Add support for asynchronous Rpc (#38)

* Add @AsyncRpc annotation to mark Rpc methods that trigger async events.
* Add `EventCache`, which is the repo of events.
* Add `EventSnippet`, which has Rpc methods for client to poll events.
* Add `SnippetEvent` type to represent an event.
* Add `callbackId` field to Rpc protocol's server resp msg.

1 files changed, 39 insertions, 0 deletions

diff --git a/examples/ex1_standalone_app/src/main/java/com/google/android/mobly/snippet/example1/ExampleSnippet2.java b/examples/ex1_standalone_app/src/main/java/com/google/android/mobly/snippet/example1/ExampleSnippet2.java
index 3077869..97a8b27 100644
--- a/examples/ex1_standalone_app/src/main/java/com/google/android/mobly/snippet/example1/ExampleSnippet2.java
+++ b/examples/ex1_standalone_app/src/main/java/com/google/android/mobly/snippet/example1/ExampleSnippet2.java
@@ -17,10 +17,20 @@
 package com.google.android.mobly.snippet.example1;
 
 import com.google.android.mobly.snippet.Snippet;
+import com.google.android.mobly.snippet.event.EventCache;
+import com.google.android.mobly.snippet.event.SnippetEvent;
+import com.google.android.mobly.snippet.rpc.AsyncRpc;
 import com.google.android.mobly.snippet.rpc.Rpc;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
 import java.io.IOException;
 
 public class ExampleSnippet2 implements Snippet {
+
+    private final EventCache mEventQueue = EventCache.getInstance();
+
     @Rpc(description = "Returns the given string with the prefix \"bar\"")
     public String getBar(String input) {
         return "bar " + input;
@@ -31,6 +41,35 @@ public class ExampleSnippet2 implements Snippet {
         throw new IOException("Example exception from throwSomething()");
     }
 
+    /**
+     * An Rpc method demonstrating the async event mechanism.
+     *
+     * Expect to see an event on the client side that looks like:
+     * {
+     *  'name': 'ExampleEvent',
+     *  'time': <timestamp>,
+     *  'data': {
+     *      'exampleData': "Here's a simple event.",
+     *      'secret': 42.24,
+     *      'isSecretive': True
+     *  }
+     * }
+     *
+     * @param eventId
+     * @throws JSONException
+     */
+    @AsyncRpc(description = "This call puts an event in the event queue.")
+    public void tryEvent(String eventId) throws JSONException {
+        SnippetEvent event = new SnippetEvent(eventId, "ExampleEvent");
+        event.addData("exampleData", "Here's a simple event.");
+        event.addData("secret", 42.24);
+        event.addData("isSecretive", true);
+        JSONObject moreData = new JSONObject();
+        moreData.put("evenMoreData", "More Data!");
+        event.addData("moreData", moreData);
+        mEventQueue.postEvent(event);
+    }
+
     @Override
     public void shutdown() {}
 }