Add listen methods to Locker to simplify event listening code

src/dev/peerat/framework/Locker.java

@@ -5,6 +5,10 @@ import java.util.Map;
 import java.util.Map.Entry;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.LinkedBlockingQueue;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
+
+import dev.peerat.framework.Locker.Key;
 
 public class Locker<V>{
 	
@@ -55,5 +59,51 @@ public class Locker<V>{
 		}
 	}
 	
+	public void listen(Consumer<V> action){
+		Key key = new Key();
+		init(key);
+		try {
+			while(true){
+				lock(key);
+				V value = getValue(key);
+				action.accept(value);
+			}
+		}catch(Exception e){}
+		remove(key);
+	}
+	
+	public void listen(Supplier<Boolean> condition,Consumer<V> action){
+		Key key = new Key();
+		init(key);
+		try {
+			while(condition.get()){
+				lock(key);
+				V value = getValue(key);
+				action.accept(value);
+			}
+		}catch(Exception e){}
+		remove(key);
+	}
+	
+	public Thread listenAsync(Consumer<V> action){
+		Thread thread = new Thread(new Runnable(){
+			public void run(){
+				listen(action);
+			}
+		});
+		thread.start();
+		return thread;
+	}
+	
+	public Thread listenAsync(Supplier<Boolean> condition,Consumer<V> action){
+		Thread thread = new Thread(new Runnable(){
+			public void run(){
+				listen(condition, action);
+			}
+		});
+		thread.start();
+		return thread;
+	}
+	
 	public static class Key{ public Key(){} }
 }