Index: media/capture/video/scoped_result_callback.h |
diff --git a/media/capture/video/scoped_result_callback.h b/media/capture/video/scoped_result_callback.h |
new file mode 100644 |
index 0000000000000000000000000000000000000000..9c937e8a2815b2ecbd883f3397d2a40344ff9e4d |
--- /dev/null |
+++ b/media/capture/video/scoped_result_callback.h |
@@ -0,0 +1,58 @@ |
+// Copyright 2016 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. |
+ |
+#ifndef MEDIA_CAPTURE_VIDEO_SCOPED_RESULT_CALLBACK_H_ |
+#define MEDIA_CAPTURE_VIDEO_SCOPED_RESULT_CALLBACK_H_ |
+ |
+#include "base/callback_forward.h" |
+#include "mojo/public/cpp/bindings/callback.h" |
+ |
+namespace media { |
+ |
+// This class guarantees that |callback_| has either been called or will pass it |
+// to |on_error_callback_| on destruction. Inspired by ScopedWebCallbacks<>. |
+template <typename CallbackType> |
+class ScopedResultCallback { |
+ MOVE_ONLY_TYPE_FOR_CPP_03(ScopedResultCallback); |
+ |
+ public: |
+ using OnErrorCallback = base::Callback<void(const CallbackType&)>; |
+ ScopedResultCallback(const CallbackType& callback, |
+ const OnErrorCallback& on_error_callback) |
+ : callback_(callback), on_error_callback_(on_error_callback) {} |
+ |
+ ~ScopedResultCallback() { |
+ if (!callback_.is_null()) |
+ on_error_callback_.Run(callback_); |
+ } |
+ |
+ ScopedResultCallback(ScopedResultCallback&& other) { |
+ *this = std::move(other); |
+ } |
+ |
+ ScopedResultCallback& operator=(ScopedResultCallback&& other) { |
+ callback_ = other.callback_; |
+ other.callback_.reset(); |
+ on_error_callback_ = other.on_error_callback_; |
+ other.on_error_callback_.Reset(); |
+ return *this; |
+ } |
+ |
+ template <typename... Args> |
+ void Run(Args... args) { |
+ on_error_callback_.Reset(); |
+ // TODO(mcasas): Use base::ResetAndReturn() when mojo::Callback<> is |
+ // compatible with base::Callback<>, see https://crbug.com/596521. |
+ callback_.Run(std::forward<Args>(args)...); |
+ callback_.reset(); |
+ } |
+ |
+ private: |
+ CallbackType callback_; |
+ OnErrorCallback on_error_callback_; |
+}; |
+ |
+} // namespace media |
+ |
+#endif // MEDIA_CAPTURE_VIDEO_SCOPED_RESULT_CALLBACK_H_ |