[Qt Widgets version] qtdemo/trackaxis.cpp
#include <QApplication>
#include "trackaxis.h"
#include <sstream>
#include <algorithm>
TrackAxis::TrackAxis(QWidget *parent) :
QDialog(parent)
{
setWindowTitle("Track Line with Axis Labels");
// Create the QChartViewer and draw the chart
m_ChartViewer = new QChartViewer(this);
drawChart(m_ChartViewer);
// Set the window to be of the same size as the chart
setFixedSize(m_ChartViewer->width(), m_ChartViewer->height());
// Set up the mouseMovePlotArea handler for drawing the track cursor
connect(m_ChartViewer, SIGNAL(mouseMovePlotArea(QMouseEvent*)),
SLOT(onMouseMovePlotArea(QMouseEvent*)));
}
TrackAxis::~TrackAxis()
{
delete m_ChartViewer->getChart();
}
//
// Draw the chart and display it in the given viewer
//
void TrackAxis::drawChart(QChartViewer *viewer)
{
// Data for the chart as 2 random data series
RanSeries r(127);
DoubleArray data0 = r.getSeries(180, 10, -1.5, 1.5);
DoubleArray data1 = r.getSeries(180, 150, -15, 15);
DoubleArray timeStamps = r.getDateSeries(180, Chart::chartTime(2011, 1, 1), 86400);
// Create a XYChart object of size 670 x 400 pixels
XYChart *c = new XYChart(670, 400);
// Add a title to the chart using 18 pts Times New Roman Bold Italic font
c->addTitle("Plasma Stabilizer Energy Usage", "Times New Roman Bold Italic", 18);
// Set the plotarea at (50, 55) with width 100 pixels less than chart width, and height 90 pixels
// less than chart height. Use a vertical gradient from light blue (f0f6ff) to sky blue (a0c0ff)
// as background. Set border to transparent and grid lines to white (ffffff).
c->setPlotArea(50, 55, c->getWidth() - 100, c->getHeight() - 90, c->linearGradientColor(0, 55, 0,
c->getHeight() - 35, 0xf0f6ff, 0xa0c0ff), -1, Chart::Transparent, 0xffffff, 0xffffff);
// Add a legend box at (50, 25) using horizontal layout. Use 10pts Arial Bold as font. Set the
// background and border color to Transparent.
c->addLegend(50, 25, false, "Arial Bold", 10)->setBackground(Chart::Transparent);
// Set axis label style to 8pts Arial Bold
c->xAxis()->setLabelStyle("Arial Bold", 8);
c->yAxis()->setLabelStyle("Arial Bold", 8);
c->yAxis2()->setLabelStyle("Arial Bold", 8);
// Set the axis stem to transparent
c->xAxis()->setColors(Chart::Transparent);
c->yAxis()->setColors(Chart::Transparent);
c->yAxis2()->setColors(Chart::Transparent);
// Configure x-axis label format
c->xAxis()->setMultiFormat(Chart::StartOfYearFilter(), "{value|mm/yyyy} ",
Chart::StartOfMonthFilter(), "{value|mm}");
// Add axis title using 10pts Arial Bold Italic font
c->yAxis()->setTitle("Power Usage (Watt)", "Arial Bold Italic", 10);
c->yAxis2()->setTitle("Effective Load (kg)", "Arial Bold Italic", 10);
// Add a line layer to the chart using a line width of 2 pixels.
LineLayer *layer = c->addLineLayer();
layer->setLineWidth(2);
// Add 2 data series to the line layer
layer->setXData(timeStamps);
layer->addDataSet(data0, 0xcc0000, "Power Usage");
layer->addDataSet(data1, 0x008800, "Effective Load")->setUseYAxis2();
// Set the chart image to the QChartViewer
viewer->setChart(c);
}
//
// Draw track cursor when mouse is moving over plotarea
//
void TrackAxis::onMouseMovePlotArea(QMouseEvent *)
{
trackLineAxis((XYChart *)m_ChartViewer->getChart(), m_ChartViewer->getPlotAreaMouseX());
m_ChartViewer->updateDisplay();
// Hide the track cursor when the mouse leaves the plot area
m_ChartViewer->removeDynamicLayer("mouseLeavePlotArea");
}
//
// Draw track line with axis labels
//
void TrackAxis::trackLineAxis(XYChart *c, int mouseX)
{
// Clear the current dynamic layer and get the DrawArea object to draw on it.
DrawArea *d = c->initDynamicLayer();
// The plot area object
PlotArea *plotArea = c->getPlotArea();
// Get the data x-value that is nearest to the mouse, and find its pixel coordinate.
double xValue = c->getNearestXValue(mouseX);
int xCoor = c->getXCoor(xValue);
// The vertical track line is drawn up to the highest data point (the point with smallest
// y-coordinate). We need to iterate all datasets in all layers to determine where it is.
int minY = plotArea->getBottomY();
// Iterate through all layers to find the highest data point
for(int i = 0; i < c->getLayerCount(); ++i) {
Layer *layer = c->getLayerByZ(i);
// The data array index of the x-value
int xIndex = layer->getXIndexOf(xValue);
// Iterate through all the data sets in the layer
for(int j = 0; j < layer->getDataSetCount(); ++j) {
DataSet *dataSet = layer->getDataSetByZ(j);
double dataPoint = dataSet->getPosition(xIndex);
if ((dataPoint != Chart::NoValue) && (dataSet->getDataColor() != (int)Chart::Transparent))
minY = (std::min)(minY, c->getYCoor(dataPoint, dataSet->getUseYAxis()));
}
}
// Draw a vertical track line at the x-position up to the highest data point.
d->vline((std::max)(minY, plotArea->getTopY()), plotArea->getBottomY() + 6, xCoor,
d->dashLineColor(0x000000, 0x0101));
// Draw a label on the x-axis to show the track line position
std::ostringstream xlabel;
xlabel << "<*font,bgColor=000000*> " << c->xAxis()->getFormattedLabel(xValue, "mmm dd, yyyy")
<< " <*/font*>";
TTFText *t = d->text(xlabel.str().c_str(), "Arial Bold", 8);
t->draw(xCoor, plotArea->getBottomY() + 6, 0xffffff, Chart::Top);
t->destroy();
// Iterate through all layers to build the legend array
for(int i = 0; i < c->getLayerCount(); ++i) {
Layer *layer = c->getLayerByZ(i);
// The data array index of the x-value
int xIndex = layer->getXIndexOf(xValue);
// Iterate through all the data sets in the layer
for(int j = 0; j < layer->getDataSetCount(); ++j) {
DataSet *dataSet = layer->getDataSetByZ(j);
// The positional value, axis binding, pixel coordinate and color of the data point.
double dataPoint = dataSet->getPosition(xIndex);
Axis *yAxis = dataSet->getUseYAxis();
int yCoor = c->getYCoor(dataPoint, yAxis);
int color = dataSet->getDataColor();
// Draw the axis label only for visible data points of named data sets
if ((dataPoint != Chart::NoValue) && (color != (int)Chart::Transparent) && (yCoor >=
plotArea->getTopY()) && (yCoor <= plotArea->getBottomY())) {
// The axis label consists of 3 parts - a track dot for the data point, an axis label,
// and a line joining the track dot to the axis label.
// Draw the line first. The end point of the line at the axis label side depends on
// whether the label is at the left or right side of the axis (that is, on whether the
// axis is on the left or right side of the plot area).
int xPos = yAxis->getX() + ((yAxis->getAlignment() == Chart::Left) ? -4 : 4);
d->hline(xCoor, xPos, yCoor, d->dashLineColor(color, 0x0101));
// Draw the track dot
d->circle(xCoor, yCoor, 4, 4, color, color);
// Draw the axis label. If the axis is on the left side of the plot area, the labels
// should right aligned to the axis, and vice versa.
std::ostringstream axisLabel;
axisLabel << "<*font,bgColor=" << std::hex << color << "*> "
<< c->formatValue(dataPoint, "{value|P4}") << " <*/font*>";
t = d->text(axisLabel.str().c_str(), "Arial Bold", 8);
t->draw(xPos, yCoor, 0xffffff,
((yAxis->getAlignment() == Chart::Left) ? Chart::Right : Chart::Left));
t->destroy();
}
}
}
}
[QML/Qt Quick version] qmldemo/trackaxis.qml
import QtQuick
import QtQuick.Window
import QtQuick.Controls
import advsofteng.com 1.0
Window {
title: "Track Line with Axis Labels"
visible: true
modality: Qt.ApplicationModal
width: viewer.width
minimumWidth: viewer.width
maximumWidth: viewer.width
height: viewer.height
minimumHeight: viewer.height
maximumHeight: viewer.height
// The backend implementation of this demo.
TrackAxisDemo { id: demo }
QmlChartViewer {
id: viewer
Component.onCompleted: demo.drawChart(this)
// Update track cursor on mouse move
onMouseMovePlotArea: demo.drawTrackCursor(this, chartMouseX)
}
}
[QML/Qt Quick version] qmldemo/trackaxis.cpp
#include "trackaxis.h"
#include <sstream>
#include <algorithm>
TrackAxis::TrackAxis(QObject *parent) : QObject(parent)
{
m_currentChart = 0;
}
TrackAxis::~TrackAxis()
{
delete m_currentChart;
}
//
// Draw the chart and display it in the given viewer
//
void TrackAxis::drawChart(QmlChartViewer *viewer)
{
// Data for the chart as 2 random data series
RanSeries r(127);
DoubleArray data0 = r.getSeries(180, 10, -1.5, 1.5);
DoubleArray data1 = r.getSeries(180, 150, -15, 15);
DoubleArray timeStamps = r.getDateSeries(180, Chart::chartTime(2011, 1, 1), 86400);
// Create a XYChart object of size 670 x 400 pixels
XYChart *c = new XYChart(670, 400);
// Add a title to the chart using 18 pts Times New Roman Bold Italic font
c->addTitle("Plasma Stabilizer Energy Usage", "Times New Roman Bold Italic", 18);
// Set the plotarea at (50, 55) with width 100 pixels less than chart width, and height 90 pixels
// less than chart height. Use a vertical gradient from light blue (f0f6ff) to sky blue (a0c0ff)
// as background. Set border to transparent and grid lines to white (ffffff).
c->setPlotArea(50, 55, c->getWidth() - 100, c->getHeight() - 90, c->linearGradientColor(0, 55, 0,
c->getHeight() - 35, 0xf0f6ff, 0xa0c0ff), -1, Chart::Transparent, 0xffffff, 0xffffff);
// Add a legend box at (50, 25) using horizontal layout. Use 10pts Arial Bold as font. Set the
// background and border color to Transparent.
c->addLegend(50, 25, false, "Arial Bold", 10)->setBackground(Chart::Transparent);
// Set axis label style to 8pts Arial Bold
c->xAxis()->setLabelStyle("Arial Bold", 8);
c->yAxis()->setLabelStyle("Arial Bold", 8);
c->yAxis2()->setLabelStyle("Arial Bold", 8);
// Set the axis stem to transparent
c->xAxis()->setColors(Chart::Transparent);
c->yAxis()->setColors(Chart::Transparent);
c->yAxis2()->setColors(Chart::Transparent);
// Configure x-axis label format
c->xAxis()->setMultiFormat(Chart::StartOfYearFilter(), "{value|mm/yyyy} ",
Chart::StartOfMonthFilter(), "{value|mm}");
// Add axis title using 10pts Arial Bold Italic font
c->yAxis()->setTitle("Power Usage (Watt)", "Arial Bold Italic", 10);
c->yAxis2()->setTitle("Effective Load (kg)", "Arial Bold Italic", 10);
// Add a line layer to the chart using a line width of 2 pixels.
LineLayer *layer = c->addLineLayer();
layer->setLineWidth(2);
// Add 2 data series to the line layer
layer->setXData(timeStamps);
layer->addDataSet(data0, 0xcc0000, "Power Usage");
layer->addDataSet(data1, 0x008800, "Effective Load")->setUseYAxis2();
// Set the chart image to the QChartViewer
viewer->setChart(m_currentChart = c);
}
//
// Draw track cursor when mouse is moving over plotarea
//
void TrackAxis::drawTrackCursor(QmlChartViewer *viewer, int mouseX)
{
trackLineAxis((XYChart *)viewer->getChart(), mouseX);
viewer->updateDisplay();
viewer->removeDynamicLayer("mouseLeavePlotArea");
}
//
// Draw track line with axis labels
//
void TrackAxis::trackLineAxis(XYChart *c, int mouseX)
{
// Clear the current dynamic layer and get the DrawArea object to draw on it.
DrawArea *d = c->initDynamicLayer();
// The plot area object
PlotArea *plotArea = c->getPlotArea();
// Get the data x-value that is nearest to the mouse, and find its pixel coordinate.
double xValue = c->getNearestXValue(mouseX);
int xCoor = c->getXCoor(xValue);
// The vertical track line is drawn up to the highest data point (the point with smallest
// y-coordinate). We need to iterate all datasets in all layers to determine where it is.
int minY = plotArea->getBottomY();
// Iterate through all layers to find the highest data point
for(int i = 0; i < c->getLayerCount(); ++i) {
Layer *layer = c->getLayerByZ(i);
// The data array index of the x-value
int xIndex = layer->getXIndexOf(xValue);
// Iterate through all the data sets in the layer
for(int j = 0; j < layer->getDataSetCount(); ++j) {
DataSet *dataSet = layer->getDataSetByZ(j);
double dataPoint = dataSet->getPosition(xIndex);
if ((dataPoint != Chart::NoValue) && (dataSet->getDataColor() != (int)Chart::Transparent))
minY = (std::min)(minY, c->getYCoor(dataPoint, dataSet->getUseYAxis()));
}
}
// Draw a vertical track line at the x-position up to the highest data point.
d->vline((std::max)(minY, plotArea->getTopY()), plotArea->getBottomY() + 6, xCoor,
d->dashLineColor(0x000000, 0x0101));
// Draw a label on the x-axis to show the track line position
std::ostringstream xlabel;
xlabel << "<*font,bgColor=000000*> " << c->xAxis()->getFormattedLabel(xValue, "mmm dd, yyyy")
<< " <*/font*>";
TTFText *t = d->text(xlabel.str().c_str(), "Arial Bold", 8);
t->draw(xCoor, plotArea->getBottomY() + 6, 0xffffff, Chart::Top);
t->destroy();
// Iterate through all layers to build the legend array
for(int i = 0; i < c->getLayerCount(); ++i) {
Layer *layer = c->getLayerByZ(i);
// The data array index of the x-value
int xIndex = layer->getXIndexOf(xValue);
// Iterate through all the data sets in the layer
for(int j = 0; j < layer->getDataSetCount(); ++j) {
DataSet *dataSet = layer->getDataSetByZ(j);
// The positional value, axis binding, pixel coordinate and color of the data point.
double dataPoint = dataSet->getPosition(xIndex);
Axis *yAxis = dataSet->getUseYAxis();
int yCoor = c->getYCoor(dataPoint, yAxis);
int color = dataSet->getDataColor();
// Draw the axis label only for visible data points of named data sets
if ((dataPoint != Chart::NoValue) && (color != (int)Chart::Transparent) && (yCoor >=
plotArea->getTopY()) && (yCoor <= plotArea->getBottomY())) {
// The axis label consists of 3 parts - a track dot for the data point, an axis label,
// and a line joining the track dot to the axis label.
// Draw the line first. The end point of the line at the axis label side depends on
// whether the label is at the left or right side of the axis (that is, on whether the
// axis is on the left or right side of the plot area).
int xPos = yAxis->getX() + ((yAxis->getAlignment() == Chart::Left) ? -4 : 4);
d->hline(xCoor, xPos, yCoor, d->dashLineColor(color, 0x0101));
// Draw the track dot
d->circle(xCoor, yCoor, 4, 4, color, color);
// Draw the axis label. If the axis is on the left side of the plot area, the labels
// should right aligned to the axis, and vice versa.
std::ostringstream axisLabel;
axisLabel << "<*font,bgColor=" << std::hex << color << "*> "
<< c->formatValue(dataPoint, "{value|P4}") << " <*/font*>";
t = d->text(axisLabel.str().c_str(), "Arial Bold", 8);
t->draw(xPos, yCoor, 0xffffff,
((yAxis->getAlignment() == Chart::Left) ? Chart::Right : Chart::Left));
t->destroy();
}
}
}
}
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