The below code is related to qchart example "Custom chart" in qt examples. I tried several different solutions but failed to understand or get a proper idea as a solution. I want to get my chart to update values on run time. so the chart values don't remain static but instead, they are dynamic. I want it to be signal & slot-based. (technically signal will be coming from another file including data but here for testing purposes I tried to use that push button as signal and slot but failed to understand how to do it). I tried it but nothing happens. I just don't know where I am missing it. Below is the code.
main.cpp
#include "mainwindow.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
return a.exec();
}
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include<windows.h>
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
// int foo [5] = { 8, 9, 10, 11, 120 };
// for(int i=0;i <10; i++)
// {
// Sleep(1000);
ui->setupUi(this);
//![1]
QLineSeries *series = new QLineSeries();
*series << QPointF(0, 6) << QPointF(9, 4) << QPointF(15, 20) << QPointF(25, 12) << QPointF(29, 26);
QChart *chart = new QChart();
chart->legend()->hide();
chart->addSeries(series);
//![1]
//![2]
// Customize series
QPen pen(QRgb(0xfdb157));
pen.setWidth(5);
series->setPen(pen);
// Customize chart title
QFont font;
font.setPixelSize(18);
chart->setTitleFont(font);
chart->setTitleBrush(QBrush(Qt::white));
chart->setTitle("Customchart example");
// Customize chart background
QLinearGradient backgroundGradient;
backgroundGradient.setStart(QPointF(0, 0));
backgroundGradient.setFinalStop(QPointF(0, 1));
backgroundGradient.setColorAt(0.0, QRgb(0xd2d0d1));
backgroundGradient.setColorAt(1.0, QRgb(0x4c4547));
backgroundGradient.setCoordinateMode(QGradient::ObjectBoundingMode);
chart->setBackgroundBrush(backgroundGradient);
// Customize plot area background
QLinearGradient plotAreaGradient;
plotAreaGradient.setStart(QPointF(0, 1));
plotAreaGradient.setFinalStop(QPointF(1, 0));
plotAreaGradient.setColorAt(0.0, QRgb(0x555555));
plotAreaGradient.setColorAt(1.0, QRgb(0x55aa55));
plotAreaGradient.setCoordinateMode(QGradient::ObjectBoundingMode);
chart->setPlotAreaBackgroundBrush(plotAreaGradient);
chart->setPlotAreaBackgroundVisible(true);
//![2]
//![3]
QCategoryAxis *axisX = new QCategoryAxis();
QCategoryAxis *axisY = new QCategoryAxis();
// Customize axis label font
QFont labelsFont;
labelsFont.setPixelSize(12);
axisX->setLabelsFont(labelsFont);
axisY->setLabelsFont(labelsFont);
// Customize axis colors
QPen axisPen(QRgb(0xd18952));
axisPen.setWidth(2);
axisX->setLinePen(axisPen);
axisY->setLinePen(axisPen);
// Customize axis label colors
QBrush axisBrush(Qt::white);
axisX->setLabelsBrush(axisBrush);
axisY->setLabelsBrush(axisBrush);
// Customize grid lines and shades
axisX->setGridLineVisible(false);
axisY->setGridLineVisible(false);
axisY->setShadesPen(Qt::NoPen);
axisY->setShadesBrush(QBrush(QColor(0x99, 0xcc, 0xcc, 0x55)));
axisY->setShadesVisible(true);
//![3]
//![4]
//
axisX->append( "Monday", 0);
axisX->append("Tuesday", 10);
axisX->append("Wednesday", 15);
axisX->append("Thursday", 20);
axisX->append("Friday", 25);
axisX->append("Saturday", 30);
axisX->append("Sunday", 35);
axisX->setRange(0, 35);
axisY->append("Normal", 10);
axisY->append("Yellow", 20);
axisY->append("Red", 30);
axisY->setRange(0, 30);
chart->addAxis(axisX, Qt::AlignBottom);
chart->addAxis(axisY, Qt::AlignLeft);
series->attachAxis(axisX);
series->attachAxis(axisY);
QChartView *chartView = new QChartView(chart);
chartView->setRenderHint(QPainter::Antialiasing);
//stackoverflolwbelow
QVBoxLayout *layout = new QVBoxLayout(ui->chartframe);
layout->addWidget(chartView);
//![4]
QLCDNumber *lcd = new QLCDNumber;
lcd->display(1501);
// lcd->setMinimumSize(250,100);
//lcd->setParent(ui->lcdframe);
QVBoxLayout *layoutLCD = new QVBoxLayout(ui->lcdframe);
layoutLCD->addWidget(lcd);
//![5]
//stackoverflowabove
// chartView-> setParent(ui->chartframe);
//![5]
//!
//!
// MainWindow window;
// window.setCentralWidget(chartView);
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::on_pushButton_clicked()
{
qInfo() << "C++ Style Info Message";
QLineSeries *series = new QLineSeries();
*series << QPointF(0, 6) << QPointF(9, 4) << QPointF(15, 30) << QPointF(25, 13) << QPointF(29, 26);
QChart *chart = new QChart();
chart->legend()->hide();
chart->addSeries(series);
}
mainwindow.ui
<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
<class>MainWindow</class>
<widget class="QMainWindow" name="MainWindow">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>800</width>
<height>600</height>
</rect>
</property>
<property name="windowTitle">
<string>MainWindow</string>
</property>
<widget class="QWidget" name="centralwidget">
<layout class="QHBoxLayout" name="horizontalLayout_2">
<item>
<widget class="QFrame" name="frame">
<property name="frameShape">
<enum>QFrame::StyledPanel</enum>
</property>
<property name="frameShadow">
<enum>QFrame::Raised</enum>
</property>
<layout class="QHBoxLayout" name="horizontalLayout">
<item>
<widget class="QFrame" name="frame_2">
<property name="frameShape">
<enum>QFrame::StyledPanel</enum>
</property>
<property name="frameShadow">
<enum>QFrame::Raised</enum>
</property>
<layout class="QVBoxLayout" name="verticalLayout">
<item>
<widget class="QFrame" name="lcdframe">
<property name="maximumSize">
<size>
<width>200</width>
<height>50</height>
</size>
</property>
<property name="frameShape">
<enum>QFrame::StyledPanel</enum>
</property>
<property name="frameShadow">
<enum>QFrame::Raised</enum>
</property>
</widget>
</item>
<item>
<widget class="QFrame" name="chartframe">
<property name="minimumSize">
<size>
<width>200</width>
<height>100</height>
</size>
</property>
<property name="frameShape">
<enum>QFrame::StyledPanel</enum>
</property>
<property name="frameShadow">
<enum>QFrame::Raised</enum>
</property>
</widget>
</item>
<item>
<widget class="QPushButton" name="pushButton">
<property name="text">
<string>PushButton</string>
</property>
</widget>
</item>
</layout>
</widget>
</item>
<item>
<widget class="QFrame" name="frame_3">
<property name="frameShape">
<enum>QFrame::StyledPanel</enum>
</property>
<property name="frameShadow">
<enum>QFrame::Raised</enum>
</property>
<layout class="QVBoxLayout" name="verticalLayout_2">
<item>
<widget class="QTextEdit" name="textEdit"/>
</item>
<item>
<widget class="QLineEdit" name="lineEdit"/>
</item>
</layout>
</widget>
</item>
</layout>
</widget>
</item>
</layout>
</widget>
<widget class="QMenuBar" name="menubar">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>800</width>
<height>21</height>
</rect>
</property>
</widget>
<widget class="QStatusBar" name="statusbar"/>
<widget class="QToolBar" name="toolBar">
<property name="windowTitle">
<string>toolBar</string>
</property>
<attribute name="toolBarArea">
<enum>TopToolBarArea</enum>
</attribute>
<attribute name="toolBarBreak">
<bool>false</bool>
</attribute>
</widget>
</widget>
<resources/>
<connections/>
</ui>
I am a beginner in the qt framework and I am super short of time. I tried many solutions but couldn't reach a proper one. I will be waiting for your kind response.
you need to do like this:
QLineSeries and QChart move to main mainwindow.h
private:
QLineSeries *series;
QChart *chart;
2.in mainwindow.cpp it will already be like this
ui->setupUi(this);
//![1]
series = new QLineSeries();
*series << QPointF(0, 6) << QPointF(9, 4) << QPointF(15, 20) << QPointF(25, 12) << QPointF(29, 26);
chart = new QChart();
chart->legend()->hide();
chart->addSeries(series);
//![1]
in function on_pushButton_clicked()
series ->clear();
series ->append(QPointF(0, 6));
series ->append(QPointF(9, 4));
// or
*series << QPointF(0, 6) << QPointF(9, 4) << QPointF(15, 30) << QPointF(25, 13) << QPointF(29, 26);
no need to create new QLineSeries and QChart in on_pushButton_clicked function