PepperPlatformAudioInputImpl: support audio input device selection.

ppapi/examples/audio_input/audio_input.cc

 // 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.
 
 #include <string.h>
 
 #include <algorithm>
 #include <limits>
 #include <vector>
 
@@ skipping 96 matching lines @@
         if (audio_input_0_1_ != 0) {
           if (!audio_input_interface_0_1_->StartCapture(audio_input_0_1_))
             PostMessage(pp::Var("StartFailed"));
         } else {
           PostMessage(pp::Var("OpenFailed"));
         }
 
         audio_input_ = pp::AudioInput_Dev();
       } else if (event == "Stop") {
         Stop();
+      } else if (event == "Start") {
+        Start();
       }
     } else if (message_data.is_number()) {
       int index = message_data.AsInt();
       if (index >= 0 && index < static_cast<int>(devices_.size())) {
         Open(devices_[index]);
       } else {
         PP_NOTREACHED();
       }
     }
   }
@@ skipping 95 matching lines @@
   void Stop() {
     if (!audio_input_.is_null()) {
       if (!audio_input_.StopCapture())
         PostMessage(pp::Var("StopFailed"));
     } else if (audio_input_0_1_ != 0) {
       if (!audio_input_interface_0_1_->StopCapture(audio_input_0_1_))
         PostMessage(pp::Var("StopFailed"));
     }
   }
 
+  void Start() {
+    if (!audio_input_.is_null()) {
+      if (!audio_input_.StartCapture())

[no longer working on chromium, 2012/03/18 00:38:59]

hasn't this function been changed to void?

[yzshen1, 2012/03/19 21:47:54]

We changed PlatformAudioInput::StartCapture() to return void, but not
PPB_AudioInput_Dev.StartCapture().

As I mentioned in a previous comment, ppb_audio_input_shared maintains a simple
state machine, which makes sure PlatformAudioInput is used in a reasonable way.
So PPB_AudioInput_Dev.StartCapture() will return a boolean value, for example,
PP_FALSE when the device has been closed, etc.

+        PostMessage(pp::Var("StartFailed"));
+    } else if (audio_input_0_1_ != 0) {
+      if (!audio_input_interface_0_1_->StartCapture(audio_input_0_1_))
+        PostMessage(pp::Var("StartFailed"));
+    }
+  }
+
   void EnumerateDevicesFinished(int32_t result) {
     static const char* const kDelimiter = "#__#";
 
     if (result == PP_OK) {
       std::string device_names;
       for (size_t index = 0; index < devices_.size(); ++index) {
         pp::Var name = devices_[index].GetName();
         PP_DCHECK(name.is_string());
 
         if (index != 0)
@@ skipping 45 matching lines @@
 };
 
 namespace pp {
 
 // Factory function for your specialization of the Module object.
 Module* CreateModule() {
   return new MyModule();
 }
 
 }  // namespace pp