DrawFinancialChart::DrawFinancialChart(QWidget *parent) :
QCustomPlot(parent)
{
resize(600,400);
legend->setVisible(true);
// generate two sets of random walk data (one for candlestick and one for ohlc chart):
int n = 500;
QVector<double> time(n), value1(n), value2(n);
QDateTime start = QDateTime(QDate(2014, 6, 11));
start.setTimeSpec(Qt::UTC);
double startTime = start.toTime_t();
double binSize = 3600*24; // bin data in 1 day intervals
time[0] = startTime;
value1[0] = 60;
value2[0] = 20;
qsrand(9);
for (int i=1; i<n; ++i)
{
time[i] = startTime + 3600*i;
value1[i] = value1[i-1] + (qrand()/(double)RAND_MAX-0.5)*10;
value2[i] = value2[i-1] + (qrand()/(double)RAND_MAX-0.5)*3;
}
// create candlestick chart:
QCPFinancial *candlesticks = new QCPFinancial(xAxis, yAxis);
addPlottable(candlesticks);
QCPFinancialDataMap data1 = QCPFinancial::timeSeriesToOhlc(time, value1, binSize, startTime);
candlesticks->setName("Candlestick");
candlesticks->setChartStyle(QCPFinancial::csCandlestick);
candlesticks->setData(&data1, true);
candlesticks->setWidth(binSize*0.9);
candlesticks->setTwoColored(true);
candlesticks->setBrushPositive(QColor(245, 245, 245));
candlesticks->setBrushNegative(QColor(0, 0, 0));
candlesticks->setPenPositive(QPen(QColor(0, 0, 0)));
candlesticks->setPenNegative(QPen(QColor(0, 0, 0)));
// create ohlc chart:
QCPFinancial *ohlc = new QCPFinancial(xAxis, yAxis);
addPlottable(ohlc);
QCPFinancialDataMap data2 = QCPFinancial::timeSeriesToOhlc(time, value2, binSize/3.0, startTime); // divide binSize by 3 just to make the ohlc bars a bit denser
ohlc->setName("OHLC");
ohlc->setChartStyle(QCPFinancial::csOhlc);
ohlc->setData(&data2, true);
ohlc->setWidth(binSize*0.2);
ohlc->setTwoColored(true);
// create bottom axis rect for volume bar chart:
QCPAxisRect *volumeAxisRect = new QCPAxisRect(this);
plotLayout()->addElement(1, 0, volumeAxisRect);
volumeAxisRect->setMaximumSize(QSize(QWIDGETSIZE_MAX, 100));
volumeAxisRect->axis(QCPAxis::atBottom)->setLayer("axes");
volumeAxisRect->axis(QCPAxis::atBottom)->grid()->setLayer("grid");
// bring bottom and main axis rect closer together:
plotLayout()->setRowSpacing(0);
volumeAxisRect->setAutoMargins(QCP::msLeft|QCP::msRight|QCP::msBottom);
volumeAxisRect->setMargins(QMargins(0, 0, 0, 0));
// create two bar plottables, for positive (green) and negative (red) volume bars:
QCPBars *volumePos = new QCPBars(volumeAxisRect->axis(QCPAxis::atBottom), volumeAxisRect->axis(QCPAxis::atLeft));
QCPBars *volumeNeg = new QCPBars(volumeAxisRect->axis(QCPAxis::atBottom), volumeAxisRect->axis(QCPAxis::atLeft));
for (int i=0; i<n/5; ++i)
{
int v = qrand()%20000+qrand()%20000+qrand()%20000-10000*3;
(v < 0 ? volumeNeg : volumePos)->addData(startTime+3600*5.0*i, qAbs(v)); // add data to either volumeNeg or volumePos, depending on sign of v
}
setAutoAddPlottableToLegend(false);
addPlottable(volumePos);
addPlottable(volumeNeg);
volumePos->setWidth(3600*4);
volumePos->setPen(Qt::NoPen);
volumePos->setBrush(QColor(100, 180, 110));
volumeNeg->setWidth(3600*4);
volumeNeg->setPen(Qt::NoPen);
volumeNeg->setBrush(QColor(180, 90, 90));
// interconnect x axis ranges of main and bottom axis rects:
connect(xAxis, SIGNAL(rangeChanged(QCPRange)), volumeAxisRect->axis(QCPAxis::atBottom), SLOT(setRange(QCPRange)));
connect(volumeAxisRect->axis(QCPAxis::atBottom), SIGNAL(rangeChanged(QCPRange)), xAxis, SLOT(setRange(QCPRange)));
// configure axes of both main and bottom axis rect:
volumeAxisRect->axis(QCPAxis::atBottom)->setAutoTickStep(false);
volumeAxisRect->axis(QCPAxis::atBottom)->setTickStep(3600*24*4); // 4 day tickstep
volumeAxisRect->axis(QCPAxis::atBottom)->setTickLabelType(QCPAxis::ltDateTime);
volumeAxisRect->axis(QCPAxis::atBottom)->setDateTimeSpec(Qt::UTC);
volumeAxisRect->axis(QCPAxis::atBottom)->setDateTimeFormat("dd. MMM");
volumeAxisRect->axis(QCPAxis::atBottom)->setTickLabelRotation(15);
volumeAxisRect->axis(QCPAxis::atLeft)->setAutoTickCount(3);
xAxis->setBasePen(Qt::NoPen);
xAxis->setTickLabels(false);
xAxis->setTicks(false); // only want vertical grid in main axis rect, so hide xAxis backbone, ticks, and labels
xAxis->setAutoTickStep(false);
xAxis->setTickStep(3600*24*4); // 4 day tickstep
rescaleAxes();
xAxis->scaleRange(1.025, xAxis->range().center());
yAxis->scaleRange(1.1, yAxis->range().center());
// make axis rects' left side line up:
QCPMarginGroup *group = new QCPMarginGroup(this);
axisRect()->setMarginGroup(QCP::msLeft|QCP::msRight, group);
volumeAxisRect->setMarginGroup(QCP::msLeft|QCP::msRight, group);
}
