add OperationTimer

Author: samuelgruetter

rxjava-core/src/main/java/rx/operators/OperationTimer.java

@@ -0,0 +1,74 @@
+/**
+ * Copyright 2013 Netflix, Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package rx.operators;
+
+import java.util.concurrent.TimeUnit;
+
+import rx.Observable.OnSubscribeFunc;
+import rx.Observer;
+import rx.Scheduler;
+import rx.Subscription;
+import rx.concurrency.Schedulers;
+import rx.subscriptions.Subscriptions;
+import rx.util.functions.Action0;
+
+public final class OperationTimer {
+
+	public static OnSubscribeFunc<Void> timer(long interval, TimeUnit unit) {
+        return timer(interval, unit, Schedulers.threadPoolForComputation());
+    }
+
+    public static OnSubscribeFunc<Void> timer(final long delay, final TimeUnit unit, final Scheduler scheduler) {
+        return new OnSubscribeFunc<Void>() {
+            @Override
+            public Subscription onSubscribe(Observer<? super Void> observer) {
+                return new Timer(delay, unit, scheduler, observer).start();
+            }
+        };
+    }
+	
+	private static class Timer {
+        private final long period;
+        private final TimeUnit unit;
+        private final Scheduler scheduler;
+        private final Observer<? super Void> observer;
+        
+        private Timer(long period, TimeUnit unit, Scheduler scheduler, Observer<? super Void> observer) {
+            this.period = period;
+            this.unit = unit;
+            this.scheduler = scheduler;
+            this.observer = observer;
+        }
+
+        public Subscription start() {
+            final Subscription s = scheduler.schedule(new Action0() {
+                @Override
+                public void call() {
+                    observer.onNext(null);
+                    observer.onCompleted();
+                }
+            }, period, unit);
+
+            return Subscriptions.create(new Action0() {
+                @Override
+                public void call() {
+                    s.unsubscribe();
+                }
+            });
+        }
+    }
+
+}