view.cpp Example File | Qt Charts 5.12.11

- Qt 5.12
- Qt Charts
- Callout Example
- view.cpp Example File
- Qt Charts | Commercial or GPLv3

# view.cpp Example File

callout/view.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2016 The Qt Company Ltd.
     ** Contact: https://www.qt.io/licensing/
     **
     ** This file is part of the Qt Charts module of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:GPL$
     ** Commercial License Usage
     ** Licensees holding valid commercial Qt licenses may use this file in
     ** accordance with the commercial license agreement provided with the
     ** Software or, alternatively, in accordance with the terms contained in
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     ** information use the contact form at https://www.qt.io/contact-us.
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     ** Alternatively, this file may be used under the terms of the GNU
     ** General Public License version 3 or (at your option) any later version
     ** approved by the KDE Free Qt Foundation. The licenses are as published by
     ** the Free Software Foundation and appearing in the file LICENSE.GPL3
     ** included in the packaging of this file. Please review the following
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     #include "view.h"
     #include <QtGui/QResizeEvent>
     #include <QtWidgets/QGraphicsScene>
     #include <QtCharts/QChart>
     #include <QtCharts/QLineSeries>
     #include <QtCharts/QSplineSeries>
     #include <QtWidgets/QGraphicsTextItem>
     #include "callout.h"
     #include <QtGui/QMouseEvent>

     View::View(QWidget *parent)
         : QGraphicsView(new QGraphicsScene, parent),
           m_coordX(0),
           m_coordY(0),
           m_chart(0),
           m_tooltip(0)
     {
         setDragMode(QGraphicsView::NoDrag);
         setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
         setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

         // chart
         m_chart = new QChart;
         m_chart->setMinimumSize(640, 480);
         m_chart->setTitle("Hover the line to show callout. Click the line to make it stay");
         m_chart->legend()->hide();
         QLineSeries *series = new QLineSeries;
         series->append(1, 3);
         series->append(4, 5);
         series->append(5, 4.5);
         series->append(7, 1);
         series->append(11, 2);
         m_chart->addSeries(series);

         QSplineSeries *series2 = new QSplineSeries;
         series2->append(1.6, 1.4);
         series2->append(2.4, 3.5);
         series2->append(3.7, 2.5);
         series2->append(7, 4);
         series2->append(10, 2);
         m_chart->addSeries(series2);

         m_chart->createDefaultAxes();
         m_chart->setAcceptHoverEvents(true);

         setRenderHint(QPainter::Antialiasing);
         scene()->addItem(m_chart);

         m_coordX = new QGraphicsSimpleTextItem(m_chart);
         m_coordX->setPos(m_chart->size().width()/2 - 50, m_chart->size().height());
         m_coordX->setText("X: ");
         m_coordY = new QGraphicsSimpleTextItem(m_chart);
         m_coordY->setPos(m_chart->size().width()/2 + 50, m_chart->size().height());
         m_coordY->setText("Y: ");

         connect(series, &QLineSeries::clicked, this, &View::keepCallout);
         connect(series, &QLineSeries::hovered, this, &View::tooltip);

         connect(series2, &QSplineSeries::clicked, this, &View::keepCallout);
         connect(series2, &QSplineSeries::hovered, this, &View::tooltip);

         this->setMouseTracking(true);
     }

     void View::resizeEvent(QResizeEvent *event)
     {
         if (scene()) {
             scene()->setSceneRect(QRect(QPoint(0, 0), event->size()));
              m_chart->resize(event->size());
              m_coordX->setPos(m_chart->size().width()/2 - 50, m_chart->size().height() - 20);
              m_coordY->setPos(m_chart->size().width()/2 + 50, m_chart->size().height() - 20);
              const auto callouts = m_callouts;
              for (Callout *callout : callouts)
                  callout->updateGeometry();
         }
         QGraphicsView::resizeEvent(event);
     }

     void View::mouseMoveEvent(QMouseEvent *event)
     {
         m_coordX->setText(QString("X: %1").arg(m_chart->mapToValue(event->pos()).x()));
         m_coordY->setText(QString("Y: %1").arg(m_chart->mapToValue(event->pos()).y()));
         QGraphicsView::mouseMoveEvent(event);
     }

     void View::keepCallout()
     {
         m_callouts.append(m_tooltip);
         m_tooltip = new Callout(m_chart);
     }

     void View::tooltip(QPointF point, bool state)
     {
         if (m_tooltip == 0)
             m_tooltip = new Callout(m_chart);

         if (state) {
             m_tooltip->setText(QString("X: %1 \nY: %2 ").arg(point.x()).arg(point.y()));
             m_tooltip->setAnchor(point);
             m_tooltip->setZValue(11);
             m_tooltip->updateGeometry();
             m_tooltip->show();
         } else {
             m_tooltip->hide();
         }
     }