Fix problem with diff rows being blanked.

admin/mainwindow.cpp

@@ -257,8 +257,8 @@ MainWindow::MainWindow(QWidget *parent) :
 
     inventoryModel->setEditStrategy(QSqlTableModel::OnFieldChange);
 
-    // QObject::connect(inventoryModel, &QAbstractItemModel::dataChanged,
-    //                  this, &MainWindow::on_inventoryModel_dataChanged);
+    QObject::connect(inventoryModel, &QAbstractItemModel::dataChanged,
+                     this, &MainWindow::on_inventoryModel_dataChanged);
 
     // inventoryModel->setRelation(1, QSqlRelation("products", "id", "name"));
     inventoryModel->select();
@@ -272,9 +272,6 @@ MainWindow::MainWindow(QWidget *parent) :
     ui->inventoryCheckView->hideColumn(1);
     ui->inventoryCheckView->hideColumn(2);
 
-    // TODO this line makes stuff dis-a-pear
-    inventoryModel->setData( inventoryModel->index(0, 5) , QVariant(5));
-
     // --------------------------------------------------
 
     setMoneyDiffLabels();
@@ -331,20 +328,30 @@ MainWindow::~MainWindow()
     delete ui;
 }
 
+/*
+ * This updates the QSqlTableModel to contain the same data as the database.
+ * This is needed since it looks at a view, and can therefore not find the
+ * primary key. Requiring all the fields in the front-end and back-end database
+ * to have the exact same fields.
+ *
+ * So, the calculations here are also done in the database, and those are what
+ * should be used when doing further stuff with the data.
+ */
 void MainWindow::on_inventoryModel_dataChanged(const QModelIndex &topLeft, const QModelIndex& /*bottomRight*/, const QVector<int>& /*roles*/)
 {
-    /*
-    if (topLeft.column() != 4) return;
+    QSqlTableModel* model = (QSqlTableModel*) ui->inventoryCheckView->model();
 
-    DisablingModel* model = (DisablingModel*) ui->inventoryCheckView->model();
-    int row = topLeft.row();
-    QModelIndex index = model->index(row, 3);
-    int expected = model->data(index).toInt();
-    int actual = model->data(topLeft).toInt();
-    int diff = actual - expected
-    model->setData(model->index(row, 5), diff);
-    */
-    qDebug() << "Data Chaned" << topLeft;
+    if (model->isDirty()) {
+        int row = topLeft.row();
+
+        bool number;
+        int expected = model->data(model->index(row, 4)).toInt();
+        int actual = model->data(model->index(row, 5)).toInt(&number);
+
+        model->setData(model->index(row, 6),
+                       number ? expected - actual
+                              : QVariant());
+    }
 }
 
 /*