Added a DartExecutor API for querying # of pending channel callbacks (#10021)

adazh · web-flow · commit ef99738bafc0 · 2019-07-23T13:11:03.000-07:00
diff --git a/shell/platform/android/io/flutter/embedding/engine/dart/DartExecutor.java b/shell/platform/android/io/flutter/embedding/engine/dart/DartExecutor.java
@@ -196,6 +196,26 @@ public void send(@NonNull String channel, @Nullable ByteBuffer message, @Nullabl
   public void setMessageHandler(@NonNull String channel, @Nullable BinaryMessenger.BinaryMessageHandler handler) {
     messenger.setMessageHandler(channel, handler);
   }
+
+  /**
+   * Returns the number of pending channel callback replies.
+   *
+   * <p>When sending messages to the Flutter application using {@link BinaryMessenger#send(String,
+   * ByteBuffer, io.flutter.plugin.common.BinaryMessenger.BinaryReply)}, developers can optionally
+   * specify a reply callback if they expect a reply from the Flutter application.
+   *
+   * <p>This method tracks all the pending callbacks that are waiting for response, and is supposed
+   * to be called from the main thread (as other methods). Calling from a different thread could
+   * possibly capture an indeterministic internal state, so don't do it.
+   *
+   * <p>Currently, it's mainly useful for a testing framework like Espresso to determine whether all
+   * the async channel callbacks are handled and the app is idle.
+   */
+  @UiThread
+  public int getPendingChannelResponseCount() {
+    return messenger.getPendingChannelResponseCount();
+  }
+
   //------ END BinaryMessenger -----
 
   /**
diff --git a/shell/platform/android/io/flutter/embedding/engine/dart/DartMessenger.java b/shell/platform/android/io/flutter/embedding/engine/dart/DartMessenger.java
@@ -118,6 +118,22 @@ public void handlePlatformMessageResponse(int replyId, @Nullable byte[] reply) {
     }
   }
 
+  /**
+   * Returns the number of pending channel callback replies.
+   *
+   * <p>When sending messages to the Flutter application using {@link BinaryMessenger#send(String,
+   * ByteBuffer, io.flutter.plugin.common.BinaryMessenger.BinaryReply)}, developers can optionally
+   * specify a reply callback if they expect a reply from the Flutter application.
+   *
+   * <p>This method tracks all the pending callbacks that are waiting for response, and is supposed
+   * to be called from the main thread (as other methods). Calling from a different thread could
+   * possibly capture an indeterministic internal state, so don't do it.
+   */
+  @UiThread
+  public int getPendingChannelResponseCount() {
+    return pendingReplies.size();
+  }
+
   private static class Reply implements BinaryMessenger.BinaryReply {
     @NonNull
     private final FlutterJNI flutterJNI;
@@ -141,4 +157,4 @@ public void reply(@Nullable ByteBuffer reply) {
       }
     }
   }
-}
+}

Original file line number	Diff line number	Diff line change
`@@ -118,6 +118,22 @@ public void handlePlatformMessageResponse(int replyId, @Nullable byte[] reply) {`
`118`	`118`	`}`
`119`	`119`	`}`
`120`	`120`
	`121`	`+ /**`
	`122`	`+ * Returns the number of pending channel callback replies.`
	`123`	`+ *`
	`124`	`+ * <p>When sending messages to the Flutter application using {@link BinaryMessenger#send(String,`
	`125`	`+ * ByteBuffer, io.flutter.plugin.common.BinaryMessenger.BinaryReply)}, developers can optionally`
	`126`	`+ * specify a reply callback if they expect a reply from the Flutter application.`
	`127`	`+ *`
	`128`	`+ * <p>This method tracks all the pending callbacks that are waiting for response, and is supposed`
	`129`	`+ * to be called from the main thread (as other methods). Calling from a different thread could`
	`130`	`+ * possibly capture an indeterministic internal state, so don't do it.`
	`131`	`+ */`
	`132`	`+ @UiThread`
	`133`	`+ public int getPendingChannelResponseCount() {`
	`134`	`+ return pendingReplies.size();`
	`135`	`+ }`
	`136`	`+`
`121`	`137`	`private static class Reply implements BinaryMessenger.BinaryReply {`
`122`	`138`	`@NonNull`
`123`	`139`	`private final FlutterJNI flutterJNI;`
`@@ -141,4 +157,4 @@ public void reply(@Nullable ByteBuffer reply) {`
`141`	`157`	`}`
`142`	`158`	`}`
`143`	`159`	`}`
`144`		`-}`
	`160`	`+}`