gecko-dev/dom/audiochannel/nsIAudioChannelAgent.idl
2024-04-04 18:45:21 +00:00

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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsISupports.idl"
interface mozIDOMWindow;
typedef uint32_t nsSuspendedTypes;
[scriptable, builtinclass, uuid(2822a840-f009-11e5-a837-0800200c9a66)]
interface nsISuspendedTypes : nsISupports
{
/**
* The suspended enum is used for delaying autoplay video in non-visited tab
*
* Note: the "remote side" must control the AudioChannelAgent using
* nsIAudioChannelAgentCallback.windowSuspendChanged() callback instead using
* play/pause methods or any button in the webpage.
*
* - SUSPENDED_BLOCK
* It's used to prevent auto-playing media in inactive page in order to
* reduce the power consumption, and the media can't be resumed until the
* page becomes active again. It would change the internal state of
* MediaElement when it's being blocked/resumed, so it won't trigger the
* related JS event. eg. "play" and "pause" event.
*/
const uint32_t NONE_SUSPENDED = 0;
const uint32_t SUSPENDED_BLOCK = 1;
};
[uuid(15c05894-408e-4798-b527-a8c32d9c5f8c)]
interface nsIAudioChannelAgentCallback : nsISupports
{
/**
* Notified when the window volume/mute is changed
*/
void windowVolumeChanged(in float aVolume, in boolean aMuted);
/**
* Notified when the window needs to be suspended or resumed.
*/
void windowSuspendChanged(in uint32_t aSuspend);
/**
* Notified when the capture state is changed.
*/
void windowAudioCaptureChanged(in boolean aCapture);
};
/**
* This interface provides an agent for gecko components to participate
* in the audio channel service. Gecko components are responsible for
* 1. Notifying the agent when they start/stop using this channel.
* 2. Notifying the agent when they are audible.
*
* The agent will invoke a callback to notify Gecko components of
* 1. Changes to the playable status of this channel.
*/
[uuid(4d212770-5d7b-446f-9394-632e351d96ee)]
interface nsIAudioChannelAgent : nsISupports
{
const long AUDIO_AGENT_STATE_NORMAL = 0;
const long AUDIO_AGENT_STATE_MUTED = 1;
const long AUDIO_AGENT_STATE_FADED = 2;
/**
* Initialize the agent with a channel type.
* Note: This function should only be called once.
*
* @param window
* The window
* @param callback
* 1. Once the playable status changes, agent uses this callback function
* to notify Gecko component.
* 2. The callback is allowed to be null. Ex: telephony doesn't need to
* listen change of the playable status.
* 3. The AudioChannelAgent keeps a strong reference to the callback
* object.
*/
void init(in mozIDOMWindow window, in nsIAudioChannelAgentCallback callback);
/**
* This method is just like init(), except the audio channel agent keeps a
* weak reference to the callback object.
*
* In order for this to work, |callback| must implement
* nsISupportsWeakReference.
*/
void initWithWeakCallback(in mozIDOMWindow window,
in nsIAudioChannelAgentCallback callback);
/**
* Notify the agent that we want to start playing.
* Note: Gecko component SHOULD call this function first then start to
* play audio stream only when return value is true.
*/
void notifyStartedPlaying(in uint8_t audible);
/**
* Notify the agent we no longer want to play.
*
* Note : even if notifyStartedPlaying() returned false, the agent would
* still be registered with the audio channel service and receive callbacks
* for status changes. So notifyStoppedPlaying must still eventually be
* called to unregister the agent with the channel service.
*/
void notifyStoppedPlaying();
/**
* Notify agent that we already start producing audible data.
*
* Note : sometime audio might become silent during playing, this method is used to
* notify the actually audible state to other services which want to know
* about that, ex. tab sound indicator.
*/
void notifyStartedAudible(in uint8_t audible, in uint32_t reason);
};