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
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
/* 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/. */

//! This module contains traits in script used generically in the rest of Servo.
//! The traits are here instead of in script so that these modules won't have
//! to depend on script.

#![deny(missing_docs)]
#![deny(unsafe_code)]

mod script_msg;
pub mod serializable;
pub mod transferable;
pub mod webdriver_msg;

use std::borrow::Cow;
use std::collections::{HashMap, VecDeque};
use std::fmt;
use std::sync::Arc;
use std::time::Duration;

use background_hang_monitor_api::BackgroundHangMonitorRegister;
use base::cross_process_instant::CrossProcessInstant;
use base::id::{
    BlobId, BrowsingContextId, HistoryStateId, MessagePortId, PipelineId, PipelineNamespaceId,
    TopLevelBrowsingContextId,
};
use base::Epoch;
use bitflags::bitflags;
use bluetooth_traits::BluetoothRequest;
use canvas_traits::webgl::WebGLPipeline;
use crossbeam_channel::{RecvTimeoutError, Sender};
use devtools_traits::{DevtoolScriptControlMsg, ScriptToDevtoolsControlMsg, WorkerId};
use embedder_traits::CompositorEventVariant;
use euclid::default::Point2D;
use euclid::{Rect, Scale, Size2D, UnknownUnit, Vector2D};
use http::{HeaderMap, Method};
use ipc_channel::ipc::{IpcReceiver, IpcSender};
use ipc_channel::Error as IpcError;
use keyboard_types::webdriver::Event as WebDriverInputEvent;
use keyboard_types::{CompositionEvent, KeyboardEvent};
use libc::c_void;
use log::warn;
use malloc_size_of::malloc_size_of_is_0;
use malloc_size_of_derive::MallocSizeOf;
use media::WindowGLContext;
use net_traits::image_cache::ImageCache;
use net_traits::request::{Referrer, RequestBody};
use net_traits::storage_thread::StorageType;
use net_traits::{FetchResponseMsg, ReferrerPolicy, ResourceThreads};
use pixels::{Image, PixelFormat};
use profile_traits::{mem, time as profile_time};
use serde::{Deserialize, Deserializer, Serialize, Serializer};
use servo_atoms::Atom;
use servo_url::{ImmutableOrigin, ServoUrl};
use style_traits::{CSSPixel, SpeculativePainter};
use webgpu::WebGPUMsg;
use webrender_api::units::{DeviceIntSize, DevicePixel, LayoutPixel};
use webrender_api::{DocumentId, ExternalScrollId, ImageKey};
use webrender_traits::{
    CrossProcessCompositorApi, UntrustedNodeAddress as WebRenderUntrustedNodeAddress,
};

pub use crate::script_msg::{
    DOMMessage, EventResult, HistoryEntryReplacement, IFrameSizeMsg, Job, JobError, JobResult,
    JobResultValue, JobType, LayoutMsg, LogEntry, SWManagerMsg, SWManagerSenders, ScopeThings,
    ScriptMsg, ServiceWorkerMsg, TraversalDirection,
};
use crate::serializable::{BlobData, BlobImpl};
use crate::transferable::MessagePortImpl;
use crate::webdriver_msg::{LoadStatus, WebDriverScriptCommand};

/// The address of a node. Layout sends these back. They must be validated via
/// `from_untrusted_node_address` before they can be used, because we do not trust layout.
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub struct UntrustedNodeAddress(pub *const c_void);

malloc_size_of_is_0!(UntrustedNodeAddress);

#[allow(unsafe_code)]
unsafe impl Send for UntrustedNodeAddress {}

impl From<WebRenderUntrustedNodeAddress> for UntrustedNodeAddress {
    fn from(o: WebRenderUntrustedNodeAddress) -> Self {
        UntrustedNodeAddress(o.0)
    }
}

impl From<style_traits::dom::OpaqueNode> for UntrustedNodeAddress {
    fn from(o: style_traits::dom::OpaqueNode) -> Self {
        UntrustedNodeAddress(o.0 as *const c_void)
    }
}

impl Serialize for UntrustedNodeAddress {
    fn serialize<S: Serializer>(&self, s: S) -> Result<S::Ok, S::Error> {
        (self.0 as usize).serialize(s)
    }
}

impl<'de> Deserialize<'de> for UntrustedNodeAddress {
    fn deserialize<D: Deserializer<'de>>(d: D) -> Result<UntrustedNodeAddress, D::Error> {
        let value: usize = Deserialize::deserialize(d)?;
        Ok(UntrustedNodeAddress::from_id(value))
    }
}

impl UntrustedNodeAddress {
    /// Creates an `UntrustedNodeAddress` from the given pointer address value.
    #[inline]
    pub fn from_id(id: usize) -> UntrustedNodeAddress {
        UntrustedNodeAddress(id as *const c_void)
    }
}

/// The origin where a given load was initiated.
/// Useful for origin checks, for example before evaluation a JS URL.
#[derive(Clone, Debug, Deserialize, Serialize)]
pub enum LoadOrigin {
    /// A load originating in the constellation.
    Constellation,
    /// A load originating in webdriver.
    WebDriver,
    /// A load originating in script.
    Script(ImmutableOrigin),
}

/// can be passed to `LoadUrl` to load a page with GET/POST
/// parameters or headers
#[derive(Clone, Debug, Deserialize, Serialize)]
pub struct LoadData {
    /// The origin where the load started.
    pub load_origin: LoadOrigin,
    /// The URL.
    pub url: ServoUrl,
    /// The creator pipeline id if this is an about:blank load.
    pub creator_pipeline_id: Option<PipelineId>,
    /// The method.
    #[serde(
        deserialize_with = "::hyper_serde::deserialize",
        serialize_with = "::hyper_serde::serialize"
    )]
    pub method: Method,
    /// The headers.
    #[serde(
        deserialize_with = "::hyper_serde::deserialize",
        serialize_with = "::hyper_serde::serialize"
    )]
    pub headers: HeaderMap,
    /// The data that will be used as the body of the request.
    pub data: Option<RequestBody>,
    /// The result of evaluating a javascript scheme url.
    pub js_eval_result: Option<JsEvalResult>,
    /// The referrer.
    pub referrer: Referrer,
    /// The referrer policy.
    pub referrer_policy: Option<ReferrerPolicy>,

    /// The source to use instead of a network response for a srcdoc document.
    pub srcdoc: String,
    /// The inherited context is Secure, None if not inherited
    pub inherited_secure_context: Option<bool>,

    /// Servo internal: if crash details are present, trigger a crash error page with these details.
    pub crash: Option<String>,
}

/// The result of evaluating a javascript scheme url.
#[derive(Clone, Debug, Deserialize, Serialize)]
pub enum JsEvalResult {
    /// The js evaluation had a non-string result, 204 status code.
    /// <https://html.spec.whatwg.org/multipage/#navigate> 12.11
    NoContent,
    /// The js evaluation had a string result.
    Ok(Vec<u8>),
}

impl LoadData {
    /// Create a new `LoadData` object.
    pub fn new(
        load_origin: LoadOrigin,
        url: ServoUrl,
        creator_pipeline_id: Option<PipelineId>,
        referrer: Referrer,
        referrer_policy: Option<ReferrerPolicy>,
        inherited_secure_context: Option<bool>,
    ) -> LoadData {
        LoadData {
            load_origin,
            url,
            creator_pipeline_id,
            method: Method::GET,
            headers: HeaderMap::new(),
            data: None,
            js_eval_result: None,
            referrer,
            referrer_policy,
            srcdoc: "".to_string(),
            inherited_secure_context,
            crash: None,
        }
    }
}

/// The initial data required to create a new layout attached to an existing script thread.
#[derive(Debug, Deserialize, Serialize)]
pub struct NewLayoutInfo {
    /// The ID of the parent pipeline and frame type, if any.
    /// If `None`, this is a root pipeline.
    pub parent_info: Option<PipelineId>,
    /// Id of the newly-created pipeline.
    pub new_pipeline_id: PipelineId,
    /// Id of the browsing context associated with this pipeline.
    pub browsing_context_id: BrowsingContextId,
    /// Id of the top-level browsing context associated with this pipeline.
    pub top_level_browsing_context_id: TopLevelBrowsingContextId,
    /// Id of the opener, if any
    pub opener: Option<BrowsingContextId>,
    /// Network request data which will be initiated by the script thread.
    pub load_data: LoadData,
    /// Information about the initial window size.
    pub window_size: WindowSizeData,
}

/// When a pipeline is closed, should its browsing context be discarded too?
#[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, PartialEq, Serialize)]
pub enum DiscardBrowsingContext {
    /// Discard the browsing context
    Yes,
    /// Don't discard the browsing context
    No,
}

/// Is a document fully active, active or inactive?
/// A document is active if it is the current active document in its session history,
/// it is fuly active if it is active and all of its ancestors are active,
/// and it is inactive otherwise.
///
/// * <https://html.spec.whatwg.org/multipage/#active-document>
/// * <https://html.spec.whatwg.org/multipage/#fully-active>
#[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, MallocSizeOf, PartialEq, Serialize)]
pub enum DocumentActivity {
    /// An inactive document
    Inactive,
    /// An active but not fully active document
    Active,
    /// A fully active document
    FullyActive,
}

/// Type of recorded progressive web metric
#[derive(Clone, Copy, Debug, Deserialize, Serialize)]
pub enum ProgressiveWebMetricType {
    /// Time to first Paint
    FirstPaint,
    /// Time to first contentful paint
    FirstContentfulPaint,
    /// Time to interactive
    TimeToInteractive,
}

/// The reason why the pipeline id of an iframe is being updated.
#[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, MallocSizeOf, PartialEq, Serialize)]
pub enum UpdatePipelineIdReason {
    /// The pipeline id is being updated due to a navigation.
    Navigation,
    /// The pipeline id is being updated due to a history traversal.
    Traversal,
}

/// Messages sent from the constellation or layout to the script thread.
#[derive(Deserialize, Serialize)]
pub enum ConstellationControlMsg {
    /// Takes the associated window proxy out of "delaying-load-events-mode",
    /// used if a scheduled navigated was refused by the embedder.
    /// <https://html.spec.whatwg.org/multipage/#delaying-load-events-mode>
    StopDelayingLoadEventsMode(PipelineId),
    /// Sends the final response to script thread for fetching after all redirections
    /// have been resolved
    NavigationResponse(PipelineId, FetchResponseMsg),
    /// Gives a channel and ID to a layout, as well as the ID of that layout's parent
    AttachLayout(NewLayoutInfo),
    /// Window resized.  Sends a DOM event eventually, but first we combine events.
    Resize(PipelineId, WindowSizeData, WindowSizeType),
    /// Notifies script that window has been resized but to not take immediate action.
    ResizeInactive(PipelineId, WindowSizeData),
    /// Window switched from fullscreen mode.
    ExitFullScreen(PipelineId),
    /// Notifies the script that the document associated with this pipeline should 'unload'.
    UnloadDocument(PipelineId),
    /// Notifies the script that a pipeline should be closed.
    ExitPipeline(PipelineId, DiscardBrowsingContext),
    /// Notifies the script that the whole thread should be closed.
    ExitScriptThread,
    /// Sends a DOM event.
    SendEvent(PipelineId, CompositorEvent),
    /// Notifies script of the viewport.
    Viewport(PipelineId, Rect<f32, UnknownUnit>),
    /// Requests that the script thread immediately send the constellation the title of a pipeline.
    GetTitle(PipelineId),
    /// Notifies script thread of a change to one of its document's activity
    SetDocumentActivity(PipelineId, DocumentActivity),
    /// Set whether to use less resources by running timers at a heavily limited rate.
    SetThrottled(PipelineId, bool),
    /// Notify the containing iframe (in PipelineId) that the nested browsing context (BrowsingContextId) is throttled.
    SetThrottledInContainingIframe(PipelineId, BrowsingContextId, bool),
    /// Notifies script thread that a url should be loaded in this iframe.
    /// PipelineId is for the parent, BrowsingContextId is for the nested browsing context
    NavigateIframe(
        PipelineId,
        BrowsingContextId,
        LoadData,
        HistoryEntryReplacement,
    ),
    /// Post a message to a given window.
    PostMessage {
        /// The target of the message.
        target: PipelineId,
        /// The source of the message.
        source: PipelineId,
        /// The top level browsing context associated with the source pipeline.
        source_browsing_context: TopLevelBrowsingContextId,
        /// The expected origin of the target.
        target_origin: Option<ImmutableOrigin>,
        /// The source origin of the message.
        /// <https://html.spec.whatwg.org/multipage/#dom-messageevent-origin>
        source_origin: ImmutableOrigin,
        /// The data to be posted.
        data: StructuredSerializedData,
    },
    /// Updates the current pipeline ID of a given iframe.
    /// First PipelineId is for the parent, second is the new PipelineId for the frame.
    UpdatePipelineId(
        PipelineId,
        BrowsingContextId,
        TopLevelBrowsingContextId,
        PipelineId,
        UpdatePipelineIdReason,
    ),
    /// Updates the history state and url of a given pipeline.
    UpdateHistoryState(PipelineId, Option<HistoryStateId>, ServoUrl),
    /// Removes inaccesible history states.
    RemoveHistoryStates(PipelineId, Vec<HistoryStateId>),
    /// Set an iframe to be focused. Used when an element in an iframe gains focus.
    /// PipelineId is for the parent, BrowsingContextId is for the nested browsing context
    FocusIFrame(PipelineId, BrowsingContextId),
    /// Passes a webdriver command to the script thread for execution
    WebDriverScriptCommand(PipelineId, WebDriverScriptCommand),
    /// Notifies script thread that all animations are done
    TickAllAnimations(PipelineId, AnimationTickType),
    /// Notifies the script thread that a new Web font has been loaded, and thus the page should be
    /// reflowed.
    WebFontLoaded(PipelineId, bool /* success */),
    /// Cause a `load` event to be dispatched at the appropriate iframe element.
    DispatchIFrameLoadEvent {
        /// The frame that has been marked as loaded.
        target: BrowsingContextId,
        /// The pipeline that contains a frame loading the target pipeline.
        parent: PipelineId,
        /// The pipeline that has completed loading.
        child: PipelineId,
    },
    /// Cause a `storage` event to be dispatched at the appropriate window.
    /// The strings are key, old value and new value.
    DispatchStorageEvent(
        PipelineId,
        StorageType,
        ServoUrl,
        Option<String>,
        Option<String>,
        Option<String>,
    ),
    /// Report an error from a CSS parser for the given pipeline
    ReportCSSError(PipelineId, String, u32, u32, String),
    /// Reload the given page.
    Reload(PipelineId),
    /// Notifies the script thread about a new recorded paint metric.
    PaintMetric(PipelineId, ProgressiveWebMetricType, CrossProcessInstant),
    /// Notifies the media session about a user requested media session action.
    MediaSessionAction(PipelineId, MediaSessionActionType),
    /// Notifies script thread that WebGPU server has started
    SetWebGPUPort(IpcReceiver<WebGPUMsg>),
    /// The compositor scrolled and is updating the scroll states of the nodes in the given
    /// pipeline via the Constellation.
    SetScrollStates(PipelineId, Vec<ScrollState>),
    /// Send the paint time for a specific epoch.
    SetEpochPaintTime(PipelineId, Epoch, CrossProcessInstant),
}

impl fmt::Debug for ConstellationControlMsg {
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        use self::ConstellationControlMsg::*;
        let variant = match *self {
            StopDelayingLoadEventsMode(..) => "StopDelayingLoadsEventMode",
            NavigationResponse(..) => "NavigationResponse",
            AttachLayout(..) => "AttachLayout",
            Resize(..) => "Resize",
            ResizeInactive(..) => "ResizeInactive",
            UnloadDocument(..) => "UnloadDocument",
            ExitPipeline(..) => "ExitPipeline",
            ExitScriptThread => "ExitScriptThread",
            SendEvent(..) => "SendEvent",
            Viewport(..) => "Viewport",
            GetTitle(..) => "GetTitle",
            SetDocumentActivity(..) => "SetDocumentActivity",
            SetThrottled(..) => "SetThrottled",
            SetThrottledInContainingIframe(..) => "SetThrottledInContainingIframe",
            NavigateIframe(..) => "NavigateIframe",
            PostMessage { .. } => "PostMessage",
            UpdatePipelineId(..) => "UpdatePipelineId",
            UpdateHistoryState(..) => "UpdateHistoryState",
            RemoveHistoryStates(..) => "RemoveHistoryStates",
            FocusIFrame(..) => "FocusIFrame",
            WebDriverScriptCommand(..) => "WebDriverScriptCommand",
            TickAllAnimations(..) => "TickAllAnimations",
            WebFontLoaded(..) => "WebFontLoaded",
            DispatchIFrameLoadEvent { .. } => "DispatchIFrameLoadEvent",
            DispatchStorageEvent(..) => "DispatchStorageEvent",
            ReportCSSError(..) => "ReportCSSError",
            Reload(..) => "Reload",
            PaintMetric(..) => "PaintMetric",
            ExitFullScreen(..) => "ExitFullScreen",
            MediaSessionAction(..) => "MediaSessionAction",
            SetWebGPUPort(..) => "SetWebGPUPort",
            SetScrollStates(..) => "SetScrollStates",
            SetEpochPaintTime(..) => "SetEpochPaintTime",
        };
        write!(formatter, "ConstellationControlMsg::{}", variant)
    }
}

/// Used to determine if a script has any pending asynchronous activity.
#[derive(Clone, Copy, Debug, Deserialize, PartialEq, Serialize)]
pub enum DocumentState {
    /// The document has been loaded and is idle.
    Idle,
    /// The document is either loading or waiting on an event.
    Pending,
}

/// For a given pipeline, whether any animations are currently running
/// and any animation callbacks are queued
#[derive(Clone, Copy, Debug, Deserialize, Eq, PartialEq, Serialize)]
pub enum AnimationState {
    /// Animations are active but no callbacks are queued
    AnimationsPresent,
    /// Animations are active and callbacks are queued
    AnimationCallbacksPresent,
    /// No animations are active and no callbacks are queued
    NoAnimationsPresent,
    /// No animations are active but callbacks are queued
    NoAnimationCallbacksPresent,
}

/// The type of input represented by a multi-touch event.
#[derive(Clone, Copy, Debug, Deserialize, Serialize)]
pub enum TouchEventType {
    /// A new touch point came in contact with the screen.
    Down,
    /// An existing touch point changed location.
    Move,
    /// A touch point was removed from the screen.
    Up,
    /// The system stopped tracking a touch point.
    Cancel,
}

/// An opaque identifier for a touch point.
///
/// <http://w3c.github.io/touch-events/#widl-Touch-identifier>
#[derive(Clone, Copy, Debug, Deserialize, Eq, PartialEq, Serialize)]
pub struct TouchId(pub i32);

/// The mouse button involved in the event.
#[derive(Clone, Copy, Debug, Deserialize, Serialize)]
pub enum MouseButton {
    /// The left mouse button.
    Left = 1,
    /// The right mouse button.
    Right = 2,
    /// The middle mouse button.
    Middle = 4,
}

/// The types of mouse events
#[derive(Debug, Deserialize, MallocSizeOf, Serialize)]
pub enum MouseEventType {
    /// Mouse button clicked
    Click,
    /// Mouse button down
    MouseDown,
    /// Mouse button up
    MouseUp,
}

/// Mode to measure WheelDelta floats in
#[derive(Clone, Copy, Debug, Deserialize, PartialEq, Serialize)]
pub enum WheelMode {
    /// Delta values are specified in pixels
    DeltaPixel = 0x00,
    /// Delta values are specified in lines
    DeltaLine = 0x01,
    /// Delta values are specified in pages
    DeltaPage = 0x02,
}

/// The Wheel event deltas in every direction
#[derive(Clone, Copy, Debug, Deserialize, PartialEq, Serialize)]
pub struct WheelDelta {
    /// Delta in the left/right direction
    pub x: f64,
    /// Delta in the up/down direction
    pub y: f64,
    /// Delta in the direction going into/out of the screen
    pub z: f64,
    /// Mode to measure the floats in
    pub mode: WheelMode,
}

/// Events from the compositor that the script thread needs to know about
#[derive(Debug, Deserialize, Serialize)]
pub enum CompositorEvent {
    /// The window was resized.
    ResizeEvent(WindowSizeData, WindowSizeType),
    /// A mouse button state changed.
    MouseButtonEvent(
        MouseEventType,
        MouseButton,
        Point2D<f32>,
        Option<UntrustedNodeAddress>,
        Option<Point2D<f32>>,
        // Bitmask of MouseButton values representing the currently pressed buttons
        u16,
    ),
    /// The mouse was moved over a point (or was moved out of the recognizable region).
    MouseMoveEvent(
        Point2D<f32>,
        Option<UntrustedNodeAddress>,
        // Bitmask of MouseButton values representing the currently pressed buttons
        u16,
    ),
    /// A touch event was generated with a touch ID and location.
    TouchEvent(
        TouchEventType,
        TouchId,
        Point2D<f32>,
        Option<UntrustedNodeAddress>,
    ),
    /// A wheel event was generated with a delta in the X, Y, and/or Z directions
    WheelEvent(WheelDelta, Point2D<f32>, Option<UntrustedNodeAddress>),
    /// A key was pressed.
    KeyboardEvent(KeyboardEvent),
    /// An event from the IME is dispatched.
    CompositionEvent(CompositionEvent),
    /// Virtual keyboard was dismissed
    IMEDismissedEvent,
    /// Connected gamepad state updated
    GamepadEvent(GamepadEvent),
}

impl From<&CompositorEvent> for CompositorEventVariant {
    fn from(value: &CompositorEvent) -> Self {
        match value {
            CompositorEvent::ResizeEvent(..) => CompositorEventVariant::ResizeEvent,
            CompositorEvent::MouseButtonEvent(..) => CompositorEventVariant::MouseButtonEvent,
            CompositorEvent::MouseMoveEvent(..) => CompositorEventVariant::MouseMoveEvent,
            CompositorEvent::TouchEvent(..) => CompositorEventVariant::TouchEvent,
            CompositorEvent::WheelEvent(..) => CompositorEventVariant::WheelEvent,
            CompositorEvent::KeyboardEvent(..) => CompositorEventVariant::KeyboardEvent,
            CompositorEvent::CompositionEvent(..) => CompositorEventVariant::CompositionEvent,
            CompositorEvent::IMEDismissedEvent => CompositorEventVariant::IMEDismissedEvent,
            CompositorEvent::GamepadEvent(..) => CompositorEventVariant::GamepadEvent,
        }
    }
}

/// Requests a TimerEvent-Message be sent after the given duration.
#[derive(Debug, Deserialize, Serialize)]
pub struct TimerEventRequest(
    pub IpcSender<TimerEvent>,
    pub TimerSource,
    pub TimerEventId,
    pub Duration,
);

/// The message used to send a request to the timer scheduler.
#[derive(Debug, Deserialize, Serialize)]
pub struct TimerSchedulerMsg(pub TimerEventRequest);

/// Notifies the script thread to fire due timers.
/// `TimerSource` must be `FromWindow` when dispatched to `ScriptThread` and
/// must be `FromWorker` when dispatched to a `DedicatedGlobalWorkerScope`
#[derive(Debug, Deserialize, Serialize)]
pub struct TimerEvent(pub TimerSource, pub TimerEventId);

/// Describes the thread that requested the TimerEvent.
#[derive(Clone, Copy, Debug, Deserialize, MallocSizeOf, Serialize)]
pub enum TimerSource {
    /// The event was requested from a window (ScriptThread).
    FromWindow(PipelineId),
    /// The event was requested from a worker (DedicatedGlobalWorkerScope).
    FromWorker,
}

/// The id to be used for a `TimerEvent` is defined by the corresponding `TimerEventRequest`.
#[derive(Clone, Copy, Debug, Deserialize, Eq, MallocSizeOf, PartialEq, Serialize)]
pub struct TimerEventId(pub u32);

/// Data needed to construct a script thread.
///
/// NB: *DO NOT* add any Senders or Receivers here! pcwalton will have to rewrite your code if you
/// do! Use IPC senders and receivers instead.
pub struct InitialScriptState {
    /// The ID of the pipeline with which this script thread is associated.
    pub id: PipelineId,
    /// The subpage ID of this pipeline to create in its pipeline parent.
    /// If `None`, this is the root.
    pub parent_info: Option<PipelineId>,
    /// The ID of the browsing context this script is part of.
    pub browsing_context_id: BrowsingContextId,
    /// The ID of the top-level browsing context this script is part of.
    pub top_level_browsing_context_id: TopLevelBrowsingContextId,
    /// The ID of the opener, if any.
    pub opener: Option<BrowsingContextId>,
    /// Loading into a Secure Context
    pub inherited_secure_context: Option<bool>,
    /// A channel with which messages can be sent to us (the script thread).
    pub control_chan: IpcSender<ConstellationControlMsg>,
    /// A port on which messages sent by the constellation to script can be received.
    pub control_port: IpcReceiver<ConstellationControlMsg>,
    /// A channel on which messages can be sent to the constellation from script.
    pub script_to_constellation_chan: ScriptToConstellationChan,
    /// A handle to register script-(and associated layout-)threads for hang monitoring.
    pub background_hang_monitor_register: Box<dyn BackgroundHangMonitorRegister>,
    /// A sender layout to communicate to the constellation.
    pub layout_to_constellation_chan: IpcSender<LayoutMsg>,
    /// A channel to schedule timer events.
    pub scheduler_chan: IpcSender<TimerSchedulerMsg>,
    /// A channel to the resource manager thread.
    pub resource_threads: ResourceThreads,
    /// A channel to the bluetooth thread.
    pub bluetooth_thread: IpcSender<BluetoothRequest>,
    /// The image cache for this script thread.
    pub image_cache: Arc<dyn ImageCache>,
    /// A channel to the time profiler thread.
    pub time_profiler_chan: profile_traits::time::ProfilerChan,
    /// A channel to the memory profiler thread.
    pub mem_profiler_chan: mem::ProfilerChan,
    /// A channel to the developer tools, if applicable.
    pub devtools_chan: Option<IpcSender<ScriptToDevtoolsControlMsg>>,
    /// Information about the initial window size.
    pub window_size: WindowSizeData,
    /// The ID of the pipeline namespace for this script thread.
    pub pipeline_namespace_id: PipelineNamespaceId,
    /// A ping will be sent on this channel once the script thread shuts down.
    pub content_process_shutdown_chan: Sender<()>,
    /// A channel to the WebGL thread used in this pipeline.
    pub webgl_chan: Option<WebGLPipeline>,
    /// The XR device registry
    pub webxr_registry: webxr_api::Registry,
    /// The Webrender document ID associated with this thread.
    pub webrender_document: DocumentId,
    /// Access to the compositor across a process boundary.
    pub compositor_api: CrossProcessCompositorApi,
    /// Application window's GL Context for Media player
    pub player_context: WindowGLContext,
}

/// This trait allows creating a `ServiceWorkerManager` without depending on the `script`
/// crate.
pub trait ServiceWorkerManagerFactory {
    /// Create a `ServiceWorkerManager`.
    fn create(sw_senders: SWManagerSenders, origin: ImmutableOrigin);
}

/// Whether the sandbox attribute is present for an iframe element
#[derive(Clone, Copy, Debug, Deserialize, Eq, PartialEq, Serialize)]
pub enum IFrameSandboxState {
    /// Sandbox attribute is present
    IFrameSandboxed,
    /// Sandbox attribute is not present
    IFrameUnsandboxed,
}

/// Specifies the information required to load an auxiliary browsing context.
#[derive(Debug, Deserialize, Serialize)]
pub struct AuxiliaryBrowsingContextLoadInfo {
    /// Load data containing the url to load
    pub load_data: LoadData,
    /// The pipeline opener browsing context.
    pub opener_pipeline_id: PipelineId,
    /// The new top-level ID for the auxiliary.
    pub new_top_level_browsing_context_id: TopLevelBrowsingContextId,
    /// The new browsing context ID.
    pub new_browsing_context_id: BrowsingContextId,
    /// The new pipeline ID for the auxiliary.
    pub new_pipeline_id: PipelineId,
}

/// Specifies the information required to load an iframe.
#[derive(Debug, Deserialize, Serialize)]
pub struct IFrameLoadInfo {
    /// Pipeline ID of the parent of this iframe
    pub parent_pipeline_id: PipelineId,
    /// The ID for this iframe's nested browsing context.
    pub browsing_context_id: BrowsingContextId,
    /// The ID for the top-level ancestor browsing context of this iframe's nested browsing context.
    pub top_level_browsing_context_id: TopLevelBrowsingContextId,
    /// The new pipeline ID that the iframe has generated.
    pub new_pipeline_id: PipelineId,
    ///  Whether this iframe should be considered private
    pub is_private: bool,
    ///  Whether this iframe should be considered secure
    pub inherited_secure_context: Option<bool>,
    /// Wether this load should replace the current entry (reload). If true, the current
    /// entry will be replaced instead of a new entry being added.
    pub replace: HistoryEntryReplacement,
}

/// Specifies the information required to load a URL in an iframe.
#[derive(Debug, Deserialize, Serialize)]
pub struct IFrameLoadInfoWithData {
    /// The information required to load an iframe.
    pub info: IFrameLoadInfo,
    /// Load data containing the url to load
    pub load_data: LoadData,
    /// The old pipeline ID for this iframe, if a page was previously loaded.
    pub old_pipeline_id: Option<PipelineId>,
    /// Sandbox type of this iframe
    pub sandbox: IFrameSandboxState,
    /// The initial viewport size for this iframe.
    pub window_size: WindowSizeData,
}

bitflags! {
    #[derive(Debug, Default, Deserialize, Serialize)]
    /// Specifies if rAF should be triggered and/or CSS Animations and Transitions.
    pub struct AnimationTickType: u8 {
        /// Trigger a call to requestAnimationFrame.
        const REQUEST_ANIMATION_FRAME = 0b001;
        /// Trigger restyles for CSS Animations and Transitions.
        const CSS_ANIMATIONS_AND_TRANSITIONS = 0b010;
    }
}

/// The scroll state of a stacking context.
#[derive(Clone, Copy, Debug, Deserialize, PartialEq, Serialize)]
pub struct ScrollState {
    /// The ID of the scroll root.
    pub scroll_id: ExternalScrollId,
    /// The scrolling offset of this stacking context.
    pub scroll_offset: Vector2D<f32, LayoutPixel>,
}

/// Data about the window size.
#[derive(Clone, Copy, Debug, Deserialize, MallocSizeOf, PartialEq, Serialize)]
pub struct WindowSizeData {
    /// The size of the initial layout viewport, before parsing an
    /// <http://www.w3.org/TR/css-device-adapt/#initial-viewport>
    pub initial_viewport: Size2D<f32, CSSPixel>,

    /// The resolution of the window in dppx, not including any "pinch zoom" factor.
    pub device_pixel_ratio: Scale<f32, CSSPixel, DevicePixel>,
}

/// The type of window size change.
#[derive(Clone, Copy, Debug, Deserialize, Eq, MallocSizeOf, PartialEq, Serialize)]
pub enum WindowSizeType {
    /// Initial load.
    Initial,
    /// Window resize.
    Resize,
}

/// Messages to the constellation originating from the WebDriver server.
#[derive(Debug, Deserialize, Serialize)]
pub enum WebDriverCommandMsg {
    /// Get the window size.
    GetWindowSize(TopLevelBrowsingContextId, IpcSender<WindowSizeData>),
    /// Load a URL in the top-level browsing context with the given ID.
    LoadUrl(TopLevelBrowsingContextId, LoadData, IpcSender<LoadStatus>),
    /// Refresh the top-level browsing context with the given ID.
    Refresh(TopLevelBrowsingContextId, IpcSender<LoadStatus>),
    /// Pass a webdriver command to the script thread of the current pipeline
    /// of a browsing context.
    ScriptCommand(BrowsingContextId, WebDriverScriptCommand),
    /// Act as if keys were pressed in the browsing context with the given ID.
    SendKeys(BrowsingContextId, Vec<WebDriverInputEvent>),
    /// Act as if keys were pressed or release in the browsing context with the given ID.
    KeyboardAction(BrowsingContextId, KeyboardEvent),
    /// Act as if the mouse was clicked in the browsing context with the given ID.
    MouseButtonAction(MouseEventType, MouseButton, f32, f32),
    /// Act as if the mouse was moved in the browsing context with the given ID.
    MouseMoveAction(f32, f32),
    /// Set the window size.
    SetWindowSize(
        TopLevelBrowsingContextId,
        DeviceIntSize,
        IpcSender<WindowSizeData>,
    ),
    /// Take a screenshot of the window.
    TakeScreenshot(
        TopLevelBrowsingContextId,
        Option<Rect<f32, CSSPixel>>,
        IpcSender<Option<Image>>,
    ),
}

/// Resources required by workerglobalscopes
#[derive(Clone, Debug, Deserialize, Serialize)]
pub struct WorkerGlobalScopeInit {
    /// Chan to a resource thread
    pub resource_threads: ResourceThreads,
    /// Chan to the memory profiler
    pub mem_profiler_chan: mem::ProfilerChan,
    /// Chan to the time profiler
    pub time_profiler_chan: profile_time::ProfilerChan,
    /// To devtools sender
    pub to_devtools_sender: Option<IpcSender<ScriptToDevtoolsControlMsg>>,
    /// From devtools sender
    pub from_devtools_sender: Option<IpcSender<DevtoolScriptControlMsg>>,
    /// Messages to send to constellation
    pub script_to_constellation_chan: ScriptToConstellationChan,
    /// Message to send to the scheduler
    pub scheduler_chan: IpcSender<TimerSchedulerMsg>,
    /// The worker id
    pub worker_id: WorkerId,
    /// The pipeline id
    pub pipeline_id: PipelineId,
    /// The origin
    pub origin: ImmutableOrigin,
    /// The creation URL
    pub creation_url: Option<ServoUrl>,
    /// True if headless mode
    pub is_headless: bool,
    /// An optional string allowing the user agnet to be set for testing.
    pub user_agent: Cow<'static, str>,
    /// True if secure context
    pub inherited_secure_context: Option<bool>,
}

/// Common entities representing a network load origin
#[derive(Clone, Debug, Deserialize, Serialize)]
pub struct WorkerScriptLoadOrigin {
    /// referrer url
    pub referrer_url: Option<ServoUrl>,
    /// the referrer policy which is used
    pub referrer_policy: Option<ReferrerPolicy>,
    /// the pipeline id of the entity requesting the load
    pub pipeline_id: PipelineId,
}

/// Errors from executing a paint worklet
#[derive(Clone, Debug, Deserialize, Serialize)]
pub enum PaintWorkletError {
    /// Execution timed out.
    Timeout,
    /// No such worklet.
    WorkletNotFound,
}

impl From<RecvTimeoutError> for PaintWorkletError {
    fn from(_: RecvTimeoutError) -> PaintWorkletError {
        PaintWorkletError::Timeout
    }
}

/// Execute paint code in the worklet thread pool.
pub trait Painter: SpeculativePainter {
    /// <https://drafts.css-houdini.org/css-paint-api/#draw-a-paint-image>
    fn draw_a_paint_image(
        &self,
        size: Size2D<f32, CSSPixel>,
        zoom: Scale<f32, CSSPixel, DevicePixel>,
        properties: Vec<(Atom, String)>,
        arguments: Vec<String>,
    ) -> Result<DrawAPaintImageResult, PaintWorkletError>;
}

impl fmt::Debug for dyn Painter {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        fmt.debug_tuple("Painter")
            .field(&format_args!(".."))
            .finish()
    }
}

/// The result of executing paint code: the image together with any image URLs that need to be loaded.
///
/// TODO: this should return a WR display list. <https://github.com/servo/servo/issues/17497>
#[derive(Clone, Debug, Deserialize, MallocSizeOf, Serialize)]
pub struct DrawAPaintImageResult {
    /// The image height
    pub width: u32,
    /// The image width
    pub height: u32,
    /// The image format
    pub format: PixelFormat,
    /// The image drawn, or None if an invalid paint image was drawn
    pub image_key: Option<ImageKey>,
    /// Drawing the image might have requested loading some image URLs.
    pub missing_image_urls: Vec<ServoUrl>,
}

/// A Script to Constellation channel.
#[derive(Clone, Debug, Deserialize, Serialize)]
pub struct ScriptToConstellationChan {
    /// Sender for communicating with constellation thread.
    pub sender: IpcSender<(PipelineId, ScriptMsg)>,
    /// Used to identify the origin of the message.
    pub pipeline_id: PipelineId,
}

impl ScriptToConstellationChan {
    /// Send ScriptMsg and attach the pipeline_id to the message.
    pub fn send(&self, msg: ScriptMsg) -> Result<(), IpcError> {
        self.sender.send((self.pipeline_id, msg))
    }
}

/// A data-holder for serialized data and transferred objects.
/// <https://html.spec.whatwg.org/multipage/#structuredserializewithtransfer>
#[derive(Debug, Deserialize, MallocSizeOf, Serialize)]
pub struct StructuredSerializedData {
    /// Data serialized by SpiderMonkey.
    pub serialized: Vec<u8>,
    /// Serialized in a structured callback,
    pub blobs: Option<HashMap<BlobId, BlobImpl>>,
    /// Transferred objects.
    pub ports: Option<HashMap<MessagePortId, MessagePortImpl>>,
}

impl StructuredSerializedData {
    /// Clone the serialized data for use with broadcast-channels.
    pub fn clone_for_broadcast(&self) -> StructuredSerializedData {
        let serialized = self.serialized.clone();

        let blobs = if let Some(blobs) = self.blobs.as_ref() {
            let mut blob_clones = HashMap::with_capacity(blobs.len());

            for (original_id, blob) in blobs.iter() {
                let type_string = blob.type_string();

                if let BlobData::Memory(ref bytes) = blob.blob_data() {
                    let blob_clone = BlobImpl::new_from_bytes(bytes.clone(), type_string);

                    // Note: we insert the blob at the original id,
                    // otherwise this will not match the storage key as serialized by SM in `serialized`.
                    // The clone has it's own new Id however.
                    blob_clones.insert(*original_id, blob_clone);
                } else {
                    // Not panicking only because this is called from the constellation.
                    warn!("Serialized blob not in memory format(should never happen).");
                }
            }
            Some(blob_clones)
        } else {
            None
        };

        if self.ports.is_some() {
            // Not panicking only because this is called from the constellation.
            warn!("Attempt to broadcast structured serialized data including ports(should never happen).");
        }

        StructuredSerializedData {
            serialized,
            blobs,
            // Ports cannot be broadcast.
            ports: None,
        }
    }
}

/// A task on the <https://html.spec.whatwg.org/multipage/#port-message-queue>
#[derive(Debug, Deserialize, MallocSizeOf, Serialize)]
pub struct PortMessageTask {
    /// The origin of this task.
    pub origin: ImmutableOrigin,
    /// A data-holder for serialized data and transferred objects.
    pub data: StructuredSerializedData,
}

/// Messages for communication between the constellation and a global managing ports.
#[derive(Debug, Deserialize, Serialize)]
pub enum MessagePortMsg {
    /// Complete the transfer for a batch of ports.
    CompleteTransfer(HashMap<MessagePortId, VecDeque<PortMessageTask>>),
    /// Complete the transfer of a single port,
    /// whose transfer was pending because it had been requested
    /// while a previous failed transfer was being rolled-back.
    CompletePendingTransfer(MessagePortId, VecDeque<PortMessageTask>),
    /// Remove a port, the entangled one doesn't exists anymore.
    RemoveMessagePort(MessagePortId),
    /// Handle a new port-message-task.
    NewTask(MessagePortId, PortMessageTask),
}

/// Message for communication between the constellation and a global managing broadcast channels.
#[derive(Debug, Deserialize, Serialize)]
pub struct BroadcastMsg {
    /// The origin of this message.
    pub origin: ImmutableOrigin,
    /// The name of the channel.
    pub channel_name: String,
    /// A data-holder for serialized data.
    pub data: StructuredSerializedData,
}

impl Clone for BroadcastMsg {
    fn clone(&self) -> BroadcastMsg {
        BroadcastMsg {
            data: self.data.clone_for_broadcast(),
            origin: self.origin.clone(),
            channel_name: self.channel_name.clone(),
        }
    }
}

/// The type of MediaSession action.
/// <https://w3c.github.io/mediasession/#enumdef-mediasessionaction>
#[derive(Clone, Debug, Deserialize, Eq, Hash, MallocSizeOf, PartialEq, Serialize)]
pub enum MediaSessionActionType {
    /// The action intent is to resume playback.
    Play,
    /// The action intent is to pause the currently active playback.
    Pause,
    /// The action intent is to move the playback time backward by a short period (i.e. a few
    /// seconds).
    SeekBackward,
    /// The action intent is to move the playback time forward by a short period (i.e. a few
    /// seconds).
    SeekForward,
    /// The action intent is to either start the current playback from the beginning if the
    /// playback has a notion, of beginning, or move to the previous item in the playlist if the
    /// playback has a notion of playlist.
    PreviousTrack,
    /// The action is to move to the playback to the next item in the playlist if the playback has
    /// a notion of playlist.
    NextTrack,
    /// The action intent is to skip the advertisement that is currently playing.
    SkipAd,
    /// The action intent is to stop the playback and clear the state if appropriate.
    Stop,
    /// The action intent is to move the playback time to a specific time.
    SeekTo,
}

impl From<i32> for MediaSessionActionType {
    fn from(value: i32) -> MediaSessionActionType {
        match value {
            1 => MediaSessionActionType::Play,
            2 => MediaSessionActionType::Pause,
            3 => MediaSessionActionType::SeekBackward,
            4 => MediaSessionActionType::SeekForward,
            5 => MediaSessionActionType::PreviousTrack,
            6 => MediaSessionActionType::NextTrack,
            7 => MediaSessionActionType::SkipAd,
            8 => MediaSessionActionType::Stop,
            9 => MediaSessionActionType::SeekTo,
            _ => panic!("Unknown MediaSessionActionType"),
        }
    }
}

#[derive(
    Clone, Copy, Debug, Deserialize, Eq, Hash, MallocSizeOf, Ord, PartialEq, PartialOrd, Serialize,
)]
/// Index of gamepad in list of system's connected gamepads
pub struct GamepadIndex(pub usize);

#[derive(Clone, Debug, Deserialize, Serialize)]
/// The minimum and maximum values that can be reported for axis or button input from this gamepad
pub struct GamepadInputBounds {
    /// Minimum and maximum axis values
    pub axis_bounds: (f64, f64),
    /// Minimum and maximum button values
    pub button_bounds: (f64, f64),
}

#[derive(Clone, Debug, Deserialize, Serialize)]
/// The haptic effects supported by this gamepad
pub struct GamepadSupportedHapticEffects {
    /// Gamepad support for dual rumble effects
    pub supports_dual_rumble: bool,
    /// Gamepad support for trigger rumble effects
    pub supports_trigger_rumble: bool,
}

#[derive(Clone, Debug, Deserialize, Serialize)]
/// The type of Gamepad event
pub enum GamepadEvent {
    /// A new gamepad has been connected
    /// <https://www.w3.org/TR/gamepad/#event-gamepadconnected>
    Connected(
        GamepadIndex,
        String,
        GamepadInputBounds,
        GamepadSupportedHapticEffects,
    ),
    /// An existing gamepad has been disconnected
    /// <https://www.w3.org/TR/gamepad/#event-gamepaddisconnected>
    Disconnected(GamepadIndex),
    /// An existing gamepad has been updated
    /// <https://www.w3.org/TR/gamepad/#receiving-inputs>
    Updated(GamepadIndex, GamepadUpdateType),
}

#[derive(Clone, Debug, Deserialize, Serialize)]
/// The type of Gamepad input being updated
pub enum GamepadUpdateType {
    /// Axis index and input value
    /// <https://www.w3.org/TR/gamepad/#dfn-represents-a-standard-gamepad-axis>
    Axis(usize, f64),
    /// Button index and input value
    /// <https://www.w3.org/TR/gamepad/#dfn-represents-a-standard-gamepad-button>
    Button(usize, f64),
}