services/device/public/mojom/pressure_manager.mojom

// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

module device.mojom;

import "services/device/public/mojom/pressure_update.mojom";

// Result of PressureManager.AddClient().
enum PressureStatus {
  kOk,

  // The underlying platform does not report compute pressure information or
  // the renderer is not allowed access to the feature.
  kNotSupported,
};

// This interface is used to subscribe to notification about OnPressureUpdated.
//
// This interface is implemented by PressureManagerImpl in services/device.
// PressureObserverManager in Blink uses this interface to make a
// PressureClient subscribe to notification about OnPressureUpdated.
interface PressureManager {
  // Add a client that will be notified when a new PressureUpdate for `source`
  // is obtained.
  AddClient(pending_remote<PressureClient> client, PressureSource source)
    => (PressureStatus status);
};

// Interface that client of the PressureManager interface must
// implement to receive PressureUpdate.
//
// This interface is implemented by PressureObserverManager in Blink.
// PressureManagerImpl uses this interface to deliver PressureUpdate to
// its client.
interface PressureClient {
  // Interface used to deliver PressureUpdate.
  OnPressureUpdated(PressureUpdate update);
};