if only one layer -> thickness is "infinite", not "semi-infinite"

GUI/View/SampleDesigner/LayerForm.cpp

@@ -119,20 +119,27 @@ void LayerForm::updateLayerPositionDependentElements()
     const auto* multiLayer = dynamic_cast<MultiLayerItem*>(m_layer->parent());
     const bool isFirstLayer = multiLayer->layers().first() == m_layer;
     const bool isLastLayer = multiLayer->layers().last() == m_layer;
-    const bool thicknessIsSemiInfinite = isFirstLayer || isLastLayer;
+    const bool thicknessIsSemiInfinite =
+        (isFirstLayer || isLastLayer) && (multiLayer->layers().size() != 1);
+    const bool thicknessIsInfinite = multiLayer->layers().size() == 1;
 
     m_layouter->setRowVisible(m_roughnessRow, !isFirstLayer);
 
     if (m_thicknessRow == -1)
         return;
     QWidget* w = m_layouter->layout()->itemAt(m_thicknessRow, QFormLayout::FieldRole)->widget();
-    if (thicknessIsSemiInfinite && (qobject_cast<QLineEdit*>(w) == nullptr)) {
-        m_layouter->removeRow(m_thicknessRow);
-        QLineEdit* info = new QLineEdit("Semi-infinite", this);
-        info->setEnabled(false);
-        info->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
-        m_layouter->insertRow(m_thicknessRow, m_layer->thickness().label, info);
-    } else if (!thicknessIsSemiInfinite && (qobject_cast<QLineEdit*>(w) != nullptr)) {
+    if (thicknessIsSemiInfinite || thicknessIsInfinite) {
+        QLineEdit* info = qobject_cast<QLineEdit*>(w);
+        if (info == nullptr) {
+            m_layouter->removeRow(m_thicknessRow);
+            info = new QLineEdit(this);
+            info->setEnabled(false);
+            info->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
+            m_layouter->insertRow(m_thicknessRow, m_layer->thickness().label, info);
+        }
+        info->setText(thicknessIsSemiInfinite ? "Semi-infinite" : "Infinite");
+    } else if (!thicknessIsSemiInfinite && !thicknessIsInfinite
+               && (qobject_cast<QLineEdit*>(w) != nullptr)) {
         m_layouter->removeRow(m_thicknessRow);
         m_layouter->insertValue(m_thicknessRow, m_layer->thickness());
     }