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.logic.model.am2900.machine.Am2900Machine;
   8 import net.mograsim.logic.model.am2900.machine.Am2900MachineDefinition;
   9 import net.mograsim.machine.Machine;
  10 import net.mograsim.machine.MachineRegistry;
  11
  12 public class MachineContext
  13 {
  14         private Machine machine;
  15         private Set<ContextObserver> observers;
  16         private static MachineContext instance;
  17
  18         private MachineContext()
  19         {
  20                 observers = new HashSet<>();
  21         }
  22
  23         public static MachineContext getInstance()
  24         {
  25                 if (instance == null)
  26                 {
  27                         instance = new MachineContext();
  28                         instance.setMachine(new Am2900Machine((Am2900MachineDefinition) MachineRegistry.getinstalledMachines().get("Am2900")));
  29                 }
  30                 return instance;
  31         }
  32
  33         public Machine getMachine()
  34         {
  35                 return machine;
  36         }
  37
  38         public void setMachine(Machine machine)
  39         {
  40                 this.machine = machine;
  41                 notifyObservers(machine);
  42         }
  43
  44         public void registerObserver(ContextObserver ob)
  45         {
  46                 observers.add(ob);
  47                 ob.setMachine(Optional.ofNullable(machine));
  48         }
  49
  50         public void deregisterObserver(ContextObserver ob)
  51         {
  52                 observers.remove(ob);
  53         }
  54
  55         private void notifyObservers(Machine machine)
  56         {
  57                 observers.forEach(ob -> ob.setMachine(Optional.ofNullable(machine)));
  58         }
  59
  60         @FunctionalInterface
  61         public static interface ContextObserver
  62         {
  63                 void setMachine(Optional<Machine> machine);
  64         }
  65 }