Hovering over a control point in a board's Underside Display shows its node name tooltip, as it does on the board itself

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

@@ -1000,6 +1000,42 @@ public class Presenter implements IPlugInPort {
     return components;
   }
 
+  /**
+   * Lists the names of the sticky nodes under the specified point, for the hover tooltip. With a
+   * mirror board, the point is already reflected and only the parts shown in that board's
+   * Underside Display are considered.
+   */
+  private List<String> findNodeNamesAt(Point2D point, IBoard mirrorBoard) {
+    List<String> nodeInfos = new ArrayList<String>();
+    for (int i = currentProject.getComponents().size() - 1; i >= 0; i--) {
+      IDIYComponent<?> component = currentProject.getComponents().get(i);
+      if (mirrorBoard != null && !UndersideMirror.isMirrored(mirrorBoard, component)) {
+        continue;
+      }
+      for (int pointIndex = 0; pointIndex < component.getControlPointCount(); pointIndex++) {
+        try {
+          if (component.isControlPointSticky(pointIndex)) {
+            Point2D controlPoint = component.getControlPoint(pointIndex);
+            if (controlPoint != null
+                && point.distance(controlPoint) < DrawingManager.CONTROL_POINT_SIZE) {
+              String nodeName = component.getControlPointNodeName(pointIndex);
+              if (nodeName != null && !nodeName.trim().isEmpty()) {
+                String info = "<b>" + component.getName() + "</b>: " + nodeName;
+                if (!nodeInfos.contains(info)) {
+                  nodeInfos.add(info);
+                }
+              }
+            }
+          }
+        } catch (Exception e) {
+          LOG.warn("Error reading control point for component of type: "
+              + component.getClass().getName());
+        }
+      }
+    }
+    return nodeInfos;
+  }
+
   @Override
   public void mouseMoved(Point point, boolean ctrlDown, boolean shiftDown, boolean altDown) {
     if (point == null)
@@ -1085,27 +1121,14 @@ public class Presenter implements IPlugInPort {
     // Node name hover detection for sticky points
     String nodeHoverText = null;
     if (!dragInProgress && instantiationManager.getComponentTypeSlot() == null) {
-      List<String> nodeInfos = new ArrayList<String>();
-      for (int i = currentProject.getComponents().size() - 1; i >= 0; i--) {
-        IDIYComponent<?> component = currentProject.getComponents().get(i);
-        for (int pointIndex = 0; pointIndex < component.getControlPointCount(); pointIndex++) {
-          try {
-            if (component.isControlPointSticky(pointIndex)) {
-              Point2D controlPoint = component.getControlPoint(pointIndex);
-              if (controlPoint != null && previousScaledPoint.distance(controlPoint) < DrawingManager.CONTROL_POINT_SIZE) {
-                String nodeName = component.getControlPointNodeName(pointIndex);
-                if (nodeName != null && !nodeName.trim().isEmpty()) {
-                  String info = "<b>" + component.getName() + "</b>: " + nodeName;
-                  if (!nodeInfos.contains(info)) {
-                    nodeInfos.add(info);
-                  }
-                }
-              }
-            }
-          } catch (Exception e) {
-            LOG.warn("Error reading control point for component of type: " + component.getClass().getName());
-          }
+      List<String> nodeInfos = findNodeNamesAt(previousScaledPoint, null);
+      for (IBoard board :
+          UndersideMirror.findBoardsMirroredAt(currentProject, previousScaledPoint)) {
+        if (!nodeInfos.isEmpty()) {
+          break;
         }
+        nodeInfos =
+            findNodeNamesAt(UndersideMirror.reflect(board, previousScaledPoint), board);
       }
       if (!nodeInfos.isEmpty()) {
         nodeHoverText = String.join("; ", nodeInfos);

diylc/diylc-swing/src/test/java/org/diylc/PresenterTests.java

@@ -436,6 +436,37 @@ public class PresenterTests extends TestBase {
     Assert.assertEquals(jumperStart, jumper.getControlPoint(0));
   }
 
+  @Test
+  public void testNodeNameHoverThroughUndersideMirror() {
+    final String[] receivedTooltip = new String[1];
+    IPlugIn testPlugin = new IPlugIn() {
+      @Override
+      public void connect(IPlugInPort plugInPort) {}
+
+      @Override
+      public EnumSet<EventType> getSubscribedEventTypes() {
+        return EnumSet.of(EventType.NODE_NAME_HOVER_TOOLTIP);
+      }
+
+      @Override
+      public void processMessage(EventType eventType, Object... params) {
+        receivedTooltip[0] = params.length > 0 ? (String) params[0] : null;
+      }
+    };
+    presenter.installPlugin(() -> testPlugin);
+    InMemoryConfigurationManager.getInstance()
+        .writeValue(IPlugInPort.SHOW_NODE_NAME_TOOLTIPS_KEY, true);
+    instantiateTwoClick("Passive", "Resistor", new Point(1000, 1000), new Point(1200, 1000));
+    IDIYComponent<?> resistor = presenter.getCurrentProject().getComponents().get(0);
+    IBoard board = boardUnder(resistor);
+    Point inMirror = toScreen(
+        UndersideMirror.createTransform(board).transform(resistor.getControlPoint(1), null));
+
+    presenter.mouseMoved(inMirror, false, false, false);
+
+    Assert.assertEquals("<b>R1</b>: 2", receivedTooltip[0]);
+  }
+
   private IBoard boardUnder(IDIYComponent<?> component) {
     Point2D first = component.getControlPoint(0);
     Point2D last = component.getControlPoint(component.getControlPointCount() - 1);