chrome.displaySource custom bindings

extensions/renderer/display_source_custom_bindings.cc

+// Copyright 2015 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.
+
+#include "extensions/renderer/display_source_custom_bindings.h"
+
+#include "base/bind.h"
+#include "content/public/child/v8_value_converter.h"
+#include "extensions/renderer/script_context.h"
+#include "third_party/WebKit/public/platform/WebMediaStream.h"
+#include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
+#include "third_party/WebKit/public/web/WebDOMMediaStreamTrack.h"
+#include "v8/include/v8.h"
+
+namespace extensions {
+
+using content::V8ValueConverter;
+
+namespace {
+const char kErrorNotSupported[] = "Not supported";
+const char kInvalidStreamArgs[] = "Invalid stream arguments";
+const char kSessionAlreadyStarted[] = "The session has been already started";
+const char kSessionAlreadyTerminating[] = "The session is already terminating";
+const char kSessionNotFound[] = "Session not found";
+}  // namespace
+
+DisplaySourceCustomBindings::DisplaySourceCustomBindings(ScriptContext* context)
+    : ObjectBackedNativeHandler(context),
+      weak_factory_(this) {
+  RouteFunction("StartSession",
+                base::Bind(&DisplaySourceCustomBindings::StartSession,
+                           weak_factory_.GetWeakPtr()));
+  RouteFunction("TerminateSession",
+                base::Bind(&DisplaySourceCustomBindings::TerminateSession,
+                           weak_factory_.GetWeakPtr()));
+}
+
+DisplaySourceCustomBindings::~DisplaySourceCustomBindings() {
+}
+
+void DisplaySourceCustomBindings::Invalidate() {
+  session_map_.clear();
+  weak_factory_.InvalidateWeakPtrs();
+  ObjectBackedNativeHandler::Invalidate();
+}
+
+namespace {
+
+v8::Local<v8::Value> GetChildValue(v8::Local<v8::Object> value,
+                                   const std::string& key_name,
+                                   v8::Isolate* isolate) {
+  v8::Local<v8::Array> property_names(value->GetOwnPropertyNames());
+  for (uint32 i = 0; i < property_names->Length(); ++i) {
+    v8::Local<v8::Value> key(property_names->Get(i));
+    if (key_name == *v8::String::Utf8Value(key)) {
+      v8::TryCatch try_catch(isolate);
+      v8::Local<v8::Value> child_v8 = value->Get(key);
+      if (try_catch.HasCaught()) {
+        return v8::Null(isolate);
+      }
+      return child_v8;
+    }
+  }
+
+  return v8::Null(isolate);
+}
+
+}  // namespace
+
+void DisplaySourceCustomBindings::StartSession(
+    const v8::FunctionCallbackInfo<v8::Value>& args) {
+  CHECK_EQ(1, args.Length());
+  CHECK(args[0]->IsObject());
+  v8::Isolate* isolate = context()->isolate();
+  v8::Local<v8::Object> start_info = args[0].As<v8::Object>();
+
+  v8::Local<v8::Value> sink_id_val =
+      GetChildValue(start_info, "sinkId", isolate);
+  CHECK(sink_id_val->IsInt32());
+  const int sink_id = sink_id_val->ToInt32(isolate)->Value();
+  if (GetDisplaySession(sink_id)) {
+    isolate->ThrowException(v8::Exception::Error(v8::String::NewFromUtf8(
+        isolate, kSessionAlreadyStarted)));
+    return;
+  }
+
+  v8::Local<v8::Value> video_stream_val =
+      GetChildValue(start_info, "videoTrack", isolate);
+  v8::Local<v8::Value> audio_stream_val =
+      GetChildValue(start_info, "audioTrack", isolate);
+
+  if ((video_stream_val->IsNull() || video_stream_val->IsUndefined()) &&
+      (audio_stream_val->IsNull() || audio_stream_val->IsUndefined())) {
+    isolate->ThrowException(v8::Exception::Error(
+        v8::String::NewFromUtf8(isolate, kInvalidStreamArgs)));
+    return;
+  }
+
+  blink::WebMediaStreamTrack audio_track, video_track;
+
+  if (!video_stream_val->IsNull() && !video_stream_val->IsUndefined()) {
+    CHECK(video_stream_val->IsObject());
+    video_track =
+        blink::WebDOMMediaStreamTrack::fromV8Value(
+            video_stream_val).component();
+    if (video_track.isNull()) {
+      isolate->ThrowException(v8::Exception::Error(
+          v8::String::NewFromUtf8(isolate, kInvalidStreamArgs)));
+      return;
+    }
+  }
+  if (!audio_stream_val->IsNull() && !audio_stream_val->IsUndefined()) {
+    CHECK(audio_stream_val->IsObject());
+    audio_track =
+        blink::WebDOMMediaStreamTrack::fromV8Value(
+            audio_stream_val).component();
+    if (audio_track.isNull()) {
+      isolate->ThrowException(v8::Exception::Error(
+          v8::String::NewFromUtf8(isolate, kInvalidStreamArgs)));
+      return;
+    }
+  }
+
+  scoped_ptr<DisplaySourceAuthInfo> auth_info;
+  v8::Local<v8::Value> auth_info_v8_val =
+      GetChildValue(start_info, "authenticationInfo", isolate);
+  if (!auth_info_v8_val->IsNull()) {
+    CHECK(auth_info_v8_val->IsObject());
+    scoped_ptr<V8ValueConverter> converter(V8ValueConverter::create());
+    scoped_ptr<base::Value> auth_info_val(
+        converter->FromV8Value(auth_info_v8_val, context()->v8_context()));
+    CHECK(auth_info_val);
+    auth_info = DisplaySourceAuthInfo::FromValue(*auth_info_val);
+  }
+
+  scoped_ptr<DisplaySourceSession> session =
+      DisplaySourceSessionFactory::CreateSession(
+          sink_id, video_track, audio_track, std::move(auth_info));
+  if (!session) {
+    isolate->ThrowException(v8::Exception::Error(v8::String::NewFromUtf8(
+        isolate, kErrorNotSupported)));
+    return;
+  }
+
+  auto on_started_callback = base::Bind(
+      &DisplaySourceCustomBindings::OnSessionStarted,
+      weak_factory_.GetWeakPtr());
+  auto on_terminated_callback = base::Bind(
+      &DisplaySourceCustomBindings::OnSessionTerminated,
+      weak_factory_.GetWeakPtr());
+  auto on_error_callback = base::Bind(
+      &DisplaySourceCustomBindings::OnSessionError,
+      weak_factory_.GetWeakPtr());
+  session->SetCallbacks(on_started_callback,
+                        on_terminated_callback,
+                        on_error_callback);
+  session_map_.insert(std::make_pair(sink_id, std::move(session)));
+  session->Start();
+}
+
+void DisplaySourceCustomBindings::TerminateSession(
+    const v8::FunctionCallbackInfo<v8::Value>& args) {
+  CHECK_EQ(1, args.Length());
+  CHECK(args[0]->IsInt32());
+
+  v8::Isolate* isolate = context()->isolate();
+  int sink_id = args[0]->ToInt32(args.GetIsolate())->Value();
+  DisplaySourceSession* session = GetDisplaySession(sink_id);
+  if (!session) {
+    isolate->ThrowException(v8::Exception::Error(v8::String::NewFromUtf8(
+        isolate, kSessionNotFound)));
+    return;
+  }
+
+  if (session->state() == DisplaySourceSession::Terminating) {
+    isolate->ThrowException(v8::Exception::Error(v8::String::NewFromUtf8(
+        isolate, kSessionAlreadyTerminating)));
+    return;
+  }
+
+  session->Terminate();

[asargent_no_longer_on_chrome, 2015/12/07 21:47:49]

I'm assuming we rely on the concrete implementations of
DisplaySourceSession::Terminate to dispatch the termination callback, so that we
eventually should end up in OnSessionTerminated below. It might be worth just
having a comment here to direct the reader, something like "The session will get
removed from session_map_ in OnSessionTerminated" or something like that. 

[Mikhail, 2015/12/08 07:44:44]

Done.

+}
+
+void DisplaySourceCustomBindings::DispatchSessionStarted(int sink_id) const {
+  v8::Isolate* isolate = context()->isolate();
+  v8::HandleScope handle_scope(isolate);
+  v8::Context::Scope context_scope(context()->v8_context());
+  v8::Local<v8::Array> event_args = v8::Array::New(isolate, 1);
+  event_args->Set(0, v8::Integer::New(isolate, sink_id));
+  context()->DispatchEvent("displaySource.onSessionStarted", event_args);
+}
+
+void DisplaySourceCustomBindings::DispatchSessionTerminated(int sink_id) const {
+  v8::Isolate* isolate = context()->isolate();
+  v8::HandleScope handle_scope(isolate);
+  v8::Context::Scope context_scope(context()->v8_context());
+  v8::Local<v8::Array> event_args = v8::Array::New(isolate, 1);
+  event_args->Set(0, v8::Integer::New(isolate, sink_id));
+  context()->DispatchEvent("displaySource.onSessionTerminated", event_args);
+}
+
+void DisplaySourceCustomBindings::DispatchSessionError(
+    int sink_id,
+    DisplaySourceErrorType type,
+    const std::string& message) const {
+  v8::Isolate* isolate = context()->isolate();
+  v8::HandleScope handle_scope(isolate);
+  v8::Context::Scope context_scope(context()->v8_context());
+
+  api::display_source::ErrorInfo error_info;
+  error_info.type = type;
+  if (!message.empty())
+    error_info.description.reset(new std::string(message));
+
+  scoped_ptr<V8ValueConverter> converter(V8ValueConverter::create());
+  v8::Local<v8::Value> info_arg =
+      converter->ToV8Value(error_info.ToValue().get(),
+                           context()->v8_context());
+
+  v8::Local<v8::Array> event_args = v8::Array::New(isolate, 2);
+  event_args->Set(0, v8::Integer::New(isolate, sink_id));
+  event_args->Set(1, info_arg);
+  context()->DispatchEvent("displaySource.onSessionErrorOccured", event_args);
+}
+
+DisplaySourceSession* DisplaySourceCustomBindings::GetDisplaySession(
+    int sink_id) const {
+  auto iter = session_map_.find(sink_id);
+  if (iter != session_map_.end())
+    return iter->second.get();
+  return nullptr;
+}
+
+void DisplaySourceCustomBindings::OnSessionStarted(int sink_id) {
+  DispatchSessionStarted(sink_id);
+}
+
+void DisplaySourceCustomBindings::OnSessionTerminated(int sink_id) {
+  DisplaySourceSession* session = GetDisplaySession(sink_id);
+  CHECK(session);
+  session_map_.erase(sink_id);
+  DispatchSessionTerminated(sink_id);
+}
+
+void DisplaySourceCustomBindings::OnSessionError(int sink_id,
+                                                 DisplaySourceErrorType type,
+                                                 const std::string& message) {
+  DisplaySourceSession* session = GetDisplaySession(sink_id);
+  CHECK(session);
+  if (session->state() == DisplaySourceSession::Establishing) {
+    // Error has occured before the session has actually started.
+    session_map_.erase(sink_id);
+  }
+
+  DispatchSessionError(sink_id, type, message);
+}
+
+}  // extensions