| // Copyright 2016 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 CONTENT_RENDERER_MEDIA_MEDIA_DEVICES_EVENT_DISPATCHER_H_ |
| #define CONTENT_RENDERER_MEDIA_MEDIA_DEVICES_EVENT_DISPATCHER_H_ |
| |
| #include <stdint.h> |
| |
| #include <utility> |
| #include <vector> |
| |
| #include "base/macros.h" |
| #include "base/memory/weak_ptr.h" |
| #include "base/threading/thread_checker.h" |
| #include "content/common/content_export.h" |
| #include "content/common/media/media_devices.h" |
| #include "content/common/media/media_devices.mojom.h" |
| #include "content/public/renderer/render_frame_observer.h" |
| #include "content/public/renderer/render_frame_observer_tracker.h" |
| |
| namespace url { |
| class Origin; |
| } |
| |
| namespace content { |
| |
| // This class implements the logic for managing media device-change |
| // subscriptions on the renderer process. It manages the generation of |
| // subscription IDs and handles the interaction with the Mojo objects that |
| // communicate with the browser process. There is at most one instance of this |
| // class per frame. |
| class CONTENT_EXPORT MediaDevicesEventDispatcher |
| : public RenderFrameObserver, |
| public RenderFrameObserverTracker<MediaDevicesEventDispatcher>, |
| public base::SupportsWeakPtr<MediaDevicesEventDispatcher> { |
| public: |
| using SubscriptionId = uint32_t; |
| using SubscriptionIdList = std::vector<SubscriptionId>; |
| using DevicesChangedCallback = |
| base::Callback<void(MediaDeviceType, const MediaDeviceInfoArray&)>; |
| |
| // Returns a weak pointer to the MediaDevicesEventDispatcher for the given |
| // |render_frame|. |
| static base::WeakPtr<MediaDevicesEventDispatcher> GetForRenderFrame( |
| RenderFrame* render_frame); |
| |
| ~MediaDevicesEventDispatcher() override; |
| |
| // Register a callback for device-change notifications for a given device |
| // type. Returns a subscription ID that can be used to cancel the |
| // subscription. |
| SubscriptionId SubscribeDeviceChangeNotifications( |
| MediaDeviceType type, |
| const url::Origin& security_origin, |
| const DevicesChangedCallback& callback); |
| |
| // Cancels a subscription identified with |subscription_id| to device-change |
| // notifications for device type |type|. If no subscription identified with |
| // |subscription_id| exists for device type |type|, this function returns |
| // without side effects. |
| void UnsubscribeDeviceChangeNotifications(MediaDeviceType type, |
| SubscriptionId subscription_id); |
| |
| // Register a callback for device-change notifications for any device type. |
| // Returns a list of subscription IDs that can be used to cancel the |
| // subscriptions. |
| SubscriptionIdList SubscribeDeviceChangeNotifications( |
| const url::Origin& security_origin, |
| const DevicesChangedCallback& callback); |
| |
| // Cancels subscriptions identified by |subscription_ids| to device-change |
| // notifications for all device types. This is implemented by invoking the |
| // single-parameter version of UnsubscribeDeviceChangeNotifications() for all |
| // device types. |
| void UnsubscribeDeviceChangeNotifications( |
| const SubscriptionIdList& subscription_ids); |
| |
| // Dispatches an event notification to all registered callbacks for device |
| // type |type|. Should be invoked only by an object that detects changes in |
| // the set of media devices. |
| void DispatchDevicesChangedEvent(MediaDeviceType type, |
| const MediaDeviceInfoArray& device_infos); |
| |
| // RenderFrameObserver override. |
| void OnDestruct() override; |
| |
| void SetMediaDevicesDispatcherForTesting( |
| ::mojom::MediaDevicesDispatcherHostPtr media_devices_dispatcher); |
| |
| private: |
| explicit MediaDevicesEventDispatcher(RenderFrame* render_frame); |
| |
| const ::mojom::MediaDevicesDispatcherHostPtr& GetMediaDevicesDispatcher(); |
| |
| SubscriptionId current_id_; |
| |
| using Subscription = std::pair<SubscriptionId, DevicesChangedCallback>; |
| using SubscriptionList = std::vector<Subscription>; |
| SubscriptionList device_change_subscriptions_[NUM_MEDIA_DEVICE_TYPES]; |
| |
| ::mojom::MediaDevicesDispatcherHostPtr media_devices_dispatcher_; |
| |
| base::ThreadChecker thread_checker_; |
| |
| DISALLOW_COPY_AND_ASSIGN(MediaDevicesEventDispatcher); |
| }; |
| |
| } // namespace content |
| |
| #endif // CONTENT_RENDERER_MEDIA_MEDIA_DEVICES_EVENT_DISPATCHER_H_ |