1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
/* 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 https://mozilla.org/MPL/2.0/. */

use crate::dom::bindings::callback::ExceptionHandling;
use crate::dom::bindings::cell::DomRefCell;
use crate::dom::bindings::codegen::Bindings::HTMLMediaElementBinding::HTMLMediaElementMethods;
use crate::dom::bindings::codegen::Bindings::MediaMetadataBinding::MediaMetadataInit;
use crate::dom::bindings::codegen::Bindings::MediaMetadataBinding::MediaMetadataMethods;
use crate::dom::bindings::codegen::Bindings::MediaSessionBinding::MediaPositionState;
use crate::dom::bindings::codegen::Bindings::MediaSessionBinding::MediaSessionAction;
use crate::dom::bindings::codegen::Bindings::MediaSessionBinding::MediaSessionActionHandler;
use crate::dom::bindings::codegen::Bindings::MediaSessionBinding::MediaSessionMethods;
use crate::dom::bindings::codegen::Bindings::MediaSessionBinding::MediaSessionPlaybackState;
use crate::dom::bindings::error::{Error, Fallible};
use crate::dom::bindings::num::Finite;
use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
use crate::dom::bindings::root::{DomRoot, MutNullableDom};
use crate::dom::bindings::str::DOMString;
use crate::dom::htmlmediaelement::HTMLMediaElement;
use crate::dom::mediametadata::MediaMetadata;
use crate::dom::window::Window;
use crate::realms::{enter_realm, InRealm};
use dom_struct::dom_struct;
use embedder_traits::MediaMetadata as EmbedderMediaMetadata;
use embedder_traits::MediaSessionEvent;
use script_traits::MediaSessionActionType;
use script_traits::ScriptMsg;
use std::collections::HashMap;
use std::rc::Rc;

#[dom_struct]
pub struct MediaSession {
    reflector_: Reflector,
    /// https://w3c.github.io/mediasession/#dom-mediasession-metadata
    #[ignore_malloc_size_of = "defined in embedder_traits"]
    metadata: DomRefCell<Option<EmbedderMediaMetadata>>,
    /// https://w3c.github.io/mediasession/#dom-mediasession-playbackstate
    playback_state: DomRefCell<MediaSessionPlaybackState>,
    /// https://w3c.github.io/mediasession/#supported-media-session-actions
    #[ignore_malloc_size_of = "Rc"]
    action_handlers: DomRefCell<HashMap<MediaSessionActionType, Rc<MediaSessionActionHandler>>>,
    /// The media instance controlled by this media session.
    /// For now only HTMLMediaElements are controlled by media sessions.
    media_instance: MutNullableDom<HTMLMediaElement>,
}

impl MediaSession {
    #[allow(unrooted_must_root)]
    fn new_inherited() -> MediaSession {
        let media_session = MediaSession {
            reflector_: Reflector::new(),
            metadata: DomRefCell::new(None),
            playback_state: DomRefCell::new(MediaSessionPlaybackState::None),
            action_handlers: DomRefCell::new(HashMap::new()),
            media_instance: Default::default(),
        };
        media_session
    }

    pub fn new(window: &Window) -> DomRoot<MediaSession> {
        reflect_dom_object(Box::new(MediaSession::new_inherited()), window)
    }

    pub fn register_media_instance(&self, media_instance: &HTMLMediaElement) {
        self.media_instance.set(Some(media_instance));
    }

    pub fn handle_action(&self, action: MediaSessionActionType) {
        debug!("Handle media session action {:?}", action);

        if let Some(handler) = self.action_handlers.borrow().get(&action) {
            if handler.Call__(ExceptionHandling::Report).is_err() {
                warn!("Error calling MediaSessionActionHandler callback");
            }
            return;
        }

        // Default action.
        if let Some(media) = self.media_instance.get() {
            match action {
                MediaSessionActionType::Play => {
                    let realm = enter_realm(self);
                    media.Play(InRealm::Entered(&realm));
                },
                MediaSessionActionType::Pause => {
                    media.Pause();
                },
                MediaSessionActionType::SeekBackward => {},
                MediaSessionActionType::SeekForward => {},
                MediaSessionActionType::PreviousTrack => {},
                MediaSessionActionType::NextTrack => {},
                MediaSessionActionType::SkipAd => {},
                MediaSessionActionType::Stop => {},
                MediaSessionActionType::SeekTo => {},
            }
        }
    }

    pub fn send_event(&self, event: MediaSessionEvent) {
        let global = self.global();
        let window = global.as_window();
        let pipeline_id = window.pipeline_id();
        window.send_to_constellation(ScriptMsg::MediaSessionEvent(pipeline_id, event));
    }

    pub fn update_title(&self, title: String) {
        let mut metadata = self.metadata.borrow_mut();
        if let Some(ref mut metadata) = *metadata {
            // We only update the title with the data provided by the media
            // player and iff the user did not provide a title.
            if !metadata.title.is_empty() {
                return;
            }
            metadata.title = title;
        } else {
            *metadata = Some(EmbedderMediaMetadata::new(title));
        }
        self.send_event(MediaSessionEvent::SetMetadata(
            metadata.as_ref().unwrap().clone(),
        ));
    }
}

impl MediaSessionMethods for MediaSession {
    /// https://w3c.github.io/mediasession/#dom-mediasession-metadata
    fn GetMetadata(&self) -> Option<DomRoot<MediaMetadata>> {
        if let Some(ref metadata) = *self.metadata.borrow() {
            let mut init = MediaMetadataInit::empty();
            init.title = DOMString::from_string(metadata.title.clone());
            init.artist = DOMString::from_string(metadata.artist.clone());
            init.album = DOMString::from_string(metadata.album.clone());
            let global = self.global();
            Some(MediaMetadata::new(&global.as_window(), &init))
        } else {
            None
        }
    }

    /// https://w3c.github.io/mediasession/#dom-mediasession-metadata
    fn SetMetadata(&self, metadata: Option<&MediaMetadata>) {
        if let Some(ref metadata) = metadata {
            metadata.set_session(self);
        }

        let global = self.global();
        let window = global.as_window();
        let _metadata = match metadata {
            Some(m) => {
                let title = if m.Title().is_empty() {
                    window.get_url().into_string()
                } else {
                    m.Title().into()
                };
                EmbedderMediaMetadata {
                    title,
                    artist: m.Artist().into(),
                    album: m.Album().into(),
                }
            },
            None => EmbedderMediaMetadata::new(window.get_url().into_string()),
        };

        *self.metadata.borrow_mut() = Some(_metadata.clone());

        self.send_event(MediaSessionEvent::SetMetadata(_metadata));
    }

    /// https://w3c.github.io/mediasession/#dom-mediasession-playbackstate
    fn PlaybackState(&self) -> MediaSessionPlaybackState {
        *self.playback_state.borrow()
    }

    /// https://w3c.github.io/mediasession/#dom-mediasession-playbackstate
    fn SetPlaybackState(&self, state: MediaSessionPlaybackState) {
        *self.playback_state.borrow_mut() = state;
    }

    /// https://w3c.github.io/mediasession/#update-action-handler-algorithm
    fn SetActionHandler(
        &self,
        action: MediaSessionAction,
        handler: Option<Rc<MediaSessionActionHandler>>,
    ) {
        match handler {
            Some(handler) => self
                .action_handlers
                .borrow_mut()
                .insert(action.into(), handler.clone()),
            None => self.action_handlers.borrow_mut().remove(&action.into()),
        };
    }

    /// https://w3c.github.io/mediasession/#dom-mediasession-setpositionstate
    fn SetPositionState(&self, state: &MediaPositionState) -> Fallible<()> {
        // If the state is an empty dictionary then clear the position state.
        if state.duration.is_none() && state.position.is_none() && state.playbackRate.is_none() {
            if let Some(media_instance) = self.media_instance.get() {
                media_instance.reset();
            }
            return Ok(());
        }

        // If the duration is not present or its value is null, throw a TypeError.
        if state.duration.is_none() {
            return Err(Error::Type(
                "duration is not present or its value is null".to_owned(),
            ));
        }

        // If the duration is negative, throw a TypeError.
        if let Some(state_duration) = state.duration {
            if *state_duration < 0.0 {
                return Err(Error::Type("duration is negative".to_owned()));
            }
        }

        // If the position is negative or greater than duration, throw a TypeError.
        if let Some(state_position) = state.position {
            if *state_position < 0.0 {
                return Err(Error::Type("position is negative".to_owned()));
            }
            if let Some(state_duration) = state.duration {
                if *state_position > *state_duration {
                    return Err(Error::Type("position is greater than duration".to_owned()));
                }
            }
        }

        // If the playbackRate is zero throw a TypeError.
        if let Some(state_playback_rate) = state.playbackRate {
            if *state_playback_rate <= 0.0 {
                return Err(Error::Type("playbackRate is zero".to_owned()));
            }
        }

        // Update the position state and last position updated time.
        if let Some(media_instance) = self.media_instance.get() {
            media_instance.set_duration(state.duration.map(|v| *v).unwrap());
            // If the playbackRate is not present or its value is null, set it to 1.0.
            let _ =
                media_instance.SetPlaybackRate(state.playbackRate.unwrap_or(Finite::wrap(1.0)))?;
            // If the position is not present or its value is null, set it to zero.
            media_instance.SetCurrentTime(state.position.unwrap_or(Finite::wrap(0.0)));
        }

        Ok(())
    }
}

impl From<MediaSessionAction> for MediaSessionActionType {
    fn from(action: MediaSessionAction) -> MediaSessionActionType {
        match action {
            MediaSessionAction::Play => MediaSessionActionType::Play,
            MediaSessionAction::Pause => MediaSessionActionType::Pause,
            MediaSessionAction::Seekbackward => MediaSessionActionType::SeekBackward,
            MediaSessionAction::Seekforward => MediaSessionActionType::SeekForward,
            MediaSessionAction::Previoustrack => MediaSessionActionType::PreviousTrack,
            MediaSessionAction::Nexttrack => MediaSessionActionType::NextTrack,
            MediaSessionAction::Skipad => MediaSessionActionType::SkipAd,
            MediaSessionAction::Stop => MediaSessionActionType::Stop,
            MediaSessionAction::Seekto => MediaSessionActionType::SeekTo,
        }
    }
}