qwt QwtLegend示例

#include "LegendWidget.h" #include "ui_LegendWidget.h" #include "qwt_plot.h" #include "qwt_plot_curve.h" #include "qwt_text.h" #include "qwt_legend.h" #include "qwt_symbol.h" #include "qwt_plot_marker.h" #include "qwt_plot_grid.h" #include "qwt_scale_div.h" #include "qwt_plot_canvas.h" #include "qwt_plot_legenditem.h" #include "qwt_math.h" #include "qwt_plot_layout.h" class Curve : public QwtPlotCurve { public: Curve( int index ): m_index( index ) { setRenderHint( QwtPlotItem::RenderAntialiased ); initData(); } void setCurveTitle( const QString& title ) { QString txt("%1 %2"); setTitle( QString( "%1 %2" ).arg( title ).arg( m_index ) ); } void initData() { QVector< QPointF > points; double y = qwtRand() % 1000; for ( double x = 0.0; x <= 1000.0; x += 100.0 ) { double off = qwtRand() % 200 - 100; if ( y + off > 980.0 || y + off < 20.0 ) off = -off; y += off; points += QPointF( x, y ); } setSamples( points ); } private: const int m_index; }; class LegendItem : public QwtPlotLegendItem { public: LegendItem() { setRenderHint( QwtPlotItem::RenderAntialiased ); const QColor c1( Qt::white ); setTextPen( c1 ); setBorderPen( c1 ); QColor c2( Qt::gray ); c2.setAlpha( 200 ); setBackgroundBrush( c2 ); } }; QwtPlot *g_plot = nullptr; LegendWidget::LegendWidget(QWidget *parent) : QWidget(parent), ui(new Ui::LegendWidget) { ui->setupUi(this); QwtPlotCanvas* canvas = new QwtPlotCanvas(); canvas->setFocusIndicator( QwtPlotCanvas::CanvasFocusIndicator ); canvas->setFocusPolicy( Qt::StrongFocus ); canvas->setPalette( Qt::black ); //创建plot g_plot = new QwtPlot(QwtText("图列示例"),this); g_plot->setFooter( "Footer" ); g_plot->setAutoReplot( false ); g_plot->setCanvas( canvas ); //创建一个网格 QwtPlotGrid* grid = new QwtPlotGrid; grid->enableXMin( true ); grid->setMajorPen( Qt::gray, 0, Qt::DotLine ); grid->setMinorPen( Qt::darkGray, 0, Qt::DotLine ); grid->attach( g_plot ); //设置坐标轴范围 g_plot->setAxisScale( QwtAxis::YLeft, 0.0, 1000.0 ); g_plot->setAxisScale( QwtAxis::XBottom, 0.0, 1000.0 ); ui->hLayout->addWidget(g_plot); //初始化属性 Settings settings; settings.legend.isEnabled = true; settings.legend.position = QwtPlot::BottomLegend; settings.legendItem.isEnabled = false; settings.legendItem.numColumns = 1; settings.legendItem.alignment = Qt::AlignRight | Qt::AlignVCenter; settings.legendItem.backgroundMode = 0; settings.legendItem.size = g_plot->canvas()->font().pointSize(); settings.curve.numCurves = 4; settings.curve.title = "曲线"; applySettings(settings); } LegendWidget::~LegendWidget() { delete ui; } Settings LegendWidget::settings() const { Settings s; s.legend.isEnabled = ui->cboxLegendEnabled->checkState() == Qt::Checked; s.legend.position = ui->cbxPos->currentIndex(); s.legendItem.isEnabled = ui->cboxLegendItemEnabled->checkState() == Qt::Checked; s.legendItem.numColumns = ui->spinBoxColumns->value(); int align = 0; int hIndex = ui->cbxHorizontal->currentIndex(); if ( hIndex == 0 ) align |= Qt::AlignLeft; else if ( hIndex == 2 ) align |= Qt::AlignRight; else align |= Qt::AlignHCenter; int vIndex = ui->cbxVertical->currentIndex(); if ( vIndex == 0 ) align |= Qt::AlignTop; else if ( vIndex == 2 ) align |= Qt::AlignBottom; else align |= Qt::AlignVCenter; s.legendItem.alignment = align; s.legendItem.backgroundMode = ui->cbxBackGround->currentIndex(); s.legendItem.size = ui->spinBoxSize->value(); s.curve.numCurves = ui->spinBoxNum->value(); s.curve.title = ui->leTitle->text(); return s; } void LegendWidget::applySettings(const Settings &settings) { m_isDirty = false; g_plot->setAutoReplot( true ); //判断图列是否启用 if ( settings.legend.isEnabled ) { //设置图列位置 if ( settings.legend.position > QwtPlot::TopLegend ) { //如果有，就先删除 if ( g_plot->legend() ) { // remove legend controlled by the plot g_plot->insertLegend( NULL ); } //弹出的图列 if ( m_externalLegend == NULL ) { m_externalLegend = new QwtLegend(); m_externalLegend->setWindowTitle("Plot Legend"); connect( g_plot, SIGNAL(legendDataChanged(const QVariant&,const QList<QwtLegendData>&)), m_externalLegend, SLOT(updateLegend(const QVariant&,const QList<QwtLegendData>&)) ); m_externalLegend->show(); // populate the new legend g_plot->updateLegend(); } } else { delete m_externalLegend; m_externalLegend = NULL; if ( g_plot->legend() == NULL || g_plot->plotLayout()->legendPosition() != settings.legend.position ) { g_plot->insertLegend( new QwtLegend(), QwtPlot::LegendPosition( settings.legend.position ) ); } } } else { g_plot->insertLegend( NULL ); delete m_externalLegend; m_externalLegend = NULL; } //判断图例子项是否启用 if ( settings.legendItem.isEnabled ) { if ( m_legendItem == NULL ) { m_legendItem = new LegendItem(); m_legendItem->attach( g_plot ); } //设置最大列数 m_legendItem->setMaxColumns( settings.legendItem.numColumns ); //设置对齐方式 m_legendItem->setAlignmentInCanvas( Qt::Alignment( settings.legendItem.alignment ) ); //设置背景模式 m_legendItem->setBackgroundMode( QwtPlotLegendItem::BackgroundMode( settings.legendItem.backgroundMode ) ); if ( settings.legendItem.backgroundMode == QwtPlotLegendItem::ItemBackground ) { m_legendItem->setBorderRadius( 4 ); m_legendItem->setMargin( 0 ); m_legendItem->setSpacing( 4 ); m_legendItem->setItemMargin( 2 ); } else { m_legendItem->setBorderRadius( 8 ); m_legendItem->setMargin( 4 ); m_legendItem->setSpacing( 2 ); m_legendItem->setItemMargin( 0 ); } //设置字体大小 QFont font = m_legendItem->font(); font.setPointSize( settings.legendItem.size ); m_legendItem->setFont( font ); } else { delete m_legendItem; m_legendItem = NULL; } //画曲线 QwtPlotItemList curveList = g_plot->itemList( QwtPlotItem::Rtti_PlotCurve ); if ( curveList.size() != settings.curve.numCurves ) { while ( curveList.size() > settings.curve.numCurves ) { QwtPlotItem* curve = curveList.takeFirst(); delete curve; } for ( int i = curveList.size(); i < settings.curve.numCurves; i++ ) insertCurve(); } curveList = g_plot->itemList( QwtPlotItem::Rtti_PlotCurve ); for ( int i = 0; i < curveList.count(); i++ ) { Curve* curve = static_cast< Curve* >( curveList[i] );