git.gag.com Git - sw/motorsim/blob - src/com/billkuker/rocketry/motorsim/ChangeListening.aj

   1 package com.billkuker.rocketry.motorsim;
   2
   3 import java.beans.PropertyChangeEvent;
   4 import java.beans.PropertyChangeListener;
   5 import java.beans.PropertyChangeSupport;
   6 import java.lang.reflect.Method;
   7
   8 import org.apache.log4j.Logger;
   9
  10 public aspect ChangeListening {
  11
  12         private static Logger log = Logger.getLogger(ChangeListening.class);
  13         public interface Subject {
  14                 // public void addPropertyChangeListener(PropertyChangeListener l);
  15         }
  16
  17         private PropertyChangeSupport Subject.pcs;
  18
  19         public void Subject.addPropertyChangeListener(PropertyChangeListener l) {
  20                 pcs.addPropertyChangeListener(l);
  21         }
  22
  23         public void Subject.removePropertyChangeListener(PropertyChangeListener l) {
  24                 pcs.removePropertyChangeListener(l);
  25         }
  26
  27         public void Subject.firePropertyChange(PropertyChangeEvent e) {
  28                 pcs.firePropertyChange(e);
  29         }
  30
  31         declare parents: Motor || Grain || Chamber || Nozzle || Fuel implements Subject;
  32
  33         void around(Subject s, Object newVal):
  34                 execution(void Subject+.set*(..)) && target(s) && args(newVal) {
  35                 String name = thisJoinPointStaticPart.getSignature().getName();
  36                 name = name.replaceFirst("set", "");
  37                 Object old = null;
  38                 try {
  39                         String pre = "get";
  40                         if (newVal instanceof Boolean)
  41                                 pre = "is";
  42                         Method m = s.getClass().getMethod(pre + name);
  43                         old = m.invoke(s);
  44
  45                 } catch (Throwable t) {
  46                         log.warn("Error getting old value for " + name);
  47                 }
  48                 proceed(s, newVal);
  49                 if (old != newVal) {
  50                         s.pcs.firePropertyChange(name, old, newVal);
  51                 }
  52         }
  53
  54         after(Subject s) returning: this(s) && initialization(Subject.new(..)) {
  55                 s.pcs = new PropertyChangeSupport(s);
  56         }
  57 }