add modified signal to material editor

GUI/View/SampleDesigner/MaterialInplaceForm.cpp

@@ -14,9 +14,11 @@
 
 #include "GUI/View/SampleDesigner/MaterialInplaceForm.h"
 #include "Base/Util/Assert.h"
+#include "GUI/Model/Item/ItemUtils.h"
 #include "GUI/Model/Item/ItemWithMaterial.h"
 #include "GUI/Model/Item/MaterialItem.h"
 #include "GUI/Model/Item/MaterialItems.h"
+#include "GUI/Model/Item/MultiLayerItem.h"
 #include "GUI/Model/Types/DoubleDescriptor.h"
 #include "GUI/Model/Types/VectorDescriptor.h"
 #include "GUI/View/Edit/DoubleLineEdit.h"
@@ -26,7 +28,6 @@
 #include "GUI/View/SampleDesigner/LayerEditorUtils.h"
 #include "GUI/View/SampleDesigner/SampleEditorController.h"
 #include "GUI/View/Tool/LayoutUtils.h"
-
 #include <QGridLayout>
 #include <QLabel>
 #include <QPushButton>
@@ -64,6 +65,7 @@ void MaterialInplaceForm::updateValues()
 
 void MaterialInplaceForm::selectMaterial()
 {
+    const auto materialsBackup = GUI::Util::createBackup(&m_ec->multiLayerItem()->materialItems());
     const QString newMaterialIdentifier = MaterialEditorDialog::chooseMaterial(
         GUI::Global::mainWindow, m_ec->multiLayerItem(), m_item->materialIdentifier());
 
@@ -74,9 +76,15 @@ void MaterialInplaceForm::selectMaterial()
         createWidgets();
         connect(itemWithMaterial()->materialItem(), &MaterialItem::dataChanged, this,
                 &MaterialInplaceForm::onMaterialChanged);
-    } else
+    } else {
         updateValues(); // necessary, since in the material editor the values could have been
                         // changed without selecting a different material
+
+        // If the list of materials was edited (e.g. a material added), but the current was not
+        // changed, no modified signal would be sent. Check now for changes and emit if necessary.
+        if (GUI::Util::createBackup(&m_ec->multiLayerItem()->materialItems()) != materialsBackup)
+            m_ec->modified();
+    }
 }
 
 void MaterialInplaceForm::createWidgets()