Introduce PPB_AudioInput_Dev v0.3 and refactor the device enumeration code:

content/renderer/pepper/pepper_device_enumeration_host_helper.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 "content/renderer/pepper/pepper_device_enumeration_host_helper.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "base/memory/weak_ptr.h"
+#include "base/message_loop.h"
+#include "ipc/ipc_message.h"
+#include "ppapi/c/pp_errors.h"
+#include "ppapi/host/dispatch_host_message.h"
+#include "ppapi/host/host_message_context.h"
+#include "ppapi/host/ppapi_host.h"
+#include "ppapi/host/resource_host.h"
+#include "ppapi/proxy/ppapi_messages.h"
+#include "ppapi/shared_impl/ppb_device_ref_shared.h"
+#include "webkit/plugins/ppapi/plugin_delegate.h"
+
+using ppapi::host::HostMessageContext;
+using webkit::ppapi::PluginDelegate;
+
+namespace content {
+
+// Makes sure that StopEnumerateDevices() is called for each EnumerateDevices().
+class PepperDeviceEnumerationHostHelper::ScopedRequest
+    : public base::SupportsWeakPtr<ScopedRequest> {
+ public:
+  // |owner| must outlive this object.
+  ScopedRequest(PepperDeviceEnumerationHostHelper* owner,
+                const PluginDelegate::EnumerateDevicesCallback& callback)
+      : owner_(owner),
+        callback_(callback),
+        requested_(false),
+        request_id_(0),
+        sync_call_(false) {
+    PluginDelegate* plugin_delegate = owner_->delegate_->GetPluginDelegate();
+    if (!plugin_delegate)
+      return;
+
+    requested_ = true;
+
+    // Note that the callback passed into PluginDelegate::EnumerateDevices() may
+    // be called synchronously. In that case, |request_id_| hasn't been updated
+    // when the callback is called. Moreover, |callback| may destroy this
+    // object. So we don't pass in |callback| directly. Instead, we use
+    // EnumerateDevicesCallbackBody() to ensure that we always call |callback|
+    // asynchronously.
+    sync_call_ = true;
+    request_id_ = plugin_delegate->EnumerateDevices(
+        owner_->device_type_,
+        base::Bind(&ScopedRequest::EnumerateDevicesCallbackBody, AsWeakPtr()));
+    sync_call_ = false;
+  }
+
+  ~ScopedRequest() {
+    if (requested_) {
+      PluginDelegate* plugin_delegate = owner_->delegate_->GetPluginDelegate();
+      if (plugin_delegate)
+        plugin_delegate->StopEnumerateDevices(request_id_);
+    }
+  }
+
+  bool requested() const { return requested_; }
+
+ private:
+  void EnumerateDevicesCallbackBody(
+      int request_id,
+      bool succeeded,
+      const std::vector<ppapi::DeviceRefData>& devices) {
+    if (sync_call_) {
+      MessageLoop::current()->PostTask(
+          FROM_HERE,
+          base::Bind(&ScopedRequest::EnumerateDevicesCallbackBody, AsWeakPtr(),
+                     request_id, succeeded, devices));
+    } else {
+      DCHECK_EQ(request_id_, request_id);
+      callback_.Run(request_id, succeeded, devices);
+      // This object may have been destroyed at this point.
+    }
+  }
+
+  PepperDeviceEnumerationHostHelper* owner_;
+  PluginDelegate::EnumerateDevicesCallback callback_;
+  bool requested_;
+  int request_id_;
+  bool sync_call_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedRequest);
+};
+
+PepperDeviceEnumerationHostHelper::PepperDeviceEnumerationHostHelper(
+    ppapi::host::ResourceHost* resource_host,
+    Delegate* delegate,
+    PP_DeviceType_Dev device_type)
+    : resource_host_(resource_host),
+      delegate_(delegate),
+      device_type_(device_type) {
+}
+
+PepperDeviceEnumerationHostHelper::~PepperDeviceEnumerationHostHelper() {
+}
+
+bool PepperDeviceEnumerationHostHelper::HandleResourceMessage(
+    const IPC::Message& msg,
+    HostMessageContext* context,
+    int32_t* result) {
+  bool return_value = false;
+  *result = InternalHandleResourceMessage(msg, context, &return_value);
+  return return_value;
+}
+
+int32_t PepperDeviceEnumerationHostHelper::InternalHandleResourceMessage(
+    const IPC::Message& msg,
+    HostMessageContext* context,
+    bool* handled) {
+  *handled = true;
+  IPC_BEGIN_MESSAGE_MAP(PepperDeviceEnumerationHostHelper, msg)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(
+        PpapiHostMsg_DeviceEnumeration_EnumerateDevices, OnMsgEnumerateDevices)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL(
+        PpapiHostMsg_DeviceEnumeration_MonitorDeviceChange,
+        OnMsgMonitorDeviceChange)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(
+        PpapiHostMsg_DeviceEnumeration_StopMonitoringDeviceChange,
+        OnMsgStopMonitoringDeviceChange)
+  IPC_END_MESSAGE_MAP()
+
+  *handled = false;
+  return PP_ERROR_FAILED;
+}
+
+int32_t PepperDeviceEnumerationHostHelper::OnMsgEnumerateDevices(
+    HostMessageContext* context) {
+  if (enumerate_devices_context_.get())
+    return PP_ERROR_INPROGRESS;
+
+  enumerate_.reset(new ScopedRequest(
+      this,
+      base::Bind(&PepperDeviceEnumerationHostHelper::OnEnumerateDevicesComplete,
+                 base::Unretained(this))));
+  if (!enumerate_->requested())
+    return PP_ERROR_FAILED;
+
+  enumerate_devices_context_.reset(
+      new ppapi::host::ReplyMessageContext(context->MakeReplyMessageContext()));
+  return PP_OK_COMPLETIONPENDING;
+}
+
+int32_t PepperDeviceEnumerationHostHelper::OnMsgMonitorDeviceChange(
+    HostMessageContext* /* context */,
+    uint32_t callback_id) {
+  monitor_.reset(new ScopedRequest(
+      this,
+      base::Bind(&PepperDeviceEnumerationHostHelper::OnNotifyDeviceChange,
+                 base::Unretained(this), callback_id)));
+
+  return monitor_->requested() ? PP_OK : PP_ERROR_FAILED;
+}
+
+int32_t PepperDeviceEnumerationHostHelper::OnMsgStopMonitoringDeviceChange(
+    HostMessageContext* /* context */) {
+  monitor_.reset(NULL);
+  return PP_OK;
+}
+
+void PepperDeviceEnumerationHostHelper::OnEnumerateDevicesComplete(
+    int /* request_id */,
+    bool succeeded,
+    const std::vector<ppapi::DeviceRefData>& devices) {
+  DCHECK(enumerate_devices_context_.get());
+
+  enumerate_.reset(NULL);
+
+  enumerate_devices_context_->params.set_result(
+      succeeded ? PP_OK : PP_ERROR_FAILED);
+  resource_host_->host()->SendReply(
+      *enumerate_devices_context_,
+      PpapiPluginMsg_DeviceEnumeration_EnumerateDevicesReply(
+          succeeded ? devices : std::vector<ppapi::DeviceRefData>()));
+  enumerate_devices_context_.reset();
+}
+
+void PepperDeviceEnumerationHostHelper::OnNotifyDeviceChange(
+    uint32_t callback_id,
+    int /* request_id */,
+    bool succeeded,
+    const std::vector<ppapi::DeviceRefData>& devices) {
+  resource_host_->host()->SendUnsolicitedReply(
+      resource_host_->pp_resource(),
+      PpapiPluginMsg_DeviceEnumeration_NotifyDeviceChange(
+          callback_id,
+          succeeded ? devices : std::vector<ppapi::DeviceRefData>()));
+}
+
+}  // namespace content