Add video player (#2)

https://github.com/sony/flutter-embedded-linux/issues/124

packages/video_player/elinux/video_player_stream_handler_impl.h

@@ -0,0 +1,58 @@
+// Copyright 2021 Sony Group Corporation. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef PACKAGES_VIDEO_PLAYER_VIDEO_PLAYER_ELINUX_VIDEO_PLAYER_STREAM_HANDLER_IMPL_H_
+#define PACKAGES_VIDEO_PLAYER_VIDEO_PLAYER_ELINUX_VIDEO_PLAYER_STREAM_HANDLER_IMPL_H_
+
+#include <functional>
+
+#include "video_player_stream_handler.h"
+
+class VideoPlayerStreamHandlerImpl : public VideoPlayerStreamHandler {
+ public:
+  using OnNotifyInitialized = std::function<void()>;
+  using OnNotifyFrameDecoded = std::function<void()>;
+  using OnNotifyCompleted = std::function<void()>;
+
+  VideoPlayerStreamHandlerImpl(OnNotifyInitialized on_notify_initialized,
+                               OnNotifyFrameDecoded on_notify_frame_decoded,
+                               OnNotifyCompleted on_notify_completed)
+      : on_notify_initialized_(on_notify_initialized),
+        on_notify_frame_decoded_(on_notify_frame_decoded),
+        on_notify_completed_(on_notify_completed) {}
+  virtual ~VideoPlayerStreamHandlerImpl() = default;
+
+  // Prevent copying.
+  VideoPlayerStreamHandlerImpl(VideoPlayerStreamHandlerImpl const&) = delete;
+  VideoPlayerStreamHandlerImpl& operator=(VideoPlayerStreamHandlerImpl const&) =
+      delete;
+
+ protected:
+  // |VideoPlayerStreamHandler|
+  void OnNotifyInitializedInternal() {
+    if (on_notify_initialized_) {
+      on_notify_initialized_();
+    }
+  }
+
+  // |VideoPlayerStreamHandler|
+  void OnNotifyFrameDecodedInternal() {
+    if (on_notify_frame_decoded_) {
+      on_notify_frame_decoded_();
+    }
+  }
+
+  // |VideoPlayerStreamHandler|
+  void OnNotifyCompletedInternal() {
+    if (on_notify_completed_) {
+      on_notify_completed_();
+    }
+  }
+
+  OnNotifyInitialized on_notify_initialized_;
+  OnNotifyFrameDecoded on_notify_frame_decoded_;
+  OnNotifyCompleted on_notify_completed_;
+};
+
+#endif  // PACKAGES_VIDEO_PLAYER_VIDEO_PLAYER_ELINUX_VIDEO_PLAYER_STREAM_HANDLER_IMPL_H_