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authorLars Knoll <lars.knoll@nokia.com>2009-03-23 09:18:55 (GMT)
committerSimon Hausmann <simon.hausmann@nokia.com>2009-03-23 09:18:55 (GMT)
commite5fcad302d86d316390c6b0f62759a067313e8a9 (patch)
treec2afbf6f1066b6ce261f14341cf6d310e5595bc1 /examples/itemviews/chart/pieview.cpp
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Long live Qt 4.5!
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+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, 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 1.0, included in the file LGPL_EXCEPTION.txt in this
+** package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <math.h>
+#include <QtGui>
+
+#ifndef M_PI
+#define M_PI 3.1415927
+#endif
+
+#include "pieview.h"
+
+PieView::PieView(QWidget *parent)
+ : QAbstractItemView(parent)
+{
+ horizontalScrollBar()->setRange(0, 0);
+ verticalScrollBar()->setRange(0, 0);
+
+ margin = 8;
+ totalSize = 300;
+ pieSize = totalSize - 2*margin;
+ validItems = 0;
+ totalValue = 0.0;
+ rubberBand = 0;
+}
+
+void PieView::dataChanged(const QModelIndex &topLeft,
+ const QModelIndex &bottomRight)
+{
+ QAbstractItemView::dataChanged(topLeft, bottomRight);
+
+ 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).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 = pow(pow(cx, 2) + pow(cy, 2), 0.5);
+
+ if (d == 0 || d > pieSize/2)
+ return QModelIndex();
+
+ // Determine the angle of the point.
+ double angle = (180 / M_PI) * acos(cx/d);
+ if (cy < 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) {
+
+ int listItem = 0;
+ for (int row = index.row()-1; row >= 0; --row) {
+ if (model()->data(model()->index(row, 1, rootIndex())).toDouble() > 0.0)
+ listItem++;
+ }
+
+ double itemHeight;
+
+ switch (index.column()) {
+ case 0:
+ itemHeight = QFontMetrics(viewOptions().font).height();
+
+ return QRect(totalSize,
+ int(margin + listItem*itemHeight),
+ totalSize - margin, int(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, this);
+ 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();
+ QStyle::State state = option.state;
+
+ QBrush background = option.palette.base();
+ QPen foreground(option.palette.color(QPalette::WindowText));
+ QPen textPen(option.palette.color(QPalette::Text));
+ QPen highlightedPen(option.palette.color(QPalette::HighlightedText));
+
+ QPainter painter(viewport());
+ painter.setRenderHint(QPainter::Antialiasing);
+
+ painter.fillRect(event->rect(), background);
+ painter.setPen(foreground);
+
+ // Viewport rectangles
+ QRect pieRect = QRect(margin, margin, pieSize, pieSize);
+ QPoint keyPoint = QPoint(totalSize - horizontalScrollBar()->value(),
+ margin - verticalScrollBar()->value());
+
+ if (validItems > 0) {
+
+ 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.intersect(contentsRect).isEmpty())
+ indexes.append(index);
+ }
+ }
+
+ if (indexes.size() > 0) {
+ int firstRow = indexes[0].row();
+ int lastRow = indexes[0].row();
+ int firstColumn = indexes[0].column();
+ int lastColumn = indexes[0].column();
+
+ for (int i = 1; i < indexes.size(); ++i) {
+ firstRow = qMin(firstRow, indexes[i].row());
+ lastRow = qMax(lastRow, indexes[i].row());
+ firstColumn = qMin(firstColumn, indexes[i].column());
+ lastColumn = qMax(lastColumn, indexes[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 QRect(rect.left() - horizontalScrollBar()->value(),
+ rect.top() - verticalScrollBar()->value(),
+ rect.width(), rect.height());
+ else
+ return rect;
+}
+
+/*
+ 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) {
+ 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;
+}