qt-everywhere-src-5.15.1/qtbase/examples/widgets/itemviews/chart/pieview.cpp - orbit - Git at Google

 /****************************************************************************
 **
 ** Copyright (C) 2016 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
 ** Commercial License Usage
 ** Licensees holding valid commercial Qt licenses may use this file in
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
 ** and conditions see https://www.qt.io/terms-conditions. For further
 ** information use the contact form at https://www.qt.io/contact-us.
 **
 ** BSD License Usage
 ** Alternatively, you may use this file under the terms of the BSD license
 ** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
 ** met:
 **   * Redistributions of source code must retain the above copyright
 **     notice, this list of conditions and the following disclaimer.
 **   * Redistributions in binary form must reproduce the above copyright
 **     notice, this list of conditions and the following disclaimer in
 **     the documentation and/or other materials provided with the
 **     distribution.
 **   * Neither the name of The Qt Company Ltd nor the names of its
 **     contributors may be used to endorse or promote products derived
 **     from this software without specific prior written permission.
 **
 **
 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include "pieview.h"

 #include <QtWidgets>

 PieView::PieView(QWidget *parent)
     : QAbstractItemView(parent)
 {
     horizontalScrollBar()->setRange(0, 0);
     verticalScrollBar()->setRange(0, 0);
 }

 void PieView::dataChanged(const QModelIndex &topLeft,
                           const QModelIndex &bottomRight,
                           const QVector<int> &roles)
 {
     QAbstractItemView::dataChanged(topLeft, bottomRight, roles);

     if (!roles.contains(Qt::DisplayRole))
         return;

     validItems = 0;
     totalValue = 0.0;

     for (int row = 0; row < model()->rowCount(rootIndex()); ++row) {

         QModelIndex index = model()->index(row, 1, rootIndex());
         double value = model()->data(index, Qt::DisplayRole).toDouble();

         if (value > 0.0) {
             totalValue += value;
             validItems++;
         }
     }
     viewport()->update();
 }

 bool PieView::edit(const QModelIndex &index, EditTrigger trigger, QEvent *event)
 {
     if (index.column() == 0)
         return QAbstractItemView::edit(index, trigger, event);
     else
         return false;
 }

 /*
     Returns the item that covers the coordinate given in the view.
 */

 QModelIndex PieView::indexAt(const QPoint &point) const
 {
     if (validItems == 0)
         return QModelIndex();

     // Transform the view coordinates into contents widget coordinates.
     int wx = point.x() + horizontalScrollBar()->value();
     int wy = point.y() + verticalScrollBar()->value();

     if (wx < totalSize) {
         double cx = wx - totalSize / 2;
         double cy = totalSize / 2 - wy; // positive cy for items above the center

         // Determine the distance from the center point of the pie chart.
         double d = std::sqrt(std::pow(cx, 2) + std::pow(cy, 2));

         if (d == 0 || d > pieSize / 2)
             return QModelIndex();

         // Determine the angle of the point.
         double angle = qRadiansToDegrees(std::atan2(cy, cx));
         if (angle < 0)
             angle = 360 + angle;

         // Find the relevant slice of the pie.
         double startAngle = 0.0;

         for (int row = 0; row < model()->rowCount(rootIndex()); ++row) {

             QModelIndex index = model()->index(row, 1, rootIndex());
             double value = model()->data(index).toDouble();

             if (value > 0.0) {
                 double sliceAngle = 360 * value / totalValue;

                 if (angle >= startAngle && angle < (startAngle + sliceAngle))
                     return model()->index(row, 1, rootIndex());

                 startAngle += sliceAngle;
             }
         }
     } else {
         double itemHeight = QFontMetrics(viewOptions().font).height();
         int listItem = int((wy - margin) / itemHeight);
         int validRow = 0;

         for (int row = 0; row < model()->rowCount(rootIndex()); ++row) {

             QModelIndex index = model()->index(row, 1, rootIndex());
             if (model()->data(index).toDouble() > 0.0) {

                 if (listItem == validRow)
                     return model()->index(row, 0, rootIndex());

                 // Update the list index that corresponds to the next valid row.
                 ++validRow;
             }
         }
     }

     return QModelIndex();
 }

 bool PieView::isIndexHidden(const QModelIndex & /*index*/) const
 {
     return false;
 }

 /*
     Returns the rectangle of the item at position \a index in the
     model. The rectangle is in contents coordinates.
 */

 QRect PieView::itemRect(const QModelIndex &index) const
 {
     if (!index.isValid())
         return QRect();

     // Check whether the index's row is in the list of rows represented
     // by slices.
     QModelIndex valueIndex;

     if (index.column() != 1)
         valueIndex = model()->index(index.row(), 1, rootIndex());
     else
         valueIndex = index;

     if (model()->data(valueIndex).toDouble() <= 0.0)
         return QRect();

     int listItem = 0;
     for (int row = index.row()-1; row >= 0; --row) {
         if (model()->data(model()->index(row, 1, rootIndex())).toDouble() > 0.0)
             listItem++;
     }

     switch (index.column()) {
     case 0: {
         const qreal itemHeight = QFontMetricsF(viewOptions().font).height();

         return QRect(totalSize,
                      qRound(margin + listItem * itemHeight),
                      totalSize - margin, qRound(itemHeight));
     }
     case 1:
         return viewport()->rect();
     }
     return QRect();
 }

 QRegion PieView::itemRegion(const QModelIndex &index) const
 {
     if (!index.isValid())
         return QRegion();

     if (index.column() != 1)
         return itemRect(index);

     if (model()->data(index).toDouble() <= 0.0)
         return QRegion();

     double startAngle = 0.0;
     for (int row = 0; row < model()->rowCount(rootIndex()); ++row) {

         QModelIndex sliceIndex = model()->index(row, 1, rootIndex());
         double value = model()->data(sliceIndex).toDouble();

         if (value > 0.0) {
             double angle = 360 * value / totalValue;

             if (sliceIndex == index) {
                 QPainterPath slicePath;
                 slicePath.moveTo(totalSize / 2, totalSize / 2);
                 slicePath.arcTo(margin, margin, margin + pieSize, margin + pieSize,
                                 startAngle, angle);
                 slicePath.closeSubpath();

                 return QRegion(slicePath.toFillPolygon().toPolygon());
             }

             startAngle += angle;
         }
     }

     return QRegion();
 }

 int PieView::horizontalOffset() const
 {
     return horizontalScrollBar()->value();
 }

 void PieView::mousePressEvent(QMouseEvent *event)
 {
     QAbstractItemView::mousePressEvent(event);
     origin = event->pos();
     if (!rubberBand)
         rubberBand = new QRubberBand(QRubberBand::Rectangle, viewport());
     rubberBand->setGeometry(QRect(origin, QSize()));
     rubberBand->show();
 }

 void PieView::mouseMoveEvent(QMouseEvent *event)
 {
     if (rubberBand)
         rubberBand->setGeometry(QRect(origin, event->pos()).normalized());
     QAbstractItemView::mouseMoveEvent(event);
 }

 void PieView::mouseReleaseEvent(QMouseEvent *event)
 {
     QAbstractItemView::mouseReleaseEvent(event);
     if (rubberBand)
         rubberBand->hide();
     viewport()->update();
 }

 QModelIndex PieView::moveCursor(QAbstractItemView::CursorAction cursorAction,
                                 Qt::KeyboardModifiers /*modifiers*/)
 {
     QModelIndex current = currentIndex();

     switch (cursorAction) {
         case MoveLeft:
         case MoveUp:
             if (current.row() > 0)
                 current = model()->index(current.row() - 1, current.column(),
                                          rootIndex());
             else
                 current = model()->index(0, current.column(), rootIndex());
             break;
         case MoveRight:
         case MoveDown:
             if (current.row() < rows(current) - 1)
                 current = model()->index(current.row() + 1, current.column(),
                                          rootIndex());
             else
                 current = model()->index(rows(current) - 1, current.column(),
                                          rootIndex());
             break;
         default:
             break;
     }

     viewport()->update();
     return current;
 }

 void PieView::paintEvent(QPaintEvent *event)
 {
     QItemSelectionModel *selections = selectionModel();
     QStyleOptionViewItem option = viewOptions();

     QBrush background = option.palette.base();
     QPen foreground(option.palette.color(QPalette::WindowText));

     QPainter painter(viewport());
     painter.setRenderHint(QPainter::Antialiasing);

     painter.fillRect(event->rect(), background);
     painter.setPen(foreground);

     // Viewport rectangles
     QRect pieRect = QRect(margin, margin, pieSize, pieSize);

     if (validItems <= 0)
         return;

     painter.save();
     painter.translate(pieRect.x() - horizontalScrollBar()->value(),
                       pieRect.y() - verticalScrollBar()->value());
     painter.drawEllipse(0, 0, pieSize, pieSize);
     double startAngle = 0.0;
     int row;

     for (row = 0; row < model()->rowCount(rootIndex()); ++row) {
         QModelIndex index = model()->index(row, 1, rootIndex());
         double value = model()->data(index).toDouble();

         if (value > 0.0) {
             double angle = 360 * value / totalValue;

             QModelIndex colorIndex = model()->index(row, 0, rootIndex());
             QColor color = QColor(model()->data(colorIndex, Qt::DecorationRole).toString());

             if (currentIndex() == index)
                 painter.setBrush(QBrush(color, Qt::Dense4Pattern));
             else if (selections->isSelected(index))
                 painter.setBrush(QBrush(color, Qt::Dense3Pattern));
             else
                 painter.setBrush(QBrush(color));

             painter.drawPie(0, 0, pieSize, pieSize, int(startAngle*16), int(angle*16));

             startAngle += angle;
         }
     }
     painter.restore();

     int keyNumber = 0;

     for (row = 0; row < model()->rowCount(rootIndex()); ++row) {
         QModelIndex index = model()->index(row, 1, rootIndex());
         double value = model()->data(index).toDouble();

         if (value > 0.0) {
             QModelIndex labelIndex = model()->index(row, 0, rootIndex());

             QStyleOptionViewItem option = viewOptions();
             option.rect = visualRect(labelIndex);
             if (selections->isSelected(labelIndex))
                 option.state |= QStyle::State_Selected;
             if (currentIndex() == labelIndex)
                 option.state |= QStyle::State_HasFocus;
             itemDelegate()->paint(&painter, option, labelIndex);

             ++keyNumber;
         }
     }
 }

 void PieView::resizeEvent(QResizeEvent * /* event */)
 {
     updateGeometries();
 }

 int PieView::rows(const QModelIndex &index) const
 {
     return model()->rowCount(model()->parent(index));
 }

 void PieView::rowsInserted(const QModelIndex &parent, int start, int end)
 {
     for (int row = start; row <= end; ++row) {
         QModelIndex index = model()->index(row, 1, rootIndex());
         double value = model()->data(index).toDouble();

         if (value > 0.0) {
             totalValue += value;
             ++validItems;
         }
     }

     QAbstractItemView::rowsInserted(parent, start, end);
 }

 void PieView::rowsAboutToBeRemoved(const QModelIndex &parent, int start, int end)
 {
     for (int row = start; row <= end; ++row) {
         QModelIndex index = model()->index(row, 1, rootIndex());
         double value = model()->data(index).toDouble();
         if (value > 0.0) {
             totalValue -= value;
             --validItems;
         }
     }

     QAbstractItemView::rowsAboutToBeRemoved(parent, start, end);
 }

 void PieView::scrollContentsBy(int dx, int dy)
 {
     viewport()->scroll(dx, dy);
 }

 void PieView::scrollTo(const QModelIndex &index, ScrollHint)
 {
     QRect area = viewport()->rect();
     QRect rect = visualRect(index);

     if (rect.left() < area.left()) {
         horizontalScrollBar()->setValue(
             horizontalScrollBar()->value() + rect.left() - area.left());
     } else if (rect.right() > area.right()) {
         horizontalScrollBar()->setValue(
             horizontalScrollBar()->value() + qMin(
                 rect.right() - area.right(), rect.left() - area.left()));
     }

     if (rect.top() < area.top()) {
         verticalScrollBar()->setValue(
             verticalScrollBar()->value() + rect.top() - area.top());
     } else if (rect.bottom() > area.bottom()) {
         verticalScrollBar()->setValue(
             verticalScrollBar()->value() + qMin(
                 rect.bottom() - area.bottom(), rect.top() - area.top()));
     }

     update();
 }

 /*
     Find the indices corresponding to the extent of the selection.
 */

 void PieView::setSelection(const QRect &rect, QItemSelectionModel::SelectionFlags command)
 {
     // Use content widget coordinates because we will use the itemRegion()
     // function to check for intersections.

     QRect contentsRect = rect.translated(
                             horizontalScrollBar()->value(),
                             verticalScrollBar()->value()).normalized();

     int rows = model()->rowCount(rootIndex());
     int columns = model()->columnCount(rootIndex());
     QModelIndexList indexes;

     for (int row = 0; row < rows; ++row) {
         for (int column = 0; column < columns; ++column) {
             QModelIndex index = model()->index(row, column, rootIndex());
             QRegion region = itemRegion(index);
             if (region.intersects(contentsRect))
                 indexes.append(index);
         }
     }

     if (indexes.size() > 0) {
         int firstRow = indexes.at(0).row();
         int lastRow = firstRow;
         int firstColumn = indexes.at(0).column();
         int lastColumn = firstColumn;

         for (int i = 1; i < indexes.size(); ++i) {
             firstRow = qMin(firstRow, indexes.at(i).row());
             lastRow = qMax(lastRow, indexes.at(i).row());
             firstColumn = qMin(firstColumn, indexes.at(i).column());
             lastColumn = qMax(lastColumn, indexes.at(i).column());
         }

         QItemSelection selection(
             model()->index(firstRow, firstColumn, rootIndex()),
             model()->index(lastRow, lastColumn, rootIndex()));
         selectionModel()->select(selection, command);
     } else {
         QModelIndex noIndex;
         QItemSelection selection(noIndex, noIndex);
         selectionModel()->select(selection, command);
     }

     update();
 }

 void PieView::updateGeometries()
 {
     horizontalScrollBar()->setPageStep(viewport()->width());
     horizontalScrollBar()->setRange(0, qMax(0, 2 * totalSize - viewport()->width()));
     verticalScrollBar()->setPageStep(viewport()->height());
     verticalScrollBar()->setRange(0, qMax(0, totalSize - viewport()->height()));
 }

 int PieView::verticalOffset() const
 {
     return verticalScrollBar()->value();
 }

 /*
     Returns the position of the item in viewport coordinates.
 */

 QRect PieView::visualRect(const QModelIndex &index) const
 {
     QRect rect = itemRect(index);
     if (!rect.isValid())
         return rect;

     return QRect(rect.left() - horizontalScrollBar()->value(),
                  rect.top() - verticalScrollBar()->value(),
                  rect.width(), rect.height());
 }

 /*
     Returns a region corresponding to the selection in viewport coordinates.
 */

 QRegion PieView::visualRegionForSelection(const QItemSelection &selection) const
 {
     int ranges = selection.count();

     if (ranges == 0)
         return QRect();

     QRegion region;
     for (int i = 0; i < ranges; ++i) {
         const QItemSelectionRange &range = selection.at(i);
         for (int row = range.top(); row <= range.bottom(); ++row) {
             for (int col = range.left(); col <= range.right(); ++col) {
                 QModelIndex index = model()->index(row, col, rootIndex());
                 region += visualRect(index);
             }
         }
     }
     return region;
 }
	/****************************************************************************
	**
	** Copyright (C) 2016 The Qt Company Ltd.
	** Contact: https://www.qt.io/licensing/
	**
	** This file is part of the examples of the Qt Toolkit.
	**
	** $QT_BEGIN_LICENSE:BSD$
	** Commercial License Usage
	** Licensees holding valid commercial Qt licenses may use this file in
	** accordance with the commercial license agreement provided with the
	** Software or, alternatively, in accordance with the terms contained in
	** a written agreement between you and The Qt Company. For licensing terms
	** and conditions see https://www.qt.io/terms-conditions. For further
	** information use the contact form at https://www.qt.io/contact-us.
	**
	** BSD License Usage
	** Alternatively, you may use this file under the terms of the BSD license
	** as follows:
	**
	** "Redistribution and use in source and binary forms, with or without
	** modification, are permitted provided that the following conditions are
	** met:
	** * Redistributions of source code must retain the above copyright
	** notice, this list of conditions and the following disclaimer.
	** * Redistributions in binary form must reproduce the above copyright
	** notice, this list of conditions and the following disclaimer in
	** the documentation and/or other materials provided with the
	** distribution.
	** * Neither the name of The Qt Company Ltd nor the names of its
	** contributors may be used to endorse or promote products derived
	** from this software without specific prior written permission.
	**
	**
	** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
	**
	** $QT_END_LICENSE$
	**
	****************************************************************************/

	#include "pieview.h"

	#include <QtWidgets>

	PieView::PieView(QWidget *parent)
	: QAbstractItemView(parent)
	{
	horizontalScrollBar()->setRange(0, 0);
	verticalScrollBar()->setRange(0, 0);
	}

	void PieView::dataChanged(const QModelIndex &topLeft,
	const QModelIndex &bottomRight,
	const QVector<int> &roles)
	{
	QAbstractItemView::dataChanged(topLeft, bottomRight, roles);

	if (!roles.contains(Qt::DisplayRole))
	return;

	validItems = 0;
	totalValue = 0.0;

	for (int row = 0; row < model()->rowCount(rootIndex()); ++row) {

	QModelIndex index = model()->index(row, 1, rootIndex());
	double value = model()->data(index, Qt::DisplayRole).toDouble();

	if (value > 0.0) {
	totalValue += value;
	validItems++;
	}
	}
	viewport()->update();
	}

	bool PieView::edit(const QModelIndex &index, EditTrigger trigger, QEvent *event)
	{
	if (index.column() == 0)
	return QAbstractItemView::edit(index, trigger, event);
	else
	return false;
	}

	/*
	Returns the item that covers the coordinate given in the view.
	*/

	QModelIndex PieView::indexAt(const QPoint &point) const
	{
	if (validItems == 0)
	return QModelIndex();

	// Transform the view coordinates into contents widget coordinates.
	int wx = point.x() + horizontalScrollBar()->value();
	int wy = point.y() + verticalScrollBar()->value();

	if (wx < totalSize) {
	double cx = wx - totalSize / 2;
	double cy = totalSize / 2 - wy; // positive cy for items above the center

	// Determine the distance from the center point of the pie chart.
	double d = std::sqrt(std::pow(cx, 2) + std::pow(cy, 2));

	if (d == 0 \|\| d > pieSize / 2)
	return QModelIndex();

	// Determine the angle of the point.
	double angle = qRadiansToDegrees(std::atan2(cy, cx));
	if (angle < 0)
	angle = 360 + angle;

	// Find the relevant slice of the pie.
	double startAngle = 0.0;

	for (int row = 0; row < model()->rowCount(rootIndex()); ++row) {

	QModelIndex index = model()->index(row, 1, rootIndex());
	double value = model()->data(index).toDouble();

	if (value > 0.0) {
	double sliceAngle = 360 * value / totalValue;

	if (angle >= startAngle && angle < (startAngle + sliceAngle))
	return model()->index(row, 1, rootIndex());

	startAngle += sliceAngle;
	}
	}
	} else {
	double itemHeight = QFontMetrics(viewOptions().font).height();
	int listItem = int((wy - margin) / itemHeight);
	int validRow = 0;

	for (int row = 0; row < model()->rowCount(rootIndex()); ++row) {

	QModelIndex index = model()->index(row, 1, rootIndex());
	if (model()->data(index).toDouble() > 0.0) {

	if (listItem == validRow)
	return model()->index(row, 0, rootIndex());

	// Update the list index that corresponds to the next valid row.
	++validRow;
	}
	}
	}

	return QModelIndex();
	}

	bool PieView::isIndexHidden(const QModelIndex & /index/) const
	{
	return false;
	}

	/*
	Returns the rectangle of the item at position \a index in the
	model. The rectangle is in contents coordinates.
	*/

	QRect PieView::itemRect(const QModelIndex &index) const
	{
	if (!index.isValid())
	return QRect();

	// Check whether the index's row is in the list of rows represented
	// by slices.
	QModelIndex valueIndex;

	if (index.column() != 1)
	valueIndex = model()->index(index.row(), 1, rootIndex());
	else
	valueIndex = index;

	if (model()->data(valueIndex).toDouble() <= 0.0)
	return QRect();

	int listItem = 0;
	for (int row = index.row()-1; row >= 0; --row) {
	if (model()->data(model()->index(row, 1, rootIndex())).toDouble() > 0.0)
	listItem++;
	}

	switch (index.column()) {
	case 0: {
	const qreal itemHeight = QFontMetricsF(viewOptions().font).height();

	return QRect(totalSize,
	qRound(margin + listItem * itemHeight),
	totalSize - margin, qRound(itemHeight));
	}
	case 1:
	return viewport()->rect();
	}
	return QRect();
	}

	QRegion PieView::itemRegion(const QModelIndex &index) const
	{
	if (!index.isValid())
	return QRegion();

	if (index.column() != 1)
	return itemRect(index);

	if (model()->data(index).toDouble() <= 0.0)
	return QRegion();

	double startAngle = 0.0;
	for (int row = 0; row < model()->rowCount(rootIndex()); ++row) {

	QModelIndex sliceIndex = model()->index(row, 1, rootIndex());
	double value = model()->data(sliceIndex).toDouble();

	if (value > 0.0) {
	double angle = 360 * value / totalValue;

	if (sliceIndex == index) {
	QPainterPath slicePath;
	slicePath.moveTo(totalSize / 2, totalSize / 2);
	slicePath.arcTo(margin, margin, margin + pieSize, margin + pieSize,
	startAngle, angle);
	slicePath.closeSubpath();

	return QRegion(slicePath.toFillPolygon().toPolygon());
	}

	startAngle += angle;
	}
	}

	return QRegion();
	}

	int PieView::horizontalOffset() const
	{
	return horizontalScrollBar()->value();
	}

	void PieView::mousePressEvent(QMouseEvent *event)
	{
	QAbstractItemView::mousePressEvent(event);
	origin = event->pos();
	if (!rubberBand)
	rubberBand = new QRubberBand(QRubberBand::Rectangle, viewport());
	rubberBand->setGeometry(QRect(origin, QSize()));
	rubberBand->show();
	}

	void PieView::mouseMoveEvent(QMouseEvent *event)
	{
	if (rubberBand)
	rubberBand->setGeometry(QRect(origin, event->pos()).normalized());
	QAbstractItemView::mouseMoveEvent(event);
	}

	void PieView::mouseReleaseEvent(QMouseEvent *event)
	{
	QAbstractItemView::mouseReleaseEvent(event);
	if (rubberBand)
	rubberBand->hide();
	viewport()->update();
	}

	QModelIndex PieView::moveCursor(QAbstractItemView::CursorAction cursorAction,
	Qt::KeyboardModifiers /modifiers/)
	{
	QModelIndex current = currentIndex();

	switch (cursorAction) {
	case MoveLeft:
	case MoveUp:
	if (current.row() > 0)
	current = model()->index(current.row() - 1, current.column(),
	rootIndex());
	else
	current = model()->index(0, current.column(), rootIndex());
	break;
	case MoveRight:
	case MoveDown:
	if (current.row() < rows(current) - 1)
	current = model()->index(current.row() + 1, current.column(),
	rootIndex());
	else
	current = model()->index(rows(current) - 1, current.column(),
	rootIndex());
	break;
	default:
	break;
	}

	viewport()->update();
	return current;
	}

	void PieView::paintEvent(QPaintEvent *event)
	{
	QItemSelectionModel *selections = selectionModel();
	QStyleOptionViewItem option = viewOptions();

	QBrush background = option.palette.base();
	QPen foreground(option.palette.color(QPalette::WindowText));

	QPainter painter(viewport());
	painter.setRenderHint(QPainter::Antialiasing);

	painter.fillRect(event->rect(), background);
	painter.setPen(foreground);

	// Viewport rectangles
	QRect pieRect = QRect(margin, margin, pieSize, pieSize);

	if (validItems <= 0)
	return;

	painter.save();
	painter.translate(pieRect.x() - horizontalScrollBar()->value(),
	pieRect.y() - verticalScrollBar()->value());
	painter.drawEllipse(0, 0, pieSize, pieSize);
	double startAngle = 0.0;
	int row;

	for (row = 0; row < model()->rowCount(rootIndex()); ++row) {
	QModelIndex index = model()->index(row, 1, rootIndex());
	double value = model()->data(index).toDouble();

	if (value > 0.0) {
	double angle = 360 * value / totalValue;

	QModelIndex colorIndex = model()->index(row, 0, rootIndex());
	QColor color = QColor(model()->data(colorIndex, Qt::DecorationRole).toString());

	if (currentIndex() == index)
	painter.setBrush(QBrush(color, Qt::Dense4Pattern));
	else if (selections->isSelected(index))
	painter.setBrush(QBrush(color, Qt::Dense3Pattern));
	else
	painter.setBrush(QBrush(color));

	painter.drawPie(0, 0, pieSize, pieSize, int(startAngle16), int(angle16));

	startAngle += angle;
	}
	}
	painter.restore();

	int keyNumber = 0;

	for (row = 0; row < model()->rowCount(rootIndex()); ++row) {
	QModelIndex index = model()->index(row, 1, rootIndex());
	double value = model()->data(index).toDouble();

	if (value > 0.0) {
	QModelIndex labelIndex = model()->index(row, 0, rootIndex());

	QStyleOptionViewItem option = viewOptions();
	option.rect = visualRect(labelIndex);
	if (selections->isSelected(labelIndex))
	option.state \|= QStyle::State_Selected;
	if (currentIndex() == labelIndex)
	option.state \|= QStyle::State_HasFocus;
	itemDelegate()->paint(&painter, option, labelIndex);

	++keyNumber;
	}
	}
	}

	void PieView::resizeEvent(QResizeEvent * /* event */)
	{
	updateGeometries();
	}

	int PieView::rows(const QModelIndex &index) const
	{
	return model()->rowCount(model()->parent(index));
	}

	void PieView::rowsInserted(const QModelIndex &parent, int start, int end)
	{
	for (int row = start; row <= end; ++row) {
	QModelIndex index = model()->index(row, 1, rootIndex());
	double value = model()->data(index).toDouble();

	if (value > 0.0) {
	totalValue += value;
	++validItems;
	}
	}

	QAbstractItemView::rowsInserted(parent, start, end);
	}

	void PieView::rowsAboutToBeRemoved(const QModelIndex &parent, int start, int end)
	{
	for (int row = start; row <= end; ++row) {
	QModelIndex index = model()->index(row, 1, rootIndex());
	double value = model()->data(index).toDouble();
	if (value > 0.0) {
	totalValue -= value;
	--validItems;
	}
	}

	QAbstractItemView::rowsAboutToBeRemoved(parent, start, end);
	}

	void PieView::scrollContentsBy(int dx, int dy)
	{
	viewport()->scroll(dx, dy);
	}

	void PieView::scrollTo(const QModelIndex &index, ScrollHint)
	{
	QRect area = viewport()->rect();
	QRect rect = visualRect(index);

	if (rect.left() < area.left()) {
	horizontalScrollBar()->setValue(
	horizontalScrollBar()->value() + rect.left() - area.left());
	} else if (rect.right() > area.right()) {
	horizontalScrollBar()->setValue(
	horizontalScrollBar()->value() + qMin(
	rect.right() - area.right(), rect.left() - area.left()));
	}

	if (rect.top() < area.top()) {
	verticalScrollBar()->setValue(
	verticalScrollBar()->value() + rect.top() - area.top());
	} else if (rect.bottom() > area.bottom()) {
	verticalScrollBar()->setValue(
	verticalScrollBar()->value() + qMin(
	rect.bottom() - area.bottom(), rect.top() - area.top()));
	}

	update();
	}

	/*
	Find the indices corresponding to the extent of the selection.
	*/

	void PieView::setSelection(const QRect &rect, QItemSelectionModel::SelectionFlags command)
	{
	// Use content widget coordinates because we will use the itemRegion()
	// function to check for intersections.

	QRect contentsRect = rect.translated(
	horizontalScrollBar()->value(),
	verticalScrollBar()->value()).normalized();

	int rows = model()->rowCount(rootIndex());
	int columns = model()->columnCount(rootIndex());
	QModelIndexList indexes;

	for (int row = 0; row < rows; ++row) {
	for (int column = 0; column < columns; ++column) {
	QModelIndex index = model()->index(row, column, rootIndex());
	QRegion region = itemRegion(index);
	if (region.intersects(contentsRect))
	indexes.append(index);
	}
	}

	if (indexes.size() > 0) {
	int firstRow = indexes.at(0).row();
	int lastRow = firstRow;
	int firstColumn = indexes.at(0).column();
	int lastColumn = firstColumn;

	for (int i = 1; i < indexes.size(); ++i) {
	firstRow = qMin(firstRow, indexes.at(i).row());
	lastRow = qMax(lastRow, indexes.at(i).row());
	firstColumn = qMin(firstColumn, indexes.at(i).column());
	lastColumn = qMax(lastColumn, indexes.at(i).column());
	}

	QItemSelection selection(
	model()->index(firstRow, firstColumn, rootIndex()),
	model()->index(lastRow, lastColumn, rootIndex()));
	selectionModel()->select(selection, command);
	} else {
	QModelIndex noIndex;
	QItemSelection selection(noIndex, noIndex);
	selectionModel()->select(selection, command);
	}

	update();
	}

	void PieView::updateGeometries()
	{
	horizontalScrollBar()->setPageStep(viewport()->width());
	horizontalScrollBar()->setRange(0, qMax(0, 2 * totalSize - viewport()->width()));
	verticalScrollBar()->setPageStep(viewport()->height());
	verticalScrollBar()->setRange(0, qMax(0, totalSize - viewport()->height()));
	}

	int PieView::verticalOffset() const
	{
	return verticalScrollBar()->value();
	}

	/*
	Returns the position of the item in viewport coordinates.
	*/

	QRect PieView::visualRect(const QModelIndex &index) const
	{
	QRect rect = itemRect(index);
	if (!rect.isValid())
	return rect;

	return QRect(rect.left() - horizontalScrollBar()->value(),
	rect.top() - verticalScrollBar()->value(),
	rect.width(), rect.height());
	}

	/*
	Returns a region corresponding to the selection in viewport coordinates.
	*/

	QRegion PieView::visualRegionForSelection(const QItemSelection &selection) const
	{
	int ranges = selection.count();

	if (ranges == 0)
	return QRect();

	QRegion region;
	for (int i = 0; i < ranges; ++i) {
	const QItemSelectionRange &range = selection.at(i);
	for (int row = range.top(); row <= range.bottom(); ++row) {
	for (int col = range.left(); col <= range.right(); ++col) {
	QModelIndex index = model()->index(row, col, rootIndex());
	region += visualRect(index);
	}
	}
	}
	return region;
	}