Qt之自绘制饼图

#include "stdafx.h" #include "PieChart.h" struct PieItemPrivate { PieItem item; QPainterPath path; QPoint labelPos; QRect m_LegendRect; }; struct PieChartPrivate { bool m_bLegendVisible = true; int m_Minx = 25; int m_Miny = 25; int m_MinDiameter = 130; int m_RingWidth = 40; int m_StartRotationAngle = 0; int m_LegendWidth = 100; int m_LegendHeight = 30; double m_SumValue = 0; QRect m_PieRect; QColor m_LabelColor = QColor(0, 0, 0); QString m_RingLabel = QStringLiteral("饼图"); QVector<PieItemPrivate> m_Items; }; PieChart::PieChart(QWidget * parent) : QWidget(parent) , d_ptr(new PieChartPrivate) { setWindowTitle("Pie example"); setMinimumSize(d_ptr->m_MinDiameter + d_ptr->m_LegendWidth * 2 + d_ptr->m_Minx * 2, d_ptr->m_MinDiameter + d_ptr->m_Miny * 2); } PieChart::~PieChart() { } void PieChart::SetStartX(int x) { d_ptr->m_Minx = x; } void PieChart::SetStartY(int y) { d_ptr->m_Miny = y; } void PieChart::SetMinDiameter(int diameter) { d_ptr->m_MinDiameter = diameter; } void PieChart::SetStartAngle(int angle) { d_ptr->m_StartRotationAngle = angle; } void PieChart::SetRingWidth(int width) { d_ptr->m_RingWidth = width; } void PieChart::SetLegendVisible(bool visible) { if (d_ptr->m_bLegendVisible != visible) { d_ptr->m_bLegendVisible = visible; ConstructData(); update(); } } void PieChart::AddData(double value, const QColor & color, const QString & label) { PieItem item; item.value = qFabs(value); item.color = color; item.label = label; AddData(item); } void PieChart::AddData(const PieItem & item) { d_ptr->m_SumValue += item.value; PieItemPrivate pitem; pitem.item = item; d_ptr->m_Items.append(pitem); ConstructData(); } void PieChart::paintEvent(QPaintEvent * event) { if ( qFabs(d_ptr->m_SumValue) < 0.000001) { return; } QPainter painter(this); //反走样 painter.setRenderHint(QPainter::Antialiasing, true); int pos = 0; int angle; for (auto iter = d_ptr->m_Items.begin(); iter != d_ptr->m_Items.end(); ++iter) { painter.save(); painter.setBrush(iter->item.color); painter.drawPath(iter->path); painter.setPen(QPen(d_ptr->m_LabelColor, 1)); painter.drawText(iter->labelPos, QString("%1%").arg(iter->item.value / d_ptr->m_SumValue * 100)); //绘制legend if (d_ptr->m_bLegendVisible) { painter.fillRect(iter->m_LegendRect, iter->item.color); painter.drawText(iter->m_LegendRect, iter->item.label, QTextOption(Qt::AlignCenter)); QLine line(iter->labelPos, iter->m_LegendRect.center()); double angle = atan2(line.dy(), line.dx()); QLine line2(line.p1() + QPoint(d_ptr->m_RingWidth * qCos(angle), d_ptr->m_RingWidth * qSin(angle)) , line.p2() - QPoint(d_ptr->m_RingWidth * qCos(angle), d_ptr->m_RingWidth * qSin(angle))); painter.drawLine(line2); painter.translate(line2.p2()); painter.rotate(qRadiansToDegrees(angle) + 30); painter.drawLine(QPoint(0, 0), QPoint(-10, 0)); painter.rotate(- 60); painter.drawLine(QPoint(0, 0), QPoint(-10, 0)); } pos += angle; painter.restore(); } painter.drawText(d_ptr->m_PieRect, d_ptr->m_RingLabel, QTextOption(Qt::AlignCenter)); } void PieChart::resizeEvent(QResizeEvent * event) { ConstructRect(event->size()); ConstructData(); } void PieChart::ConstructData() { int pos = d_ptr->m_StartRotationAngle; int angle; for (auto iter = d_ptr->m_Items.begin(); iter != d_ptr->m_Items.end(); ++iter) { angle = 16 * iter->item.value / d_ptr->m_SumValue * 360; QPainterPath path; path.moveTo(d_ptr->m_PieRect.center()); path.arcTo(d_ptr->m_PieRect.x(), d_ptr->m_PieRect.y(), d_ptr->m_PieRect.width(), d_ptr->m_PieRect.height(), pos / 16.0, angle / 16.0); path.closeSubpath(); QPainterPath subPath; subPath.addEllipse(d_ptr->m_PieRect.adjusted(d_ptr->m_RingWidth, d_ptr->m_RingWidth, -d_ptr->m_RingWidth, -d_ptr->m_RingWidth)); path -= subPath; iter->path = path; double labelAngle = (pos + angle / 2) / 16; double tx = (d_ptr->m_PieRect.width() - d_ptr->m_RingWidth) / 2 * qCos(labelAngle / 360 * 2 * 3.1415926); double ty = -(d_ptr->m_PieRect.width() - d_ptr->m_RingWidth) / 2 * qSin(labelAngle / 360 * 2 * 3.1415926); iter->labelPos = QPoint(tx, ty) + d_ptr->m_PieRect.center(); pos += angle; } } void PieChart::ConstructRect(const QSize & size) { switch (d_ptr->m_Items.size()) { case 4: ConstructCornerLayout(size); default: break; } } void PieChart::ConstructCornerLayout(const QSize & size) { int currentR = d_ptr->m_MinDiameter; int diameter; int horiWidth = size.width(); if (d_ptr->m_bLegendVisible) { horiWidth -= d_ptr->m_LegendWidth * 2; } if (horiWidth > size.height()) { diameter = size.height(); } else { diameter = horiWidth; } int x, y; int r = diameter - d_ptr->m_Minx * 2; if (d_ptr->m_bLegendVisible) { currentR = r > currentR ? r : currentR; x = d_ptr->m_Minx + d_ptr->m_LegendWidth; y = (size.height() - currentR) / 2; d_ptr->m_Items[1].m_LegendRect = QRect(d_ptr->m_Minx, d_ptr->m_Miny, d_ptr->m_LegendWidth, d_ptr->m_LegendHeight); d_ptr->m_Items[0].m_LegendRect = QRect(x + r, d_ptr->m_Miny, d_ptr->m_LegendWidth, d_ptr->m_LegendHeight); d_ptr->m_Items[3].m_LegendRect = QRect(x + r, size.height() - d_ptr->m_Miny - 30, d_ptr->m_LegendWidth, d_ptr->m_LegendHeight); d_ptr->m_Items[2].m_LegendRect = QRect(d_ptr->m_Minx, size.height() - d_ptr->m_Miny - 30, d_ptr->m_LegendWidth, d_ptr->m_LegendHeight); } else { x = d_ptr->m_Minx; y = d_ptr->m_Miny; } d_ptr->m_PieRect = QRect(x, y, currentR, currentR); }