pieview.cpp Example File

itemviews/chart/pieview.cpp
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#include <QtWidgets> #include <qmath.h> #include <cmath> #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, const QVector<int> &) { 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 = 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++; } 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, 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[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 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) { 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; }

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