plugins/net.mograsim.plugin.core/src/net/mograsim/plugin/MachineContext.java

   1 package net.mograsim.plugin;
   2
   3 import java.util.HashSet;
   4 import java.util.Optional;
   5 import java.util.Set;
   6
   7 import net.mograsim.machine.Machine;
   8 import net.mograsim.machine.MachineRegistry;
   9
  10 public class MachineContext
  11 {
  12         private Machine machine;
  13         private Set<ContextObserver> observers;
  14         private static MachineContext instance;
  15
  16         private MachineContext()
  17         {
  18                 observers = new HashSet<>();
  19         }
  20
  21         public static MachineContext getInstance()
  22         {
  23                 if (instance == null)
  24                 {
  25                         instance = new MachineContext();
  26                         // TODO don't hardcode the Am2900
  27                         instance.setMachine(MachineRegistry.getinstalledMachines().get("Am2900").createNew());
  28                 }
  29                 return instance;
  30         }
  31
  32         public Machine getMachine()
  33         {
  34                 return machine;
  35         }
  36
  37         public void setMachine(Machine machine)
  38         {
  39                 this.machine = machine;
  40                 notifyObservers(machine);
  41         }
  42
  43         public void registerObserver(ContextObserver ob)
  44         {
  45                 observers.add(ob);
  46                 ob.setMachine(Optional.ofNullable(machine));
  47         }
  48
  49         public void deregisterObserver(ContextObserver ob)
  50         {
  51                 observers.remove(ob);
  52         }
  53
  54         private void notifyObservers(Machine machine)
  55         {
  56                 observers.forEach(ob -> ob.setMachine(Optional.ofNullable(machine)));
  57         }
  58
  59         @FunctionalInterface
  60         public static interface ContextObserver
  61         {
  62                 void setMachine(Optional<Machine> machine);
  63         }
  64 }