

    52     mTotalSlides = totalSlides;

    53 }

    54 

    55 //---------------------------------------------------------------

    56 //UniScrollArea :: resetCurrentSlide

    57 // @see header file

    58 //---------------------------------------------------------------

    59 void UniScrollArea::resetCurrentSlide()

    60 {

    61     mCurrentSlide = 0;

    62 }

    63 

    64 //---------------------------------------------------------------

    65 //UniScrollArea :: handleScrollingEnded

    66 // @see header file

    67 //---------------------------------------------------------------

    68 void UniScrollArea::handleScrollingEnded()

    69 {

    70     // TODO : reduce the complexity , code readability

    71     // TODO : avoid calculating the heights every time

    72     int currentSlide = -1;

    73     QList<qreal> heights;

    74     heights.clear();

    75     // contents() is not available so replaced with contentWidget()

    76     //    mScrollEndPoint = this->contents()->pos();

    77     mScrollEndPoint = this->contentWidget()->pos();

    78     // contents() is not available so replaced with contentWidget()

    79     QList<QGraphicsItem *> list = this->contentWidget()->childItems();

    80     for (int i = 0; i < list.size(); i++)

    81     {

    82         QRectF rect = list[i]->boundingRect();

    83         heights.append(- (rect.height()));

    84     }

    85 

    86     qreal h = 0.0;

    87     for (int i = 0; i < heights.size(); i++)

    88     {

    89         h += heights.at(i);

    90         if (mScrollEndPoint.y() > h)

    91         {

    92             currentSlide = i;

    93             break;

    94         }

    95     }

    96 

    97     if (mScrollEndPoint.y() < mScrollStartPoint.y())

    98     {

    99         //Identify if we are in last slide / last but one slide as we always

   100         // assume the slide next to current slide is always loaded

   101         //(Assumtion is based on slide initial load count of 2)

   102         if (currentSlide >= mTotalSlides - 1)

   103         {

   104             return;

   105         }

   106         //(This can be removed and emit signal if we cross 50% of last slide)

   107         if (currentSlide >= mTotalSlides - 2)

   108         {

   109             return;

   110         }

   111 

   112         //Determine how much we have scrolled & if we have scrolled beyond 50%

   113         //of current slide load the slide next to next slide

   114         qreal delta = heights.at(currentSlide) / 2;

   115         qreal fh = h - delta;

   116         if (mScrollEndPoint.y() < fh)

   117         {

   118             emit scrolledToNextSlide();

   119         }

   120     }

   121 

   122 }

   123 

   124 //---------------------------------------------------------------

   125 //UniScrollArea :: handleScrollingStarted

   126 // @see header file

   127 //---------------------------------------------------------------

   128 void UniScrollArea::handleScrollingStarted()

   129 {

   130     // contents() is not available so replaced with contentWidget()

   131     //   mScrollStartPoint = this->contents()->pos();

   132     mScrollStartPoint = this->contentWidget()->pos();

   133 }

   134 

   135 //---------------------------------------------------------------

   136 //UniScrollArea :: setPosToStart

   137 // @see header file

   138 //---------------------------------------------------------------

   139 void UniScrollArea::setPosToStart()

   140 {

   141     // contents() is not available so replaced with contentWidget()

   142     QGraphicsItem* widgetItem = this->contentWidget();

   143     widgetItem->setPos(0, 0);

   144 }

   145 

   146 

   147 // EOF