Traces, curved traces, ground fills, solder pads and PCB text call their layer 'Board Side', like every other part, and count as Board Side components in code; the saved field is still 'layer'

diylc/diylc-core/src/main/java/org/diylc/core/IBoardSideComponent.java

@@ -24,11 +24,11 @@ package org.diylc.core;
 import org.diylc.common.PCBLayer;
 
 /**
- * Interface for components mounted on one side of a board, such as a resistor or an IC. The side
+ * Interface for components on one side of a board, such as a resistor, an IC or a trace. The side
  * says where the part sits physically; it is separate from {@link ILayeredComponent}, which drives
  * continuity, because the leads of a through-hole part connect to copper on both sides whichever
- * side the part is mounted on. Components whose copper already has a layer (traces, pads, ground
- * fills) do not implement it.
+ * side the part is mounted on. Copper implements it through {@link IPCBLayerComponent}, whose layer
+ * is its side and also drives its continuity.
  * 
  * @author Branislav Stojkovic
  */

diylc/diylc-core/src/main/java/org/diylc/core/IPCBLayerComponent.java

@@ -25,14 +25,27 @@ import org.diylc.common.PCBLayer;
 
 /**
  * Interface for copper drawn on a layer of a PCB, such as a trace, pad, ground fill or PCB text.
- * Unlike {@link IBoardSideComponent}, the layer is where the copper itself is, and it also decides
- * which other copper it connects to.
+ * The layer is the copper's board side, shown to the user as 'Board Side', but unlike the side of a
+ * mounted part it also decides which other copper the copper connects to.
  * 
  * @author Branislav Stojkovic
  */
-public interface IPCBLayerComponent {
+public interface IPCBLayerComponent extends IBoardSideComponent {
 
   PCBLayer getLayer();
 
   void setLayer(PCBLayer layer);
+
+  /**
+   * @return the layer, with the deprecated inner layers counted as the bottom
+   */
+  @Override
+  default PCBLayer getBoardSide() {
+    return getLayer() == PCBLayer._2 ? PCBLayer._2 : PCBLayer._1;
+  }
+
+  @Override
+  default void setBoardSide(PCBLayer boardSide) {
+    setLayer(boardSide);
+  }
 }

diylc/diylc-core/src/main/java/org/diylc/presenter/MirrorPlacement.java

@@ -26,12 +26,11 @@ import java.util.Collection;
 import org.diylc.common.PCBLayer;
 import org.diylc.core.IBoardSideComponent;
 import org.diylc.core.IDIYComponent;
-import org.diylc.core.IPCBLayerComponent;
 
 /**
- * Puts components placed through an Underside Display mirror on the bottom of the board. A part
- * that is mounted on a side goes to the bottom, copper with a {@link PCBLayer} goes to the bottom
- * layer, and anything else is left as it is. Nothing is mirrored.
+ * Puts components placed through an Underside Display mirror on the bottom of the board. Parts and
+ * copper that have a board side go to the bottom, and anything else is left as it is. Nothing is
+ * mirrored.
  */
 public class MirrorPlacement {
 
@@ -42,8 +41,6 @@ public class MirrorPlacement {
     for (IDIYComponent<?> component : components) {
       if (component instanceof IBoardSideComponent sided) {
         sided.setBoardSide(PCBLayer._1);
-      } else if (component instanceof IPCBLayerComponent copper) {
-        copper.setLayer(PCBLayer._1);
       }
     }
   }

diylc/diylc-core/src/main/resources/update.xml

@@ -657,6 +657,10 @@
 					<changeType>IMPROVEMENT</changeType>
 					<description>Inner layers 1 to 6 are no longer offered for traces, pads and other copper, since boards are two-sided; projects that use them still open unchanged</description>
 				</org.diylc.appframework.update.Change>
+				<org.diylc.appframework.update.Change>
+					<changeType>IMPROVEMENT</changeType>
+					<description>The 'Layer' property of traces, curved traces, ground fills, solder pads and PCB text is now called 'Board Side', the same as on resistors, ICs and other parts</description>
+				</org.diylc.appframework.update.Change>
 				<org.diylc.appframework.update.Change>
 					<changeType>BUG_FIX</changeType>
 					<description>Rotated labels in pasted components and building blocks were drawn in the wrong place and at the wrong angle while following the mouse, until the components were placed</description>