source: tspsg-svn/trunk/src/mainwindow.cpp @ 52

/*
 *  TSPSG: TSP Solver and Generator
 *  Copyright (C) 2007-2009 Lёppa <contacts[at]oleksii[dot]name>
 *
 *  $Id: mainwindow.cpp 52 2009-08-04 16:18:14Z laleppa $
 *  $URL: https://tspsg.svn.sourceforge.net/svnroot/tspsg/trunk/src/mainwindow.cpp $
 *
 *  This file is part of TSPSG.
 *
 *  TSPSG is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  TSPSG is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with TSPSG.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
        : QMainWindow(parent)
{
        settings = new QSettings(QSettings::IniFormat,QSettings::UserScope,"TSPSG","tspsg");
        loadLanguage();
        setupUi(this);
        initDocStyleSheet();
        solutionText->document()->setDefaultFont(settings->value("Output/Font",QFont(DEF_FONT_FAMILY,DEF_FONT_SIZE)).value<QFont>());
        solutionText->setTextColor(settings->value("Output/Color",DEF_FONT_COLOR).value<QColor>());
        solutionText->setWordWrapMode(QTextOption::WordWrap);
#ifdef Q_OS_WINCE
        // A little hack for toolbar icons to have sane size.
int s = qMin(QApplication::desktop()->screenGeometry().width(),QApplication::desktop()->screenGeometry().height());
        toolBar->setIconSize(QSize(s / 10,s / 10));
#endif
#ifndef Q_OS_WINCE
        printer = new QPrinter(QPrinter::HighResolution);
#endif // Q_OS_WINCE
        groupSettingsLanguageList = new QActionGroup(this);
        actionSettingsLanguageEnglish->setData("en");
        actionSettingsLanguageEnglish->setActionGroup(groupSettingsLanguageList);
        loadLangList();
        spinCities->setMaximum(MAX_NUM_CITIES);
        actionSettingsLanguageAutodetect->setChecked(settings->value("Language","").toString().isEmpty());
        connect(actionFileNew,SIGNAL(triggered()),this,SLOT(actionFileNewTriggered()));
        connect(actionFileOpen,SIGNAL(triggered()),this,SLOT(actionFileOpenTriggered()));
        connect(actionFileSave,SIGNAL(triggered()),this,SLOT(actionFileSaveTriggered()));
        connect(actionFileSaveAsTask,SIGNAL(triggered()),this,SLOT(actionFileSaveAsTaskTriggered()));
        connect(actionFileSaveAsSolution,SIGNAL(triggered()),this,SLOT(actionFileSaveAsSolutionTriggered()));
        connect(actionSettingsPreferences,SIGNAL(triggered()),this,SLOT(actionSettingsPreferencesTriggered()));
        connect(actionSettingsLanguageAutodetect,SIGNAL(triggered(bool)),this,SLOT(actionSettingsLanguageAutodetectTriggered(bool)));
        connect(groupSettingsLanguageList,SIGNAL(triggered(QAction *)),this,SLOT(groupSettingsLanguageListTriggered(QAction *)));
        connect(actionHelpAboutQt,SIGNAL(triggered()),qApp,SLOT(aboutQt()));
        connect(actionHelpAbout,SIGNAL(triggered()),this,SLOT(actionHelpAboutTriggered()));
#ifndef Q_OS_WINCE
        connect(actionFilePrintPreview,SIGNAL(triggered()),this,SLOT(actionFilePrintPreviewTriggered()));
        connect(actionFilePrint,SIGNAL(triggered()),this,SLOT(actionFilePrintTriggered()));
#endif // Q_OS_WINCE
        connect(buttonSolve,SIGNAL(clicked()),this,SLOT(buttonSolveClicked()));
        connect(buttonRandom,SIGNAL(clicked()),this,SLOT(buttonRandomClicked()));
        connect(buttonBackToTask,SIGNAL(clicked()),this,SLOT(buttonBackToTaskClicked()));
        connect(spinCities,SIGNAL(valueChanged(int)),this,SLOT(spinCitiesValueChanged(int)));
        setCentralWidget(tabWidget);
QRect rect = geometry();
#ifndef Q_OS_WINCE
        if (settings->value("SavePos",false).toBool()) {
                // Loading of saved window state
                settings->beginGroup("MainWindow");
                resize(settings->value("Size",size()).toSize());
                move(settings->value("Position",pos()).toPoint());
                if (settings->value("Maximized",false).toBool())
                        setWindowState(windowState() | Qt::WindowMaximized);
                settings->endGroup();
        } else {
                // Centering main window
                rect.moveCenter(QApplication::desktop()->availableGeometry(this).center());
                setGeometry(rect);
        }
#endif // Q_OS_WINCE
        qsrand(QDateTime().currentDateTime().toTime_t());
        tspmodel = new CTSPModel();
        taskView->setModel(tspmodel);
        connect(tspmodel,SIGNAL(numCitiesChanged(int)),this,SLOT(numCitiesChanged(int)));
        connect(tspmodel,SIGNAL(dataChanged(const QModelIndex &, const QModelIndex &)),this,SLOT(dataChanged()));
        connect(tspmodel,SIGNAL(layoutChanged()),this,SLOT(dataChanged()));
        if ((QCoreApplication::arguments().count() > 1) && (tspmodel->loadTask(QCoreApplication::arguments().at(1))))
                setFileName(QCoreApplication::arguments().at(1));
        else {
                setFileName();
                spinCities->setValue(settings->value("NumCities",DEF_NUM_CITIES).toInt());
                spinCitiesValueChanged(spinCities->value());
        }
        setWindowModified(false);
}

void MainWindow::enableSolutionActions(bool enable)
{
        buttonSaveSolution->setEnabled(enable);
        actionFileSaveAsSolution->setEnabled(enable);
        solutionText->setEnabled(enable);
        if (!enable)
                output.clear();
#ifndef Q_OS_WINCE
        actionFilePrint->setEnabled(enable);
        actionFilePrintPreview->setEnabled(enable);
#endif // Q_OS_WINCE
}

bool MainWindow::loadLanguage(QString lang)
{
// i18n
bool ad = false;
        if (lang.isEmpty()) {
                ad = settings->value("Language","").toString().isEmpty();
                lang = settings->value("Language",QLocale::system().name()).toString();
        }
static QTranslator *qtTranslator; // Qt library translator
        if (qtTranslator) {
                qApp->removeTranslator(qtTranslator);
                delete qtTranslator;
                qtTranslator = NULL;
        }
        qtTranslator = new QTranslator();
static QTranslator *translator; // Application translator
        if (translator) {
                qApp->removeTranslator(translator);
                delete translator;
        }
        translator = new QTranslator();
        if (lang.compare("en") && !lang.startsWith("en_")) {
                // Trying to load system Qt library translation...
                if (qtTranslator->load("qt_" + lang,QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
                        qApp->installTranslator(qtTranslator);
                else
                        // No luck. Let's try to load bundled one.
                        if (qtTranslator->load("qt_" + lang,"i18n"))
                                qApp->installTranslator(qtTranslator);
                        else {
                                // Qt library translation unavailable
                                delete qtTranslator;
                                qtTranslator = NULL;
                        }
                // Now let's load application translation.
                if (translator->load(lang,"i18n"))
                        qApp->installTranslator(translator);
                else {
                        if (!ad)
                                QMessageBox(QMessageBox::Warning,trUtf8("Language Change"),trUtf8("Unable to load translation language."),QMessageBox::Ok,this).exec();
                        delete translator;
                        translator = NULL;
                        return false;
                }
        }
        return true;
}

void MainWindow::initDocStyleSheet()
{
QColor color = settings->value("Output/Color",DEF_FONT_COLOR).value<QColor>();
QColor hilight;
        if (color.value() < 192)
                hilight.setHsv(color.hue(),color.saturation(),127 + qRound(color.value() / 2));
        else
                hilight.setHsv(color.hue(),color.saturation(),color.value() / 2);
        solutionText->document()->setDefaultStyleSheet("* {color: " + color.name() +";} p {margin: 0px 10px;} table {margin: 5px;} td {padding: 1px 5px;} .hasalts {color: " + hilight.name() + ";} .selected {color: #A00000; font-weight: bold;} .alternate {color: #008000; font-weight: bold;}");
        solutionText->document()->setDefaultFont(settings->value("Output/Font",QFont(DEF_FONT_FAMILY,DEF_FONT_SIZE)).value<QFont>());
}

void MainWindow::setFileName(QString fileName)
{
        this->fileName = fileName;
        setWindowTitle(QString("%1[*] - %2").arg(QFileInfo(fileName).completeBaseName()).arg(trUtf8("Travelling Salesman Problem")));
}

void MainWindow::spinCitiesValueChanged(int n)
{
int count = tspmodel->numCities();
        tspmodel->setNumCities(n);
        if (n > count)
                for (int k = count; k < n; k++) {
                        taskView->resizeColumnToContents(k);
                        taskView->resizeRowToContents(k);
                }
}

bool MainWindow::maybeSave()
{
        if (!isWindowModified())
                return true;
int res = QMessageBox(QMessageBox::Warning,trUtf8("Unsaved Changes"),trUtf8("Would you like to save changes in current task?"),QMessageBox::Save | QMessageBox::Discard | QMessageBox::Cancel,this).exec();
        if (res == QMessageBox::Save)
                return saveTask();
        else if (res == QMessageBox::Cancel)
                return false;
        else
                return true;
}

void MainWindow::actionFileNewTriggered()
{
        if (!maybeSave())
                return;
        tspmodel->clear();
        taskView->resizeColumnsToContents();
        taskView->resizeRowsToContents();
        setFileName();
        setWindowModified(false);
        tabWidget->setCurrentIndex(0);
        solutionText->clear();
        enableSolutionActions(false);
}

void MainWindow::actionFileOpenTriggered()
{
        if (!maybeSave())
                return;
QFileDialog od(this);
        od.setAcceptMode(QFileDialog::AcceptOpen);
        od.setFileMode(QFileDialog::ExistingFile);
QStringList filters(trUtf8("All Supported Formats") + " (*.tspt *.zkt)");
        filters.append(trUtf8("%1 Task Files").arg("TSPSG") + " (*.tspt)");
        filters.append(trUtf8("%1 Task Files").arg("ZKomModRd") + " (*.zkt)");
        filters.append(trUtf8("All Files") + " (*)");
        od.setNameFilters(filters);
        if (od.exec() != QDialog::Accepted)
                return;
QStringList files = od.selectedFiles();
        if (files.empty())
                return;
        QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
        if (!tspmodel->loadTask(files.first())) {
                QApplication::restoreOverrideCursor();
                return;
        }
        setFileName(files.first());
        taskView->resizeColumnsToContents();
        taskView->resizeRowsToContents();
        tabWidget->setCurrentIndex(0);
        setWindowModified(false);
        solutionText->clear();
        enableSolutionActions(false);
        QApplication::restoreOverrideCursor();
}

void MainWindow::actionFileSaveTriggered()
{
        if ((fileName == trUtf8("Untitled") + ".tspt") || (!fileName.endsWith(".tspt",Qt::CaseInsensitive)))
                saveTask();
        else {
                QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
                if (tspmodel->saveTask(fileName))
                        setWindowModified(false);
                QApplication::restoreOverrideCursor();
        }
}

void MainWindow::actionFileSaveAsTaskTriggered()
{
        saveTask();
}

void MainWindow::actionFileSaveAsSolutionTriggered()
{
static QString selectedFile;
        if (selectedFile.isEmpty())
                selectedFile = "solution.html";
QFileDialog sd(this);
        sd.setAcceptMode(QFileDialog::AcceptSave);
QStringList filters(trUtf8("HTML Files") + " (*.html *.htm)");
#if QT_VERSION >= 0x040500
        filters.append(trUtf8("OpenDocument Files") + " (*.odt)");
#endif // QT_VERSION >= 0x040500
        filters.append(trUtf8("All Files") + " (*)");
        sd.setNameFilters(filters);
        sd.selectFile(selectedFile);
        if (sd.exec() != QDialog::Accepted)
                return;
QStringList files = sd.selectedFiles();
        if (files.empty())
                return;
        selectedFile = files.first();
        QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
#if QT_VERSION >= 0x040500
QTextDocumentWriter dw(selectedFile);
        if (!(selectedFile.endsWith(".htm",Qt::CaseInsensitive) || selectedFile.endsWith(".html",Qt::CaseInsensitive) || selectedFile.endsWith(".odt",Qt::CaseInsensitive) || selectedFile.endsWith(".txt",Qt::CaseInsensitive)))
                dw.setFormat("plaintext");
        dw.write(solutionText->document());
#else
        // Qt < 4.5 has no QTextDocumentWriter class
QFile file(selectedFile);
        if (!file.open(QFile::WriteOnly)) {
                QApplication::restoreOverrideCursor();
                return;
        }
QTextStream ts(&file);
        ts.setCodec(QTextCodec::codecForName("UTF-8"));
        ts << solutionText->document()->toHtml("UTF-8");
        file.close();
#endif // QT_VERSION >= 0x040500
        QApplication::restoreOverrideCursor();
}

bool MainWindow::saveTask() {
QFileDialog sd(this);
        sd.setAcceptMode(QFileDialog::AcceptSave);
QStringList filters(trUtf8("%1 Task File").arg("TSPSG") + " (*.tspt)");
        filters.append(trUtf8("All Files") + " (*)");
        sd.setNameFilters(filters);
        sd.setDefaultSuffix("tspt");
        if (fileName.endsWith(".tspt",Qt::CaseInsensitive))
                sd.selectFile(fileName);
        else
                sd.selectFile(QFileInfo(fileName).canonicalPath() + "/" + QFileInfo(fileName).completeBaseName() + ".tspt");
        if (sd.exec() != QDialog::Accepted)
                return false;
QStringList files = sd.selectedFiles();
        if (files.empty())
                return false;
        QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
        if (tspmodel->saveTask(files.first())) {
                setFileName(files.first());
                setWindowModified(false);
                QApplication::restoreOverrideCursor();
                return true;
        }
        QApplication::restoreOverrideCursor();
        return false;
}

void MainWindow::actionSettingsPreferencesTriggered()
{
SettingsDialog sd(this);
        if (sd.exec() != QDialog::Accepted)
                return;
        if (sd.colorChanged() || sd.fontChanged()) {
                initDocStyleSheet();
                if (!output.isEmpty() && sd.colorChanged() && (QMessageBox(QMessageBox::Question,trUtf8("Settings Changed"),trUtf8("You have changed color settings.\nDo you wish to apply them to current solution text?"),QMessageBox::Yes | QMessageBox::No,this).exec() == QMessageBox::Yes)) {
                        QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
                        solutionText->clear();
                        solutionText->setHtml(output.join(""));
                        QApplication::restoreOverrideCursor();
                }
        }
}

#ifndef Q_OS_WINCE
void MainWindow::printPreview(QPrinter *printer)
{
        solutionText->print(printer);
}

void MainWindow::actionFilePrintPreviewTriggered()
{
QPrintPreviewDialog ppd(printer, this);
    connect(&ppd,SIGNAL(paintRequested(QPrinter *)),SLOT(printPreview(QPrinter *)));
    ppd.exec();
}

void MainWindow::actionFilePrintTriggered()
{
QPrintDialog pd(printer,this);
#if QT_VERSION >= 0x040500
        // No such methods in Qt < 4.5
        pd.setOption(QAbstractPrintDialog::PrintSelection,false);
        pd.setOption(QAbstractPrintDialog::PrintPageRange,false);
#endif
        if (pd.exec() != QDialog::Accepted)
                return;
        solutionText->document()->print(printer);
}
#endif // Q_OS_WINCE

void MainWindow::buttonRandomClicked()
{
        tspmodel->randomize();
        setWindowModified(true);
        taskView->resizeColumnsToContents();
        taskView->resizeRowsToContents();
}

void MainWindow::buttonBackToTaskClicked()
{
        tabWidget->setCurrentIndex(0);
}

void MainWindow::outputMatrix(tMatrix matrix, QStringList &output, int nRow, int nCol)
{
int n = spinCities->value();
QString line="";
        output.append("<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">");
        for (int r = 0; r < n; r++) {
                line = "<tr>";
                for (int c = 0; c < n; c++) {
                        if (matrix[r][c] == INFINITY)
                                line += "<td align=\"center\">"INFSTR"</td>";
                        else if ((r == nRow) && (c == nCol))
                                line += "<td align=\"center\" class=\"selected\">" + QVariant(matrix[r][c]).toString() + "</td>";
                        else
                                line += "<td align=\"center\">" + QVariant(matrix[r][c]).toString() + "</td>";
                }
                line += "</tr>";
                output.append(line);
        }
        output.append("</table>");
}

void MainWindow::buttonSolveClicked()
{
tMatrix matrix;
QList<double> row;
int n = spinCities->value();
bool ok;
        for (int r = 0; r < n; r++) {
                row.clear();
                for (int c = 0; c < n; c++) {
                        row.append(tspmodel->index(r,c).data(Qt::UserRole).toDouble(&ok));
                        if (!ok) {
                                QMessageBox(QMessageBox::Critical,trUtf8("Data error"),trUtf8("Error in cell [Row %1; Column %2]: Invalid data format.").arg(r + 1).arg(c + 1),QMessageBox::Ok,this).exec();
                                return;
                        }
                }
                matrix.append(row);
        }
CTSPSolver solver;
sStep *root = solver.solve(n,matrix,this);
        if (!root)
                return;
        QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
QColor color = settings->value("Output/Color",DEF_FONT_COLOR).value<QColor>();
        output.clear();
        output.append("<p>" + trUtf8("Variant #%1").arg(spinVariant->value()) + "</p>");
        output.append("<p>" + trUtf8("Task:") + "</p>");
        outputMatrix(matrix,output);
        output.append("<hr>");
        output.append("<p>" + trUtf8("Solution of Variant #%1 task").arg(spinVariant->value()) + "</p>");
sStep *step = root;
        n = 1;
QString path = "";
        while (n <= spinCities->value()) {
                if (step->prNode->prNode != NULL || (step->prNode->prNode == NULL && step->plNode->prNode == NULL)) {
                        if (n != spinCities->value()) {
                                output.append("<p>" + trUtf8("Step #%1").arg(n++) + "</p>");
                                outputMatrix(step->matrix,output,step->candidate.nRow,step->candidate.nCol);
                                if (step->alts)
                                        output.append("<p class=\"hasalts\">" + trUtf8("This step has alternate candidates for branching.") + "</p>");
                                output.append("<p>&nbsp;</p>");
                        }
                        path += QString(" (%1,%2)").arg(step->candidate.nRow + 1).arg(step->candidate.nCol + 1);
                }
                if (step->prNode->prNode != NULL)
                        step = step->prNode;
                else if (step->plNode->prNode != NULL)
                        step = step->plNode;
                else
                        break;
        }
        output.append("<p>" + trUtf8("Optimal path:") + "</p>");
        output.append("<p>&nbsp;&nbsp;" + path + "</p>");
        output.append("<p>" + trUtf8("The price is <b>%1</b> units.").arg(step->price) + "</p>");
        solutionText->setHtml(output.join(""));
        solutionText->setDocumentTitle(trUtf8("Solution of Variant #%1 task").arg(spinVariant->value()));
        enableSolutionActions();
        tabWidget->setCurrentIndex(1);
        QApplication::restoreOverrideCursor();
}

void MainWindow::actionHelpAboutTriggered()
{
        // TODO: Normal about window :-)
QString about = QString::fromUtf8("TSPSG - TSP Solver and Generator\n");
        about += QString::fromUtf8("    Version: "BUILD_VERSION"\n");
        about += QString::fromUtf8("    Copyright (C) 2007-%1 Lёppa <contacts[at]oleksii[dot]name>\n").arg(QDate::currentDate().toString("yyyy"));
        about += QString::fromUtf8("Target OS: %1\n").arg(OS);
        about += "Qt library:\n";
        about += QString::fromUtf8("    Compile time: %1\n").arg(QT_VERSION_STR);
        about += QString::fromUtf8("    Runtime: %1\n").arg(qVersion());
        about += QString::fromUtf8("Built on %1 at %2\n").arg(__DATE__).arg(__TIME__);
        about += "\n";
        about += "TSPSG is licensed under the terms of the GNU General Public License. You should have received a copy of the GNU General Public License along with TSPSG.";
        QMessageBox(QMessageBox::Information,"About",about,QMessageBox::Ok,this).exec();
}

void MainWindow::loadLangList()
{
QSettings langinfo("i18n/languages.ini",QSettings::IniFormat);
#if QT_VERSION >= 0x040500
        // In Qt < 4.5 QSettings doesn't have method setIniCodec.
        langinfo.setIniCodec("UTF-8");
#endif
QDir dir("i18n","*.qm",QDir::Name | QDir::IgnoreCase,QDir::Files);
        if (!dir.exists())
                return;
QFileInfoList langs = dir.entryInfoList();
        if (langs.size() <= 0)
                return;
QAction *a;
        for (int k = 0; k < langs.size(); k++) {
                QFileInfo lang = langs.at(k);
                if (!lang.completeBaseName().startsWith("qt_") && lang.completeBaseName().compare("en")) {
#if QT_VERSION >= 0x040500
                        a = menuSettingsLanguage->addAction(langinfo.value(lang.completeBaseName() + "/NativeName",lang.completeBaseName()).toString());
#else
                        // We use Name if Qt < 4.5 because NativeName is in UTF-8, QSettings
                        // reads .ini file as ASCII and there is no way to set file encoding.
                        a = menuSettingsLanguage->addAction(langinfo.value(lang.completeBaseName() + "/Name",lang.completeBaseName()).toString());
#endif
                        a->setData(lang.completeBaseName());
                        a->setCheckable(true);
                        a->setActionGroup(groupSettingsLanguageList);
                        if (settings->value("Language",QLocale::system().name()).toString().startsWith(lang.completeBaseName()))
                                a->setChecked(true);
                }
        }
}

void MainWindow::actionSettingsLanguageAutodetectTriggered(bool checked)
{
        if (checked) {
                settings->remove("Language");
                QMessageBox(QMessageBox::Information,trUtf8("Language change"),trUtf8("Language will be autodetected on next application start."),QMessageBox::Ok,this).exec();
        } else
                settings->setValue("Language",groupSettingsLanguageList->checkedAction()->data().toString());
}

void MainWindow::groupSettingsLanguageListTriggered(QAction *action)
{
        if (actionSettingsLanguageAutodetect->isChecked()) {
                // We have language autodetection. It needs to be disabled to change language.
                if (QMessageBox(QMessageBox::Question,trUtf8("Language change"),trUtf8("You have language autodetection turned on.\nIt needs to be off.\nDo you wish to turn it off?"),QMessageBox::Yes | QMessageBox::No,this).exec() == QMessageBox::Yes) {
                        actionSettingsLanguageAutodetect->trigger();
                } else
                        return;
        }
bool untitled = (fileName == trUtf8("Untitled") + ".tspt");
        if (loadLanguage(action->data().toString())) {
                settings->setValue("Language",action->data().toString());
                retranslateUi(this);
                if (untitled)
                        setFileName();
        }
}

void MainWindow::closeEvent(QCloseEvent *event)
{
        if (!maybeSave()) {
                event->ignore();
                return;
        }
        settings->setValue("NumCities",spinCities->value());
#ifndef Q_OS_WINCE
        // Saving windows state
        if (settings->value("SavePos",false).toBool()) {
                settings->beginGroup("MainWindow");
                settings->setValue("Maximized",isMaximized());
                if (!isMaximized()) {
                        settings->setValue("Size",size());
                        settings->setValue("Position",pos());
                }
                settings->endGroup();
        }
#endif // Q_OS_WINCE
        QMainWindow::closeEvent(event);
}

void MainWindow::dataChanged()
{
        setWindowModified(true);
}

void MainWindow::numCitiesChanged(int nCities)
{
        blockSignals(true);
        spinCities->setValue(nCities);
        blockSignals(false);
}