Make the preset combo box display empty when the preset is lost due to changes in parameters.

core/src/net/sf/openrocket/gui/adaptors/BodyTubePresetModel.java

@@ -4,16 +4,12 @@ import java.util.List;
 
 import javax.swing.AbstractListModel;
 import javax.swing.ComboBoxModel;
-import javax.swing.event.ListDataListener;
 
 import net.sf.openrocket.preset.ComponentPreset;
-import net.sf.openrocket.rocketcomponent.ComponentChangeEvent;
-import net.sf.openrocket.rocketcomponent.ComponentChangeListener;
 import net.sf.openrocket.rocketcomponent.RocketComponent;
 import net.sf.openrocket.startup.Application;
 
-public class BodyTubePresetModel extends AbstractListModel implements
+public class BodyTubePresetModel extends AbstractListModel implements ComboBoxModel {
-		ComboBoxModel, ComponentChangeListener {
 
 	private final RocketComponent component;
 
@@ -25,13 +21,18 @@ public class BodyTubePresetModel extends AbstractListModel implements
 	}
 	
 	public static class BodyTubePresetAdapter {
+		// If the ComponentPreset bt is null, then no preset is selected.
 		private ComponentPreset bt;
 		private BodyTubePresetAdapter( ComponentPreset bt ) {
 			this.bt = bt;
 		}
 		@Override
 		public String toString() {
+			if ( bt != null ) {
 				return bt.getManufacturer() + " " + bt.getPartNo();
+			} else {
+				return "";
+			}
 		}
 		@Override
 		public int hashCode() {
@@ -65,32 +66,21 @@ public class BodyTubePresetModel extends AbstractListModel implements
 
 	@Override
 	public Object getElementAt(int index) {
+		if ( index < 0 ) {
+			return null;
+		}
 		return new BodyTubePresetAdapter(presets.get(index));
 	}
 
-	@Override
-	public void addListDataListener(ListDataListener l) {
-		// TODO Auto-generated method stub
-
-	}
-
-	@Override
-	public void removeListDataListener(ListDataListener l) {
-		// TODO Auto-generated method stub
-
-	}
-
-	@Override
-	public void componentChanged(ComponentChangeEvent e) {
-		// TODO Auto-generated method stub
-
-	}
-
 	@Override
 	public void setSelectedItem(Object anItem) {
 		BodyTubePresetAdapter selected = (BodyTubePresetAdapter) anItem;
+		if ( selected == null ) {
+			component.loadPreset(null);
+		} else {
 			component.loadPreset(selected.bt);
 		}
+	}
 
 	@Override
 	public Object getSelectedItem() {

core/src/net/sf/openrocket/gui/configdialog/BodyTubeConfig.java

@@ -28,6 +28,8 @@ public class BodyTubeConfig extends RocketComponentConfig {
 
 	private ComponentChangeListener listener;
 	private MotorConfig motorConfigPane = null;
+	private DoubleModel maxLength;
+	private JComboBox presetComboBox;
 	private static final Translator trans = Application.getTranslator();
 
 	public BodyTubeConfig(OpenRocketDocument d, RocketComponent c) {
@@ -37,15 +39,13 @@ public class BodyTubeConfig extends RocketComponentConfig {
 
 		////  Body tube template
 		panel.add( new JLabel(trans.get("BodyTubecfg.lbl.Bodytubepreset")) );
-		{
+		presetComboBox = new JComboBox(new BodyTubePresetModel(component));
-		JComboBox combo = new JComboBox(new BodyTubePresetModel(component));
+		panel.add(presetComboBox, "wrap");
-		panel.add(combo, "wrap");
-		}
 
 		////  Body tube length
 		panel.add(new JLabel(trans.get("BodyTubecfg.lbl.Bodytubelength")));
 
-		final DoubleModel maxLength = new DoubleModel(2.0);
+		maxLength = new DoubleModel(2.0);
 		DoubleModel length = new DoubleModel(component, "Length", UnitGroup.UNITS_LENGTH, 0);
 
 		JSpinner spin = new JSpinner(length.getSpinnerModel());
@@ -122,22 +122,13 @@ public class BodyTubeConfig extends RocketComponentConfig {
 		tabbedPane.setSelectedIndex(0);
 
 		// need to work in the max length for body tubes based on presets...
-		BodyTube bt = (BodyTube) component;
+		adjustPresetState();
-		if ( bt.getPresetComponent() != null ) {
-			BodyTube btPreset = (BodyTube) bt.getPresetComponent().getPrototype();
-			maxLength.setValue( btPreset.getLength() );
-		}
 
 		listener = new ComponentChangeListener() {
 
 			@Override
 			public void componentChanged(ComponentChangeEvent e) {
-				BodyTube bt = (BodyTube) component;
+				adjustPresetState();
-				if ( bt.getPresetComponent() != null ) {
-					BodyTube btPreset = (BodyTube) bt.getPresetComponent().getPrototype();
-					maxLength.setValue(btPreset.getLength());
-				}
-				
 			}
 
 		};
@@ -158,4 +149,18 @@ public class BodyTubeConfig extends RocketComponentConfig {
 		component.removeChangeListener(listener);
 	}
 
+	private void adjustPresetState() {
+		BodyTube bt = (BodyTube) component;
+		if ( bt.getPresetComponent() != null ) {
+			BodyTube btPreset = (BodyTube) bt.getPresetComponent().getPrototype();
+			maxLength.setValue( btPreset.getLength() );
+		} else {
+			// here we should be able to force the preset combo box to display empty.
+			// We set the selected index to -1 (undefined), then force a repaint.
+			presetComboBox.setSelectedIndex(-1);
+			presetComboBox.repaint();
+			maxLength.setValue(2.0);
+		}
+	}
+
 }