Support RockSim booster importing

core/src/net/sf/openrocket/file/rocksim/importt/PodHandler.java

@@ -6,30 +6,43 @@ import net.sf.openrocket.file.rocksim.RockSimCommonConstants;
 import net.sf.openrocket.file.simplesax.ElementHandler;
 import net.sf.openrocket.file.simplesax.PlainTextHandler;
 import net.sf.openrocket.material.Material;
+import net.sf.openrocket.rocketcomponent.ComponentAssembly;
+import net.sf.openrocket.rocketcomponent.ParallelStage;
 import net.sf.openrocket.rocketcomponent.PodSet;
 import net.sf.openrocket.rocketcomponent.RocketComponent;
+import net.sf.openrocket.rocketcomponent.position.AnglePositionable;
 import net.sf.openrocket.rocketcomponent.position.RadiusMethod;
 import org.xml.sax.SAXException;
 
 import java.util.HashMap;
 
-public class PodHandler extends PositionDependentHandler<PodSet> {
+public class PodHandler extends PositionDependentHandler<ComponentAssembly> {
     /**
      * The OpenRocket BodyTube.
      */
+    private final RocketComponent parent;
     private final PodSet podSet;
+    private final ParallelStage parallelStage;      // A RockSim podset can be an OpenRocket PodSet, or a ParallelStage if it is detachable
+    private boolean isDetachable = false;
+    private boolean isEjected = false;
 
     public PodHandler(DocumentLoadingContext context, RocketComponent c, WarningSet warnings) {
         super(context);
         if (c == null) {
             throw new IllegalArgumentException("The parent component of a pod set may not be null.");
         }
+        this.parent = c;
         podSet = new PodSet();
+        parallelStage = new ParallelStage();
+        podSet.addConfigListener(parallelStage);        // The booster will now follow the same config changes as the podset
         podSet.setInstanceCount(1);     // RockSim only supports one pod instance
         podSet.setRadiusMethod(RadiusMethod.FREE);   // RockSim radial offset is relative to the center of the parent
         if (isCompatible(c, PodSet.class, warnings)) {
             c.addChild(podSet);
         }
+        if (isCompatible(c, ParallelStage.class, warnings)) {
+            c.addChild(parallelStage);
+        }
     }
 
     @Override
@@ -52,10 +65,71 @@ public class PodHandler extends PositionDependentHandler<PodSet> {
         if (RockSimCommonConstants.RADIAL_LOC.equals(element)) {
             podSet.setRadiusOffset(Double.parseDouble(content) / RockSimCommonConstants.ROCKSIM_TO_OPENROCKET_LENGTH);
         }
+        if (RockSimCommonConstants.DETACHABLE.equals(element)) {
+            int value = Integer.parseInt(content);
+            isDetachable = value == 1;
+        }
+        if (RockSimCommonConstants.REMOVED.equals(element)) {
+            int value = Integer.parseInt(content);
+            isEjected = value == 1;
+        }
     }
 
     @Override
-    protected PodSet getComponent() {
+    public void endHandler(String element, HashMap<String, String> attributes, String content, WarningSet warnings) throws SAXException {
+        super.endHandler(element, attributes, content, warnings);
+
+        // Since RockSim stores the angle offset of pod children in absolute coordinates (not relative to the parent pod set),
+        // we need to subtract the parent pod set angle offset from this component's offset
+        subtractAngleOffset(podSet, podSet.getAngleOffset());
+
+        if (isDetachable || isEjected) {
+            // The offsets of the parallel stage can change due to the children, so copy them from the podset and then apply
+            // it later
+            double axialOffset = podSet.getAxialOffset();
+            double radiusOffset = podSet.getRadiusOffset();
+
+            // Copy the children from the pod to the booster
+            int childCount = podSet.getChildCount();
+            for (int i = 0; i < childCount; i++) {
+                RocketComponent child = podSet.getChild(0);
+                podSet.removeChild(child);
+                if (parallelStage.isCompatible(child)) {
+                    parallelStage.addChild(child);
+                } else {
+                    warnings.add("The child component " + child.getName() + " of the podset " + podSet.getName() + " is not compatible with a parallel stage.");
+                }
+            }
+
+            // Apply the offsets
+            parallelStage.setAxialOffset(axialOffset);
+            parallelStage.setRadiusOffset(radiusOffset);
+
+            // Remove the podset from the parent
+            parent.removeChild(podSet);
+
+            if (isEjected) {
+                parent.getRocket().getSelectedConfiguration()._setStageActive(parallelStage.getStageNumber(), false);
+            }
+        } else {
+            // It's a normal podset, so remove the booster placeholder
+            parent.removeChild(parallelStage);
+        }
+    }
+
+    private void subtractAngleOffset(RocketComponent c, double angleOffset) {
+        for (RocketComponent child : c.getChildren()) {
+            if (child instanceof AnglePositionable anglePositionable) {
+                anglePositionable.setAngleOffset(anglePositionable.getAngleOffset() - angleOffset);
+            }
+            if (!(child instanceof ComponentAssembly)) {
+                subtractAngleOffset(child, angleOffset);
+            }
+        }
+    }
+
+    @Override
+    protected ComponentAssembly getComponent() {
         return podSet;
     }
 

core/src/net/sf/openrocket/rocketcomponent/RocketComponent.java

@@ -2059,7 +2059,7 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 	
 	
 	/**
-	 * Move a child to another position.
+	 * Move a child to another position within this component.
 	 *
 	 * @param component	the component to move
 	 * @param index	the component's new position