The PropertyProxyModel now properly maps the second column to the active row of the source.

It has a slot to receive the activeRow.
Used this in the TablesPage to let the property tab follow the currentIndex in the list of tables.

pglab/PropertyProxyModel.cpp

@@ -1,6 +1,11 @@
 #include "PropertyProxyModel.h"
 /*
  * Code borrowed from: https://stackoverflow.com/questions/21653253/how-to-change-orientation-of-qt-tableview
+ *
+ * Originally it was called Horizontal_proxy_model however some adjustments were made to it.
+ * Instead of the column headers becoming row headers we now convert them to the first column.
+ * The second column show the values of a single row from the source model. Which is determined
+ * by the setActiveRow call.
  */
 
 
@@ -12,16 +17,23 @@ PropertyProxyModel::PropertyProxyModel(QObject *parent)
 QModelIndex PropertyProxyModel::mapToSource(const QModelIndex &proxyIndex) const
 {
 	if (sourceModel()) {
-		return sourceModel()->index(proxyIndex.column(), proxyIndex.row());
+		if (activeRow >= 0) {
+			if (proxyIndex.column() == valueColumn) {
+				return sourceModel()->index(activeRow, proxyIndex.row());
+			}
+		}
 	}
-	else {
 	return QModelIndex();
 }
-}
 
 QModelIndex PropertyProxyModel::mapFromSource(const QModelIndex &sourceIndex) const
 {
-	return index(sourceIndex.column(), sourceIndex.row());
+	if (activeRow >= 0) {
+		if (sourceIndex.row() == activeRow) {
+			return index(sourceIndex.column(), valueColumn);
+		}
+	}
+	return QModelIndex();
 }
 
 QModelIndex PropertyProxyModel::index(int row, int column, const QModelIndex &) const
@@ -41,16 +53,52 @@ int PropertyProxyModel::rowCount(const QModelIndex &) const
 
 int PropertyProxyModel::columnCount(const QModelIndex &) const
 {
-  return sourceModel() ? sourceModel()->rowCount() : 0;
+  return 2;
 }
 
 QVariant PropertyProxyModel::headerData(
 		   int section, Qt::Orientation orientation, int role) const
 {
-	if (!sourceModel()) {
+//	if (!sourceModel()) {
+//		return QVariant();
+//	}
+//	Qt::Orientation new_orientation = orientation == Qt::Horizontal ?
+//			Qt::Vertical : Qt::Horizontal;
+//	return sourceModel()->headerData(section, new_orientation, role);
+	if (orientation == Qt::Horizontal) {
+		if (role == Qt::DisplayRole) {
+			switch (section) {
+			case 0:
+				return tr("Property");
+			case 1:
+				return tr("Value");
+			}
+		}
+	}
 	return QVariant();
 }
-	Qt::Orientation new_orientation = orientation == Qt::Horizontal ?
-			Qt::Vertical : Qt::Horizontal;
-	return sourceModel()->headerData(section, new_orientation, role);
+
+QVariant PropertyProxyModel::data(const QModelIndex &proxyIndex, int role) const
+{
+	auto sm = sourceModel();
+	if (sm) {
+		switch (proxyIndex.column()) {
+		case 0:
+			// return source header data
+			return sm->headerData(proxyIndex.row(), Qt::Horizontal, role);
+		case 1:
+			// return value if activeRow is set
+			if (activeRow >= 0) {
+				return QIdentityProxyModel::data(proxyIndex, role);
+			}
+		}
+	}
+	//return d->model->data(mapToSource(proxyIndex), role);
+	return QVariant();
+}
+
+void PropertyProxyModel::setActiveRow(int row)
+{
+	activeRow = row;
+	emit dataChanged(index(0, valueColumn), index(rowCount(QModelIndex()), valueColumn), QVector<int>() << Qt::DisplayRole);
 }

pglab/PropertyProxyModel.h

@@ -4,6 +4,7 @@
 #include <QIdentityProxyModel>
 
 class PropertyProxyModel : public QIdentityProxyModel {
+	Q_OBJECT
 public:
 	PropertyProxyModel(QObject * parent = nullptr);
 	QModelIndex mapToSource(const QModelIndex &proxyIndex) const;
@@ -13,6 +14,17 @@ public:
 	int rowCount(const QModelIndex &parent) const;
 	int columnCount(const QModelIndex &parent) const;
 	QVariant headerData(int section, Qt::Orientation orientation, int role) const;
+	QVariant data(const QModelIndex &proxyIndex, int role) const;
+
+public Q_SLOTS:
+	void setActiveRow(int row);
+
+private:
+	enum Columns {
+		propertyColumn = 0,
+		valueColumn
+	};
+	int activeRow = -1;
 };
 
 #endif // HORIZONTALPROXYMODEL_H

pglab/TablesPage.cpp

@@ -53,9 +53,19 @@ TablesPage::TablesPage(MainWindow *parent)
 	ui->indexesTable->setItemDelegate(new PgLabItemDelegate(ui->indexesTable));
 	ui->indexesTable->setItemDelegateForColumn(0, delegate);
 
-	PropertyProxyModel* proxy_model = new PropertyProxyModel(this);
-	proxy_model->setSourceModel(m_tablesModel);
-	ui->tablePropertiesTable->setModel(proxy_model);
+	PropertyProxyModel* property_model = new PropertyProxyModel(this);
+	property_model->setSourceModel(m_tablesModel);
+	ui->tablePropertiesTable->setModel(property_model);
+
+	connect(ui->tableListTable->selectionModel(), &QItemSelectionModel::currentChanged,
+			[property_model](const QModelIndex &current, const QModelIndex &) {
+				int row = -1;
+				if (current.isValid())
+					row = current.row();
+
+				property_model->setActiveRow(row);
+			});
+
 
 	//m_namespaceFilterWidget = new NamespaceFilterWidget(this);
 	//ui->verticalLayoutTableView->addWidget(m_namespaceFilterWidget);