messagingapp/msgui/unifiedviewer/src/uniscrollarea.cpp
changeset 23 238255e8b033
child 27 e4592d119491
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/messagingapp/msgui/unifiedviewer/src/uniscrollarea.cpp	Fri Apr 16 14:56:15 2010 +0300
@@ -0,0 +1,164 @@
+/*
+ * Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).
+ * All rights reserved.
+ * This component and the accompanying materials are made available
+ * under the terms of "Eclipse Public License v1.0"
+ * which accompanies this distribution, and is available
+ * at the URL "http://www.eclipse.org/legal/epl-v10.html".
+ *
+ * Initial Contributors:
+ * Nokia Corporation - initial contribution.
+ *
+ * Contributors:
+ *
+ * Description: Customized scroll area which handles dynamic slide loading in
+ *              unifiedviewer
+ *
+ */
+
+#include "uniscrollarea.h"
+
+#include <HbScrollBar>
+
+//---------------------------------------------------------------
+//UniScrollArea :: UniScrollArea
+// @see header file
+//---------------------------------------------------------------
+UniScrollArea::UniScrollArea(QGraphicsItem * parent) :
+    HbScrollArea(parent), mCurrentSlide(0), mTotalSlides(0)
+{
+    bool flag = connect(this, SIGNAL(scrollingEnded()),
+    this, SLOT(handleScrollingEnded()));
+    bool flag1 = connect(this, SIGNAL(scrollingStarted()),
+    this, SLOT(handleScrollingStarted()));
+
+}
+
+//---------------------------------------------------------------
+//UniScrollArea :: ~UniScrollArea
+// @see header file
+//---------------------------------------------------------------
+UniScrollArea::~UniScrollArea()
+{
+
+}
+
+//---------------------------------------------------------------
+//UniScrollArea :: setTotalSlides
+// @see header file
+//---------------------------------------------------------------
+void UniScrollArea::setTotalSlides(int totalSlides)
+{
+    mTotalSlides = totalSlides;
+}
+
+//---------------------------------------------------------------
+//UniScrollArea :: resetCurrentSlide
+// @see header file
+//---------------------------------------------------------------
+void UniScrollArea::resetCurrentSlide()
+{
+    mCurrentSlide = 0;
+}
+
+//---------------------------------------------------------------
+//UniScrollArea :: handleScrollingEnded
+// @see header file
+//---------------------------------------------------------------
+void UniScrollArea::handleScrollingEnded()
+{
+    // TODO : reduce the complexity , code readability
+    // TODO : avoid calculating the heights every time
+    int currentSlide = -1;
+    QList<qreal> heights;
+    heights.clear();
+    // contents() is not available so replaced with contentWidget()
+    //    mScrollEndPoint = this->contents()->pos();
+    mScrollEndPoint = this->contentWidget()->pos();
+    // contents() is not available so replaced with contentWidget()
+    QList<QGraphicsItem *> list = this->contentWidget()->childItems();
+    for (int i = 0; i < list.size(); i++)
+    {
+        QRectF rect = list[i]->boundingRect();
+        heights.append(- (rect.height()));
+    }
+
+    qreal h = 0.0;
+    for (int i = 0; i < heights.size(); i++)
+    {
+        h += heights.at(i);
+        if (mScrollEndPoint.y() > h)
+        {
+            currentSlide = i;
+            break;
+        }
+    }
+
+    if (mScrollEndPoint.y() < mScrollStartPoint.y())
+    {
+        //Identify if we are in last slide / last but one slide as we always
+        // assume the slide next to current slide is always loaded
+        //(Assumtion is based on slide initial load count of 2)
+        if (currentSlide >= mTotalSlides - 1)
+        {
+            return;
+        }
+        //(This can be removed and emit signal if we cross 50% of last slide)
+        if (currentSlide >= mTotalSlides - 2)
+        {
+            return;
+        }
+
+        //Determine how much we have scrolled & if we have scrolled beyond 50%
+        //of current slide load the slide next to next slide
+        qreal delta = heights.at(currentSlide) / 2;
+        qreal fh = h - delta;
+        if (mScrollEndPoint.y() < fh)
+        {
+            emit scrolledToNextSlide();
+        }
+    }
+
+}
+
+//---------------------------------------------------------------
+//UniScrollArea :: handleScrollingStarted
+// @see header file
+//---------------------------------------------------------------
+void UniScrollArea::handleScrollingStarted()
+{
+    // contents() is not available so replaced with contentWidget()
+    //   mScrollStartPoint = this->contents()->pos();
+    mScrollStartPoint = this->contentWidget()->pos();
+}
+
+//---------------------------------------------------------------
+//UniScrollArea :: setPosToStart
+// @see header file
+//---------------------------------------------------------------
+void UniScrollArea::setPosToStart()
+{
+    // contents() is not available so replaced with contentWidget()
+    QGraphicsItem* widgetItem = this->contentWidget();
+    widgetItem->setPos(0, 0);
+}
+
+//---------------------------------------------------------------
+//UniScrollArea :: upGesture
+// @see header file
+//---------------------------------------------------------------
+void UniScrollArea::upGesture(int value)
+{
+    Q_UNUSED(value)
+}
+
+//---------------------------------------------------------------
+//UniScrollArea :: downGesture
+// @see header file
+//---------------------------------------------------------------
+void UniScrollArea::downGesture(int value)
+{
+    Q_UNUSED(value)
+}
+
+// EOF