[#2079] Display percentage length unit in stability info

core/src/net/sf/openrocket/unit/UnitGroup.java

@@ -456,7 +456,7 @@ public class UnitGroup {
 	 * @param rocket	the rocket from which to calculate the caliber
 	 * @return			the unit group
 	 */
-	public static UnitGroup stabilityUnits(Rocket rocket) {
+	public static StabilityUnitGroup stabilityUnits(Rocket rocket) {
 		return new StabilityUnitGroup(rocket);
 	}
 	
@@ -467,7 +467,7 @@ public class UnitGroup {
 	 * @param config	the rocket configuration from which to calculate the caliber
 	 * @return			the unit group
 	 */
-	public static UnitGroup stabilityUnits(FlightConfiguration config) {
+	public static StabilityUnitGroup stabilityUnits(FlightConfiguration config) {
 		return new StabilityUnitGroup(config);
 	}
 	
@@ -717,7 +717,8 @@ public class UnitGroup {
 	 * A private class that switches the CaliberUnit to a rocket-specific CaliberUnit.
 	 * All other methods are passed through to UNITS_STABILITY.
 	 */
-	private static class StabilityUnitGroup extends UnitGroup {
+	public static class StabilityUnitGroup extends UnitGroup {
+		private final PercentageOfLengthUnit percentageOfLengthUnit;
 		
 		public StabilityUnitGroup(double ref) { this(new CaliberUnit(ref), new PercentageOfLengthUnit(ref)); }
 		
@@ -728,6 +729,7 @@ public class UnitGroup {
 		public StabilityUnitGroup(FlightConfiguration config) { this(new CaliberUnit(config), new PercentageOfLengthUnit(config)); }
 		
 		private StabilityUnitGroup(CaliberUnit caliberUnit, PercentageOfLengthUnit percentageOfLengthUnit) {
+			this.percentageOfLengthUnit = percentageOfLengthUnit;
 			this.units.addAll(UnitGroup.UNITS_STABILITY.units);
 			this.defaultUnit = UnitGroup.UNITS_STABILITY.defaultUnit;
 			for (int i = 0; i < units.size(); i++) {
@@ -746,5 +748,13 @@ public class UnitGroup {
 			super.setDefaultUnit(n);
 			UNITS_STABILITY.setDefaultUnit(n);
 		}
+
+		/**
+		 * Returns the percentage of length unit. (Stability in %)
+		 * @return the percentage of length unit.
+		 */
+		public Unit getPercentageOfLengthUnit() {
+			return this.percentageOfLengthUnit;
+		}
 	}
 }

swing/src/net/sf/openrocket/gui/figureelements/RocketInfo.java

@@ -41,7 +41,7 @@ public class RocketInfo implements FigureElement {
 	private final Caret cpCaret = new CPCaret(0,0);
 	private final Caret cgCaret = new CGCaret(0,0);
 	
-	private UnitGroup stabilityUnits;
+	private UnitGroup.StabilityUnitGroup stabilityUnits;
 	
 	private FlightConfiguration configuration;
 	private double cg = 0, cp = 0;
@@ -201,7 +201,7 @@ public class RocketInfo implements FigureElement {
 		
 		GlyphVector cgValue = createText(getCg());
 		GlyphVector cpValue = createText(getCp());
-		GlyphVector stabValue = createText(getStability());
+		GlyphVector stabValue = createText(getStabilityCombined());
 		
 		//// CG:		
 		GlyphVector cgText = createText(trans.get("RocketInfo.cgText"));
@@ -276,16 +276,47 @@ public class RocketInfo implements FigureElement {
     public String getMassWithMotors(Unit u) {
         return u.toStringUnit(massWithMotors);
     }
-    
+
+
     /**
-     * Get the stability, in calibers.
+     * Get the stability in both the selected stability unit and in percentage, e.g. "2.4 cal (14.1 %)".
+	 * If the current unit is already the percentage length unit, only use that.
      * 
-     * @return  the current stability margin
+     * @return the current stability margin in the currently selected stability unit and in percentage
      */
-    public String getStability () {
-        return stabilityUnits.getDefaultUnit().toStringUnit(cp-cg);
+    public String getStabilityCombined() {
+		Unit defaultUnit = stabilityUnits.getDefaultUnit();
+		String stability = getStability();
+
+		if (Double.isNaN(getStabilityValue()) || defaultUnit == stabilityUnits.getPercentageOfLengthUnit()) {
+			return stability;
+		}
+
+		String stabilityPercentage = getStabilityPercentage();
+
+		return stability + " (" + stabilityPercentage + ")";
     }
 
+	/**
+	 * Get the stability in the currently selected unit.
+	 * @return the current stability margin in the currently selected stability unit
+	 */
+	private String getStability() {
+		return stabilityUnits.getDefaultUnit().toStringUnit(getStabilityValue());
+	}
+
+	/**
+	 * Get the stability in the percentage length unit.
+	 * @return the current stability margin in the percentage length unit
+	 */
+	private String getStabilityPercentage() {
+		return stabilityUnits.getPercentageOfLengthUnit().toStringUnit(getStabilityValue());
+	}
+
+	private double getStabilityValue() {
+		return cp - cg;
+	}
+
     /**
      * Get the center of pressure in default length units.
      * 

swing/src/net/sf/openrocket/gui/print/DesignReport.java

@@ -256,7 +256,7 @@ public class DesignReport {
 		canvas.showText(text.getMassWithMotors(UnitGroup.UNITS_MASS.getDefaultUnit()));
 		
 		canvas.newlineShowText(STABILITY);
-		canvas.showText(text.getStability());
+		canvas.showText(text.getStabilityCombined());
 		
 		canvas.newlineShowText(CG);
 		canvas.showText(text.getCg());