##// END OF EJS Templates
Better way to enable features to user. Do less, but expose signals to user and allow user to descide what to do.
Better way to enable features to user. Do less, but expose signals to user and allow user to descide what to do.

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widget.cpp
227 lines | 8.0 KiB | text/x-c | CppLexer
/*!
\class Widget
\brief Ui for the application.
\internal
*/
#include "widget.h"
#include <QGridLayout>
#include <QPushButton>
#include <QLabel>
#include <QSqlQuery>
#include <qscatterseries.h>
#include <qchartview.h>
#include <qchartaxis.h>
#include <qbarset.h>
#include <QListWidget>
#include <QPrinter>
#include <QPrintDialog>
#include <QRadioButton>
#include <QStringList>
QTCOMMERCIALCHART_USE_NAMESPACE
Widget::Widget(QWidget *parent)
: QWidget(parent)
{
setGeometry(100, 100, 1000, 600);
// right panel layout
barChartRadioButton = new QRadioButton(tr("Bar chart"));
barChartRadioButton->setChecked(true);
scatterChartRadioButton = new QRadioButton(tr("Scatter chart"));
scatterChartRadioButton->setChecked(false);
countrieslist = new QListWidget;
countrieslist->setSelectionMode(QAbstractItemView::MultiSelection);
yearslist = new QListWidget;
yearslist->setSelectionMode(QAbstractItemView::ExtendedSelection);
for (int i = 1990; i < 2011; i++)
yearslist->addItem(QString("%1").arg(i));
QPushButton* refreshButton = new QPushButton(tr("Refresh"));
connect(refreshButton, SIGNAL(clicked()), this, SLOT(refreshChart()));
QPushButton* printButton = new QPushButton(tr("Print chart"));
connect(printButton, SIGNAL(clicked()), this, SLOT(printChart()));
QVBoxLayout* rightPanelLayout = new QVBoxLayout;
rightPanelLayout->addWidget(barChartRadioButton);
rightPanelLayout->addWidget(scatterChartRadioButton);
rightPanelLayout->addWidget(countrieslist);
rightPanelLayout->addWidget(yearslist);
rightPanelLayout->addWidget(refreshButton);
rightPanelLayout->addWidget(printButton);
rightPanelLayout->setStretch(0, 1);
rightPanelLayout->setStretch(1, 0);
// main layout
chartArea = new QChartView(this);
chartArea->setChartTitle("GDP by country");
QGridLayout* mainLayout = new QGridLayout;
mainLayout->addWidget(chartArea, 0, 0);
mainLayout->addLayout(rightPanelLayout, 0, 1);
mainLayout->setColumnStretch(0,1);
setLayout(mainLayout);
// connect to the database
db = QSqlDatabase::addDatabase("QSQLITE");
db.setDatabaseName("gdpData");
if(!db.open())
{
qDebug() << "could not open database. SQLite db file missing (?)";
return;
}
// get the list of all countires and regions.
QSqlQuery query;
query.exec("SELECT DISTINCT country FROM gdp2");
// add the countries to the country filter
while (query.next()) {
countrieslist->addItem(query.value(0).toString());
}
// hide axis X labels
QChartAxis* axis = chartArea->axisX();
// axis->setLabelsVisible(false);
// newAxis.setLabelsOrientation(QChartAxis::LabelsOrientationSlide);
}
Widget::~Widget()
{
//
db.close();
}
/*!
refreshes the chart
*/
void Widget::refreshChart()
{
chartArea->removeAllSeries();
// selected countries items list is not sorted. copy the values to QStringlist and sort them.
QStringList selectedCountriesStrings;
QList<QListWidgetItem*> selectedCountriesItems = countrieslist->selectedItems();
for (int i = 0; i < selectedCountriesItems.size(); i++)
selectedCountriesStrings.append(selectedCountriesItems[i]->text());
selectedCountriesStrings.sort();
QSqlQuery query;
// selected years items list is not sorted. copy the values to QList<Integer> and sort them.
QList<int> selectedYearsInts;
QList<QListWidgetItem*> selectedYearsItems = yearslist->selectedItems();
for (int i = 0; i < selectedYearsItems.size(); i++)
selectedYearsInts.append(selectedYearsItems[i]->text().toInt());
qSort(selectedYearsInts.begin(), selectedYearsInts.end(), qGreater<int>());
if (barChartRadioButton->isChecked())
{
// use the sorted selected coutries list to initialize BarCategory
QStringList category;
for (int i = 0; i < selectedCountriesStrings.size(); i++)
category << selectedCountriesStrings[i];
series0 = new QBarSeries(category);
// prepare the selected counries SQL query
QString countriesQuery = "country IN (";
for (int i = 0; i < selectedCountriesStrings.size(); i++)
{
countriesQuery.append("'" + selectedCountriesStrings[i] + "'");
if ( i < selectedCountriesStrings.size() - 1)
countriesQuery.append(",");
else
countriesQuery.append(")");
}
// perform a query for each selected year
for (int i = 0; i < selectedYearsInts.size(); i++)
{
query.exec("SELECT country,gdpvalue FROM gdp2 where year=" + QString("%1").arg(selectedYearsInts[i]) + " AND " + countriesQuery);
QBarSet* barSet = new QBarSet("Barset" + QString::number(i));
// while (query.next()) {
// qDebug() << query.value(0).toString() << " : " << query.value(1).toString();
// }
query.first();
// the data for some of the coutries for some years might be missing.
// QBarChart needs bars to have same size
for (int k = 0; k < selectedCountriesStrings.size(); k++)
{
if (selectedCountriesStrings[k] == query.value(0).toString())
{
*barSet << query.value(1).toReal();
qDebug() << query.value(0).toString() << query.value(1).toReal() << " : " << QString("%1").arg(selectedYearsInts[i]);
query.next();
}
else
{
// data missing, put 0
*barSet << 0.0f;
qDebug() << "Putting 0 for Bosnia" << " : " << QString("%1").arg(selectedYearsInts[i]);
}
}
series0->addBarSet(barSet);
}
// add the serie to the chart
chartArea->addSeries(series0);
}
else if (scatterChartRadioButton->isChecked())
{
QString yearsQuery = "year IN (";
for (int i = 0; i < selectedYearsInts.size(); i++)
{
yearsQuery.append("'" + QString("%1").arg(selectedYearsInts[i]) + "'");
if ( i < selectedYearsInts.size() - 1)
yearsQuery.append(",");
else
yearsQuery.append(")");
}
// perform a query for each selected year
for (int i = 0; i < selectedCountriesStrings.size(); i++)
{
query.exec("SELECT year,gdpvalue FROM gdp2 where country='" + selectedCountriesStrings[i] + "' AND " + yearsQuery);
query.first();
QScatterSeries* series = new QScatterSeries;
// the data for some of the coutries for some years might be missing.
for (int k = 0; k < selectedYearsInts.size(); k++)
{
if (selectedYearsInts[k] == query.value(0).toInt())
{
*series << QPointF(query.value(0).toInt() , query.value(1).toReal());
qDebug() << query.value(0).toString() << query.value(1).toReal() << " : " << QString("%1").arg(selectedYearsInts[k]);
query.next();
}
else
{
// data missing, put 0
*series << QPointF(selectedYearsInts[k] , 0.0f);
qDebug() << "Putting 0 for Bosnia" << " : " << QString("%1").arg(selectedYearsInts[i]) << " " << query.value(0).toInt();
}
}
// chartArea->axisX()->setRange(selectedYearsInts[selectedYearsInts.size() - 1] + 1, selectedYearsInts[0] - 1);
chartArea->addSeries(series);
}
chartArea->axisX()->setRange(selectedYearsInts[selectedYearsInts.size() - 1] + 1, selectedYearsInts[0] - 1);
}
}
void Widget::printChart()
{
QPrinter printer;
// QPrinter printer(QPrinter::HighResolution);
printer.setOutputFormat(QPrinter::PdfFormat);
printer.setOrientation(QPrinter::Landscape);
printer.setOutputFileName("print.pdf");
QPainter painter;
painter.begin(&printer);
chartArea->render(&painter);
}