Consolidate and lean up lazy bindings

Author: thomasnield

src/main/java/rx/subscribers/BindingSubscriber.java

@@ -22,20 +22,37 @@
 import javafx.beans.value.ChangeListener;
 import javafx.beans.value.ObservableValue;
 import javafx.collections.ObservableList;
+import rx.Observable;
 import rx.Subscriber;
 import rx.Subscription;
 import rx.functions.Action1;
 
 
 final class BindingSubscriber<T> extends Subscriber<T> implements ObservableValue<T>, Binding<T>, Subscription {
 
+    private final Observable<T> observable;
     private final Action1<Throwable> onError;
+    private Subscription subscription;
     private ExpressionHelper<T> helper;
     private T value;
 
-    BindingSubscriber(final Action1<Throwable> onError) {
+    private BindingSubscriber(Observable<T> observable, Action1<Throwable> onError) {
+        this.observable = observable;
         this.onError = onError;
     }
+
+    public static <T> BindingSubscriber<T> forObservable(Observable<T> observable, Action1<Throwable> onError, boolean isLazy) {
+        BindingSubscriber<T> bindingSubscriber = new BindingSubscriber<>(observable, onError);
+
+        if (!isLazy) {
+            bindingSubscriber.connect();
+        }
+
+        return bindingSubscriber;
+    }
+    private void connect() {
+        subscription = observable.subscribe(this);
+    }
     @Override
     public void onCompleted() {
         //do nothing
@@ -53,6 +70,9 @@ public void onNext(T t) {
     }
     @Override
     public T getValue() {
+        if (subscription == null) {
+            connect();
+        }
         return value;
     }
     @Override

src/main/java/rx/subscribers/JavaFxSubscriber.java

@@ -26,17 +26,13 @@ public enum JavaFxSubscriber {
      * Turns an Observable into an eager JavaFX Binding that subscribes immediately to the Observable. Calling the Binding's dispose() method will handle the unsubscription.
      */
     public static <T> Binding<T> toBinding(Observable<T> obs) {
-        BindingSubscriber<T> bindingSubscriber = new BindingSubscriber<>(e -> {});
-        obs.subscribe(bindingSubscriber);
-        return bindingSubscriber;
+        return BindingSubscriber.forObservable(obs, e -> {}, false);
     }
     /**
      * Turns an Observable into an eager JavaFX Binding that subscribes immediately to the Observable. Calling the Binding's dispose() method will handle the unsubscription.
      */
     public static <T> Binding<T> toBinding(Observable<T> obs, Action1<Throwable> onErrorAction ) {
-        BindingSubscriber<T> bindingSubscriber = new BindingSubscriber<>(onErrorAction);
-        obs.subscribe(bindingSubscriber);
-        return bindingSubscriber;
+        return BindingSubscriber.forObservable(obs, onErrorAction, false);
     }
 
     /**
@@ -50,7 +46,6 @@ public static <T> Binding<T> toLazyBinding(Observable<T> obs) {
      * Turns an Observable into a lazy JavaFX Binding that subscribes to the Observable the first time the Binding's getValue() method is called. Calling the Binding's dispose() method will handle the unsubscription.
      */
     public static <T> Binding<T> toLazyBinding(Observable<T> obs, Action1<Throwable> onErrorAction ) {
-        BindingSubscriber<T> bindingSubscriber = new BindingSubscriber<>(onErrorAction);
-        return new LazyBindingSubscriber<>(obs, bindingSubscriber);
+        return BindingSubscriber.forObservable(obs, onErrorAction, true);
     }
 }