Using QDataWidgetMapper in ItemDetailMapper to work with the model data (current index of the TableView).

dialogs/edititemdialog.cpp

@@ -4,8 +4,9 @@
 
 #include "../views/itemdetailmapper.h"
 
-EditItemDialog::EditItemDialog(QWidget* parent)
+EditItemDialog::EditItemDialog(QTableView* tableView, QWidget* parent)
-    : AbstractDialog(parent) {}
+    : AbstractDialog(parent)
+    , m_tableView(tableView) {}
 
 void EditItemDialog::createContent() {
   if (m_contentContainer) {
@@ -14,7 +15,18 @@ void EditItemDialog::createContent() {
 
   setWindowTitle(tr("Edit item..."));
 
-  m_contentContainer = new ItemDetailMapper(this);
+  m_detailMapper = new ItemDetailMapper(this);
+  m_detailMapper->setModelMappings(m_tableView);
+  m_contentContainer = m_detailMapper;
 
   m_outerLayout->insertWidget(0, m_contentContainer);
+
+void EditItemDialog::accept() {
+  m_detailMapper->submit();
+  QDialog::accept();
+}
+
+void EditItemDialog::reject() {
+  m_detailMapper->revert();
+  QDialog::reject();
 }

dialogs/edititemdialog.h

@@ -7,16 +7,26 @@ class QDoubleSpinBox;
 class QLineEdit;
 class QSpinBox;
 class QLabel;
+class QTableView;
+
+class ItemDetailMapper;
 
 class EditItemDialog : public AbstractDialog {
   Q_OBJECT
  public:
-  EditItemDialog(QWidget* parent = nullptr);
+  EditItemDialog(QTableView* tableView, QWidget* parent = nullptr);
 
   /// AbstractDialog interface
   void createContent() override;
 
+ public slots:
+  void accept() override;
+  void reject() override;
+
  private:
+  QTableView* m_tableView = nullptr;
+  ItemDetailMapper* m_detailMapper;
+
   QLabel* m_nameLabel   = nullptr;
   QLineEdit* m_nameEdit = nullptr;
 

mainwindow.cpp

@@ -53,10 +53,13 @@ MainWindow::MainWindow(QWidget* parent)
   connect(this, &MainWindow::checkForUpdates, this,
           &MainWindow::on_actionCheck_for_update_triggered, Qt::QueuedConnection);
 
-  connect(ui->tableView->selectionModel(), &QItemSelectionModel::selectionChanged, this,
+  // connect(ui->tableView->selectionModel(), &QItemSelectionModel::selectionChanged, this,
-          &MainWindow::onSelectionChanged);
+  //         &MainWindow::onSelectionChanged);
+  connect(ui->tableView->selectionModel(), &QItemSelectionModel::currentChanged, this,
+          &MainWindow::onCurrentChanged);
 
   onSelectionChanged(QItemSelection(), QItemSelection());
+  onCurrentChanged(QModelIndex(), QModelIndex());
 }
 
 MainWindow::~MainWindow() { delete ui; }
@@ -104,6 +107,20 @@ void MainWindow::showStatusMessage(const QString 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);
@@ -162,6 +179,17 @@ void MainWindow::openEditItemDialog() {
   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_tableModel->removeRows(currentIndex.row(), 1);
+  }
+}
+
 void MainWindow::deleteSelectedtItems() {
   showStatusMessage(tr("Invoked 'Edit|Delete Item'"));
   QItemSelection localSelection = ui->tableView->selectionModel()->selection();
@@ -349,7 +377,8 @@ void MainWindow::createEditActions() {
   m_deleteItemAct = make_unique<QAction>(tr("&Delete item(s)"), this);
   m_deleteItemAct->setShortcuts(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::deleteSelectedtItems);
+  connect(m_deleteItemAct.get(), &QAction::triggered, this, &MainWindow::deleteCurrentItem);
   ui->menu_Edit->addAction(m_deleteItemAct.get());
 
   ui->menu_Edit->addSeparator();
@@ -379,6 +408,6 @@ void MainWindow::createGuiDialogs() {
   connect(m_newItemDialog.get(), &NewItemDialog::addItems, m_tableModel.get(),
           &TableModel::appendItems);
   /// edit item dialog
-  m_editItemDialog = make_unique<EditItemDialog>(this);
+  m_editItemDialog = make_unique<EditItemDialog>(ui->tableView, this);
   m_editItemDialog->createContent();
 }

mainwindow.h

@@ -37,6 +37,7 @@ class MainWindow : public QMainWindow {
 
  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();
@@ -47,6 +48,7 @@ class MainWindow : public QMainWindow {
   /// slots for menu actions
   void openNewItemDialog();
   void openEditItemDialog();
+  void deleteCurrentItem();
   void deleteSelectedtItems();
 
   void onCleanStateChanged(bool clean);

views/itemdetailmapper.cpp

@@ -1,14 +1,30 @@
 #include "itemdetailmapper.h"
 
+#include <QAbstractItemModel>
+#include <QDataWidgetMapper>
 #include <QGridLayout>
 #include <QJsonArray>
 #include <QJsonObject>
 #include <QLabel>
 #include <QLineEdit>
+#include <QPushButton>
 #include <QSpinBox>
+#include <QTableView>
 
 ItemDetailMapper::ItemDetailMapper(QWidget* parent)
     : QWidget{parent} {
+  /// model mapping
+  m_mapper = std::make_unique<QDataWidgetMapper>(this);
+  m_mapper->setSubmitPolicy(QDataWidgetMapper::ManualSubmit);
+
+  /// model mapping buttons
+  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);
+
+  /// the individual widgets
   // REFACTOR deduce label names and types from meta data & use a factory
   m_nameLabel = new QLabel("&Name");
   m_nameEdit  = new QLineEdit();
@@ -44,5 +60,83 @@ ItemDetailMapper::ItemDetailMapper(QWidget* parent)
   layout->addWidget(m_factorLabel, 4, 0, 1, 1);
   layout->addWidget(m_factorBox, 4, 1, 1, 1);
 
+  layout->addWidget(m_previousButton, 5, 0, 1, 1);
+  layout->addWidget(m_nextButton, 5, 1, 1, 1);
+
   setLayout(layout);
 }
+
+void ItemDetailMapper::setModelMappings(QTableView* tableView) {
+  qDebug() << "Setting model...";
+  m_tableView      = tableView;
+  m_model          = tableView->model();
+  m_selectionModel = tableView->selectionModel();
+
+  m_mapper->setModel(m_model);
+  m_mapper->addMapping(m_nameEdit, 0);
+  m_mapper->addMapping(m_descriptionEdit, 1);
+  m_mapper->addMapping(m_infoEdit, 2);
+  m_mapper->addMapping(m_amountBox, 3);
+  m_mapper->addMapping(m_factorBox, 4);
+
+  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());
+}
+
+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());
+}
+
+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) {
+    setEnabled(false);
+
+    m_nameEdit->clear();
+    m_descriptionEdit->clear();
+    m_infoEdit->clear();
+    m_amountBox->clear();
+    m_factorBox->clear();
+  }
+
+  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);
+}

views/itemdetailmapper.h

@@ -1,21 +1,48 @@
 #ifndef ITEMDETAILMAPPER_H
 #define ITEMDETAILMAPPER_H
 
+#include <QDataWidgetMapper>
 #include <QWidget>
 
 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(QWidget* parent = nullptr);
 
+  void setModelMappings(QTableView* tableView);
+
+  bool submit();
+  void revert();
+
  signals:
 
+ 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);
+
  private:
+  /// *** members ***
+  /// Model stuff
+  QTableView* m_tableView               = nullptr;
+  QAbstractItemModel* m_model           = nullptr;
+  QItemSelectionModel* m_selectionModel = nullptr;
+
+  std::unique_ptr<QDataWidgetMapper> m_mapper;
+
+  /// GUI elements
   QLabel* m_nameLabel   = nullptr;
   QLineEdit* m_nameEdit = nullptr;
 
@@ -30,6 +57,9 @@ class ItemDetailMapper : public QWidget {
 
   QLabel* m_factorLabel       = nullptr;
   QDoubleSpinBox* m_factorBox = nullptr;
+
+  QPushButton* m_nextButton;
+  QPushButton* m_previousButton;
 };
 
 #endif  // ITEMDETAILMAPPER_H