chromium/third_party/blink/renderer/modules/media_controls/media_controls_orientation_lock_delegate.h

// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_MEDIA_CONTROLS_MEDIA_CONTROLS_ORIENTATION_LOCK_DELEGATE_H_
#define THIRD_PARTY_BLINK_RENDERER_MODULES_MEDIA_CONTROLS_MEDIA_CONTROLS_ORIENTATION_LOCK_DELEGATE_H_

#include <optional>

#include "services/device/public/mojom/screen_orientation.mojom-blink.h"
#include "services/device/public/mojom/screen_orientation_lock_types.mojom-shared.h"
#include "third_party/blink/renderer/core/dom/events/native_event_listener.h"
#include "third_party/blink/renderer/modules/modules_export.h"
#include "third_party/blink/renderer/platform/mojo/heap_mojo_remote.h"
#include "third_party/blink/renderer/platform/scheduler/public/post_cancellable_task.h"

namespace blink {

class DeviceOrientationData;
class DeviceOrientationEvent;
class Document;
class HTMLVideoElement;

// MediaControlsOrientationLockDelegate is implementing the orientation lock
// feature when a <video> is fullscreen. It is meant to be created by
// `MediaControlsImpl` when the feature applies. Once created, it will use
// events to change state.
//
// The behavior depends on whether MediaControlsRotateToFullscreenDelegate is
// enabled. If it is enabled and the user has not locked the screen orientation
// at the OS level, then the orientation lock is only held until the user
// rotates their device to match the orientation of the video; otherwise it is
// held until fullscreen is exited.
//
// The different states of the class are:
// - PendingFullscreen: the object is created and it is either waiting for the
//   associated <video> to go fullscreen in order to apply an orientation lock,
//   or it already went fullscreen then the lock was unlocked since the user
//   rotated their device, and now it is waiting until fullscreen is re-entered;
// - PendingMetadata: the <video> is fullscreen but the metadata have not been
//   downloaded yet. It can happen because of network latency or because the
//   <video> went fullscreen before playback and download started;
// - MaybeLockedFullscreen: the <video> is fullscreen and a screen orientation
//   lock is applied.
//
// The possible state transitions are:
// - PendingFullscreen => PendingMetadata: on fullscreenchange event (entering
//   fullscreen) when metadata are not available;
// - PendingFullscreen => MaybeLockedFullscreen: on fullscreenchange event
//   (entering fullscreen) when metadata are available;
// - PendingMetadata => MaybeLockedFullscreen: on loadedmetadata;
// - PendingMetadata => PendingFullscreen: on fullscreenchange event (exiting
//   fullscreen);
// - MaybeLockedFullscreen => PendingFullscreen: on fullscreenchange event
//   (exiting fullscreen) or on deviceorientation event (rotated to match the
//   orientation of the video).
class MediaControlsOrientationLockDelegate final : public NativeEventListener { … };

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_MODULES_MEDIA_CONTROLS_MEDIA_CONTROLS_ORIENTATION_LOCK_DELEGATE_H_