add OperationDelay

Author: samuelgruetter

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

@@ -0,0 +1,42 @@
+/**
+ * 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;
+import rx.Scheduler;
+import rx.observables.ConnectableObservable;
+import rx.util.functions.Func1;
+
+public final class OperationDelay {
+
+    public static <T> Observable<T> delay(Observable<T> observable, final long delay, final TimeUnit unit, final Scheduler scheduler) {
+        // observable.map(x => Observable.timer(t).map(_ => x).startItAlreadyNow()).concat()
+        Observable<Observable<T>> seqs = observable.map(new Func1<T, Observable<T>>() {
+            public Observable<T> call(final T x) {
+                ConnectableObservable<T> co = Observable.timer(delay, unit, scheduler).map(new Func1<Void, T>() {
+                    public T call(Void ignored) {
+                        return x;
+                    }
+                }).replay();
+                co.connect();
+                return co;
+            }
+        });
+        return Observable.concat(seqs);
+    }
+}