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Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/ActionContext.cs

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+using System.Collections.Generic;
+using System.Linq;
+using UnityEngine;
+using UnityEngine.Playables;
+using UnityEngine.Timeline;
+
+namespace UnityEditor.Timeline.Actions
+{
+    /// <summary>
+    /// Action context to be used by actions.
+    /// </summary>
+    /// <seealso cref="Invoker"/>
+    /// <seealso cref="TimelineAction"/>
+    public struct ActionContext
+    {
+        IEnumerable<TrackAsset> m_Tracks;
+        IEnumerable<TimelineClip> m_Clips;
+        IEnumerable<IMarker> m_Markers;
+
+        /// <summary>
+        ///  The Timeline asset that is currently opened in the Timeline window.
+        /// </summary>
+        public TimelineAsset timeline;
+
+        /// <summary>
+        ///  The PlayableDirector that is used to play the current Timeline asset.
+        /// </summary>
+        public PlayableDirector director;
+
+        /// <summary>
+        ///  Time based on the position of the cursor on the timeline (in seconds).
+        ///  null if the time is not available (in case of a shortcut for example).
+        /// </summary>
+        public double? invocationTime;
+
+        /// <summary>
+        ///  Tracks that will be used by the actions.
+        /// </summary>
+        public IEnumerable<TrackAsset> tracks
+        {
+            get => m_Tracks ?? Enumerable.Empty<TrackAsset>();
+            set => m_Tracks = value;
+        }
+
+        /// <summary>
+        ///  Clips that will be used by the actions.
+        /// </summary>
+        public IEnumerable<TimelineClip> clips
+        {
+            get => m_Clips ?? Enumerable.Empty<TimelineClip>();
+            set => m_Clips = value;
+        }
+
+        /// <summary>
+        ///  Markers that will be used by the actions.
+        /// </summary>
+        public IEnumerable<IMarker> markers
+        {
+            get => m_Markers ?? Enumerable.Empty<IMarker>();
+            set => m_Markers = value;
+        }
+    }
+}

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/ActionContext.cs.meta

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Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/ActionManager.cs

@@ -0,0 +1,306 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using UnityEngine;
+using UnityEngine.Timeline;
+
+namespace UnityEditor.Timeline.Actions
+{
+    static class ActionManager
+    {
+        static bool s_ShowActionTriggeredByShortcut = false;
+
+        public static readonly IReadOnlyList<TimelineAction> TimelineActions = InstantiateClassesOfType<TimelineAction>();
+        public static readonly IReadOnlyList<ClipAction> ClipActions = InstantiateClassesOfType<ClipAction>();
+        public static readonly IReadOnlyList<TrackAction> TrackActions = InstantiateClassesOfType<TrackAction>();
+        public static readonly IReadOnlyList<MarkerAction> MarkerActions = InstantiateClassesOfType<MarkerAction>();
+
+        public static readonly IReadOnlyList<TimelineAction> TimelineActionsWithShortcuts = ActionsWithShortCuts(TimelineActions);
+        public static readonly IReadOnlyList<ClipAction> ClipActionsWithShortcuts = ActionsWithShortCuts(ClipActions);
+        public static readonly IReadOnlyList<TrackAction> TrackActionsWithShortcuts = ActionsWithShortCuts(TrackActions);
+        public static readonly IReadOnlyList<MarkerAction> MarkerActionsWithShortcuts = ActionsWithShortCuts(MarkerActions);
+
+        public static readonly HashSet<Type> ActionsWithAutoUndo = TypesWithAttribute<ApplyDefaultUndoAttribute>();
+
+        public static TU GetCachedAction<T, TU>(this IReadOnlyList<TU> list) where T : TU
+        {
+            return list.FirstOrDefault(x => x.GetType() == typeof(T));
+        }
+
+        public static void GetMenuEntries(IReadOnlyList<TimelineAction> actions, Vector2? mousePos, List<MenuActionItem> menuItems)
+        {
+            var globalContext = TimelineEditor.CurrentContext(mousePos);
+            foreach (var action in actions)
+            {
+                try
+                {
+                    BuildMenu(action, globalContext, menuItems);
+                }
+                catch (Exception e)
+                {
+                    Debug.LogException(e);
+                }
+            }
+        }
+
+        public static void GetMenuEntries(IReadOnlyList<TrackAction> actions, List<MenuActionItem> menuItems)
+        {
+            var tracks = SelectionManager.SelectedTracks();
+            if (!tracks.Any())
+                return;
+
+            foreach (var action in actions)
+            {
+                try
+                {
+                    BuildMenu(action, tracks, menuItems);
+                }
+                catch (Exception e)
+                {
+                    Debug.LogException(e);
+                }
+            }
+        }
+
+        public static void GetMenuEntries(IReadOnlyList<ClipAction> actions, List<MenuActionItem> menuItems)
+        {
+            var clips = SelectionManager.SelectedClips();
+            bool any = clips.Any();
+            if (!clips.Any())
+                return;
+
+            foreach (var action in actions)
+            {
+                try
+                {
+                    if (action is EditSubTimeline editSubTimelineAction)
+                        editSubTimelineAction.AddMenuItem(menuItems);
+                    else if (any)
+                        BuildMenu(action, clips, menuItems);
+                }
+                catch (Exception e)
+                {
+                    Debug.LogException(e);
+                }
+            }
+        }
+
+        public static void GetMenuEntries(IReadOnlyList<MarkerAction> actions, List<MenuActionItem> menuItems)
+        {
+            var markers = SelectionManager.SelectedMarkers();
+            if (!markers.Any())
+                return;
+
+            foreach (var action in actions)
+            {
+                try
+                {
+                    BuildMenu(action, markers, menuItems);
+                }
+                catch (Exception e)
+                {
+                    Debug.LogException(e);
+                }
+            }
+        }
+
+        static void BuildMenu(TimelineAction action, ActionContext context, List<MenuActionItem> menuItems)
+        {
+            BuildMenu(action, action.Validate(context), () => ExecuteTimelineAction(action, context), menuItems);
+        }
+
+        static void BuildMenu(TrackAction action, IEnumerable<TrackAsset> tracks, List<MenuActionItem> menuItems)
+        {
+            BuildMenu(action, action.Validate(tracks), () => ExecuteTrackAction(action, tracks), menuItems);
+        }
+
+        static void BuildMenu(ClipAction action, IEnumerable<TimelineClip> clips, List<MenuActionItem> menuItems)
+        {
+            BuildMenu(action, action.Validate(clips), () => ExecuteClipAction(action, clips), menuItems);
+        }
+
+        static void BuildMenu(MarkerAction action, IEnumerable<IMarker> markers, List<MenuActionItem> menuItems)
+        {
+            BuildMenu(action, action.Validate(markers), () => ExecuteMarkerAction(action, markers), menuItems);
+        }
+
+        static void BuildMenu(IAction action, ActionValidity validity, GenericMenu.MenuFunction executeFunction, List<MenuActionItem> menuItems)
+        {
+            var menuAttribute = action.GetType().GetCustomAttribute<MenuEntryAttribute>(false);
+            if (menuAttribute == null)
+                return;
+
+            if (validity == ActionValidity.NotApplicable)
+                return;
+
+            var menuActionItem = new MenuActionItem
+            {
+                state = validity,
+                entryName = action.GetMenuEntryName(),
+                priority = menuAttribute.priority,
+                category = menuAttribute.subMenuPath,
+                isActiveInMode = action.IsActionActiveInMode(TimelineWindow.instance.currentMode.mode),
+                shortCut = action.GetShortcut(),
+                callback = executeFunction,
+                isChecked = action.IsChecked()
+            };
+            menuItems.Add(menuActionItem);
+        }
+
+        internal static void BuildMenu(GenericMenu menu, List<MenuActionItem> items)
+        {
+            // sorted the outer menu by priority, then sort the innermenu by priority
+            var sortedItems =
+                items.GroupBy(x => string.IsNullOrEmpty(x.category) ? x.entryName : x.category).OrderBy(x => x.Min(y => y.priority)).SelectMany(x => x.OrderBy(z => z.priority));
+
+            int lastPriority = Int32.MinValue;
+            string lastCategory = string.Empty;
+
+            foreach (var s in sortedItems)
+            {
+                if (s.state == ActionValidity.NotApplicable)
+                    continue;
+
+                var priority = s.priority;
+                if (lastPriority != int.MinValue && priority / MenuPriority.separatorAt > lastPriority / MenuPriority.separatorAt)
+                {
+                    string path = string.Empty;
+                    if (lastCategory == s.category)
+                        path = s.category;
+                    menu.AddSeparator(path);
+                }
+
+                lastPriority = priority;
+                lastCategory = s.category;
+
+                string entry = s.category + s.entryName;
+                if (!string.IsNullOrEmpty(s.shortCut))
+                    entry += " " + s.shortCut;
+
+                if (s.state == ActionValidity.Valid && s.isActiveInMode)
+                    menu.AddItem(new GUIContent(entry), s.isChecked, s.callback);
+                else
+                    menu.AddDisabledItem(new GUIContent(entry), s.isChecked);
+            }
+        }
+
+        public static bool HandleShortcut(Event evt)
+        {
+            if (EditorGUI.IsEditingTextField())
+                return false;
+
+            return HandleShortcut(evt, TimelineActionsWithShortcuts, (x) => ExecuteTimelineAction(x, TimelineEditor.CurrentContext())) ||
+                HandleShortcut(evt, ClipActionsWithShortcuts, (x => ExecuteClipAction(x, SelectionManager.SelectedClips()))) ||
+                HandleShortcut(evt, TrackActionsWithShortcuts, (x => ExecuteTrackAction(x, SelectionManager.SelectedTracks()))) ||
+                HandleShortcut(evt, MarkerActionsWithShortcuts, (x => ExecuteMarkerAction(x, SelectionManager.SelectedMarkers())));
+        }
+
+        public static bool HandleShortcut<T>(Event evt, IReadOnlyList<T> actions, Func<T, bool> invoke) where T : class, IAction
+        {
+            for (int i = 0; i < actions.Count; i++)
+            {
+                var action = actions[i];
+                var attr = action.GetType().GetCustomAttributes(typeof(ShortcutAttribute), true);
+
+                foreach (ShortcutAttribute shortcut in attr)
+                {
+                    if (shortcut.MatchesEvent(evt))
+                    {
+                        if (s_ShowActionTriggeredByShortcut)
+                            Debug.Log(action.GetType().Name);
+
+                        if (!action.IsActionActiveInMode(TimelineWindow.instance.currentMode.mode))
+                            continue;
+
+                        if (invoke(action))
+                            return true;
+                    }
+                }
+            }
+
+            return false;
+        }
+
+        public static bool ExecuteTimelineAction(TimelineAction timelineAction, ActionContext context)
+        {
+            if (timelineAction.Validate(context) == ActionValidity.Valid)
+            {
+                if (timelineAction.HasAutoUndo())
+                    UndoExtensions.RegisterContext(context, timelineAction.GetUndoName());
+                return timelineAction.Execute(context);
+            }
+            return false;
+        }
+
+        public static bool ExecuteTrackAction(TrackAction trackAction, IEnumerable<TrackAsset> tracks)
+        {
+            if (tracks != null && tracks.Any() && trackAction.Validate(tracks) == ActionValidity.Valid)
+            {
+                if (trackAction.HasAutoUndo())
+                    UndoExtensions.RegisterTracks(tracks, trackAction.GetUndoName());
+                return trackAction.Execute(tracks);
+            }
+            return false;
+        }
+
+        public static bool ExecuteClipAction(ClipAction clipAction, IEnumerable<TimelineClip> clips)
+        {
+            if (clips != null && clips.Any() && clipAction.Validate(clips) == ActionValidity.Valid)
+            {
+                if (clipAction.HasAutoUndo())
+                    UndoExtensions.RegisterClips(clips, clipAction.GetUndoName());
+                return clipAction.Execute(clips);
+            }
+            return false;
+        }
+
+        public static bool ExecuteMarkerAction(MarkerAction markerAction, IEnumerable<IMarker> markers)
+        {
+            if (markers != null && markers.Any() && markerAction.Validate(markers) == ActionValidity.Valid)
+            {
+                if (markerAction.HasAutoUndo())
+                    UndoExtensions.RegisterMarkers(markers, markerAction.GetUndoName());
+                return markerAction.Execute(markers);
+            }
+            return false;
+        }
+
+        static List<T> InstantiateClassesOfType<T>() where T : class
+        {
+            var typeCollection = TypeCache.GetTypesDerivedFrom(typeof(T));
+            var list = new List<T>(typeCollection.Count);
+            for (int i = 0; i < typeCollection.Count; i++)
+            {
+                if (typeCollection[i].IsAbstract || typeCollection[i].IsGenericType)
+                    continue;
+
+                if (typeCollection[i].GetConstructor(Type.EmptyTypes) == null)
+                {
+                    Debug.LogWarning($"{typeCollection[i].FullName} requires a default constructor to be automatically instantiated by Timeline");
+                    continue;
+                }
+
+                list.Add((T)Activator.CreateInstance(typeCollection[i]));
+            }
+            return list;
+        }
+
+        static List<T> ActionsWithShortCuts<T>(IReadOnlyList<T> list)
+        {
+            return list.Where(x => x.GetType().GetCustomAttributes(typeof(ShortcutAttribute), true).Length > 0).ToList();
+        }
+
+        static HashSet<System.Type> TypesWithAttribute<T>() where T : Attribute
+        {
+            var hashSet = new HashSet<System.Type>();
+            var typeCollection = TypeCache.GetTypesWithAttribute(typeof(T));
+            for (int i = 0; i < typeCollection.Count; i++)
+            {
+                hashSet.Add(typeCollection[i]);
+            }
+
+            return hashSet;
+        }
+    }
+}

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/ActionManager.cs.meta

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+  assetBundleVariant: 

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/ClipAction.cs

@@ -0,0 +1,36 @@
+using System.Collections.Generic;
+using UnityEngine.Timeline;
+
+namespace UnityEditor.Timeline.Actions
+{
+    /// <summary>
+    /// Base class for a clip action.
+    /// Inherit from this class to make an action that would react on selected clips after a menu click and/or a key shortcut.
+    /// </summary>
+    /// <example>
+    /// Simple Clip Action example (with context menu and shortcut support).
+    /// <code source="../../DocCodeExamples/ActionExamples.cs" region="declare-sampleClipAction" title="SampleClipAction"/>
+    /// </example>
+    /// <remarks>
+    /// To add an action as a menu item in the Timeline context menu, add <see cref="MenuEntryAttribute"/> on the action class.
+    /// To make an action to react to a shortcut, use the Shortcut Manager API with <see cref="TimelineShortcutAttribute"/>.
+    /// <seealso cref="UnityEditor.ShortcutManagement.ShortcutAttribute"/>
+    /// </remarks>
+    [ActiveInMode(TimelineModes.Default)]
+    public abstract class ClipAction : IAction
+    {
+        /// <summary>
+        /// Execute the action based on clips.
+        /// </summary>
+        /// <param name="clips">clips that the action will act on.</param>
+        /// <returns>Returns true if the action has been correctly executed, false otherwise.</returns>
+        public abstract bool Execute(IEnumerable<TimelineClip> clips);
+
+        /// <summary>
+        ///  Defines the validity of an Action for a given set of clips.
+        /// </summary>
+        ///  <param name="clips">The clips that the action will act on.</param>
+        /// <returns>The validity of the set of clips.</returns>
+        public abstract ActionValidity Validate(IEnumerable<TimelineClip> clips);
+    }
+}

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/ClipAction.cs.meta

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Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/ClipsActions.cs

@@ -0,0 +1,392 @@
+using System.Collections.Generic;
+using System.Linq;
+using JetBrains.Annotations;
+using UnityEditor.Timeline.Actions;
+using UnityEngine;
+using UnityEngine.Timeline;
+using UnityEngine.Playables;
+
+namespace UnityEditor.Timeline
+{
+    [MenuEntry("Edit in Animation Window", MenuPriority.ClipEditActionSection.editInAnimationWindow), UsedImplicitly]
+    class EditClipInAnimationWindow : ClipAction
+    {
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips)
+        {
+            if (!GetEditableClip(clips, out _, out _))
+                return ActionValidity.NotApplicable;
+            return ActionValidity.Valid;
+        }
+
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            TimelineClip clip;
+            AnimationClip clipToEdit;
+            if (!GetEditableClip(clips, out clip, out clipToEdit))
+                return false;
+
+            GameObject gameObject = null;
+            if (TimelineEditor.inspectedDirector != null)
+                gameObject = TimelineUtility.GetSceneGameObject(TimelineEditor.inspectedDirector, clip.GetParentTrack());
+
+            var timeController = TimelineAnimationUtilities.CreateTimeController(clip);
+            TimelineAnimationUtilities.EditAnimationClipWithTimeController(
+                clipToEdit, timeController, clip.animationClip != null ? gameObject : null);
+
+            return true;
+        }
+
+        private static bool GetEditableClip(IEnumerable<TimelineClip> clips, out TimelineClip clip, out AnimationClip animClip)
+        {
+            clip = null;
+            animClip = null;
+
+            if (clips.Count() != 1)
+                return false;
+
+            clip = clips.FirstOrDefault();
+            if (clip == null)
+                return false;
+
+            if (clip.animationClip != null)
+                animClip = clip.animationClip;
+            else if (clip.curves != null && !clip.curves.empty)
+                animClip = clip.curves;
+
+            return animClip != null;
+        }
+    }
+
+    [MenuEntry("Edit Sub-Timeline", MenuPriority.ClipEditActionSection.editSubTimeline), UsedImplicitly]
+    class EditSubTimeline : ClipAction
+    {
+        private static readonly string MultiItemPrefix = "Edit Sub-Timelines/";
+        private static readonly string SingleItemPrefix = "Edit ";
+
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips)
+        {
+            if (clips == null || clips.Count() != 1 || TimelineEditor.inspectedDirector == null)
+                return ActionValidity.NotApplicable;
+
+            var clip = clips.First();
+            var directors = TimelineUtility.GetSubTimelines(clip, TimelineEditor.inspectedDirector);
+            return directors.Any(x => x != null) ? ActionValidity.Valid : ActionValidity.NotApplicable;
+        }
+
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            if (Validate(clips) != ActionValidity.Valid) return false;
+
+            var clip = clips.First();
+
+            var directors = TimelineUtility.GetSubTimelines(clip, TimelineEditor.inspectedDirector);
+            ExecuteInternal(directors, 0, clip);
+
+            return true;
+        }
+
+        static void ExecuteInternal(IList<PlayableDirector> directors, int directorIndex, TimelineClip clip)
+        {
+            SelectionManager.Clear();
+            TimelineWindow.instance.SetCurrentTimeline(directors[directorIndex], clip);
+        }
+
+        internal void AddMenuItem(List<MenuActionItem> menuItems)
+        {
+            var clips = TimelineEditor.selectedClips;
+            if (clips == null || clips.Length != 1)
+                return;
+
+            var mode = TimelineWindow.instance.currentMode.mode;
+            MenuEntryAttribute menuAttribute = GetType().GetCustomAttributes(typeof(MenuEntryAttribute), false).OfType<MenuEntryAttribute>().FirstOrDefault();
+            var menuItem = new MenuActionItem()
+            {
+                category = menuAttribute.subMenuPath ?? string.Empty,
+                entryName = menuAttribute.name,
+                isActiveInMode = this.IsActionActiveInMode(mode),
+                priority = menuAttribute.priority,
+                state = Validate(clips),
+                callback = null
+            };
+
+            var subDirectors = TimelineUtility.GetSubTimelines(clips[0], TimelineEditor.inspectedDirector);
+            if (subDirectors.Count == 1)
+            {
+                menuItem.entryName = SingleItemPrefix + DisplayNameHelper.GetDisplayName(subDirectors[0]);
+                menuItem.callback = () =>
+                {
+                    Execute(clips);
+                };
+                menuItems.Add(menuItem);
+            }
+            else
+            {
+                for (int i = 0; i < subDirectors.Count; i++)
+                {
+                    var index = i;
+                    menuItem.category = MultiItemPrefix;
+                    menuItem.entryName = DisplayNameHelper.GetDisplayName(subDirectors[i]);
+                    menuItem.callback = () =>
+                    {
+                        ExecuteInternal(subDirectors, index, clips[0]);
+                    };
+                    menuItems.Add(menuItem);
+                }
+            }
+        }
+    }
+
+    [MenuEntry("Editing/Trim Start", MenuPriority.ClipActionSection.trimStart)]
+    [Shortcut(Shortcuts.Clip.trimStart), UsedImplicitly]
+    class TrimStart : ClipAction
+    {
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips)
+        {
+            return clips.All(x => TimelineEditor.inspectedSequenceTime <= x.start || TimelineEditor.inspectedSequenceTime >= x.start + x.duration) ? ActionValidity.Invalid : ActionValidity.Valid;
+        }
+
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            return ClipModifier.TrimStart(clips, TimelineEditor.inspectedSequenceTime);
+        }
+    }
+
+    [MenuEntry("Editing/Trim End", MenuPriority.ClipActionSection.trimEnd), UsedImplicitly]
+    [Shortcut(Shortcuts.Clip.trimEnd)]
+    class TrimEnd : ClipAction
+    {
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips)
+        {
+            return clips.All(x => TimelineEditor.inspectedSequenceTime <= x.start || TimelineEditor.inspectedSequenceTime >= x.start + x.duration) ? ActionValidity.Invalid : ActionValidity.Valid;
+        }
+
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            return ClipModifier.TrimEnd(clips, TimelineEditor.inspectedSequenceTime);
+        }
+    }
+
+    [Shortcut(Shortcuts.Clip.split)]
+    [MenuEntry("Editing/Split", MenuPriority.ClipActionSection.split), UsedImplicitly]
+    class Split : ClipAction
+    {
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips)
+        {
+            return clips.All(x => TimelineEditor.inspectedSequenceTime <= x.start || TimelineEditor.inspectedSequenceTime >= x.start + x.duration) ? ActionValidity.Invalid : ActionValidity.Valid;
+        }
+
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            bool success = ClipModifier.Split(clips, TimelineEditor.inspectedSequenceTime, TimelineEditor.inspectedDirector);
+            if (success)
+                TimelineEditor.Refresh(RefreshReason.ContentsAddedOrRemoved);
+            return success;
+        }
+    }
+
+    [MenuEntry("Editing/Complete Last Loop", MenuPriority.ClipActionSection.completeLastLoop), UsedImplicitly]
+    class CompleteLastLoop : ClipAction
+    {
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips)
+        {
+            bool canDisplay = clips.Any(TimelineHelpers.HasUsableAssetDuration);
+            return canDisplay ? ActionValidity.Valid : ActionValidity.Invalid;
+        }
+
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            return ClipModifier.CompleteLastLoop(clips);
+        }
+    }
+
+    [MenuEntry("Editing/Trim Last Loop", MenuPriority.ClipActionSection.trimLastLoop), UsedImplicitly]
+    class TrimLastLoop : ClipAction
+    {
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips)
+        {
+            bool canDisplay = clips.Any(TimelineHelpers.HasUsableAssetDuration);
+            return canDisplay ? ActionValidity.Valid : ActionValidity.Invalid;
+        }
+
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            return ClipModifier.TrimLastLoop(clips);
+        }
+    }
+
+    [MenuEntry("Editing/Match Duration", MenuPriority.ClipActionSection.matchDuration), UsedImplicitly]
+    class MatchDuration : ClipAction
+    {
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips)
+        {
+            return clips.Count() > 1 ? ActionValidity.Valid : ActionValidity.Invalid;
+        }
+
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            return ClipModifier.MatchDuration(clips);
+        }
+    }
+
+    [MenuEntry("Editing/Double Speed", MenuPriority.ClipActionSection.doubleSpeed), UsedImplicitly]
+    class DoubleSpeed : ClipAction
+    {
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips)
+        {
+            bool canDisplay = clips.All(x => x.SupportsSpeedMultiplier());
+
+            return canDisplay ? ActionValidity.Valid : ActionValidity.Invalid;
+        }
+
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            return ClipModifier.DoubleSpeed(clips);
+        }
+    }
+
+    [MenuEntry("Editing/Half Speed", MenuPriority.ClipActionSection.halfSpeed), UsedImplicitly]
+    class HalfSpeed : ClipAction
+    {
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips)
+        {
+            bool canDisplay = clips.All(x => x.SupportsSpeedMultiplier());
+
+            return canDisplay ? ActionValidity.Valid : ActionValidity.Invalid;
+        }
+
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            return ClipModifier.HalfSpeed(clips);
+        }
+    }
+
+    [MenuEntry("Editing/Reset Duration", MenuPriority.ClipActionSection.resetDuration), UsedImplicitly]
+    class ResetDuration : ClipAction
+    {
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips)
+        {
+            bool canDisplay = clips.Any(TimelineHelpers.HasUsableAssetDuration);
+            return canDisplay ? ActionValidity.Valid : ActionValidity.Invalid;
+        }
+
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            return ClipModifier.ResetEditing(clips);
+        }
+    }
+
+    [MenuEntry("Editing/Reset Speed", MenuPriority.ClipActionSection.resetSpeed), UsedImplicitly]
+    class ResetSpeed : ClipAction
+    {
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips)
+        {
+            bool canDisplay = clips.All(x => x.SupportsSpeedMultiplier());
+
+            return canDisplay ? ActionValidity.Valid : ActionValidity.Invalid;
+        }
+
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            return ClipModifier.ResetSpeed(clips);
+        }
+    }
+
+    [MenuEntry("Editing/Reset All", MenuPriority.ClipActionSection.resetAll), UsedImplicitly]
+    class ResetAll : ClipAction
+    {
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips)
+        {
+            bool canDisplay = clips.Any(TimelineHelpers.HasUsableAssetDuration) || clips.All(x => x.SupportsSpeedMultiplier());
+
+            return canDisplay ? ActionValidity.Valid : ActionValidity.Invalid;
+        }
+
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            var speedResult = ClipModifier.ResetSpeed(clips);
+            var editResult = ClipModifier.ResetEditing(clips);
+            return speedResult || editResult;
+        }
+    }
+
+    [MenuEntry("Tile", MenuPriority.ClipActionSection.tile), UsedImplicitly]
+    class Tile : ClipAction
+    {
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips)
+        {
+            return clips.Count() > 1 ? ActionValidity.Valid : ActionValidity.Invalid;
+        }
+
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            return ClipModifier.Tile(clips);
+        }
+    }
+
+    [MenuEntry("Find Source Asset", MenuPriority.ClipActionSection.findSourceAsset), UsedImplicitly]
+    [ActiveInMode(TimelineModes.Default | TimelineModes.ReadOnly)]
+    class FindSourceAsset : ClipAction
+    {
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips)
+        {
+            if (clips.Count() > 1)
+                return ActionValidity.Invalid;
+
+            if (GetUnderlyingAsset(clips.First()) == null)
+                return ActionValidity.Invalid;
+
+            return ActionValidity.Valid;
+        }
+
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            EditorGUIUtility.PingObject(GetUnderlyingAsset(clips.First()));
+            return true;
+        }
+
+        private static UnityEngine.Object GetExternalPlayableAsset(TimelineClip clip)
+        {
+            if (clip.asset == null)
+                return null;
+
+            if ((clip.asset.hideFlags & HideFlags.HideInHierarchy) != 0)
+                return null;
+
+            return clip.asset;
+        }
+
+        private static UnityEngine.Object GetUnderlyingAsset(TimelineClip clip)
+        {
+            var asset = clip.asset as ScriptableObject;
+            if (asset == null)
+                return null;
+
+            var fields = ObjectReferenceField.FindObjectReferences(asset.GetType());
+            if (fields.Length == 0)
+                return GetExternalPlayableAsset(clip);
+
+            // Find the first non-null field
+            foreach (var field in fields)
+            {
+                // skip scene refs in asset mode
+                if (TimelineEditor.inspectedDirector == null && field.isSceneReference)
+                    continue;
+                var obj = field.Find(asset, TimelineEditor.inspectedDirector);
+                if (obj != null)
+                    return obj;
+            }
+
+            return GetExternalPlayableAsset(clip);
+        }
+    }
+
+    class CopyClipsToClipboard : ClipAction
+    {
+        public override ActionValidity Validate(IEnumerable<TimelineClip> clips) => ActionValidity.Valid;
+        public override bool Execute(IEnumerable<TimelineClip> clips)
+        {
+            TimelineEditor.clipboard.CopyItems(clips.ToItems());
+            return true;
+        }
+    }
+}

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/ClipsActions.cs.meta

@@ -0,0 +1,11 @@
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Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/IAction.cs

@@ -0,0 +1,123 @@
+using System;
+using System.ComponentModel;
+using System.Linq;
+using System.Reflection;
+using UnityEditor.ShortcutManagement;
+using UnityEngine;
+
+namespace UnityEditor.Timeline.Actions
+{
+    /// interface indicating an Action class
+    interface IAction { }
+
+    /// extension methods for IActions
+    static class ActionExtensions
+    {
+        const string kActionPostFix = "Action";
+
+        public static string GetUndoName(this IAction action)
+        {
+            if (action == null)
+                throw new ArgumentNullException(nameof(action));
+
+            var attr = action.GetType().GetCustomAttribute<ApplyDefaultUndoAttribute>(false);
+            if (attr != null && !string.IsNullOrWhiteSpace(attr.UndoTitle))
+                return attr.UndoTitle;
+
+            return action.GetDisplayName();
+        }
+
+        public static string GetMenuEntryName(this IAction action)
+        {
+            var menuAction = action as IMenuName;
+            if (menuAction != null && !string.IsNullOrWhiteSpace(menuAction.menuName))
+                return menuAction.menuName;
+
+            var attr = action.GetType().GetCustomAttribute<MenuEntryAttribute>(false);
+            if (attr != null && !string.IsNullOrWhiteSpace(attr.name))
+                return attr.name;
+
+            return action.GetDisplayName();
+        }
+
+        public static string GetDisplayName(this IAction action)
+        {
+            if (action == null)
+                throw new ArgumentNullException(nameof(action));
+
+            var attr = action.GetType().GetCustomAttribute<DisplayNameAttribute>(false);
+            if (attr != null && !string.IsNullOrEmpty(attr.DisplayName))
+                return attr.DisplayName;
+
+            var name = action.GetType().Name;
+            if (name.EndsWith(kActionPostFix))
+                return ObjectNames.NicifyVariableName(name.Substring(0, name.Length - kActionPostFix.Length));
+
+            return ObjectNames.NicifyVariableName(name);
+        }
+
+        public static bool HasAutoUndo(this IAction action)
+        {
+            return action != null && ActionManager.ActionsWithAutoUndo.Contains(action.GetType());
+        }
+
+        public static bool IsChecked(this IAction action)
+        {
+            return (action is IMenuChecked menuAction) && menuAction.isChecked;
+        }
+
+        public static bool IsActionActiveInMode(this IAction action, TimelineModes mode)
+        {
+            var attr = action.GetType().GetCustomAttribute<ActiveInModeAttribute>(true);
+            return attr != null && (attr.modes & mode) != 0;
+        }
+
+        public static string GetShortcut(this IAction action)
+        {
+            if (action == null)
+                throw new ArgumentNullException(nameof(action));
+
+            var shortcutAttribute = GetShortcutAttributeForAction(action);
+            var shortCut = shortcutAttribute == null ? string.Empty : shortcutAttribute.GetMenuShortcut();
+            if (string.IsNullOrWhiteSpace(shortCut))
+            {
+                //Check if there is a static method with attribute
+                var customShortcutMethod = action.GetType().GetMethods().FirstOrDefault(m => m.GetCustomAttribute<TimelineShortcutAttribute>(true) != null);
+                if (customShortcutMethod != null)
+                {
+                    var shortcutId = customShortcutMethod.GetCustomAttribute<TimelineShortcutAttribute>(true).identifier;
+                    var shortcut = ShortcutIntegration.instance.directory.FindShortcutEntry(shortcutId);
+                    if (shortcut != null && shortcut.combinations.Any())
+                        shortCut = KeyCombination.SequenceToMenuString(shortcut.combinations);
+                }
+            }
+
+            return shortCut;
+        }
+
+        static ShortcutAttribute GetShortcutAttributeForAction(this IAction action)
+        {
+            if (action == null)
+                throw new ArgumentNullException(nameof(action));
+
+            var shortcutAttributes = action.GetType()
+                .GetCustomAttributes(typeof(ShortcutAttribute), true)
+                .Cast<ShortcutAttribute>();
+
+            foreach (var shortcutAttribute in shortcutAttributes)
+            {
+                if (shortcutAttribute is ShortcutPlatformOverrideAttribute shortcutOverride)
+                {
+                    if (shortcutOverride.MatchesCurrentPlatform())
+                        return shortcutOverride;
+                }
+                else
+                {
+                    return shortcutAttribute;
+                }
+            }
+
+            return null;
+        }
+    }
+}

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/IAction.cs.meta

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Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/IMenuChecked.cs

@@ -0,0 +1,9 @@
+using System;
+
+namespace UnityEditor.Timeline
+{
+    interface IMenuChecked
+    {
+        bool isChecked { get; }
+    }
+}

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/IMenuChecked.cs.meta

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+timeCreated: 1591130283

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/IMenuName.cs

@@ -0,0 +1,9 @@
+using System;
+
+namespace UnityEditor.Timeline
+{
+    interface IMenuName
+    {
+        string menuName { get; }
+    }
+}

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/IMenuName.cs.meta

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Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/Invoker.cs

@@ -0,0 +1,101 @@
+using System;
+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.Timeline;
+
+namespace UnityEditor.Timeline.Actions
+{
+    /// <summary>
+    /// Class containing methods to invoke actions.
+    /// </summary>
+    public static class Invoker
+    {
+        /// <summary>
+        /// Execute a given action with a context parameter.
+        /// </summary>
+        /// <typeparam name="T">Action type to execute.</typeparam>
+        /// <param name="context">Context for the action.</param>
+        /// <returns>True if the action has been executed, false otherwise.</returns>
+        public static bool Invoke<T>(this ActionContext context) where T : TimelineAction
+        {
+            var action = ActionManager.TimelineActions.GetCachedAction<T, TimelineAction>();
+            return ActionManager.ExecuteTimelineAction(action, context);
+        }
+
+        /// <summary>
+        /// Execute a given action with tracks
+        /// </summary>
+        /// <typeparam name="T">Action type to execute.</typeparam>
+        ///  <param name="tracks">Tracks that the action will act on.</param>
+        /// <returns>True if the action has been executed, false otherwise.</returns>
+        public static bool Invoke<T>(this IEnumerable<TrackAsset> tracks) where T : TrackAction
+        {
+            var action = ActionManager.TrackActions.GetCachedAction<T, TrackAction>();
+            return ActionManager.ExecuteTrackAction(action, tracks);
+        }
+
+        /// <summary>
+        /// Execute a given action with clips
+        /// </summary>
+        /// <typeparam name="T">Action type to execute.</typeparam>
+        ///  <param name="clips">Clips that the action will act on.</param>
+        /// <returns>True if the action has been executed, false otherwise.</returns>
+        public static bool Invoke<T>(this IEnumerable<TimelineClip> clips) where T : ClipAction
+        {
+            var action = ActionManager.ClipActions.GetCachedAction<T, ClipAction>();
+            return ActionManager.ExecuteClipAction(action, clips);
+        }
+
+        /// <summary>
+        /// Execute a given action with markers
+        /// </summary>
+        /// <typeparam name="T">Action type to execute.</typeparam>
+        /// <param name="markers">Markers that the action will act on.</param>
+        /// <returns>True if the action has been executed, false otherwise.</returns>
+        public static bool Invoke<T>(this IEnumerable<IMarker> markers) where T : MarkerAction
+        {
+            var action = ActionManager.MarkerActions.GetCachedAction<T, MarkerAction>();
+            return ActionManager.ExecuteMarkerAction(action, markers);
+        }
+
+        /// <summary>
+        /// Execute a given timeline action with the selected clips, tracks and markers.
+        /// </summary>
+        /// <typeparam name="T">Action type to execute.</typeparam>
+        /// <returns>True if the action has been executed, false otherwise.</returns>
+        public static bool InvokeWithSelected<T>() where T : TimelineAction
+        {
+            return Invoke<T>(TimelineEditor.CurrentContext());
+        }
+
+        /// <summary>
+        /// Execute a given clip action with the selected clips.
+        /// </summary>
+        /// <typeparam name="T">Action type to execute.</typeparam>
+        /// <returns>True if the action has been executed, false otherwise.</returns>
+        public static bool InvokeWithSelectedClips<T>() where T : ClipAction
+        {
+            return Invoke<T>(SelectionManager.SelectedClips());
+        }
+
+        /// <summary>
+        /// Execute a given track action with the selected tracks.
+        /// </summary>
+        /// <typeparam name="T">Action type to execute.</typeparam>
+        /// <returns>True if the action has been executed, false otherwise.</returns>
+        public static bool InvokeWithSelectedTracks<T>() where T : TrackAction
+        {
+            return Invoke<T>(SelectionManager.SelectedTracks());
+        }
+
+        /// <summary>
+        /// Execute a given marker action with the selected markers.
+        /// </summary>
+        /// <typeparam name="T">Action type to execute.</typeparam>
+        /// <returns>True if the action has been executed, false otherwise.</returns>
+        public static bool InvokeWithSelectedMarkers<T>() where T : MarkerAction
+        {
+            return Invoke<T>(SelectionManager.SelectedMarkers());
+        }
+    }
+}

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/Invoker.cs.meta

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Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/MarkerAction.cs

@@ -0,0 +1,35 @@
+using System.Collections.Generic;
+using UnityEngine.Timeline;
+
+namespace UnityEditor.Timeline.Actions
+{
+    /// <summary>
+    /// Base class for a marker action.
+    /// Inherit from this class to make an action that would react on selected markers after a menu click and/or a key shortcut.
+    /// </summary>
+    /// <example>
+    /// Simple track Action example (with context menu and shortcut support).
+    /// <code source="../../DocCodeExamples/ActionExamples.cs" region="declare-sampleMarkerAction" title="SampleMarkerAction"/>
+    /// </example>
+    /// <remarks>
+    /// To add an action as a menu item in the Timeline context menu, add <see cref="MenuEntryAttribute"/> on the action class.
+    /// To make an action to react to a shortcut, use the Shortcut Manager API with <see cref="TimelineShortcutAttribute"/>.
+    /// <seealso cref="UnityEditor.ShortcutManagement.ShortcutAttribute"/>
+    /// </remarks>
+    [ActiveInMode(TimelineModes.Default)]
+    public abstract class MarkerAction : IAction
+    {
+        /// <summary>
+        ///  Execute the action.
+        /// </summary>
+        /// <param name="markers">Markers that will be used for the action. </param>
+        /// <returns>true if the action has been executed. false otherwise</returns>
+        public abstract bool Execute(IEnumerable<IMarker> markers);
+        /// <summary>
+        ///  Defines the validity of an Action for a given set of markers.
+        /// </summary>
+        /// <param name="markers">Markers that will be used for the action. </param>
+        /// <returns>The validity of the set of markers.</returns>
+        public abstract ActionValidity Validate(IEnumerable<IMarker> markers);
+    }
+}

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/MarkerAction.cs.meta

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Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/MarkerActions.cs

@@ -0,0 +1,20 @@
+using System.Collections.Generic;
+using JetBrains.Annotations;
+using UnityEditor.Timeline.Actions;
+using UnityEngine;
+using UnityEngine.Timeline;
+
+namespace UnityEditor.Timeline
+{
+    [UsedImplicitly]
+    class CopyMarkersToClipboard : MarkerAction
+    {
+        public override ActionValidity Validate(IEnumerable<IMarker> markers) => ActionValidity.Valid;
+
+        public override bool Execute(IEnumerable<IMarker> markers)
+        {
+            TimelineEditor.clipboard.CopyItems(markers.ToItems());
+            return true;
+        }
+    }
+}

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/MarkerActions.cs.meta

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Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/Menus.meta

@@ -0,0 +1,8 @@
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Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/Menus/MenuItemActionBase.cs

@@ -0,0 +1,36 @@
+namespace UnityEditor.Timeline.Actions
+{
+    /// <summary>
+    /// Indicates the validity of an action for a given data set.
+    /// </summary>
+    public enum ActionValidity
+    {
+        /// <summary>
+        /// Action is valid in the provided context.
+        /// If the action is linked to a menu item, the menu item will be visible.
+        /// </summary>
+        Valid,
+        /// <summary>
+        /// Action is not applicable in the current context.
+        /// If the action is linked to a menu item, the menu item will not be shown.
+        /// </summary>
+        NotApplicable,
+        /// <summary>
+        /// Action is not valid in the current context.
+        /// If the action is linked to a menu item, the menu item will be shown but grayed out.
+        /// </summary>
+        Invalid
+    }
+
+    struct MenuActionItem
+    {
+        public string category;
+        public string entryName;
+        public string shortCut;
+        public int priority;
+        public bool isActiveInMode;
+        public ActionValidity state;
+        public bool isChecked;
+        public GenericMenu.MenuFunction callback;
+    }
+}

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/Menus/MenuItemActionBase.cs.meta

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Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/Menus/TimelineContextMenu.cs

@@ -0,0 +1,381 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using UnityEditor.Timeline.Actions;
+using UnityEngine;
+using UnityEngine.Timeline;
+using Object = UnityEngine.Object;
+
+namespace UnityEditor.Timeline
+{
+    static class SequencerContextMenu
+    {
+        static class Styles
+        {
+            public static readonly string addItemFromAssetTemplate = L10n.Tr("Add {0} From {1}");
+            public static readonly string addSingleItemFromAssetTemplate = L10n.Tr("Add From {1}");
+            public static readonly string addItemTemplate = L10n.Tr("Add {0}");
+            public static readonly string typeSelectorTemplate = L10n.Tr("Select {0}");
+            public static readonly string trackGroup = L10n.Tr("Track Group");
+            public static readonly string trackSubGroup = L10n.Tr("Track Sub-Group");
+            public static readonly string addTrackLayer = L10n.Tr("Add Layer");
+            public static readonly string layerName = L10n.Tr("Layer {0}");
+        }
+
+        public static void ShowNewTracksContextMenu(ICollection<TrackAsset> tracks, WindowState state)
+        {
+            var menu = new GenericMenu();
+            List<MenuActionItem> items = new List<MenuActionItem>(100);
+            BuildNewTracksContextMenu(items, tracks, state);
+            ActionManager.BuildMenu(menu, items);
+            menu.ShowAsContext();
+        }
+
+        public static void ShowNewTracksContextMenu(ICollection<TrackAsset> tracks, WindowState state, Rect rect)
+        {
+            var menu = new GenericMenu();
+            List<MenuActionItem> items = new List<MenuActionItem>(100);
+            BuildNewTracksContextMenu(items, tracks, state);
+            ActionManager.BuildMenu(menu, items);
+            menu.DropDown(rect);
+        }
+
+        public static void ShowTrackContextMenu(Vector2? mousePosition)
+        {
+            var items = new List<MenuActionItem>();
+            var menu = new GenericMenu();
+            BuildTrackContextMenu(items, mousePosition);
+            ActionManager.BuildMenu(menu, items);
+            menu.ShowAsContext();
+        }
+
+        public static void ShowItemContextMenu(Vector2 mousePosition)
+        {
+            var menu = new GenericMenu();
+            var items = new List<MenuActionItem>();
+            BuildItemContextMenu(items, mousePosition);
+            ActionManager.BuildMenu(menu, items);
+            menu.ShowAsContext();
+        }
+
+        public static void BuildItemContextMenu(List<MenuActionItem> items, Vector2 mousePosition)
+        {
+            ActionManager.GetMenuEntries(ActionManager.TimelineActions, mousePosition, items);
+            ActionManager.GetMenuEntries(ActionManager.ClipActions, items);
+            ActionManager.GetMenuEntries(ActionManager.MarkerActions, items);
+
+            var clips = TimelineEditor.selectedClips;
+            if (clips.Length > 0)
+                AddMarkerMenuCommands(items, clips.Select(c => c.GetParentTrack()).Distinct().ToList(), TimelineHelpers.GetCandidateTime(mousePosition));
+        }
+
+        public static void BuildNewTracksContextMenu(List<MenuActionItem> menuItems, ICollection<TrackAsset> parentTracks, WindowState state, string format = null)
+        {
+            if (parentTracks == null)
+                parentTracks = new TrackAsset[0];
+
+            if (string.IsNullOrEmpty(format))
+                format = "{0}";
+
+            // Add Group or SubGroup
+            var title = string.Format(format, parentTracks.Any(t => t != null) ? Styles.trackSubGroup : Styles.trackGroup);
+            var menuState = ActionValidity.Valid;
+            if (state.editSequence.isReadOnly)
+                menuState = ActionValidity.Invalid;
+            if (parentTracks.Any() && parentTracks.Any(t => t != null && t.lockedInHierarchy))
+                menuState = ActionValidity.Invalid;
+
+            GenericMenu.MenuFunction command = () =>
+            {
+                SelectionManager.Clear();
+                if (parentTracks.Count == 0)
+                    Selection.Add(TimelineHelpers.CreateTrack<GroupTrack>(null, title));
+
+                foreach (var parentTrack in parentTracks)
+                    Selection.Add(TimelineHelpers.CreateTrack<GroupTrack>(parentTrack, title));
+
+                TimelineEditor.Refresh(RefreshReason.ContentsAddedOrRemoved);
+            };
+
+            menuItems.Add(
+                new MenuActionItem()
+                {
+                    category = string.Empty,
+                    entryName = title,
+                    isActiveInMode = true,
+                    priority = MenuPriority.AddItem.addGroup,
+                    state = menuState,
+                    isChecked = false,
+                    callback = command
+                }
+            );
+
+
+            var allTypes = TypeUtility.AllTrackTypes().Where(x => x != typeof(GroupTrack) && !TypeUtility.IsHiddenInMenu(x)).ToList();
+
+            int builtInPriority = MenuPriority.AddItem.addTrack;
+            int customPriority = MenuPriority.AddItem.addCustomTrack;
+            foreach (var trackType in allTypes)
+            {
+                var trackItemType = trackType;
+
+                command = () =>
+                {
+                    SelectionManager.Clear();
+
+                    if (parentTracks.Count == 0)
+                        SelectionManager.Add(TimelineHelpers.CreateTrack((Type)trackItemType, null));
+
+                    foreach (var parentTrack in parentTracks)
+                        SelectionManager.Add(TimelineHelpers.CreateTrack((Type)trackItemType, parentTrack));
+                };
+
+                menuItems.Add(
+                    new MenuActionItem()
+                    {
+                        category = TimelineHelpers.GetTrackCategoryName(trackType),
+                        entryName = string.Format(format, TimelineHelpers.GetTrackMenuName(trackItemType)),
+                        isActiveInMode = true,
+                        priority = TypeUtility.IsBuiltIn(trackType) ? builtInPriority++ : customPriority++,
+                        state = menuState,
+                        callback = command
+                    }
+                );
+            }
+        }
+
+        public static void BuildTrackContextMenu(List<MenuActionItem> items, Vector2? mousePosition)
+        {
+            var tracks = SelectionManager.SelectedTracks().ToArray();
+            if (tracks.Length == 0)
+                return;
+
+            ActionManager.GetMenuEntries(ActionManager.TimelineActions, mousePosition, items);
+            ActionManager.GetMenuEntries(ActionManager.TrackActions, items);
+            AddLayeredTrackCommands(items, tracks);
+
+            var first = tracks.First().GetType();
+            var allTheSame = tracks.All(t => t.GetType() == first);
+            if (allTheSame)
+            {
+                if (first != typeof(GroupTrack))
+                {
+                    var candidateTime = TimelineHelpers.GetCandidateTime(mousePosition, tracks);
+                    AddClipMenuCommands(items, tracks, candidateTime);
+                    AddMarkerMenuCommands(items, tracks, candidateTime);
+                }
+                else
+                {
+                    BuildNewTracksContextMenu(items, tracks, TimelineWindow.instance.state, Styles.addItemTemplate);
+                }
+            }
+        }
+
+        static void AddLayeredTrackCommands(List<MenuActionItem> menuItems, ICollection<TrackAsset> tracks)
+        {
+            if (tracks.Count == 0)
+                return;
+
+            var layeredType = tracks.First().GetType();
+            // animation tracks have a special menu.
+            if (layeredType == typeof(AnimationTrack))
+                return;
+
+            // must implement ILayerable
+            if (!typeof(UnityEngine.Timeline.ILayerable).IsAssignableFrom(layeredType))
+                return;
+
+            if (tracks.Any(t => t.GetType() != layeredType))
+                return;
+
+            // only supported on the master track no nesting.
+            if (tracks.Any(t => t.isSubTrack))
+                return;
+
+            var enabled = tracks.All(t => t != null && !t.lockedInHierarchy) && !TimelineWindow.instance.state.editSequence.isReadOnly;
+            int priority = MenuPriority.AddTrackMenu.addLayerTrack;
+            GenericMenu.MenuFunction menuCallback = () =>
+            {
+                foreach (var track in tracks)
+                    TimelineHelpers.CreateTrack(layeredType, track, string.Format(Styles.layerName, track.GetChildTracks().Count() + 1));
+            };
+
+            var entryName = Styles.addTrackLayer;
+            menuItems.Add(
+                new MenuActionItem()
+                {
+                    category = string.Empty,
+                    entryName = entryName,
+                    isActiveInMode = true,
+                    priority = priority++,
+                    state = enabled ? ActionValidity.Valid : ActionValidity.Invalid,
+                    callback = menuCallback
+                }
+            );
+        }
+
+        static void AddClipMenuCommands(List<MenuActionItem> menuItems, ICollection<TrackAsset> tracks, double candidateTime)
+        {
+            if (!tracks.Any())
+                return;
+
+            var trackAsset = tracks.First();
+            var trackType = trackAsset.GetType();
+            if (tracks.Any(t => t.GetType() != trackType))
+                return;
+
+            var enabled = tracks.All(t => t != null && !t.lockedInHierarchy) && !TimelineWindow.instance.state.editSequence.isReadOnly;
+            var assetTypes = TypeUtility.GetPlayableAssetsHandledByTrack(trackType);
+            var visibleAssetTypes = TypeUtility.GetVisiblePlayableAssetsHandledByTrack(trackType);
+
+            // skips the name if there is only a single type
+            var commandNameTemplate = assetTypes.Count() == 1 ? Styles.addSingleItemFromAssetTemplate : Styles.addItemFromAssetTemplate;
+            int builtInPriority = MenuPriority.AddItem.addClip;
+            int customPriority = MenuPriority.AddItem.addCustomClip;
+            foreach (var assetType in assetTypes)
+            {
+                var assetItemType = assetType;
+                var category = TimelineHelpers.GetItemCategoryName(assetType);
+                Action<Object> onObjectChanged = obj =>
+                {
+                    if (obj != null)
+                    {
+                        foreach (var t in tracks)
+                        {
+                            TimelineHelpers.CreateClipOnTrack(assetItemType, obj, t, candidateTime);
+                        }
+                    }
+                };
+
+                foreach (var objectReference in TypeUtility.ObjectReferencesForType(assetType))
+                {
+                    var isSceneReference = objectReference.isSceneReference;
+                    var dataType = objectReference.type;
+                    GenericMenu.MenuFunction menuCallback = () =>
+                    {
+                        ObjectSelector.get.Show(null, dataType, null, isSceneReference, null, (obj) => onObjectChanged(obj), null);
+                        ObjectSelector.get.titleContent = EditorGUIUtility.TrTextContent(string.Format(Styles.typeSelectorTemplate, TypeUtility.GetDisplayName(dataType)));
+                    };
+
+                    menuItems.Add(
+                        new MenuActionItem()
+                        {
+                            category = category,
+                            entryName = string.Format(commandNameTemplate, TypeUtility.GetDisplayName(assetType), TypeUtility.GetDisplayName(objectReference.type)),
+                            isActiveInMode = true,
+                            priority = TypeUtility.IsBuiltIn(assetType) ? builtInPriority++ : customPriority++,
+                            state = enabled ? ActionValidity.Valid : ActionValidity.Invalid,
+                            callback = menuCallback
+                        }
+                    );
+                }
+            }
+
+            foreach (var assetType in visibleAssetTypes)
+            {
+                var assetItemType = assetType;
+                var category = TimelineHelpers.GetItemCategoryName(assetType);
+                var commandName = string.Format(Styles.addItemTemplate, TypeUtility.GetDisplayName(assetType));
+                GenericMenu.MenuFunction command = () =>
+                {
+                    foreach (var t in tracks)
+                    {
+                        TimelineHelpers.CreateClipOnTrack(assetItemType, t, candidateTime);
+                    }
+                };
+
+                menuItems.Add(
+                    new MenuActionItem()
+                    {
+                        category = category,
+                        entryName = commandName,
+                        isActiveInMode = true,
+                        priority = TypeUtility.IsBuiltIn(assetItemType) ? builtInPriority++ : customPriority++,
+                        state = enabled ? ActionValidity.Valid : ActionValidity.Invalid,
+                        callback = command
+                    }
+                );
+            }
+        }
+
+        static void AddMarkerMenuCommands(List<MenuActionItem> menu, IEnumerable<Type> markerTypes, Action<Type, Object> addMarkerCommand, bool enabled)
+        {
+            int builtInPriority = MenuPriority.AddItem.addMarker;
+            int customPriority = MenuPriority.AddItem.addCustomMarker;
+            foreach (var markerType in markerTypes)
+            {
+                var markerItemType = markerType;
+                string category = TimelineHelpers.GetItemCategoryName(markerItemType);
+                menu.Add(
+                    new MenuActionItem()
+                    {
+                        category = category,
+                        entryName = string.Format(Styles.addItemTemplate, TypeUtility.GetDisplayName(markerType)),
+                        isActiveInMode = true,
+                        priority = TypeUtility.IsBuiltIn(markerType) ? builtInPriority++ : customPriority++,
+                        state = enabled ? ActionValidity.Valid : ActionValidity.Invalid,
+                        callback = () => addMarkerCommand(markerItemType, null)
+                    }
+                );
+
+                foreach (var objectReference in TypeUtility.ObjectReferencesForType(markerType))
+                {
+                    var isSceneReference = objectReference.isSceneReference;
+                    GenericMenu.MenuFunction menuCallback = () =>
+                    {
+                        Type assetDataType = objectReference.type;
+                        ObjectSelector.get.titleContent = EditorGUIUtility.TrTextContent(string.Format(Styles.typeSelectorTemplate, TypeUtility.GetDisplayName(assetDataType)));
+                        ObjectSelector.get.Show(null, assetDataType, null, isSceneReference, null, obj =>
+                        {
+                            if (obj != null)
+                                addMarkerCommand(markerItemType, obj);
+                        }, null);
+                    };
+
+                    menu.Add(
+                        new MenuActionItem
+                        {
+                            category = TimelineHelpers.GetItemCategoryName(markerItemType),
+                            entryName = string.Format(Styles.addItemFromAssetTemplate, TypeUtility.GetDisplayName(markerType), TypeUtility.GetDisplayName(objectReference.type)),
+                            isActiveInMode = true,
+                            priority = TypeUtility.IsBuiltIn(markerType) ? builtInPriority++ : customPriority++,
+                            state = enabled ? ActionValidity.Valid : ActionValidity.Invalid,
+                            callback = menuCallback
+                        }
+                    );
+                }
+            }
+        }
+
+        static void AddMarkerMenuCommands(List<MenuActionItem> menuItems, ICollection<TrackAsset> tracks, double candidateTime)
+        {
+            if (tracks.Count == 0)
+                return;
+
+            var enabled = tracks.All(t => !t.lockedInHierarchy) && !TimelineWindow.instance.state.editSequence.isReadOnly;
+            var addMarkerCommand = new Action<Type, Object>((type, obj) => AddMarkersCallback(tracks, type, candidateTime, obj));
+
+            AddMarkerMenuCommands(menuItems, tracks, addMarkerCommand, enabled);
+        }
+
+        static void AddMarkerMenuCommands(List<MenuActionItem> menuItems, ICollection<TrackAsset> tracks, Action<Type, Object> command, bool enabled)
+        {
+            var markerTypes = TypeUtility.GetBuiltInMarkerTypes().Union(TypeUtility.GetUserMarkerTypes());
+            if (tracks != null)
+                markerTypes = markerTypes.Where(x => tracks.All(track => (track == null) || TypeUtility.DoesTrackSupportMarkerType(track, x))); // null track indicates marker track to be created
+
+            AddMarkerMenuCommands(menuItems, markerTypes, command, enabled);
+        }
+
+        static void AddMarkersCallback(ICollection<TrackAsset> targets, Type markerType, double time, Object obj)
+        {
+            SelectionManager.Clear();
+            foreach (var target in targets)
+            {
+                var marker = TimelineHelpers.CreateMarkerOnTrack(markerType, obj, target, time);
+                SelectionManager.Add(marker);
+            }
+            TimelineEditor.Refresh(RefreshReason.ContentsAddedOrRemoved);
+        }
+    }
+}

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/Menus/TimelineContextMenu.cs.meta

@@ -0,0 +1,11 @@
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Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/TimelineAction.cs

@@ -0,0 +1,34 @@
+namespace UnityEditor.Timeline.Actions
+{
+    /// <summary>
+    /// Base class for a timeline action.
+    /// Inherit from this class to make an action on a timeline after a menu click and/or a key shortcut.
+    /// </summary>
+    /// <remarks>
+    /// To add an action as a menu item in the Timeline context menu, add <see cref="MenuEntryAttribute"/> on the action class.
+    /// To make an action to react to a shortcut, use the Shortcut Manager API with <see cref="TimelineShortcutAttribute"/>.
+    /// <seealso cref="UnityEditor.ShortcutManagement.ShortcutAttribute"/>
+    /// <seealso cref="ActiveInModeAttribute"/>
+    /// </remarks>
+    /// <example>
+    /// Simple Timeline Action example (with context menu and shortcut support).
+    /// <code source="../../DocCodeExamples/ActionExamples.cs" region="declare-sampleTimelineAction" title="SampleTimelineAction"/>
+    /// </example>
+    [ActiveInMode(TimelineModes.Default)]
+    public abstract class TimelineAction : IAction
+    {
+        /// <summary>
+        ///  Execute the action.
+        /// </summary>
+        /// <param name="context">Context for the action.</param>
+        /// <returns>true if the action has been executed. false otherwise</returns>
+        public abstract bool Execute(ActionContext context);
+
+        /// <summary>
+        /// Defines the validity of an Action based on the context.
+        /// </summary>
+        /// <param name="context">Context for the action.</param>
+        /// <returns>Visual state of the menu for the action.</returns>
+        public abstract ActionValidity Validate(ActionContext context);
+    }
+}

Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/TimelineAction.cs.meta

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Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/TimelineActions.cs.meta

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Library/PackageCache/com.unity.timeline@1.7.6/Editor/Actions/TrackAction.cs

@@ -0,0 +1,36 @@
+using System.Collections.Generic;
+using UnityEngine.Timeline;
+
+namespace UnityEditor.Timeline.Actions
+{
+    /// <summary>
+    /// Base class for a track action.
+    /// Inherit from this class to make an action that would react on selected tracks after a menu click and/or a key shortcut.
+    /// </summary>
+    /// <example>
+    /// Simple track Action example (with context menu and shortcut support).
+    /// <code source="../../DocCodeExamples/ActionExamples.cs" region="declare-sampleTrackAction" title="SampleTrackAction"/>
+    /// </example>
+    /// <remarks>
+    /// To add an action as a menu item in the Timeline context menu, add <see cref="MenuEntryAttribute"/> on the action class.
+    /// To make an action to react to a shortcut, use the Shortcut Manager API with <see cref="TimelineShortcutAttribute"/>.
+    /// <seealso cref="UnityEditor.ShortcutManagement.ShortcutAttribute"/>
+    /// </remarks>
+    [ActiveInMode(TimelineModes.Default)]
+    public abstract class TrackAction : IAction
+    {
+        /// <summary>
+        ///  Execute the action.
+        /// </summary>
+        /// <param name="tracks">Tracks that will be used for the action. </param>
+        /// <returns>true if the action has been executed. false otherwise</returns>
+        public abstract bool Execute(IEnumerable<TrackAsset> tracks);
+
+        /// <summary>
+        ///  Defines the validity of an Action for a given set of tracks.
+        /// </summary>
+        ///  <param name="tracks">tracks that the action would act on.</param>
+        /// <returns>The validity of the set of tracks.</returns>
+        public abstract ActionValidity Validate(IEnumerable<TrackAsset> tracks);
+    }
+}

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