Refactored the creation of control widgets.

.gitignore

@@ -0,0 +1,83 @@
+# This file is used to ignore files which are generated
+# ----------------------------------------------------------------------------
+
+*~
+*.autosave
+*.a
+*.core
+*.moc
+*.o
+*.obj
+*.orig
+*.rej
+*.so
+*.so.*
+*_pch.h.cpp
+*_resource.rc
+*.qm
+.#*
+*.*#
+core
+!core/
+tags
+.DS_Store
+.directory
+*.debug
+Makefile*
+*.prl
+*.app
+moc_*.cpp
+ui_*.h
+qrc_*.cpp
+Thumbs.db
+*.res
+*.rc
+/.qmake.cache
+/.qmake.stash
+
+# qtcreator generated files
+*.pro.user*
+*.qbs.user*
+CMakeLists.txt.user*
+
+# xemacs temporary files
+*.flc
+
+# Vim temporary files
+.*.swp
+
+# Visual Studio generated files
+*.ib_pdb_index
+*.idb
+*.ilk
+*.pdb
+*.sln
+*.suo
+*.vcproj
+*vcproj.*.*.user
+*.ncb
+*.sdf
+*.opensdf
+*.vcxproj
+*vcxproj.*
+
+# MinGW generated files
+*.Debug
+*.Release
+
+# Python byte code
+*.pyc
+
+# Binaries
+# --------
+*.dll
+*.exe
+
+# Directories with generated files
+.moc/
+.obj/
+.pch/
+.rcc/
+.uic/
+/build*/
+_build*/

CMakeLists.txt

@@ -0,0 +1,97 @@
+cmake_minimum_required(VERSION 3.16)
+
+set(TARGET_APP "GenericQtClient-Widgets")
+project(${TARGET_APP} VERSION 0.3.0 LANGUAGES CXX)
+
+set(CMAKE_AUTOUIC ON)
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+find_package(QT NAMES Qt6 Qt5 REQUIRED COMPONENTS Widgets LinguistTools)
+find_package(Qt${QT_VERSION_MAJOR} REQUIRED COMPONENTS Widgets LinguistTools)
+
+set(TS_FILES ${TARGET_APP}_en_US.ts)
+
+set(PROJECT_SOURCES
+    main.cpp
+    mainwindow.cpp
+    mainwindow.h
+    mainwindow.ui
+    ${TS_FILES}
+)
+
+if(${QT_VERSION_MAJOR} GREATER_EQUAL 6)
+    qt_add_executable(${TARGET_APP}
+        MANUAL_FINALIZATION
+        ${PROJECT_SOURCES}
+
+        assets/icons.qrc
+        dialogs/abstractdialog.h dialogs/abstractdialog.cpp
+        dialogs/newitemdialog.h dialogs/newitemdialog.cpp
+        dialogs/edititemdialog.h dialogs/edititemdialog.cpp
+        dialogs/settingsdialog.h dialogs/settingsdialog.cpp
+        views/itemdetailmapper.h views/itemdetailmapper.cpp
+        widgets/controls/comboboxdelegate.h widgets/controls/comboboxdelegate.cpp
+        widgethelper.h widgethelper.cpp
+        widgets/controls/spinboxdelegate.h widgets/controls/spinboxdelegate.cpp
+    )
+# Define target properties for Android with Qt 6 as:
+#    set_property(TARGET ${TARGET_APP} APPEND PROPERTY QT_ANDROID_PACKAGE_SOURCE_DIR
+#                 ${CMAKE_CURRENT_SOURCE_DIR}/android)
+# For more information, see https://doc.qt.io/qt-6/qt-add-executable.html#target-creation
+
+# qt_create_translation(QM_FILES ${CMAKE_SOURCE_DIR} ${TS_FILES})
+
+else()
+    if(ANDROID)
+        add_library(${TARGET_APP} SHARED
+            ${PROJECT_SOURCES}
+        )
+    # Define properties for Android with Qt 5 after find_package() calls as:
+    #    set(ANDROID_PACKAGE_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/android")
+else()
+    add_executable(${TARGET_APP}
+        ${PROJECT_SOURCES}
+    )
+endif()
+
+qt5_create_translation(QM_FILES ${CMAKE_SOURCE_DIR} ${TS_FILES})
+endif()
+
+include_directories(${CMAKE_CURRENT_BINARY_DIR})
+
+target_link_libraries(${TARGET_APP} PRIVATE Qt${QT_VERSION_MAJOR}::Widgets)
+
+target_include_directories(${TARGET_APP} PRIVATE ${CORE_LIB_DIR}/)
+target_link_libraries(${TARGET_APP} PRIVATE GenericCore)
+target_include_directories(${TARGET_APP} PRIVATE ${QR_LIB_DIR}/src)
+target_link_libraries(${TARGET_APP} PRIVATE qrcode)
+
+
+# Qt for iOS sets MACOSX_BUNDLE_GUI_IDENTIFIER automatically since Qt 6.1.
+# If you are developing for iOS or macOS you should consider setting an
+# explicit, fixed bundle identifier manually though.
+if(${QT_VERSION} VERSION_LESS 6.1.0)
+    set(BUNDLE_ID_OPTION MACOSX_BUNDLE_GUI_IDENTIFIER com.example.${TARGET_APP})
+endif()
+set_target_properties(${TARGET_APP} PROPERTIES
+    ${BUNDLE_ID_OPTION}
+    MACOSX_BUNDLE_BUNDLE_VERSION ${PROJECT_VERSION}
+    MACOSX_BUNDLE_SHORT_VERSION_STRING ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}
+    MACOSX_BUNDLE TRUE
+    WIN32_EXECUTABLE TRUE
+)
+
+include(GNUInstallDirs)
+install(TARGETS ${TARGET_APP}
+    BUNDLE DESTINATION .
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+)
+
+if(QT_VERSION_MAJOR EQUAL 6)
+    qt_finalize_executable(${TARGET_APP})
+endif()

GenericQtClient-Widgets_en_US.ts

@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE TS>
+<TS version="2.1" language="en_US"></TS>

assets/icons.qrc

@@ -0,0 +1,6 @@
+<RCC>
+    <qresource prefix="/">
+        <file>software-application.png</file>
+        <file>no-picture-taking.png</file>
+    </qresource>
+</RCC>

assets/urls.txt

@@ -0,0 +1,5 @@
+software-application.png:
+https://www.flaticon.com/free-icon/software-application_5063917 
+
+feature.png:
+https://www.flaticon.com/free-icon/feature_1085784

dialogs/abstractdialog.cpp

@@ -0,0 +1,51 @@
+#include "abstractdialog.h"
+
+#include <QDialogButtonBox>
+#include <QGuiApplication>
+#include <QLabel>
+#include <QScreen>
+#include <QVBoxLayout>
+
+AbstractDialog::AbstractDialog(QDialogButtonBox::StandardButtons buttons, QWidget* parent)
+    : QDialog(parent) {
+  setWindowTitle(tr("Dialog does what?..."));
+  setModal(true);
+
+  m_buttonBox = new QDialogButtonBox(buttons, this);
+  connect(m_buttonBox, &QDialogButtonBox::accepted, this, &AbstractDialog::accept);
+  connect(m_buttonBox, &QDialogButtonBox::rejected, this, &AbstractDialog::reject);
+
+  m_contentContainer = new QLabel("content", this);
+
+  m_outerLayout = new QVBoxLayout;
+  m_outerLayout->addWidget(m_contentContainer);
+  m_outerLayout->addWidget(m_buttonBox);
+
+  setLayout(m_outerLayout);
+}
+
+void AbstractDialog::show() {
+  centerInParent();
+  QWidget::show();
+}
+
+void AbstractDialog::accept() { QDialog::accept(); }
+
+void AbstractDialog::reject() { QDialog::reject(); }
+
+void AbstractDialog::centerInParent() {
+  // BUG the centering in the parent doesn't work the first time (and the later ones seem off too)
+  QWidget* parent = parentWidget();
+
+  if (parent) {
+    auto parentRect = parent->geometry();
+    move(parentRect.center() - rect().center());
+  } else {
+    QRect screenGeometry = QGuiApplication::screens().at(0)->geometry();
+    int x                = (screenGeometry.width() - width()) / 2;
+    int y                = (screenGeometry.height() - height()) / 2;
+    move(x, y);
+  }
+}
+
+void AbstractDialog::closeEvent(QCloseEvent* event) { QWidget::closeEvent(event); }

dialogs/abstractdialog.h

@@ -0,0 +1,33 @@
+#ifndef ABSTRACTDIALOG_H
+#define ABSTRACTDIALOG_H
+
+#include <QDialog>
+#include <QDialogButtonBox>
+
+class QGridLayout;
+class QVBoxLayout;
+
+class AbstractDialog : public QDialog {
+  Q_OBJECT
+ public:
+  AbstractDialog(QDialogButtonBox::StandardButtons buttons, QWidget* parent = nullptr);
+  virtual void createContent() = 0;
+
+  /// QDialog interface
+ public slots:
+  void show();
+  void accept() override;
+  void reject() override;
+
+ protected:
+  void centerInParent();
+
+ protected:
+  QWidget* m_contentContainer;
+  QVBoxLayout* m_outerLayout;
+  QDialogButtonBox* m_buttonBox = nullptr;
+
+  void closeEvent(QCloseEvent* event) override;
+};
+
+#endif  // ABSTRACTDIALOG_H

dialogs/edititemdialog.cpp

@@ -0,0 +1,56 @@
+#include "edititemdialog.h"
+
+#include <QDialogButtonBox>
+#include <QLabel>
+#include <QVBoxLayout>
+
+#include "../views/itemdetailmapper.h"
+
+EditItemDialog::EditItemDialog(QTableView* tableView, QWidget* parent)
+    : AbstractDialog(QDialogButtonBox::Ok, parent)
+    , m_tableView(tableView)
+    , m_qrCodeDisplay(new QLabel("QR Code")) {}
+
+void EditItemDialog::createContent() {
+  if (m_contentContainer) {
+    delete m_contentContainer;
+  }
+
+  setWindowTitle(tr("Edit item..."));
+
+  m_contentContainer       = new QWidget(this);
+  QHBoxLayout* innerLayout = new QHBoxLayout();
+  m_contentContainer->setLayout(innerLayout);
+
+  m_detailMapper = new ItemDetailMapper(m_tableView, this);
+  innerLayout->addWidget(m_detailMapper);
+
+  updateQRCode();
+  connect(m_detailMapper, &ItemDetailMapper::contentChanged, this, &EditItemDialog::updateQRCode);
+  innerLayout->addWidget(m_qrCodeDisplay);
+
+  m_outerLayout->insertWidget(0, m_contentContainer);
+}
+
+void EditItemDialog::accept() {
+  m_detailMapper->submit();
+  QDialog::accept();
+}
+
+void EditItemDialog::reject() {
+  m_detailMapper->revert();
+  QDialog::reject();
+}
+
+void EditItemDialog::updateQRCode(const QString text) {
+  QImage unscaledImage;
+  if (text.isEmpty()) {
+    unscaledImage = QImage("://no-picture-taking.png");
+  } else {
+    unscaledImage = m_generator.generateQr(text);
+  }
+  QImage image = unscaledImage.scaled(250, 250);
+
+  m_qrCodeDisplay->setPixmap(QPixmap::fromImage(image));
+  m_qrCodeDisplay->setToolTip(text);
+}

dialogs/edititemdialog.h

@@ -0,0 +1,53 @@
+#ifndef EDITITEMDIALOG_H
+#define EDITITEMDIALOG_H
+
+#include "QrCodeGenerator.h"
+#include "abstractdialog.h"
+
+class QDoubleSpinBox;
+class QLineEdit;
+class QSpinBox;
+class QLabel;
+class QTableView;
+
+class ItemDetailMapper;
+
+class EditItemDialog : public AbstractDialog {
+  Q_OBJECT
+ public:
+  EditItemDialog(QTableView* tableView, QWidget* parent = nullptr);
+
+  /// AbstractDialog interface
+  void createContent() override;
+
+ public slots:
+  void accept() override;
+  void reject() override;
+
+ private slots:
+  void updateQRCode(const QString text = "");
+
+ private:
+  QTableView* m_tableView = nullptr;
+  ItemDetailMapper* m_detailMapper;
+
+  QLabel* m_nameLabel   = nullptr;
+  QLineEdit* m_nameEdit = nullptr;
+
+  QLabel* m_descriptionLabel   = nullptr;
+  QLineEdit* m_descriptionEdit = nullptr;
+
+  QLabel* m_infoLabel   = nullptr;
+  QLineEdit* m_infoEdit = nullptr;
+
+  QLabel* m_amountLabel = nullptr;
+  QSpinBox* m_amountBox = nullptr;
+
+  QLabel* m_factorLabel       = nullptr;
+  QDoubleSpinBox* m_factorBox = nullptr;
+
+  QLabel* m_qrCodeDisplay = nullptr;
+  QrCodeGenerator m_generator;
+};
+
+#endif  // EDITITEMDIALOG_H

dialogs/newitemdialog.cpp

@@ -0,0 +1,108 @@
+#include "newitemdialog.h"
+
+#include <QComboBox>
+#include <QGridLayout>
+#include <QJsonArray>
+#include <QJsonObject>
+#include <QLabel>
+#include <QLineEdit>
+#include <QSpinBox>
+#include <QStringListModel>
+
+#include "../widgethelper.h"
+#include "formats/jsonparser.h"
+#include "model/metadata.h"
+
+NewItemDialog::NewItemDialog(QWidget* parent)
+    : AbstractDialog(QDialogButtonBox::Ok | QDialogButtonBox::Cancel, parent) {}
+
+void NewItemDialog::createContent() {
+  if (m_contentContainer) {
+    delete m_contentContainer;
+  }
+
+  setWindowTitle(tr("New item..."));
+
+  m_contentContainer = new QWidget(this);
+
+  m_layout = new QGridLayout();
+
+  for (int i = 0; i < USER_FACING_ROLES.size(); ++i) {
+    setupWidgetPairForColumn(i);
+  }
+
+  m_contentContainer->setLayout(m_layout);
+
+  m_outerLayout->insertWidget(0, m_contentContainer);
+}
+
+void NewItemDialog::accept() {
+  addItemToModel();
+
+  resetContent();
+
+  AbstractDialog::accept();
+}
+
+void NewItemDialog::setupWidgetPairForColumn(const int column) {
+  // REFACTOR consolidate NewItemDialog::setupWidgetPairForColumn(...)
+  //          with ItemDetailMapper::setupWidgetPairForColumn(...)
+  const UserRoles role = GET_ROLE_FOR_COLUMN(column);
+
+  QWidget* control = WidgetHelper::createControlWidget(role, this);
+
+  const QString string = QString("&%1").arg(GET_HEADER_FOR_COLUMN(column));
+  QLabel* label        = new QLabel(string);
+  label->setBuddy(control);
+
+  m_layout->addWidget(label, column, 0);
+  m_layout->addWidget(control, column, 1);
+  m_controlWidgets.append(control);
+}
+
+void NewItemDialog::addItemToModel() {
+  ModelItemValues itemValues;
+
+  for (int i = 0; i < m_controlWidgets.size(); ++i) {
+    const UserRoles role = GET_ROLE_FOR_COLUMN(i);
+    if (STRING_ROLES.contains(role)) {
+      QLineEdit* lineEdit = dynamic_cast<QLineEdit*>(m_controlWidgets[i]);
+      itemValues.insert(role, lineEdit->text());
+    } else if (TYPE_ROLES.contains(role)) {
+      QComboBox* comboBox = dynamic_cast<QComboBox*>(m_controlWidgets[i]);
+      itemValues.insert(role, comboBox->currentText());
+    } else if (INT_ROLES.contains(role)) {
+      QSpinBox* spinBox = dynamic_cast<QSpinBox*>(m_controlWidgets[i]);
+      itemValues.insert(role, spinBox->value());
+    } else if (DOUBLE_ROLES.contains(role)) {
+      QDoubleSpinBox* doubleSpinBox = dynamic_cast<QDoubleSpinBox*>(m_controlWidgets[i]);
+      itemValues.insert(role, doubleSpinBox->value());
+    } else {
+      qCritical() << "Could not reset content for control widget in column:" << i << "!";
+    }
+  }
+
+  const QByteArray jsonDoc = JsonParser::itemValuesListToJson({itemValues}, ITEMS_KEY_STRING);
+  emit addItems(jsonDoc);
+}
+
+void NewItemDialog::resetContent() {
+  for (int i = 0; i < m_controlWidgets.size(); ++i) {
+    const UserRoles role = GET_ROLE_FOR_COLUMN(i);
+    if (STRING_ROLES.contains(role)) {
+      QLineEdit* lineEdit = dynamic_cast<QLineEdit*>(m_controlWidgets[i]);
+      lineEdit->clear();
+    } else if (TYPE_ROLES.contains(role)) {
+      QComboBox* comboBox = dynamic_cast<QComboBox*>(m_controlWidgets[i]);
+      comboBox->setCurrentText("");
+    } else if (INT_ROLES.contains(role)) {
+      QSpinBox* spinBox = dynamic_cast<QSpinBox*>(m_controlWidgets[i]);
+      spinBox->setValue(0);
+    } else if (DOUBLE_ROLES.contains(role)) {
+      QDoubleSpinBox* doubleSpinBox = dynamic_cast<QDoubleSpinBox*>(m_controlWidgets[i]);
+      doubleSpinBox->setValue(0.0);
+    } else {
+      qCritical() << "Could not reset content for control widget in column:" << i << "!";
+    }
+  }
+}

dialogs/newitemdialog.h

@@ -0,0 +1,36 @@
+#ifndef NEWITEMDIALOG_H
+#define NEWITEMDIALOG_H
+
+#include "abstractdialog.h"
+
+class QDoubleSpinBox;
+class QLineEdit;
+class QSpinBox;
+class QLabel;
+
+class NewItemDialog : public AbstractDialog {
+  Q_OBJECT
+
+ public:
+  NewItemDialog(QWidget* parent = nullptr);
+
+  void createContent() override;
+
+ signals:
+  void addItems(const QByteArray& jsonDoc);
+
+ public slots:
+  void accept() override;
+  // void reject() override;
+
+ private:
+  QGridLayout* m_layout;
+  QList<QWidget*> m_controlWidgets;
+
+  void setupWidgetPairForColumn(const int column);
+
+  void addItemToModel();
+  void resetContent();
+};
+
+#endif  // NEWITEMDIALOG_H

dialogs/settingsdialog.cpp

@@ -0,0 +1,63 @@
+#include "settingsdialog.h"
+
+#include <QCoreApplication>
+#include <QGridLayout>
+#include <QLabel>
+#include <QLineEdit>
+#include <QTabWidget>
+
+SettingsDialog::SettingsDialog(QWidget* parent)
+    : AbstractDialog(QDialogButtonBox::Ok | QDialogButtonBox::Cancel, parent) {}
+
+void SettingsDialog::createContent() {
+  if (m_contentContainer) {
+    delete m_contentContainer;
+  }
+
+  const QString dialogTitle     = tr("Settings - ");
+  const QString applicationName = QCoreApplication::applicationName();
+
+  setWindowTitle(dialogTitle + applicationName);
+  setModal(true);
+  setGeometry(0, 0, 350, 250);
+  QGridLayout* serverLayout = new QGridLayout();
+  QLabel* urlLabel          = new QLabel("Server URL:");
+  m_urlEdit                 = new QLineEdit();
+  serverLayout->addWidget(urlLabel, 0, 0);
+  serverLayout->addWidget(m_urlEdit, 0, 1);
+  QLabel* emailLabel = new QLabel("Email:");
+  m_emailEdit        = new QLineEdit();
+  m_emailEdit->setEnabled(false);
+  serverLayout->addWidget(emailLabel, 1, 0);
+  serverLayout->addWidget(m_emailEdit, 1, 1);
+  QLabel* passwordLabel = new QLabel("Password:");
+  m_passwordEdit        = new QLineEdit();
+  m_passwordEdit->setEnabled(false);
+  m_passwordEdit->setEchoMode(QLineEdit::Password);
+  serverLayout->addWidget(passwordLabel, 2, 0);
+  serverLayout->addWidget(m_passwordEdit, 2, 1);
+
+  QWidget* serverTab = new QWidget();
+  serverTab->setLayout(serverLayout);
+
+  QTabWidget* widget = new QTabWidget();
+  widget->addTab(serverTab, "Server");
+
+  m_contentContainer = widget;
+  m_outerLayout->insertWidget(0, m_contentContainer);
+}
+
+void SettingsDialog::fillContent(const QVariantMap& settings) {
+  m_urlEdit->setText(settings.value("url").toString());
+  m_emailEdit->setText(settings.value("email").toString());
+  m_passwordEdit->setText(settings.value("password").toString());
+}
+
+QVariantMap SettingsDialog::getSettings() const {
+  QVariantMap result;
+  result.insert("url", m_urlEdit->text());
+  result.insert("email", m_emailEdit->text());
+  result.insert("password", m_passwordEdit->text());
+
+  return result;
+}

dialogs/settingsdialog.h

@@ -0,0 +1,23 @@
+#ifndef SETTINGSDIALOG_H
+#define SETTINGSDIALOG_H
+
+#include "abstractdialog.h"
+
+class QLineEdit;
+
+class SettingsDialog : public AbstractDialog {
+  Q_OBJECT
+ public:
+  SettingsDialog(QWidget* parent = nullptr);
+
+  void createContent() override;
+  void fillContent(const QVariantMap& settings);
+  QVariantMap getSettings() const;
+
+ private:
+  QLineEdit* m_urlEdit      = nullptr;
+  QLineEdit* m_emailEdit    = nullptr;
+  QLineEdit* m_passwordEdit = nullptr;
+};
+
+#endif  // SETTINGSDIALOG_H

main.cpp

@@ -0,0 +1,29 @@
+#include "mainwindow.h"
+
+#include <QApplication>
+#include <QLocale>
+#include <QTranslator>
+
+#ifdef QT_DEBUG
+#include "utils/messagehandler.h"
+#endif
+
+int main(int argc, char* argv[]) {
+#ifdef QT_DEBUG
+  qInstallMessageHandler(consoleHandlerColoredVerboseInDarkTheme);
+#endif
+  QApplication a(argc, argv);
+
+  QTranslator translator;
+  const QStringList uiLanguages = QLocale::system().uiLanguages();
+  for (const QString& locale : uiLanguages) {
+    const QString baseName = "GenericWidgets_" + QLocale(locale).name();
+    if (translator.load(":/i18n/" + baseName)) {
+      a.installTranslator(&translator);
+      break;
+    }
+  }
+  MainWindow w;
+  w.show();
+  return a.exec();
+}

mainwindow.cpp

@@ -0,0 +1,565 @@
+#include "mainwindow.h"
+#include "./ui_mainwindow.h"
+
+#include <QCloseEvent>
+#include <QFileDialog>
+#include <QInputDialog>
+#include <QMessageBox>
+#include <QStandardPaths>
+#include <QUndoStack>
+#include <QUndoView>
+
+#include "../../ApplicationConfig.h"
+#include "dialogs/edititemdialog.h"
+#include "dialogs/newitemdialog.h"
+#include "dialogs/settingsdialog.h"
+#include "genericcore.h"
+#include "model/generalsortfiltermodel.h"
+#include "model/metadata.h"
+#include "model/tablemodel.h"
+#include "widgets/controls/comboboxdelegate.h"
+#include "widgets/controls/spinboxdelegate.h"
+
+static QStandardPaths::StandardLocation standardLocation = QStandardPaths::HomeLocation;
+static QString updateTextClean = "Do you want to update the application now?";
+static QString updateTextDirty = "Do you want to save the tasks & update the application now?";
+
+MainWindow::MainWindow(QWidget* parent)
+    : QMainWindow(parent)
+    , ui(new Ui::MainWindow) {
+  ui->setupUi(this);
+
+  m_core = std::make_unique<GenericCore>();
+
+  setWindowTitle(QCoreApplication::applicationName() + " [*]");
+
+  /// application icon
+  const QString iconString = "://software-application.png";
+#ifdef QT_DEBUG
+  QPixmap pixmap       = QPixmap(iconString);
+  QTransform transform = QTransform();
+  transform.rotate(180);
+  QPixmap rotated = pixmap.transformed(transform);
+  QIcon appIcon   = QIcon(rotated);
+  setWindowIcon(QIcon(rotated));
+#else
+  setWindowIcon(QIcon(iconString));
+#endif
+
+  const QVariantMap settings = m_core->getSettings("GUI");
+  restoreGeometry(settings.value("geometry").toByteArray());
+  restoreState(settings.value("windowState").toByteArray());
+
+  setupModelViews();
+
+  createActions();
+  createHelpMenu();
+  createGuiDialogs();
+
+  connect(m_core.get(), &GenericCore::displayStatusMessage, this,
+          &MainWindow::displayStatusMessage);
+  connect(this, &MainWindow::displayStatusMessage, this, &MainWindow::showStatusMessage);
+  connect(this, &MainWindow::checkForUpdates, this,
+          &MainWindow::on_actionCheck_for_update_triggered, Qt::QueuedConnection);
+
+  // connect(ui->tableView->selectionModel(), &QItemSelectionModel::selectionChanged, this,
+  //         &MainWindow::onSelectionChanged);
+  connect(ui->tableView->selectionModel(), &QItemSelectionModel::currentChanged, this,
+          &MainWindow::onCurrentChanged);
+
+  onSelectionChanged(QItemSelection(), QItemSelection());
+  onCurrentChanged(QModelIndex(), QModelIndex());
+}
+
+MainWindow::~MainWindow() { delete ui; }
+
+void MainWindow::closeEvent(QCloseEvent* event) {
+  if (isWindowModified()) {
+    QMessageBox msgBox;
+    msgBox.setWindowTitle(windowTitle() + " - Save dialog");
+    msgBox.setText("The document has been modified.");
+    msgBox.setInformativeText("Do you want to save your changes?");
+    msgBox.setStandardButtons(QMessageBox::Save | QMessageBox::Discard | QMessageBox::Cancel);
+    msgBox.setDefaultButton(QMessageBox::Save);
+    int ret = msgBox.exec();
+
+    switch (ret) {
+      case QMessageBox::Save:
+        emit saveItems();
+        event->accept();
+        break;
+      case QMessageBox::Discard:
+        event->accept();
+        break;
+      case QMessageBox::Cancel:
+        event->ignore();
+        break;
+      default:
+        /// should never be reached
+        qCritical() << "unexpected switch case in closeEvent:" << ret;
+        event->ignore();
+        break;
+    }
+  } else {
+    event->accept();
+  }
+
+  if (event->isAccepted()) {
+    qInfo() << "Saving GUI settings...";
+    m_core->applySettings({{"geometry", saveGeometry()}, {"windowState", saveState()}}, "GUI");
+  }
+}
+
+void MainWindow::showStatusMessage(const QString text) {
+  qInfo() << text;
+  ui->statusbar->showMessage(text);
+}
+
+void MainWindow::onCurrentChanged(const QModelIndex& current, const QModelIndex& previous) {
+  // Q_UNUSED(current);
+  Q_UNUSED(previous);
+
+  // QItemSelection localSelection = ui->tableView->selectionModel()->selection();
+  if (current == QModelIndex()) {
+    // qDebug() << "Nothing selected. Disabling delete action";
+    m_deleteItemAct->setEnabled(false);
+  } else {
+    // qDebug() << "Something selected. Enabling delete action";
+    m_deleteItemAct->setEnabled(true);
+  }
+}
+
+void MainWindow::onSelectionChanged(const QItemSelection& selected,
+                                    const QItemSelection& deselected) {
+  Q_UNUSED(selected);
+  Q_UNUSED(deselected);
+
+  QItemSelection localSelection = ui->tableView->selectionModel()->selection();
+  if (localSelection.empty()) {
+    // qDebug() << "Nothing selected. Disabling delete action";
+    m_deleteItemAct->setEnabled(false);
+  } else {
+    // qDebug() << "Something selected. Enabling delete action";
+    m_deleteItemAct->setEnabled(true);
+  }
+}
+
+void MainWindow::onAboutClicked() {
+  const QString applicationName = APPLICATION_NAME;
+  const QString titlePrefix     = tr("About ");
+  const QString aboutText =
+      tr(QString("<b>%1 v%2</b> is a template for Qt applications."
+                 "<br><br><a href=\"https://working-copy.org/\">Working-Copy_Collective website</a>"
+                 "<br><br><a href=\"mailto:support@working-copy.org\">Mail to support</a>"
+                 "<br><br>It uses the <a href=\"https://qt.io\">Qt Framework</a>.")
+             .arg(applicationName)
+             .arg(APPLICATION_VERSION)
+             .toLatin1());
+  QMessageBox::about(this, titlePrefix + applicationName, aboutText);
+}
+
+void MainWindow::on_actionCheck_for_update_triggered() {
+  showStatusMessage("Checking for update...");
+  const bool updateAvailable = m_core->isApplicationUpdateAvailable();
+  if (updateAvailable) {
+    const QString text = isWindowModified() ? updateTextDirty : updateTextClean;
+    const QMessageBox::StandardButton clickedButton = QMessageBox::question(
+        this, tr("Update available."), text, QMessageBox::Yes | QMessageBox::No, QMessageBox::Yes);
+    if (clickedButton == QMessageBox::Yes) {
+      m_core->triggerApplicationUpdate(true);
+      close();
+    }
+  }
+}
+
+void MainWindow::on_pushButton_clicked() {
+  const QString prefix("Backend provided by: ");
+  ui->label->setText(prefix + m_core->toString());
+}
+
+void MainWindow::openNewItemDialog() {
+  showStatusMessage(tr("Invoked 'Edit|New Item'"));
+  m_newItemDialog->show();
+}
+
+void MainWindow::openEditItemDialog() {
+  showStatusMessage(tr("Invoked 'Edit|Edit Item'"));
+  m_editItemDialog->show();
+}
+
+void MainWindow::deleteCurrentItem() {
+  showStatusMessage(tr("Invoked 'Edit|Delete Item'"));
+  // QItemSelection localSelection  = ui->tableView->selectionModel()->selection();
+  const QModelIndex currentIndex = ui->tableView->selectionModel()->currentIndex();
+  if (currentIndex == QModelIndex()) {
+    qDebug() << "No current item. Nothing to remove.";
+  } else {
+    m_proxyModel->removeRows(currentIndex.row(), 1);
+  }
+}
+
+void MainWindow::deleteSelectedtItems() {
+  showStatusMessage(tr("Invoked 'Edit|Delete Item'"));
+  QItemSelection localSelection = ui->tableView->selectionModel()->selection();
+  if (localSelection.empty()) {
+    qDebug() << "No items selected. Nothing to remove.";
+  } else {
+    for (QList<QItemSelectionRange>::reverse_iterator iter = localSelection.rbegin(),
+                                                      rend = localSelection.rend();
+         iter != rend; ++iter) {
+      // qInfo() << "iter:" << *iter;
+      // const QModelIndex parentIndex = iter->parent();
+      const int topRow    = iter->top();
+      const int bottomRow = iter->bottom();
+      const int nRows     = bottomRow - topRow + 1;
+      m_proxyModel->removeRows(topRow, nRows);
+    }
+  }
+}
+
+void MainWindow::onCleanStateChanged(bool clean) {
+  qInfo() << "Slot onCleanStateChanged triggered: clean:" << clean;
+  setWindowModified(!clean);
+  if (!clean) {
+    ui->statusbar->clearMessage();
+  }
+}
+
+void MainWindow::onShowUndoViewToggled(bool checked) {
+  //  qInfo() << "Slot onShowUndoViewToggled toggled: checked:" << checked;
+  //  m_undoView->setVisible(checked);
+
+  /// workaround until m_showUndoViewAction is checkable
+  qInfo() << "Slot onShowUndoViewToggled triggered, toggleing undo view...";
+  Q_UNUSED(checked);
+  if (m_modelUndoView->isVisible()) {
+    m_modelUndoView->setVisible(false);
+
+  } else {
+    m_modelUndoView->setVisible(true);
+  }
+}
+
+void MainWindow::saveItems() {
+  showStatusMessage(tr("Invoked 'File|Save'"));
+  m_core->saveItems();
+}
+
+void MainWindow::importCSV() {
+  showStatusMessage(tr("Invoked 'File|Import CSV'"));
+  const QString csvFilePath = QFileDialog::getOpenFileName(
+      this, tr("Import CSV"), QStandardPaths::standardLocations(standardLocation).first(),
+      tr("CSV Files (*.csv)"));
+  if (QFileInfo::exists(csvFilePath)) {
+    m_core->importCSVFile(csvFilePath);
+  } else {
+    qWarning() << "Selected CSV file path doesn't exist. Doing nothing...";
+    showStatusMessage(tr("Could't find CSV file!"));
+  }
+}
+
+void MainWindow::exportCSV() {
+  showStatusMessage(tr("Invoked 'File|Export'"));
+  const QString filter   = tr("CSV Files (*.csv)");
+  const QString location = QStandardPaths::standardLocations(standardLocation).first();
+  QFileDialog dialog(this, "Export CSV File", location, "Comma-separated file (*.csv)");
+  dialog.setDefaultSuffix(".csv");
+  dialog.setAcceptMode(QFileDialog::AcceptSave);
+  if (dialog.exec()) {
+    const QString csvFilePath = dialog.selectedFiles().first();
+    const bool successful     = m_core->exportCSVFile(csvFilePath);
+    if (successful) {
+      const QString message = QString(tr("CSV exported to: %1")).arg(csvFilePath);
+      showStatusMessage(message);
+    }
+  } else {
+    qWarning() << "Selected CSV file path doesn't exist. Doing nothing...";
+  }
+}
+
+void MainWindow::findItems() {
+  showStatusMessage(tr("Invoked 'Edit|Find items'"));
+
+  bool ok;
+  QString text = QInputDialog::getText(this, tr("Find items"), tr("Enter the text to search for:"),
+                                       QLineEdit::Normal, "", &ok);
+  if (ok && !text.isEmpty()) {
+    const QItemSelection itemsToSelect = m_proxyModel->findItems(text);
+    if (itemsToSelect.empty()) {
+      ui->tableView->setCurrentIndex(QModelIndex());
+      ui->tableView->selectionModel()->select(QModelIndex(), QItemSelectionModel::ClearAndSelect);
+    } else {
+      ui->tableView->setCurrentIndex(itemsToSelect.first().topLeft());
+      ui->tableView->selectionModel()->select(itemsToSelect, QItemSelectionModel::ClearAndSelect);
+    }
+  }
+}
+
+void MainWindow::fetchItems() {
+  showStatusMessage(tr("Invoked 'Server|Fetch items'"));
+  emit m_core->fetchItemsFromServer();
+}
+
+void MainWindow::postItems() {
+  showStatusMessage(tr("Invoked 'Server|Post items'"));
+  const QModelIndex currentIndex = ui->tableView->currentIndex();
+  const QByteArray jsonData      = m_proxyModel->jsonDataForServer(currentIndex);
+  emit m_core->postItemToServer(jsonData);
+}
+
+void MainWindow::deleteItem() {
+  showStatusMessage(tr("Invoked 'Server|Delete items'"));
+  const QModelIndex currentIndex = ui->tableView->currentIndex();
+  // const QByteArray jsonData      = m_proxyModel->jsonDataForServer(currentIndex);
+  const QString currentId = m_proxyModel->getUuid(currentIndex);
+  emit m_core->deleteItemFromServer(currentId);
+}
+
+void MainWindow::execSettingsDialog() {
+  showStatusMessage(tr("Invoked 'Tools|Settings'"));
+  QVariantMap oldSettings = m_core->getSettings("Server");
+  // SettingsDialog* settingsDialog         = new SettingsDialog(settingMap, this);
+  SettingsDialog* settingsDialog = new SettingsDialog(this);
+  settingsDialog->createContent();
+  settingsDialog->fillContent(oldSettings);
+
+  int returnCode = settingsDialog->exec();
+  if (returnCode == QDialog::Accepted) {
+    qDebug() << "Settings dialog accepted, writing settings...";
+    const QVariantMap settings = settingsDialog->getSettings();
+
+    m_core->applySettings(settings, "Server");
+    // TODO use signal-slot connection Core::syncServerSetupChanged(bool enabled) ->
+    // MainWindow::onSyncServerSetupChanged(bool enabled)
+
+    // enableDisableServerActions();
+  } else {
+    qDebug() << "Settings dialog rejected";
+  }
+  delete settingsDialog;
+}
+
+void MainWindow::setupModelViews() {
+  // m_tableModel = m_core->getModel();
+  // ui->tableView->setModel(m_tableModel.get());
+  m_proxyModel = m_core->getSortFilterModel();
+
+  // TODO iterate over INT_ROLES and DOUBLE_ROLES to set spinbox delegate
+  /// setting number delegates to combo boxes
+  SpinboxDelegate* spinboxDelegate = new SpinboxDelegate(this);
+  const int amountColumn           = GET_COLUMN_FOR_ROLE(AmountRole);
+  ui->tableView->setItemDelegateForColumn(amountColumn, spinboxDelegate);
+  const int factorColumn = GET_COLUMN_FOR_ROLE(FactorRole);
+  ui->tableView->setItemDelegateForColumn(factorColumn, spinboxDelegate);
+
+  // TODO iterate over TYPE_ROLES to set combobox delegate
+  /// setting type delegates to combo boxes
+  const int typeColumn                = GET_COLUMN_FOR_ROLE(TypeRole);
+  ComboboxDelegate* shareTypeDelegate = new ComboboxDelegate(TYPES, this);
+  ui->tableView->setItemDelegateForColumn(typeColumn, shareTypeDelegate);
+
+  ui->tableView->setModel((QAbstractItemModel*)m_proxyModel.get());
+  ui->tableView->setSortingEnabled(true);
+}
+
+void MainWindow::createActions() {
+  // TODO add generic menu actions (file/new, edit/cut, ...)
+  createFileActions();
+  createUndoActions();
+  createEditActions();
+  createServerActions();
+  createToolsActions();
+}
+
+void MainWindow::createFileActions() {
+  m_newFileAct = make_unique<QAction>(tr("&New File"), this);
+  m_newFileAct->setShortcut(QKeySequence(Qt::CTRL | Qt::SHIFT | Qt::Key_N));
+  m_newFileAct->setStatusTip(tr("Create a new file"));
+  // connect(m_newAct, &QAction::triggered, this, &MainWindow::newFile);
+  m_newFileAct->setEnabled(false);
+  ui->menu_File->addAction(m_newFileAct.get());
+
+  m_openAct = make_unique<QAction>(tr("&Open..."), this);
+  m_openAct->setShortcuts(QKeySequence::Open);
+  m_openAct->setStatusTip(tr("Open an existing file"));
+  // connect(m_openAct, &QAction::triggered, this, &MainWindow::open);
+  m_openAct->setEnabled(false);
+  ui->menu_File->addAction(m_openAct.get());
+
+  m_saveAct = make_unique<QAction>(tr("&Save"), this);
+  m_saveAct->setShortcuts(QKeySequence::Save);
+  m_saveAct->setStatusTip(tr("Save the document to disk"));
+  connect(m_saveAct.get(), &QAction::triggered, this, &MainWindow::saveItems);
+  ui->menu_File->addAction(m_saveAct.get());
+
+  ui->menu_File->addSeparator();
+
+  m_importAct = make_unique<QAction>(tr("&Import CSV..."), this);
+  m_importAct->setStatusTip(tr("Import an existing CSV file"));
+  connect(m_importAct.get(), &QAction::triggered, this, &MainWindow::importCSV);
+  ui->menu_File->addAction(m_importAct.get());
+
+  m_exportAct = make_unique<QAction>(tr("&Export CSV..."), this);
+  m_exportAct->setStatusTip(tr("Export content to a CSV document to disk"));
+  connect(m_exportAct.get(), &QAction::triggered, this, &MainWindow::exportCSV);
+  ui->menu_File->addAction(m_exportAct.get());
+
+  ui->menu_File->addSeparator();
+
+  m_printAct = make_unique<QAction>(tr("&Print..."), this);
+  m_printAct->setShortcuts(QKeySequence::Print);
+  m_printAct->setStatusTip(tr("Print the document"));
+  // connect(m_printAct, &QAction::triggered, this, &MainWindow::print);
+  m_printAct->setEnabled(false);
+  ui->menu_File->addAction(m_printAct.get());
+
+  ui->menu_File->addSeparator();
+
+  m_exitAct = make_unique<QAction>(tr("E&xit"), this);
+  m_exitAct->setShortcuts(QKeySequence::Quit);
+  m_exitAct->setStatusTip(tr("Exit the application"));
+  connect(m_exitAct.get(), &QAction::triggered, this, &QWidget::close);
+  ui->menu_File->addAction(m_exitAct.get());
+}
+
+void MainWindow::createUndoActions() {
+  if (!m_core) {
+    qCritical() << "No core instance set, aborting...";
+    return;
+  }
+  m_modelUndoStack = m_core->getModelUndoStack();
+
+  connect(m_modelUndoStack, &QUndoStack::cleanChanged, this, &MainWindow::onCleanStateChanged);
+
+  m_undoAct.reset(m_modelUndoStack->createUndoAction(this, tr("&Undo")));
+  m_undoAct->setShortcuts(QKeySequence::Undo);
+  m_undoAct->setStatusTip(tr("Undo the last operation"));
+  ui->menu_Edit->addAction(m_undoAct.get());
+
+  m_redoAct.reset(m_modelUndoStack->createRedoAction(this, tr("&Redo")));
+  m_redoAct->setShortcuts(QKeySequence::Redo);
+  m_redoAct->setStatusTip(tr("Redo the last operation"));
+  ui->menu_Edit->addAction(m_redoAct.get());
+
+  m_modelUndoView = make_unique<QUndoView>(m_modelUndoStack);
+  m_modelUndoView->setWindowTitle(tr("Undo list"));
+  m_modelUndoView->setAttribute(Qt::WA_QuitOnClose, false);
+  m_modelUndoView->setMinimumSize(450, 600);
+  m_showModelUndoViewAct = make_unique<QAction>(tr("Show undo/redo window"), this);
+  m_showModelUndoViewAct->setStatusTip(tr("Opens a window displaying the items on the undo stack"));
+
+  // TODO showUndoViewAction should be checkable
+  //  m_showUndoViewAction->setCheckable(true);
+  //  connect(m_showUndoViewAction, &QAction::toggled, this, &MainWindow::onShowUndoViewToggled);
+  connect(m_showModelUndoViewAct.get(), &QAction::triggered, this,
+          &MainWindow::onShowUndoViewToggled);
+  ui->menu_View->addAction(m_showModelUndoViewAct.get());
+}
+
+void MainWindow::createEditActions() {
+  m_cutAct = make_unique<QAction>(tr("Cu&t"), this);
+  m_cutAct->setShortcuts(QKeySequence::Cut);
+  m_cutAct->setStatusTip(
+      tr("Cut the current selection's contents to the "
+         "clipboard"));
+  // connect(m_cutAct, &QAction::triggered, this, &MainWindow::cut);
+  m_cutAct->setEnabled(false);
+  ui->menu_Edit->addAction(m_cutAct.get());
+
+  m_copyAct = make_unique<QAction>(tr("&Copy"), this);
+  m_copyAct->setShortcuts(QKeySequence::Copy);
+  m_copyAct->setStatusTip(
+      tr("Copy the current selection's contents to the "
+         "clipboard"));
+  // connect(m_copyAct, &QAction::triggered, this, &MainWindow::copy);
+  m_copyAct->setEnabled(false);
+  ui->menu_Edit->addAction(m_copyAct.get());
+
+  m_pasteAct = make_unique<QAction>(tr("&Paste"), this);
+  m_pasteAct->setShortcuts(QKeySequence::Paste);
+  m_pasteAct->setStatusTip(
+      tr("Paste the clipboard's contents into the current "
+         "selection"));
+  // connect(m_pasteAct, &QAction::triggered, this, &MainWindow::paste);
+  m_pasteAct->setEnabled(false);
+  ui->menu_Edit->addAction(m_pasteAct.get());
+
+  ui->menu_Edit->addSeparator();
+
+  m_openNewItemDialogAct = make_unique<QAction>(tr("&New item"), this);
+  m_openNewItemDialogAct->setShortcut(QKeySequence::New);
+  m_openNewItemDialogAct->setStatusTip(tr("Opens a dialog to add a new item"));
+  connect(m_openNewItemDialogAct.get(), &QAction::triggered, this, &MainWindow::openNewItemDialog);
+  ui->menu_Edit->addAction(m_openNewItemDialogAct.get());
+
+  m_openEditItemDialogAct = make_unique<QAction>(tr("&Edit item"), this);
+  m_openEditItemDialogAct->setShortcut(QKeySequence(Qt::CTRL | Qt::Key_E));
+  m_openEditItemDialogAct->setStatusTip(tr("Opens a edit dialog for the current item"));
+  connect(m_openEditItemDialogAct.get(), &QAction::triggered, this,
+          &MainWindow::openEditItemDialog);
+  ui->menu_Edit->addAction(m_openEditItemDialogAct.get());
+
+  m_deleteItemAct = make_unique<QAction>(tr("&Delete item(s)"), this);
+  m_deleteItemAct->setShortcut(QKeySequence::Delete);
+  m_deleteItemAct->setStatusTip(tr("Delete currently selected item(s)"));
+  // connect(m_deleteItemAct.get(), &QAction::triggered, this, &MainWindow::deleteSelectedtItems);
+  connect(m_deleteItemAct.get(), &QAction::triggered, this, &MainWindow::deleteCurrentItem);
+  ui->menu_Edit->addAction(m_deleteItemAct.get());
+
+  ui->menu_Edit->addSeparator();
+
+  m_findItemAct = make_unique<QAction>(tr("&Find item(s)"), this);
+  m_findItemAct->setShortcuts(QKeySequence::Find);
+  m_findItemAct->setStatusTip(tr("Opens a dialog to find item(s) by containing text"));
+  connect(m_findItemAct.get(), &QAction::triggered, this, &MainWindow::findItems);
+  ui->menu_Edit->addAction(m_findItemAct.get());
+}
+
+void MainWindow::createServerActions() {
+  m_fetchItemsAct = make_unique<QAction>(tr("&Fetch item(s)"), this);
+  m_fetchItemsAct->setShortcut(QKeySequence(Qt::CTRL | Qt::ALT | Qt::Key_Down));
+  m_fetchItemsAct->setStatusTip(tr("Fetches all item on configured server"));
+  connect(m_fetchItemsAct.get(), &QAction::triggered, this, &MainWindow::fetchItems);
+  ui->menu_Server->addAction(m_fetchItemsAct.get());
+
+  m_postItemsAct = make_unique<QAction>(tr("&Post item(s)"), this);
+  m_postItemsAct->setShortcut(QKeySequence(Qt::CTRL | Qt::ALT | Qt::Key_Up));
+  // m_postItemsAct->setStatusTip(tr("Posts the selected items on configured server"));
+  m_postItemsAct->setStatusTip(tr("Posts the current item on configured server"));
+  connect(m_postItemsAct.get(), &QAction::triggered, this, &MainWindow::postItems);
+  ui->menu_Server->addAction(m_postItemsAct.get());
+
+  m_deleteItemsAct = make_unique<QAction>(tr("&Delete item"), this);
+  m_deleteItemsAct->setShortcut(QKeySequence(Qt::CTRL | Qt::ALT | Qt::Key_Backspace));
+  // m_deleteItemsAct->setStatusTip(tr("Deletes the selected items on configured server"));
+  m_deleteItemsAct->setStatusTip(tr("Deletes the current item on configured server"));
+  connect(m_deleteItemsAct.get(), &QAction::triggered, this, &MainWindow::deleteItem);
+  ui->menu_Server->addAction(m_deleteItemsAct.get());
+}
+
+void MainWindow::createToolsActions() {
+  QMenu* menu          = ui->menu_Tools;
+  QAction* settingsAct = menu->addAction(tr("&Settings"), this, &MainWindow::execSettingsDialog);
+  settingsAct->setStatusTip(tr("Opens a dialog to configure applications settings."));
+}
+
+void MainWindow::createHelpMenu() {
+  QMenu* helpMenu = ui->menu_Help;
+  helpMenu->addSeparator();
+  QAction* aboutAct = helpMenu->addAction(tr("&About"), this, &MainWindow::onAboutClicked);
+  aboutAct->setStatusTip(tr("Show the application's About box"));
+
+  QAction* aboutQtAct = helpMenu->addAction(tr("About &Qt"), qApp, &QApplication::aboutQt);
+  aboutQtAct->setStatusTip(tr("Show the Qt library's About box"));
+}
+
+void MainWindow::createGuiDialogs() {
+  /// new item dialog
+  m_newItemDialog = make_unique<NewItemDialog>(this);
+  m_newItemDialog->createContent();
+  connect(m_newItemDialog.get(), &NewItemDialog::addItems, m_proxyModel.get(),
+          &GeneralSortFilterModel::appendItems);
+  /// edit item dialog
+  m_editItemDialog = make_unique<EditItemDialog>(ui->tableView, this);
+  m_editItemDialog->createContent();
+}

mainwindow.h

@@ -0,0 +1,123 @@
+#ifndef MAINWINDOW_H
+#define MAINWINDOW_H
+
+#include <QItemSelection>
+#include <QMainWindow>
+
+QT_BEGIN_NAMESPACE
+
+class QUndoStack;
+
+class QUndoView;
+namespace Ui {
+class MainWindow;
+}
+QT_END_NAMESPACE
+
+class GenericCore;
+class TableModel;
+class GeneralSortFilterModel;
+class NewItemDialog;
+class EditItemDialog;
+
+using namespace std;
+
+class MainWindow : public QMainWindow {
+  Q_OBJECT
+
+ public:
+  MainWindow(QWidget* parent = nullptr);
+  ~MainWindow();
+
+ signals:
+  void displayStatusMessage(QString message);
+  void checkForUpdates();
+
+ protected:
+  void closeEvent(QCloseEvent* event) override;
+
+ private slots:
+  void showStatusMessage(const QString text);
+  void onCurrentChanged(const QModelIndex& current, const QModelIndex& previous);
+  void onSelectionChanged(const QItemSelection& selected, const QItemSelection& deselected);
+
+  void onAboutClicked();
+  void on_actionCheck_for_update_triggered();
+
+  void on_pushButton_clicked();
+
+  /// slots for menu actions
+  void openNewItemDialog();
+  void openEditItemDialog();
+  void deleteCurrentItem();
+  void deleteSelectedtItems();
+
+  void onCleanStateChanged(bool clean);
+  void onShowUndoViewToggled(bool checked);
+
+  /// 'File' slots
+  void saveItems();
+  void importCSV();
+  void exportCSV();
+
+  /// 'Edit' slots
+  void findItems();
+
+  /// 'Server' slots
+  void fetchItems();
+  void postItems();
+  void deleteItem();
+
+  /// 'Tools' slots
+  void execSettingsDialog();
+
+ private:
+  Ui::MainWindow* ui;
+
+  unique_ptr<GenericCore> m_core;
+  shared_ptr<GeneralSortFilterModel> m_proxyModel;
+  QUndoStack* m_modelUndoStack;
+  unique_ptr<QUndoView> m_modelUndoView;
+
+  /// File actions
+  unique_ptr<QAction> m_newFileAct;
+  unique_ptr<QAction> m_openAct;
+  unique_ptr<QAction> m_saveAct;
+  unique_ptr<QAction> m_importAct;
+  unique_ptr<QAction> m_exportAct;
+  unique_ptr<QAction> m_printAct;
+  unique_ptr<QAction> m_exitAct;
+  /// Edit actions
+  unique_ptr<QAction> m_undoAct;
+  unique_ptr<QAction> m_redoAct;
+  unique_ptr<QAction> m_cutAct;
+  unique_ptr<QAction> m_copyAct;
+  unique_ptr<QAction> m_pasteAct;
+  unique_ptr<QAction> m_openNewItemDialogAct;
+  unique_ptr<QAction> m_openEditItemDialogAct;
+  unique_ptr<QAction> m_deleteItemAct;
+  unique_ptr<QAction> m_findItemAct;
+  /// Server actions
+  unique_ptr<QAction> m_fetchItemsAct;
+  unique_ptr<QAction> m_postItemsAct;
+  unique_ptr<QAction> m_deleteItemsAct;
+
+  /// View actions
+  unique_ptr<QAction> m_showModelUndoViewAct;
+
+  /// Dialogs
+  unique_ptr<NewItemDialog> m_newItemDialog;
+  unique_ptr<EditItemDialog> m_editItemDialog;
+
+  /// Setup functions
+  void setupModelViews();
+  void createActions();
+  void createFileActions();
+  void createUndoActions();
+  void createEditActions();
+  void createServerActions();
+  void createToolsActions();
+  void createHelpMenu();
+  void createGuiDialogs();
+};
+#endif  // MAINWINDOW_H

mainwindow.ui

@@ -0,0 +1,96 @@
+<?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>GenericQtClient</string>
+  </property>
+  <widget class="QWidget" name="centralwidget">
+   <layout class="QVBoxLayout" name="verticalLayout">
+    <item>
+     <widget class="QTableView" name="tableView"/>
+    </item>
+    <item>
+     <widget class="QLabel" name="label">
+      <property name="text">
+       <string>Push the button!</string>
+      </property>
+     </widget>
+    </item>
+    <item>
+     <widget class="QPushButton" name="pushButton">
+      <property name="text">
+       <string>Button</string>
+      </property>
+     </widget>
+    </item>
+   </layout>
+  </widget>
+  <widget class="QMenuBar" name="menubar">
+   <property name="geometry">
+    <rect>
+     <x>0</x>
+     <y>0</y>
+     <width>800</width>
+     <height>22</height>
+    </rect>
+   </property>
+   <widget class="QMenu" name="menu_File">
+    <property name="title">
+     <string>&amp;File</string>
+    </property>
+   </widget>
+   <widget class="QMenu" name="menu_Edit">
+    <property name="title">
+     <string>&amp;Edit</string>
+    </property>
+   </widget>
+   <widget class="QMenu" name="menu_View">
+    <property name="title">
+     <string>&amp;View</string>
+    </property>
+   </widget>
+   <widget class="QMenu" name="menu_Help">
+    <property name="title">
+     <string>&amp;Help</string>
+    </property>
+    <addaction name="actionCheck_for_update"/>
+   </widget>
+   <widget class="QMenu" name="menu_Server">
+    <property name="title">
+     <string>&amp;Server</string>
+    </property>
+   </widget>
+   <widget class="QMenu" name="menu_Tools">
+    <property name="title">
+     <string>&amp;Tools</string>
+    </property>
+   </widget>
+   <addaction name="menu_File"/>
+   <addaction name="menu_Edit"/>
+   <addaction name="menu_View"/>
+   <addaction name="menu_Server"/>
+   <addaction name="menu_Tools"/>
+   <addaction name="menu_Help"/>
+  </widget>
+  <widget class="QStatusBar" name="statusbar"/>
+  <action name="actionCheck_for_update">
+   <property name="text">
+    <string>Check for &amp;update</string>
+   </property>
+  </action>
+ </widget>
+ <resources/>
+ <connections/>
+ <slots>
+  <slot>onPushButtonClicked()</slot>
+ </slots>
+</ui>

views/itemdetailmapper.cpp

@@ -0,0 +1,191 @@
+#include "itemdetailmapper.h"
+
+#include <QAbstractItemModel>
+#include <QDataWidgetMapper>
+#include <QGridLayout>
+#include <QJsonArray>
+#include <QJsonObject>
+#include <QLabel>
+#include <QLineEdit>
+#include <QPushButton>
+#include <QSpinBox>
+#include <QTableView>
+
+#include "../widgethelper.h"
+
+ItemDetailMapper::ItemDetailMapper(QTableView* tableView, QWidget* parent)
+    : QWidget{parent} {
+  /// model mapping
+  m_mapper = std::make_unique<QDataWidgetMapper>(this);
+  /// BUG: If multiple columns are changed not all changes are applied.
+  ///     Multiple changes are set individually by calling setData().
+  ///     Probably due to a conflicting dataChanged signal for too many roles&columns the data of
+  ///     the remaining columns is reset before setData is called.
+  ///     And a manual submit would also create multiple undo steps anyway.
+  /// Workaround: ManualSubmit -> AutoSubmit
+  // m_mapper->setSubmitPolicy(QDataWidgetMapper::ManualSubmit);
+  m_mapper->setSubmitPolicy(QDataWidgetMapper::AutoSubmit);
+
+  qDebug() << "Setting model...";
+  m_tableView      = tableView;
+  m_model          = tableView->model();
+  m_selectionModel = tableView->selectionModel();
+
+  m_mapper->setModel(m_model);
+
+  setupWidgets();
+
+  setupConnections();
+}
+
+bool ItemDetailMapper::submit() { return m_mapper->submit(); }
+
+void ItemDetailMapper::revert() { m_mapper->revert(); }
+
+void ItemDetailMapper::onCurrentIndexChanged(const QModelIndex& current,
+                                             const QModelIndex& /*previous*/) {
+  if (!isEnabled()) {
+    setEnabled(true);
+  }
+  m_mapper->setCurrentModelIndex(current);
+  updateButtons(current.row());
+  emitContentChanged(current);
+}
+
+void ItemDetailMapper::rowsInserted(const QModelIndex& parent, int start, int end) {
+  updateButtons(m_mapper->currentIndex());
+}
+
+void ItemDetailMapper::rowsRemoved(const QModelIndex& parent, int start, int end) {
+  if (m_model->rowCount() == 0) {
+    clearControlWidgets();
+  }
+
+  updateButtons(m_mapper->currentIndex());
+}
+
+void ItemDetailMapper::toPrevious() {
+  int currentRow            = m_selectionModel->currentIndex().row();
+  QModelIndex previousIndex = m_selectionModel->currentIndex().siblingAtRow(currentRow - 1);
+  if (previousIndex.isValid()) {
+    m_selectionModel->setCurrentIndex(previousIndex, QItemSelectionModel::ClearAndSelect);
+  }
+}
+
+void ItemDetailMapper::toNext() {
+  int currentRow        = m_selectionModel->currentIndex().row();
+  QModelIndex nextIndex = m_selectionModel->currentIndex().siblingAtRow(currentRow + 1);
+  if (nextIndex.isValid()) {
+    m_selectionModel->setCurrentIndex(nextIndex, QItemSelectionModel::ClearAndSelect);
+  }
+}
+
+void ItemDetailMapper::updateButtons(int row) {
+  m_previousButton->setEnabled(row > 0);
+  m_nextButton->setEnabled(row < m_model->rowCount() - 1);
+}
+
+void ItemDetailMapper::emitContentChanged(const QModelIndex& currentIndex) {
+  // BUG QR-Code isn't updated after changes through the ItemDetailMapper #18
+  QString toStringText = "";
+  if (currentIndex.isValid()) {
+    toStringText = currentIndex.data(ToStringRole).toString();
+  }
+  emit contentChanged(toStringText);
+}
+
+void ItemDetailMapper::setupConnections() {
+  m_mapper->setCurrentIndex(m_selectionModel->currentIndex().row());
+
+  connect(m_model, &QAbstractItemModel::rowsInserted, this, &ItemDetailMapper::rowsInserted);
+  connect(m_model, &QAbstractItemModel::rowsRemoved, this, &ItemDetailMapper::rowsRemoved);
+  connect(m_selectionModel, &QItemSelectionModel::currentChanged, this,
+          &ItemDetailMapper::onCurrentIndexChanged);
+
+  updateButtons(m_selectionModel->currentIndex().row());
+}
+
+void ItemDetailMapper::setupNavigationButtons() {
+  m_nextButton     = new QPushButton(tr("Ne&xt"));
+  m_previousButton = new QPushButton(tr("&Previous"));
+
+  connect(m_previousButton, &QAbstractButton::clicked, this, &ItemDetailMapper::toPrevious);
+  connect(m_nextButton, &QAbstractButton::clicked, this, &ItemDetailMapper::toNext);
+
+  const int nRows = m_layout->rowCount();
+  m_layout->addWidget(m_previousButton, nRows, 0);
+  m_layout->addWidget(m_nextButton, nRows, 1);
+}
+
+void ItemDetailMapper::setupWidgets() {
+  m_layout = new QGridLayout();
+
+  for (int i = 0; i < USER_FACING_ROLES.size(); ++i) {
+    setupWidgetPairForColumn(i);
+  }
+  setupNavigationButtons();
+
+  setLayout(m_layout);
+}
+
+void ItemDetailMapper::setupWidgetPairForColumn(const int column) {
+  // REFACTOR consolidate ItemDetailMapper::setupWidgetPairForColumn(...)
+  //          with NewItemDialog::setupWidgetPairForColumn(...)
+  const UserRoles role = GET_ROLE_FOR_COLUMN(column);
+
+  QWidget* control = WidgetHelper::createControlWidget(role, this);
+
+  const QString string = QString("&%1").arg(GET_HEADER_FOR_COLUMN(column));
+  QLabel* label        = new QLabel(string);
+  label->setBuddy(control);
+
+  m_layout->addWidget(label, column, 0);
+  m_layout->addWidget(control, column, 1);
+  m_controlWidgets.append(control);
+
+  if (TYPE_ROLES.contains(role)) {
+    m_mapper->addMapping(control, column, "currentText");
+  } else {
+    m_mapper->addMapping(control, column);
+  }
+}
+
+void ItemDetailMapper::clearControlWidgets() {
+  setEnabled(false);
+
+  for (int i = 0; i < m_controlWidgets.size(); ++i) {
+    const UserRoles role = GET_ROLE_FOR_COLUMN(i);
+    if (STRING_ROLES.contains(role)) {
+      clearLineEdit(i);
+    } else if (TYPE_ROLES.contains(role)) {
+      clearComboBox(i);
+    } else if (INT_ROLES.contains(role)) {
+      clearSpinBox(i);
+    } else if (DOUBLE_ROLES.contains(role)) {
+      clearSpinBox(i);
+    } else {
+      qCritical() << "Could not reset content for control widget in column:" << i << "!";
+    }
+  }
+}
+
+void ItemDetailMapper::clearLineEdit(const int column) {
+  QLineEdit* lineEdit = dynamic_cast<QLineEdit*>(m_controlWidgets[column]);
+  if (lineEdit) {
+    lineEdit->clear();
+  }
+}
+
+void ItemDetailMapper::clearComboBox(const int column) {
+  QComboBox* comboBox = dynamic_cast<QComboBox*>(m_controlWidgets[column]);
+  if (comboBox) {
+    comboBox->setCurrentText("");
+  }
+}
+
+void ItemDetailMapper::clearSpinBox(const int column) {
+  QAbstractSpinBox* spinBox = dynamic_cast<QAbstractSpinBox*>(m_controlWidgets[column]);
+  if (spinBox) {
+    spinBox->clear();
+  }
+}

views/itemdetailmapper.h

@@ -0,0 +1,68 @@
+#ifndef ITEMDETAILMAPPER_H
+#define ITEMDETAILMAPPER_H
+
+#include <QComboBox>
+#include <QDataWidgetMapper>
+#include <QStringListModel>
+#include <QWidget>
+#include "model/metadata.h"
+
+class QGridLayout;
+class QLabel;
+class QLineEdit;
+class QDoubleSpinBox;
+class QSpinBox;
+class QPushButton;
+class QAbstractItemModel;
+class QItemSelectionModel;
+class QTableView;
+
+class ItemDetailMapper : public QWidget {
+  Q_OBJECT
+ public:
+  explicit ItemDetailMapper(QTableView* tableView, QWidget* parent = nullptr);
+
+  bool submit();
+  void revert();
+
+ signals:
+  void contentChanged(const QString text);
+
+ private slots:
+  void onCurrentIndexChanged(const QModelIndex& current, const QModelIndex& previous);
+  void rowsInserted(const QModelIndex& parent, int start, int end);
+  void rowsRemoved(const QModelIndex& parent, int start, int end);
+  void toPrevious();
+  void toNext();
+  void updateButtons(int row);
+  void emitContentChanged(const QModelIndex& currentIndex);
+
+ private:
+  /// *** members ***
+  /// Model stuff
+  QTableView* m_tableView               = nullptr;
+  QAbstractItemModel* m_model           = nullptr;
+  QItemSelectionModel* m_selectionModel = nullptr;
+
+  std::unique_ptr<QDataWidgetMapper> m_mapper;
+
+  /// GUI elements
+  QGridLayout* m_layout;
+  QList<QWidget*> m_controlWidgets;
+
+  QPushButton* m_nextButton;
+  QPushButton* m_previousButton;
+
+  void setupConnections();
+  void setupNavigationButtons();
+  void setupWidgets();
+
+  void setupWidgetPairForColumn(const int column);
+
+  void clearControlWidgets();
+  void clearLineEdit(const int column);
+  void clearComboBox(const int column);
+  void clearSpinBox(const int column);
+};
+
+#endif  // ITEMDETAILMAPPER_H

widgethelper.cpp

@@ -0,0 +1,66 @@
+#include "widgethelper.h"
+
+#include <QComboBox>
+#include <QLineEdit>
+#include <QSpinBox>
+#include <QStringListModel>
+
+QWidget* WidgetHelper::createControlWidget(const UserRoles role, QWidget* parent) {
+  QWidget* control;
+  if (STRING_ROLES.contains(role)) {
+    control = createLineEdit(role, parent);
+  } else if (TYPE_ROLES.contains(role)) {
+    control = createComboBox(role, parent);
+  } else if (NUMBER_ROLES.contains(role)) {
+    control = createSpinBox(role, parent);
+  } else {
+    qCritical() << QString("Unsupported role %1!!!").arg(role);
+    qDebug() << "Using line edit as well and pretend it's a string role...";
+    control = createLineEdit(role, parent);
+  }
+  return control;
+}
+
+WidgetHelper::WidgetHelper() {}
+
+QWidget* WidgetHelper::createLineEdit(const UserRoles role, QWidget* /*parent*/) {
+  QLineEdit* lineEdit = new QLineEdit();
+  if (READ_ONLY_ROLES.contains(role)) {
+    lineEdit->setReadOnly(true);
+  }
+  return lineEdit;
+}
+
+QWidget* WidgetHelper::createSpinBox(const UserRoles role, QWidget* /*parent*/) {
+  QAbstractSpinBox* abstractSpinBox;
+  if (DOUBLE_ROLES.contains(role)) {
+    QDoubleSpinBox* spinBox = new QDoubleSpinBox();
+    spinBox->setMaximum(1000);
+    abstractSpinBox = spinBox;
+  } else {
+    QSpinBox* spinBox = new QSpinBox();
+    spinBox->setMaximum(1000);
+    abstractSpinBox = spinBox;
+  }
+
+  if (READ_ONLY_ROLES.contains(role)) {
+    abstractSpinBox->setReadOnly(true);
+  }
+  return abstractSpinBox;
+}
+
+QWidget* WidgetHelper::createComboBox(const UserRoles role, QWidget* parent) {
+  // TODO add support for read only type roles?
+  QStringListModel* typeModel;
+  if (role == TypeRole) {
+    typeModel = new QStringListModel(TYPES, parent);
+  } else {
+    qCritical() << "Unsupported type with role:" << role
+                << "- Using string list model with only one empty string!";
+    typeModel = new QStringListModel({""}, parent);
+  }
+  QComboBox* comboBox = new QComboBox();
+  comboBox->setModel(typeModel);
+  comboBox->setCurrentText("");
+  return comboBox;
+}

widgethelper.h

@@ -0,0 +1,20 @@
+#ifndef WIDGETHELPER_H
+#define WIDGETHELPER_H
+
+#include "model/metadata.h"
+
+class QWidget;
+
+class WidgetHelper {
+ public:
+  static QWidget* createControlWidget(const UserRoles role, QWidget* parent);
+
+ private:
+  explicit WidgetHelper();
+
+  static QWidget* createLineEdit(const UserRoles role, QWidget* parent);
+  static QWidget* createSpinBox(const UserRoles role, QWidget* parent);
+  static QWidget* createComboBox(const UserRoles role, QWidget* parent);
+};
+
+#endif  // WIDGETHELPER_H

widgets/controls/comboboxdelegate.cpp

@@ -0,0 +1,57 @@
+#include "comboboxdelegate.h"
+
+#include <QComboBox>
+#include <QStringListModel>
+#include "model/metadata.h"
+
+ComboboxDelegate::ComboboxDelegate(const QStringList items, QObject* parent)
+    : QStyledItemDelegate(parent)
+    , m_types(new QStringListModel(items)) {}
+
+void ComboboxDelegate::paint(QPainter* painter,
+                             const QStyleOptionViewItem& option,
+                             const QModelIndex& index) const {
+  QStyledItemDelegate::paint(painter, option, index);
+}
+
+QSize ComboboxDelegate::sizeHint(const QStyleOptionViewItem& option,
+                                 const QModelIndex& index) const {
+  return QStyledItemDelegate::sizeHint(option, index);
+}
+
+QWidget* ComboboxDelegate::createEditor(QWidget* parent,
+                                        const QStyleOptionViewItem& /*option*/,
+                                        const QModelIndex& /*index*/) const {
+  QComboBox* editor = new QComboBox(parent);
+  editor->setModel(m_types);
+  return editor;
+  // return QStyledItemDelegate::createEditor(parent, option, index);
+}
+
+void ComboboxDelegate::setEditorData(QWidget* editor, const QModelIndex& index) const {
+  /// Get the value via index of the Model
+  const QAbstractItemModel* localModel = index.model();
+  const QString headerText = localModel->headerData(index.column(), Qt::Horizontal).toString();
+
+  const UserRoles role = GET_ROLE_FOR_COLUMN(index.column());
+  const bool isType    = TYPE_ROLES.contains(role);
+  /// Put the value into the SpinBox
+  if (isType) {
+    const QString valueString = index.model()->data(index, TypeRole).toString();
+    int value                 = TYPES.indexOf(valueString);
+
+    QComboBox* combobox = static_cast<QComboBox*>(editor);
+    combobox->setCurrentIndex(value);
+    // QStyledItemDelegate::setEditorData(editor, index);
+  } else {
+    qCritical() << "Could not find the correct type role for index:" << index << "!!!";
+    QComboBox* combobox = static_cast<QComboBox*>(editor);
+    combobox->setCurrentIndex(-1);
+  }
+}
+
+void ComboboxDelegate::setModelData(QWidget* editor,
+                                    QAbstractItemModel* model,
+                                    const QModelIndex& index) const {
+  QStyledItemDelegate::setModelData(editor, model, index);
+}

widgets/controls/comboboxdelegate.h

@@ -0,0 +1,31 @@
+#ifndef COMBOBOXDELEGATE_H
+#define COMBOBOXDELEGATE_H
+
+#include <QStyledItemDelegate>
+class QStringListModel;
+
+class ComboboxDelegate : public QStyledItemDelegate {
+  // TODO move source code files into subfolder "widgets/delegate"
+  Q_OBJECT
+ public:
+  explicit ComboboxDelegate(const QStringList items, QObject* parent = nullptr);
+
+  /// QAbstractItemDelegate interface
+ public:
+  void paint(QPainter* painter,
+             const QStyleOptionViewItem& option,
+             const QModelIndex& index) const override;
+  QSize sizeHint(const QStyleOptionViewItem& option, const QModelIndex& index) const override;
+  QWidget* createEditor(QWidget* parent,
+                        const QStyleOptionViewItem& option,
+                        const QModelIndex&) const override;
+  void setEditorData(QWidget* editor, const QModelIndex& index) const override;
+  void setModelData(QWidget* editor,
+                    QAbstractItemModel* model,
+                    const QModelIndex& index) const override;
+
+ private:
+  QStringListModel* m_types = nullptr;
+};
+
+#endif  // COMBOBOXDELEGATE_H

widgets/controls/spinboxdelegate.cpp

@@ -0,0 +1,69 @@
+#include "spinboxdelegate.h"
+
+#include <QSpinBox>
+
+#include "model/metadata.h"
+
+SpinboxDelegate::SpinboxDelegate(QObject* parent)
+    : QStyledItemDelegate(parent) {}
+
+void SpinboxDelegate::paint(QPainter* painter,
+                            const QStyleOptionViewItem& option,
+                            const QModelIndex& index) const {
+  QStyledItemDelegate::paint(painter, option, index);
+}
+
+QSize SpinboxDelegate::sizeHint(const QStyleOptionViewItem& option,
+                                const QModelIndex& index) const {
+  return QStyledItemDelegate::sizeHint(option, index);
+}
+
+QWidget* SpinboxDelegate::createEditor(QWidget* parent,
+                                       const QStyleOptionViewItem&  /*option*/,
+                                       const QModelIndex& index) const {
+  const QAbstractItemModel* localModel = index.model();
+  QString headerText = localModel->headerData(index.column(), Qt::Horizontal).toString();
+
+  const UserRoles role = GET_ROLE_FOR_COLUMN(index.column());
+  const bool isInt     = INT_ROLES.contains(role);
+  if (isInt) {
+    QSpinBox* editor = new QSpinBox(parent);
+    editor->setMinimum(0);
+    editor->setMaximum(23000);
+    return editor;
+  } else {
+    QDoubleSpinBox* editor = new QDoubleSpinBox(parent);
+    editor->setMinimum(0);
+    editor->setMaximum(23000);
+    return editor;
+  }
+  // return QStyledItemDelegate::createEditor(parent, option, index);
+}
+
+void SpinboxDelegate::setEditorData(QWidget* editor, const QModelIndex& index) const {
+  // Get the value via index of the Model
+  const QAbstractItemModel* localModel = index.model();
+  QString headerText = localModel->headerData(index.column(), Qt::Horizontal).toString();
+
+  const UserRoles role = GET_ROLE_FOR_COLUMN(index.column());
+  const bool isInt     = INT_ROLES.contains(role);
+  if (isInt) {
+    int value = index.model()->data(index, Qt::EditRole).toInt();
+    // Put the value into the SpinBox
+    QSpinBox* spinbox = static_cast<QSpinBox*>(editor);
+    spinbox->setValue(value);
+  } else {
+    // Put the value into the SpinBox
+    qreal value             = index.model()->data(index, Qt::EditRole).toReal();
+    QDoubleSpinBox* spinbox = static_cast<QDoubleSpinBox*>(editor);
+    spinbox->setValue(value);
+  }
+
+  // QStyledItemDelegate::setEditorData(editor, index);
+}
+
+void SpinboxDelegate::setModelData(QWidget* editor,
+                                   QAbstractItemModel* model,
+                                   const QModelIndex& index) const {
+  QStyledItemDelegate::setModelData(editor, model, index);
+}

widgets/controls/spinboxdelegate.h

@@ -0,0 +1,27 @@
+#ifndef SPINBOXDELEGATE_H
+#define SPINBOXDELEGATE_H
+
+#include <QStyledItemDelegate>
+
+class SpinboxDelegate : public QStyledItemDelegate {
+  // TODO move source code files into subfolder "widgets/delegate"
+  Q_OBJECT
+ public:
+  explicit SpinboxDelegate(QObject* parent = nullptr);
+
+  /// QAbstractItemDelegate interface
+ public:
+  void paint(QPainter* painter,
+             const QStyleOptionViewItem& option,
+             const QModelIndex& index) const override;
+  QSize sizeHint(const QStyleOptionViewItem& option, const QModelIndex& index) const override;
+  QWidget* createEditor(QWidget* parent,
+                        const QStyleOptionViewItem& option,
+                        const QModelIndex& index) const override;
+  void setEditorData(QWidget* editor, const QModelIndex& index) const override;
+  void setModelData(QWidget* editor,
+                    QAbstractItemModel* model,
+                    const QModelIndex& index) const override;
+};
+
+#endif  // SPINBOXDELEGATE_H