Weakened references to static listener types for unit pref change and fuel change.
[sw/motorsim] / src / com / billkuker / rocketry / motorsim / RocketScience.java
1 package com.billkuker.rocketry.motorsim;\r
2 \r
3 import java.lang.ref.WeakReference;\r
4 import java.lang.reflect.Field;\r
5 import java.lang.reflect.Modifier;\r
6 import java.text.DecimalFormat;\r
7 import java.text.NumberFormat;\r
8 import java.util.HashSet;\r
9 import java.util.Iterator;\r
10 import java.util.Set;\r
11 import java.util.prefs.Preferences;\r
12 \r
13 import javax.measure.quantity.Pressure;\r
14 import javax.measure.quantity.Quantity;\r
15 import javax.measure.unit.NonSI;\r
16 import javax.measure.unit.ProductUnit;\r
17 import javax.measure.unit.SI;\r
18 import javax.measure.unit.Unit;\r
19 import javax.measure.unit.UnitFormat;\r
20 \r
21 import org.apache.log4j.Logger;\r
22 import org.jscience.physics.amount.Amount;\r
23 \r
24 public class RocketScience {\r
25         private static final Logger log = Logger.getLogger(RocketScience.class);\r
26         \r
27         public static Unit<Pressure> PSI = new ProductUnit<Pressure>(NonSI.POUND_FORCE.divide(NonSI.INCH.pow(2)));\r
28         public static Unit<Impulse> NEWTON_SECOND = new ProductUnit<Impulse>(SI.NEWTON.times(SI.SECOND));\r
29         public static Unit<Impulse> POUND_SECOND = new ProductUnit<Impulse>(NonSI.POUND_FORCE.times(SI.SECOND));\r
30         static{\r
31                 UnitFormat.getInstance().label(PSI, "psi");\r
32                 UnitFormat.getInstance().label(NEWTON_SECOND, "Ns");\r
33         }\r
34 \r
35         public interface MolarWeight extends Quantity {\r
36                 public static final Unit<MolarWeight> UNIT = new ProductUnit<MolarWeight>(\r
37                                 SI.KILOGRAM.divide(SI.MOLE));\r
38         }\r
39         \r
40         public interface Impulse extends Quantity {\r
41                 public static Unit<Impulse> UNIT = NEWTON_SECOND;\r
42         }\r
43         \r
44         private static HashSet<WeakReference<UnitPreferenceListener>> prefListeners = new HashSet<WeakReference<UnitPreferenceListener>>();\r
45         public static interface UnitPreferenceListener{\r
46                 public void preferredUnitsChanged();\r
47         }\r
48         public static void addUnitPreferenceListener(UnitPreferenceListener l){\r
49                 prefListeners.add(new WeakReference<RocketScience.UnitPreferenceListener>(l));\r
50         }\r
51 \r
52         public static enum UnitPreference{\r
53                 SI(new Unit[]{\r
54                                 javax.measure.unit.SI.MILLIMETER.pow(2),\r
55                                 javax.measure.unit.SI.MILLIMETER,\r
56                                 javax.measure.unit.SI.MILLIMETER.divide(javax.measure.unit.SI.SECOND),\r
57                                 javax.measure.unit.SI.NEWTON,\r
58                                 javax.measure.unit.SI.GRAM,\r
59                                 javax.measure.unit.SI.MEGA(javax.measure.unit.SI.PASCAL),\r
60                                 NEWTON_SECOND\r
61                 }),\r
62                 NONSI(new Unit[]{\r
63                                 javax.measure.unit.NonSI.INCH.pow(2),\r
64                                 javax.measure.unit.NonSI.INCH,\r
65                                 javax.measure.unit.NonSI.POUND_FORCE,\r
66                                 javax.measure.unit.NonSI.OUNCE,\r
67                                 javax.measure.unit.NonSI.INCH.divide(javax.measure.unit.SI.SECOND),\r
68                                 PSI,\r
69                                 POUND_SECOND\r
70                 });\r
71                 \r
72                 private static UnitPreference preference = SI;\r
73 \r
74                 static {\r
75                         Preferences prefs = Preferences.userNodeForPackage(RocketScience.class);\r
76                         String p = prefs.get("PreferedUnits", "SI");\r
77                         preference = UnitPreference.valueOf(p);\r
78                 }\r
79                 \r
80                 public static UnitPreference getUnitPreference(){\r
81                         return preference;\r
82                 }\r
83                 \r
84                 public static void setUnitPreference( final UnitPreference up ){\r
85                         if ( preference == up )\r
86                                 return;\r
87                         preference = up;\r
88                         Preferences prefs = Preferences.userNodeForPackage(RocketScience.class);\r
89                         prefs.put("PreferedUnits", up.toString());\r
90                         Iterator<WeakReference<UnitPreferenceListener>> weakIter = prefListeners.iterator();\r
91                         while (weakIter.hasNext()) {\r
92                                 WeakReference<UnitPreferenceListener> weak = weakIter.next();\r
93                                 UnitPreferenceListener l = weak.get();\r
94                                 if (l != null) {\r
95                                         l.preferredUnitsChanged();\r
96                                 } else {\r
97                                         log.debug("Weak reference to UPE is null");\r
98                                         weakIter.remove();\r
99                                 }\r
100                         }\r
101                 }\r
102                 \r
103                 protected Set<Unit<?>> units = new HashSet<Unit<?>>();\r
104                 \r
105                 UnitPreference( Unit<?> u[] ){\r
106                         for ( Unit<?> uu : u )\r
107                                 units.add(uu);\r
108                 }\r
109                 \r
110                 @SuppressWarnings("unchecked")\r
111                 public <T extends Quantity> Unit<T> getPreferredUnit(Unit<T> u){\r
112                         if ( units.contains(u) )\r
113                                 return u;\r
114                         for( Unit<?> ret : units ){\r
115                                 if ( ret.isCompatible(u) ){\r
116                                         return (Unit<T>) ret;\r
117                                 }\r
118                         }\r
119                         return u;\r
120                 }\r
121                 \r
122                 @SuppressWarnings("unchecked")\r
123                 public <T extends Quantity> Unit<T> getPreferredUnit(Class<T> q){\r
124                         for( Unit<?> u : units ){\r
125                                 try {\r
126                                         return u.asType(q); \r
127                                 } catch ( ClassCastException e ) {\r
128                                         //Not compatible\r
129                                 }\r
130                         }\r
131                         try {\r
132                                 Field f = q.getDeclaredField("UNIT");\r
133                                 if ( Modifier.isStatic(f.getModifiers()) ){\r
134                                         if ( Unit.class.isAssignableFrom(f.getType())){\r
135                                                 return (Unit<T>)f.get(null);\r
136                                         }\r
137                                 }\r
138                         } catch (SecurityException e) {\r
139                                 e.printStackTrace();\r
140                         } catch (NoSuchFieldException e) {\r
141                                 e.printStackTrace();\r
142                         } catch (IllegalArgumentException e) {\r
143                                 // TODO Auto-generated catch block\r
144                                 e.printStackTrace();\r
145                         } catch (IllegalAccessException e) {\r
146                                 // TODO Auto-generated catch block\r
147                                 e.printStackTrace();\r
148                         }\r
149                         return null;\r
150                 }\r
151         }\r
152 \r
153         public static <T extends Quantity> String ammountToString(Amount<T> a) {\r
154                 if ( a == null )\r
155                         return "Null";\r
156                 final NumberFormat nf = new DecimalFormat("##########.###");\r
157                 return nf.format(a.doubleValue(a.getUnit())) + " " + a.getUnit();\r
158         }\r
159         \r
160         public static <T extends Quantity> String ammountToRoundedString(Amount<T> a) {\r
161                 if (a == null)\r
162                         return "Null";\r
163                 Unit<T> u = RocketScience.UnitPreference.preference.getPreferredUnit(a\r
164                                 .getUnit());\r
165                 double d = a.doubleValue(u);\r
166 \r
167                 DecimalFormat df;\r
168 \r
169                 if (Math.abs(d) < 10.0) {\r
170                         df = new DecimalFormat("#.##");\r
171                 } else if (Math.abs(d) < 100.0) {\r
172                         df = new DecimalFormat("#.#");\r
173                 } else {\r
174                         df = new DecimalFormat("#");\r
175                 }\r
176 \r
177                 return df.format(d) + " " + u.toString();\r
178         }\r
179 \r
180 }\r