add undo/redo for adding a layer

GUI/View/SampleDesigner/SampleEditorCommands.cpp

@@ -50,6 +50,29 @@ void CommandRemoveLayer::undo()
     emit m_ec->modified();
 }
 
+// --------------------------------------------------------------------------------------------- //
+
+CommandAddLayer::CommandAddLayer(SampleEditorController* ec, int atIndex, QUndoCommand* parent)
+    : m_ec(ec)
+    , m_atIndex(atIndex)
+{
+    setText("Add layer");
+}
+
+void CommandAddLayer::redo()
+{
+    m_ec->addLayerFromUndo(m_atIndex);
+}
+
+void CommandAddLayer::undo()
+{
+    // no backup of the layer has to be stored, since redo always creates the layer
+    // from scratch - no contents required for this
+    m_ec->removeLayerFromUndo(m_atIndex);
+}
+
+// --------------------------------------------------------------------------------------------- //
+
 CommandChangeValue::CommandChangeValue(const QString& label, SampleEditorController* ec,
                                        double oldValue, double newValue, const QString& path,
                                        QUndoCommand* parent /*= nullptr*/)

GUI/View/SampleDesigner/SampleEditorCommands.h

@@ -40,6 +40,19 @@ private:
     bool m_isFirst = true;
 };
 
+//! Command to add a layer to a multilayer
+class CommandAddLayer : public QUndoCommand {
+public:
+    CommandAddLayer(SampleEditorController* ec, int atIndex, QUndoCommand* parent = nullptr);
+
+    void redo() override;
+    void undo() override;
+
+private:
+    SampleEditorController* m_ec;
+    int m_atIndex;
+};
+
 //! Command to remove a layer from a multilayer
 class CommandRemoveLayer : public QUndoCommand {
 public:

GUI/View/SampleDesigner/SampleEditorController.cpp

@@ -62,8 +62,13 @@ MultiLayerItem* SampleEditorController::multiLayerItem() const
 
 void SampleEditorController::addLayer(LayerItem* before)
 {
-    const int rowInMultiLayer = (before != nullptr) ? m_multiLayerItem->layers().indexOf(before)
-                                                    : m_multiLayerItem->layers().size();
+    const int newIndex = (before != nullptr) ? m_multiLayerItem->layers().indexOf(before)
+                                             : m_multiLayerItem->layers().size();
+    m_undoStack.push(new CommandAddLayer(this, newIndex));
+}
+
+void SampleEditorController::addLayerFromUndo(int atIndex)
+{
 
     // -- find a color for the new layer
     QColor color;
@@ -85,11 +90,10 @@ void SampleEditorController::addLayer(LayerItem* before)
             [&](const QColor& a, const QColor& b) { return usage[a.name()] < usage[b.name()]; });
 
 
-        const QColor above = (rowInMultiLayer > 0)
-                                 ? m_multiLayerItem->layers()[rowInMultiLayer - 1]->color()
-                                 : QColor();
-        const QColor below = (rowInMultiLayer < m_multiLayerItem->layers().size())
-                                 ? m_multiLayerItem->layers()[rowInMultiLayer]->color()
+        const QColor above =
+            (atIndex > 0) ? m_multiLayerItem->layers()[atIndex - 1]->color() : QColor();
+        const QColor below = (atIndex < m_multiLayerItem->layers().size())
+                                 ? m_multiLayerItem->layers()[atIndex]->color()
                                  : QColor();
 
         for (const auto& col : sortedByUsage)
@@ -100,7 +104,7 @@ void SampleEditorController::addLayer(LayerItem* before)
     }
 
     // - create new layer
-    LayerItem* layer = m_multiLayerItem->addLayer(rowInMultiLayer);
+    LayerItem* layer = m_multiLayerItem->addLayer(atIndex);
     layer->setMaterial(materialItems()->defaultMaterial());
     layer->setColor(color);
 

GUI/View/SampleDesigner/SampleEditorController.h

@@ -74,6 +74,7 @@ public:
     ProjectDocument* projectDocument() const;
 
     void addLayer(LayerItem* before);
+    void addLayerFromUndo(int atIndex);
     void removeLayer(LayerItem* layerItem);
     void removeLayerFromUndo(int atIndex);
     void addLayout(LayerForm* layerItem);