Encrypted Media: Replace DecryptorClient with key event callbacks.

media/base/decryptor.h

 // Copyright (c) 2012 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_BASE_DECRYPTOR_H_
 #define MEDIA_BASE_DECRYPTOR_H_
 
 #include <list>
 #include <string>
 
@@ skipping 72 matching lines @@
                       const uint8* key,
                       int key_length,
                       const uint8* init_data,
                       int init_data_length,
                       const std::string& session_id) = 0;
 
   // Cancels the key request specified by |session_id|.
   virtual void CancelKeyRequest(const std::string& key_system,
                                 const std::string& session_id) = 0;
 
-  // Indicates that a key has been added to the Decryptor.
-  typedef base::Callback<void()> KeyAddedCB;
+  // Indicates that a new key has been added to the Decryptor.

[ddorwin, 2012/12/21 04:19:06]

Is it really "new"? It could be called when we get an updated license for an
existing key id, right?

[xhwang, 2012/12/21 05:50:07]

I added "new" here only to make is consistent with the callback name. In some
sense, an updated license is a new license... WDYT?

+  typedef base::Callback<void()> NewKeyCB;

[ddorwin, 2012/12/21 04:19:06]

Should CB's have verb names? (I realize the ones from the spec below do not.)

[xhwang, 2012/12/21 05:50:07]

At least this is not a rule in media code. We hace PipelineStatusCB,
BufferingStateCB, etc.

 
-  // Registers a KeyAddedCB which should be called when a key is added to the
-  // decryptor. Only one KeyAddedCB can be registered for one |stream_type|.
+  // Registers a NewKeyCB which should be called when a new key is added to the
+  // decryptor. Only one NewKeyCB can be registered for one |stream_type|.
   // If this function is called multiple times for the same |stream_type|, the
   // previously registered callback will be replaced. In other words,
   // registering a null callback cancels the originally registered callback.
-  virtual void RegisterKeyAddedCB(StreamType stream_type,
-                                  const KeyAddedCB& key_added_cb) = 0;
+  virtual void RegisterNewKeyCB(StreamType stream_type,
+                                const NewKeyCB& key_added_cb) = 0;
 
   // Indicates completion of a decryption operation.
   //
   // First parameter: The status of the decryption operation.
   // - Set to kSuccess if the encrypted buffer is successfully decrypted and
   //   the decrypted buffer is ready to be read.
   // - Set to kNoKey if no decryption key is available to decrypt the encrypted
   //   buffer. In this case the decrypted buffer must be NULL.
   // - Set to kError if unexpected error has occurred. In this case the
   //   decrypted buffer must be NULL.
@@ skipping 96 matching lines @@
 
 // Callback to set/cancel a DecryptorReadyCB.
 // Calling this callback with a non-null callback registers decryptor ready
 // notification. When the decryptor is ready, notification will be sent
 // through the provided callback.
 // Calling this callback with a null callback cancels previously registered
 // decryptor ready notification. Any previously provided callback will be
 // fired immediately with NULL.
 typedef base::Callback<void(const DecryptorReadyCB&)> SetDecryptorReadyCB;
 
+
+// Key event callbacks. See the spec for details:
+// http://dvcs.w3.org/hg/html-media/raw-file/tip/encrypted-media/encrypted-media.html#event-summary

[ddorwin, 2012/12/21 04:19:06]

s/tip/eme-v0.1b/. These don't exist (in the same form) in the tip.

[xhwang, 2012/12/21 05:50:07]

Done.

+typedef base::Callback<void(const std::string& key_system,
+                            const std::string& session_id)> KeyAddedCB;
+
+typedef base::Callback<void(const std::string& key_system,
+                            const std::string& session_id,
+                            media::Decryptor::KeyError error_code,
+                            int system_code)> KeyErrorCB;
+
+typedef base::Callback<void(const std::string& key_system,
+                            const std::string& session_id,
+                            const std::string& message,
+                            const std::string& default_url)> KeyMessageCB;
+
+typedef base::Callback<void(const std::string& key_system,
+                            const std::string& session_id,
+                            const std::string& type,
+                            scoped_array<uint8> init_data,

[ddorwin, 2012/12/21 04:19:06]

Odd that message is a string but init_data isn't. I guess that's another cleanup
we should do.

[xhwang, 2012/12/21 05:50:07]

Agreed. I talked to dmichael the other day. We all agreed that vector<unit8>
should be best for binary arrays. But we have had too many uses of std::string
for binary arrays (following crypto's convention), sigh...

+                            int init_data_size)> NeedKeyCB;
+
 }  // namespace media
 
 #endif  // MEDIA_BASE_DECRYPTOR_H_