add color property to LayerItem (necessary for the upcoming layer-oriented sample editor)

GUI/Models/LayerItem.cpp

@@ -41,6 +41,8 @@ LayerItem::LayerItem() : SessionGraphicsItem(M_TYPE), ItemWithMaterial(M_TYPE)
         ->setLimits(RealLimits::lowerLimited(0.0))
         .setToolTip(layer_nslices_tooltip);
 
+    addProperty(P_COLOR, QColor()); // initially no color
+
     GroupInfo info;
     info.add(LayerBasicRoughnessItem::M_TYPE, "Basic");
     info.add(LayerZeroRoughnessItem::M_TYPE, "No");
@@ -124,6 +126,16 @@ void LayerItem::removeLayout(ParticleLayoutItem* layout)
     model()->removeItem(layout);
 }
 
+QColor LayerItem::color() const
+{
+    return getItemValue(P_COLOR).value<QColor>();
+}
+
+void LayerItem::setColor(const QColor& color)
+{
+    setItemValue(P_COLOR, color);
+}
+
 void LayerItem::updateAppearance(SessionItem* new_parent)
 {
     if (!new_parent) {

GUI/Models/LayerItem.h

@@ -31,6 +31,7 @@ private:
     static constexpr auto P_ROUGHNESS{"Top roughness"};
     static constexpr auto P_NSLICES{"Number of slices"};
     static constexpr auto T_LAYOUTS{"Layout tag"};
+    static constexpr auto P_COLOR{"Color"};
 
 public:
     static constexpr auto M_TYPE{"Layer"};
@@ -53,6 +54,9 @@ public:
     QVector<ParticleLayoutItem*> layouts() const;
     void removeLayout(ParticleLayoutItem* layout);
 
+    QColor color() const;
+    void setColor(const QColor& color);
+
 private:
     void updateAppearance(SessionItem* new_parent);