// 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);

}