Add HandlerThreadScheduler which schedules actions on an Android Handler thread

Author: mttkay

rxjava-contrib/rxjava-android/src/main/java/rx/concurrency/HandlerThreadScheduler.java

@@ -0,0 +1,54 @@
+package rx.concurrency;
+
+import android.os.Handler;
+import rx.Scheduler;
+import rx.Subscription;
+import rx.operators.AtomicObservableSubscription;
+import rx.util.functions.Func2;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Schedules actions to run on an Android Handler thread.
+ */
+public class HandlerThreadScheduler extends Scheduler {
+
+    private final Handler handler;
+
+    public HandlerThreadScheduler(Handler handler) {
+        this.handler = handler;
+    }
+
+    @Override
+    public <T> Subscription schedule(final T state, final Func2<Scheduler, T, Subscription> action) {
+        final AtomicObservableSubscription subscription = new AtomicObservableSubscription();
+        final Scheduler _scheduler = this;
+
+        handler.post(new Runnable() {
+            @Override
+            public void run() {
+                subscription.wrap(action.call(_scheduler, state));
+            }
+        });
+        return subscription;
+    }
+
+    @Override
+    public <T> Subscription schedule(final T state, final Func2<Scheduler, T, Subscription> action, long delayTime, TimeUnit unit) {
+        if (delayTime == 0) {
+            return schedule(state, action);
+        } else {
+            final AtomicObservableSubscription subscription = new AtomicObservableSubscription();
+            final Scheduler _scheduler = this;
+            handler.postDelayed(new Runnable() {
+                @Override
+                public void run() {
+                    subscription.wrap(action.call(_scheduler, state));
+                }
+            }, unit.toMillis(delayTime));
+            return subscription;
+        }
+    }
+}
+
+