--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/org.chromium.sdk/src/org/chromium/sdk/internal/tools/v8/V8BlockingCallback.java	Wed Dec 23 17:13:18 2009 -0800
@@ -0,0 +1,34 @@
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.sdk.internal.tools.v8;
+
+import org.chromium.sdk.internal.protocol.CommandResponse;
+import org.chromium.sdk.internal.protocol.SuccessCommandResponse;
+
+/**
+ * The callback that handles JSON response to a VM command. The command-sender is staying
+ * blocked until callback finishes, which allows the callback to return a result of
+ * user-specified type {@code RES}.
+ * <p>User should subclass this and implement
+ * {@link #handleSuccessfulResponse(SuccessCommandResponse)} method.
+ * @param <RES> type of result value that is passed back to caller
+ */
+public abstract class V8BlockingCallback<RES> {
+  public RES messageReceived(CommandResponse response) {
+    SuccessCommandResponse successResponse = response.asSuccess();
+    if (successResponse == null) {
+      throw new RuntimeException("Unsuccessful command " +
+          response.asFailure().getMessage());
+    }
+    return handleSuccessfulResponse(successResponse);
+  }
+
+  /**
+   * User-implementable method that handled successful json response and pass result back to
+   * command-sender.
+   * @param response with "success=true"
+   */
+  protected abstract RES handleSuccessfulResponse(SuccessCommandResponse response);
+}