Removed a bunch of stuff; Changes

1 files changed, 0 insertions, 683 deletions

diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Editor/treeview/TimelineDragging.cs b/Library/PackageCache/com.unity.timeline@1.2.13/Editor/treeview/TimelineDragging.cs
deleted file mode 100644
index 8162c06..0000000
--- a/Library/PackageCache/com.unity.timeline@1.2.13/Editor/treeview/TimelineDragging.cs
+++ /dev/null
@@ -1,683 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using UnityEditor.IMGUI.Controls;
-using UnityEditor.Timeline;
-using UnityEngine;
-using UnityEngine.Timeline;
-using UnityEngine.Playables;
-using UnityObject = UnityEngine.Object;
-
-namespace UnityEditor
-{
-    class TimelineDragging : TreeViewDragging
-    {
-        public delegate bool TypeResolver(IEnumerable<Type> types, Action<Type> onComplete, string format);
-
-        private static readonly string k_SelectTrackWithBinding = LocalizationDatabase.GetLocalizedString("Add {0}");
-        private static readonly string k_SelectTrackWithClip = LocalizationDatabase.GetLocalizedString("Add Clip With {0}");
-        private static readonly string k_SelectClip = LocalizationDatabase.GetLocalizedString("Add {0}");
-
-
-        const string k_GenericDragId = "TimelineDragging";
-        readonly int kDragSensitivity = 2;
-        readonly TimelineAsset m_Timeline;
-        readonly TimelineWindow m_Window;
-
-        class TimelineDragData
-        {
-            public TimelineDragData(List<TreeViewItem> draggedItems)
-            {
-                this.draggedItems = draggedItems;
-            }
-
-            public readonly List<TreeViewItem> draggedItems;
-        }
-
-        public TimelineDragging(TreeViewController treeView, TimelineWindow window, TimelineAsset data)
-            : base(treeView)
-        {
-            m_Timeline = data;
-            m_Window = window;
-        }
-
-        public override bool CanStartDrag(TreeViewItem targetItem, List<int> draggedItemIDs, Vector2 mouseDownPosition)
-        {
-            if (Event.current.modifiers != EventModifiers.None)
-                return false;
-
-            // Can only drag when starting in the track header area
-            if (mouseDownPosition.x > m_Window.sequenceHeaderRect.xMax)
-                return false;
-
-            var trackBaseGUI = targetItem as TimelineTrackBaseGUI;
-
-            if (trackBaseGUI == null || trackBaseGUI.track == null)
-                return false;
-
-            if (trackBaseGUI.track.lockedInHierarchy)
-                return false;
-
-            if (Event.current.type == EventType.MouseDrag && Mathf.Abs(Event.current.delta.y) < kDragSensitivity)
-                return false;
-
-            // Make sure dragged items are selected
-            // TODO Use similar system than the SceneHierarchyWindow in order to handle selection between treeView and tracks.
-            SelectionManager.Clear();
-            var draggedTrackGUIs = m_Window.allTracks.Where(t => draggedItemIDs.Contains(t.id));
-            foreach (var trackGUI in draggedTrackGUIs)
-                SelectionManager.Add(trackGUI.track);
-
-            return true;
-        }
-
-        public override void StartDrag(TreeViewItem draggedNode, List<int> draggedItemIDs)
-        {
-            DragAndDrop.PrepareStartDrag();
-            var tvItems = SelectionManager.SelectedTrackGUI().Cast<TreeViewItem>().ToList();
-            DragAndDrop.SetGenericData(k_GenericDragId, new TimelineDragData(tvItems));
-            DragAndDrop.objectReferences = new UnityObject[] {};  // this IS required for dragging to work
-
-            string title = draggedItemIDs.Count + (draggedItemIDs.Count > 1 ? "s" : ""); // title is only shown on OSX (at the cursor)
-
-            TimelineGroupGUI groupGui = draggedNode as TimelineGroupGUI;
-            if (groupGui != null)
-            {
-                title = groupGui.displayName;
-            }
-            DragAndDrop.StartDrag(title);
-        }
-
-        public static bool IsDraggingEvent()
-        {
-            return Event.current.type == EventType.DragUpdated ||
-                Event.current.type == EventType.DragExited ||
-                Event.current.type == EventType.DragPerform;
-        }
-
-        public static bool ResolveType(IEnumerable<System.Type> types, Action<Type> onComplete, string formatString)
-        {
-            if (!types.Any() || onComplete == null)
-                return false;
-
-            if (types.Count() == 1)
-            {
-                onComplete(types.First());
-                return true;
-            }
-
-            var menu = new GenericMenu();
-
-            var builtInTypes = types.Where(TypeUtility.IsBuiltIn).OrderBy(TypeUtility.GetDisplayName).ToArray();
-            var customTypes = types.Where(x => !TypeUtility.IsBuiltIn(x)).OrderBy(TypeUtility.GetDisplayName).ToArray();
-
-            foreach (var t in builtInTypes)
-            {
-                menu.AddItem(new GUIContent(string.Format(formatString, TypeUtility.GetDisplayName(t))), false, s => onComplete((System.Type)s), t);
-            }
-
-            if (builtInTypes.Length != 0 && customTypes.Length != 0)
-                menu.AddSeparator(string.Empty);
-
-            foreach (var t in customTypes)
-            {
-                menu.AddItem(new GUIContent(string.Format(formatString, TypeUtility.GetDisplayName(t))), false, s => onComplete((System.Type)s), t);
-            }
-
-            menu.ShowAsContext();
-            return true;
-        }
-
-        public override bool DragElement(TreeViewItem targetItem, Rect targetItemRect, int row)
-        {
-            if (TimelineWindow.instance.state.editSequence.isReadOnly)
-                return false;
-            // the drop rect contains the row rect plus additional spacing. The base drag element overlaps 1/2 the height of the next track
-            // which interferes with track bindings
-            var targetTrack = targetItem as TimelineGroupGUI;
-            if (row > 0 && targetTrack != null && !targetTrack.dropRect.Contains(Event.current.mousePosition))
-                return false;
-
-            return base.DragElement(targetItem, targetItemRect, row);
-        }
-
-        TreeViewItem GetNextItem(TreeViewItem item)
-        {
-            if (item == null)
-                return null;
-
-            if (item.parent == null)
-            {
-                int row = m_Window.treeView.data.GetRow(item.id);
-                var items = m_Window.treeView.data.GetRows();
-                if (items.Count > row + 1)
-                    return items[row + 1];
-                return null;
-            }
-
-            var children = item.parent.children;
-            if (children == null)
-                return null;
-
-            for (int i = 0; i < children.Count - 1; i++)
-            {
-                if (children[i] == item)
-                    return children[i + 1];
-            }
-            return null;
-        }
-
-        private static TrackAsset GetTrack(TreeViewItem item)
-        {
-            TimelineTrackBaseGUI baseGui = item as TimelineTrackBaseGUI;
-            if (baseGui == null)
-                return null;
-            return baseGui.track;
-        }
-
-        // The drag and drop may be over an expanded group but might be between tracks
-        private void HandleNestedItemGUI(ref TreeViewItem parentItem, ref TreeViewItem targetItem, ref TreeViewItem insertBefore)
-        {
-            const float kTopPad = 5;
-            const float kBottomPad = 5;
-
-            insertBefore = null;
-
-            if (!ShouldUseHierarchyDragAndDrop())
-                return;
-
-            var targetTrack = targetItem as TimelineGroupGUI;
-            if (targetTrack == null)
-                return;
-
-            var mousePosition = Event.current.mousePosition;
-
-            var dropBefore = targetTrack.rowRect.yMin + kTopPad > mousePosition.y;
-            var dropAfter = !(targetTrack.track is GroupTrack) && (targetTrack.rowRect.yMax - kBottomPad < mousePosition.y);
-
-            targetTrack.drawInsertionMarkerBefore = dropBefore;
-            targetTrack.drawInsertionMarkerAfter = dropAfter;
-
-            if (dropBefore)
-            {
-                targetItem = parentItem;
-                parentItem = targetItem != null ? targetItem.parent : null;
-                insertBefore = targetTrack;
-            }
-            else if (dropAfter)
-            {
-                targetItem = parentItem;
-                parentItem = targetItem != null ? targetItem.parent : null;
-                insertBefore = GetNextItem(targetTrack);
-            }
-            else if (targetTrack.track is GroupTrack)
-            {
-                targetTrack.isDropTarget = true;
-            }
-        }
-
-        public override DragAndDropVisualMode DoDrag(TreeViewItem parentItem, TreeViewItem targetItem, bool perform, DropPosition dropPos)
-        {
-            m_Window.isDragging = false;
-
-            var retMode = DragAndDropVisualMode.None;
-
-            var trackDragData = DragAndDrop.GetGenericData(k_GenericDragId) as TimelineDragData;
-
-            if (trackDragData != null)
-            {
-                retMode = HandleTrackDrop(parentItem, targetItem, perform, dropPos);
-                if (retMode == DragAndDropVisualMode.Copy && targetItem != null && Event.current.type == EventType.DragUpdated)
-                {
-                    var targetActor = targetItem as TimelineGroupGUI;
-                    if (targetActor != null)
-                        targetActor.isDropTarget = true;
-                }
-            }
-            else if (DragAndDrop.objectReferences.Any())
-            {
-                var objectsBeingDropped = DragAndDrop.objectReferences.OfType<UnityObject>();
-                var director = m_Window.state.editSequence.director;
-
-                if (ShouldUseHierarchyDragAndDrop())
-                {
-                    // for object drawing
-                    var originalTarget = targetItem;
-                    TreeViewItem insertBeforeItem = null;
-                    HandleNestedItemGUI(ref parentItem, ref targetItem, ref insertBeforeItem);
-                    var track = GetTrack(targetItem);
-                    var parent = GetTrack(parentItem);
-                    var insertBefore = GetTrack(insertBeforeItem);
-                    retMode = HandleHierarchyPaneDragAndDrop(objectsBeingDropped, track, perform, m_Timeline, director, ResolveType, insertBefore);
-
-                    // fallback to old clip behaviour
-                    if (retMode == DragAndDropVisualMode.None)
-                    {
-                        retMode = HandleClipPaneObjectDragAndDrop(objectsBeingDropped, track, perform, m_Timeline, parent, director, m_Window.state.timeAreaShownRange.x, ResolveType, insertBefore);
-                    }
-
-                    // if we are rejected, clear any drop markers
-                    if (retMode == DragAndDropVisualMode.Rejected && targetItem != null)
-                    {
-                        ClearInsertionMarkers(originalTarget);
-                        ClearInsertionMarkers(targetItem);
-                        ClearInsertionMarkers(parentItem);
-                        ClearInsertionMarkers(insertBeforeItem);
-                    }
-                }
-                else
-                {
-                    var candidateTime = TimelineHelpers.GetCandidateTime(m_Window.state, Event.current.mousePosition);
-                    retMode = HandleClipPaneObjectDragAndDrop(objectsBeingDropped, GetTrack(targetItem), perform, m_Timeline, GetTrack(parentItem), director, candidateTime, ResolveType);
-                }
-            }
-
-            m_Window.isDragging = false;
-
-            return retMode;
-        }
-
-        void ClearInsertionMarkers(TreeViewItem item)
-        {
-            var trackGUI = item as TimelineTrackBaseGUI;
-            if (trackGUI != null)
-            {
-                trackGUI.drawInsertionMarkerAfter = false;
-                trackGUI.drawInsertionMarkerBefore = false;
-                trackGUI.isDropTarget = false;
-            }
-        }
-
-        bool ShouldUseHierarchyDragAndDrop()
-        {
-            return m_Window.state.IsEditingAnEmptyTimeline() || m_Window.state.sequencerHeaderWidth > Event.current.mousePosition.x;
-        }
-
-        public static DragAndDropVisualMode HandleHierarchyPaneDragAndDrop(IEnumerable<UnityObject> objectsBeingDropped, TrackAsset targetTrack, bool perform, TimelineAsset timeline, PlayableDirector director, TypeResolver typeResolver, TrackAsset insertBefore = null)
-        {
-            if (timeline == null)
-                return DragAndDropVisualMode.Rejected;
-
-            // if we are over a target track, defer to track binding system (implemented in TrackGUIs), unless we are a groupTrack
-            if (targetTrack != null && (targetTrack as GroupTrack) == null)
-                return DragAndDropVisualMode.None;
-
-            if (targetTrack != null && targetTrack.lockedInHierarchy)
-                return DragAndDropVisualMode.Rejected;
-
-            var tracksWithBinding = objectsBeingDropped.SelectMany(TypeUtility.GetTracksCreatableFromObject).Distinct();
-            if (!tracksWithBinding.Any())
-                return DragAndDropVisualMode.None;
-
-            if (perform)
-            {
-                System.Action<Type> onResolve = trackType =>
-                {
-                    foreach (var obj in objectsBeingDropped)
-                    {
-                        if (!obj.IsPrefab() && TypeUtility.IsTrackCreatableFromObject(obj, trackType))
-                        {
-                            var newTrack = TimelineHelpers.CreateTrack(timeline, trackType, targetTrack, string.Empty);
-                            if (insertBefore != null)
-                            {
-                                if (targetTrack != null)
-                                    targetTrack.MoveLastTrackBefore(insertBefore);
-                                else
-                                    timeline.MoveLastTrackBefore(insertBefore);
-                            }
-
-                            TimelineHelpers.Bind(newTrack, obj, director);
-                        }
-                    }
-                    TimelineEditor.Refresh(RefreshReason.ContentsAddedOrRemoved);
-                };
-                typeResolver(tracksWithBinding, onResolve, k_SelectTrackWithBinding);
-            }
-
-            return DragAndDropVisualMode.Copy;
-        }
-
-        public static DragAndDropVisualMode HandleClipPaneObjectDragAndDrop(IEnumerable<UnityObject> objectsBeingDropped, TrackAsset targetTrack, bool perform, TimelineAsset timeline, TrackAsset parent, PlayableDirector director, double candidateTime, TypeResolver typeResolver, TrackAsset insertBefore = null)
-        {
-            if (timeline == null)
-                return DragAndDropVisualMode.Rejected;
-
-            // locked tracks always reject
-            if (targetTrack != null && targetTrack.lockedInHierarchy)
-                return DragAndDropVisualMode.Rejected;
-
-            // treat group tracks as having no track
-            if (targetTrack is GroupTrack)
-            {
-                parent = targetTrack;
-                targetTrack = null;
-            }
-
-            // Special case for monoscripts, since they describe the type
-            if (objectsBeingDropped.Any(o => o is MonoScript))
-                return HandleClipPaneMonoScriptDragAndDrop(objectsBeingDropped.OfType<MonoScript>(), targetTrack, perform, timeline, parent, director, candidateTime);
-
-            // no unity objects, or explicit exceptions
-            if (!objectsBeingDropped.Any() || objectsBeingDropped.Any(o => !ValidateObjectDrop(o)))
-                return DragAndDropVisualMode.Rejected;
-
-            // reject scene references if we have no context
-            if (director == null && objectsBeingDropped.Any(o => o.IsSceneObject()))
-                return DragAndDropVisualMode.Rejected;
-
-            var validTrackTypes = objectsBeingDropped.SelectMany(o => TypeUtility.GetTrackTypesForObject(o)).Distinct().ToList();
-            // special case for playable assets
-            if (objectsBeingDropped.Any(o => TypeUtility.IsConcretePlayableAsset(o.GetType())))
-            {
-                var playableAssets = objectsBeingDropped.OfType<IPlayableAsset>().Where(o => TypeUtility.IsConcretePlayableAsset(o.GetType()));
-                return HandleClipPanePlayableAssetDragAndDrop(playableAssets, targetTrack, perform, timeline, parent, director, candidateTime, typeResolver);
-            }
-
-            var markerTypes = objectsBeingDropped.SelectMany(o => TypeUtility.MarkerTypesWithFieldForObject(o)).Distinct();
-
-            // Markers support all tracks
-            if (!markerTypes.Any())
-            {
-                // No tracks support this object
-                if (!validTrackTypes.Any())
-                    return DragAndDropVisualMode.Rejected;
-
-                // no tracks for this object
-                if (targetTrack != null && !validTrackTypes.Contains(targetTrack.GetType()))
-                    return DragAndDropVisualMode.Rejected;
-            }
-
-            // there is no target track, dropping to empty space, or onto a group
-            if (perform)
-            {
-                // choose track and then clip
-                if (targetTrack == null)
-                {
-                    var createdTrack = HandleTrackAndItemCreation(objectsBeingDropped, candidateTime, typeResolver, timeline, parent, validTrackTypes, insertBefore);
-                    if (!createdTrack)
-                    {
-                        timeline.CreateMarkerTrack();
-                        HandleItemCreation(objectsBeingDropped, timeline.markerTrack, candidateTime, typeResolver, true); // menu is always popped if ambiguous choice
-                    }
-                }
-                // just choose clip/marker
-                else
-                {
-                    HandleItemCreation(objectsBeingDropped, targetTrack, candidateTime, typeResolver, true); // menu is always popped if ambiguous choice
-                }
-            }
-
-            return DragAndDropVisualMode.Copy;
-        }
-
-        static bool HandleTrackAndItemCreation(IEnumerable<UnityEngine.Object> objectsBeingDropped, double candidateTime, TypeResolver typeResolver, TimelineAsset timeline, TrackAsset parent, IEnumerable<Type> validTrackTypes, TrackAsset insertBefore = null)
-        {
-            Action<Type> onResolved = t =>
-            {
-                var newTrack = TimelineHelpers.CreateTrack(timeline, t, parent, string.Empty);
-                if (insertBefore != null)
-                {
-                    if (parent != null)
-                        parent.MoveLastTrackBefore(insertBefore);
-                    else
-                        timeline.MoveLastTrackBefore(insertBefore);
-                }
-                HandleItemCreation(objectsBeingDropped, newTrack, candidateTime, typeResolver, validTrackTypes.Count() == 1); // menu is popped if ambiguous clip choice and unambiguous track choice
-            };
-            return typeResolver(validTrackTypes, t => onResolved(t), k_SelectTrackWithClip); // Did it create a track
-        }
-
-        static void HandleItemCreation(IEnumerable<UnityEngine.Object> objectsBeingDropped, TrackAsset targetTrack, double candidateTime, TypeResolver typeResolver, bool allowMenu)
-        {
-            var assetTypes = objectsBeingDropped.Select(o =>
-                TypeUtility.GetAssetTypesForObject(targetTrack.GetType(), o)
-                    .Union(TypeUtility.MarkerTypesWithFieldForObject(o))).ToList();
-            Action<Type> onCreateItem = assetType =>
-            {
-                if (typeof(PlayableAsset).IsAssignableFrom(assetType))
-                {
-                    TimelineHelpers.CreateClipsFromObjects(assetType, targetTrack, candidateTime,
-                        objectsBeingDropped);
-                }
-                else
-                {
-                    TimelineHelpers.CreateMarkersFromObjects(assetType, targetTrack, candidateTime, objectsBeingDropped);
-                }
-            };
-
-            var flatAssetTypes = assetTypes.SelectMany(x => x).Distinct();
-            // If there is a one to one mapping between assets and timeline types, no need to go through the type resolution, not ambiguous.
-            if (assetTypes.All(x => x.Count() <= 1))
-            {
-                foreach (var type in flatAssetTypes)
-                {
-                    onCreateItem(type);
-                }
-            }
-            else
-            {
-                if (!allowMenu) // If we already popped a menu, and are presented with an ambiguous choice, take the first entry
-                {
-                    flatAssetTypes = new[] {flatAssetTypes.First()};
-                }
-
-                typeResolver(flatAssetTypes, onCreateItem, k_SelectClip);
-            }
-        }
-
-        /// Handles drag and drop of a mono script.
-        public static DragAndDropVisualMode HandleClipPaneMonoScriptDragAndDrop(IEnumerable<MonoScript> scriptsBeingDropped, TrackAsset targetTrack, bool perform, TimelineAsset timeline, TrackAsset parent, PlayableDirector director, double candidateTime)
-        {
-            var playableAssetTypes = scriptsBeingDropped.Select(s => s.GetClass()).Where(TypeUtility.IsConcretePlayableAsset).Distinct();
-            if (!playableAssetTypes.Any())
-                return DragAndDropVisualMode.Rejected;
-
-            var targetTrackType = typeof(PlayableTrack);
-            if (targetTrack != null)
-                targetTrackType = targetTrack.GetType();
-
-            var trackAssetsTypes = TypeUtility.GetPlayableAssetsHandledByTrack(targetTrackType);
-            var supportedTypes = trackAssetsTypes.Intersect(playableAssetTypes);
-            if (!supportedTypes.Any())
-                return DragAndDropVisualMode.Rejected;
-
-            if (perform)
-            {
-                if (targetTrack == null)
-                    targetTrack = TimelineHelpers.CreateTrack(timeline, targetTrackType, parent, string.Empty);
-                TimelineHelpers.CreateClipsFromTypes(supportedTypes, targetTrack, candidateTime);
-            }
-
-            return DragAndDropVisualMode.Copy;
-        }
-
-        public static DragAndDropVisualMode HandleClipPanePlayableAssetDragAndDrop(IEnumerable<IPlayableAsset> assetsBeingDropped, TrackAsset targetTrack, bool perform, TimelineAsset timeline, TrackAsset parent, PlayableDirector director, double candidateTime, TypeResolver typeResolver)
-        {
-            // get the list of supported track types
-            var assetTypes = assetsBeingDropped.Select(x => x.GetType()).Distinct();
-            IEnumerable<Type> supportedTypes = null;
-            if (targetTrack == null)
-            {
-                supportedTypes = TypeUtility.AllTrackTypes().Where(t => TypeUtility.GetPlayableAssetsHandledByTrack(t).Intersect(assetTypes).Any()).ToList();
-            }
-            else
-            {
-                supportedTypes = Enumerable.Empty<Type>();
-                var trackAssetTypes = TypeUtility.GetPlayableAssetsHandledByTrack(targetTrack.GetType());
-                if (trackAssetTypes.Intersect(assetTypes).Any())
-                    supportedTypes = new[] {targetTrack.GetType()};
-            }
-
-            if (!supportedTypes.Any())
-                return DragAndDropVisualMode.Rejected;
-
-            if (perform)
-            {
-                Action<Type> onResolved = (t) =>
-                {
-                    if (targetTrack == null)
-                        targetTrack = TimelineHelpers.CreateTrack(timeline, t, parent, string.Empty);
-
-                    var clipTypes = TypeUtility.GetPlayableAssetsHandledByTrack(targetTrack.GetType());
-                    foreach (var asset in assetsBeingDropped)
-                    {
-                        if (clipTypes.Contains(asset.GetType()))
-                            TimelineHelpers.CreateClipOnTrackFromPlayableAsset(asset, targetTrack, candidateTime);
-                    }
-                };
-
-                typeResolver(supportedTypes, onResolved, k_SelectTrackWithClip);
-            }
-
-
-            return DragAndDropVisualMode.Copy;
-        }
-
-        static bool ValidateObjectDrop(UnityObject obj)
-        {
-            // legacy animation clips are not supported at all
-            AnimationClip clip = obj as AnimationClip;
-            if (clip != null && clip.legacy)
-                return false;
-
-            return !(obj is TimelineAsset);
-        }
-
-        public DragAndDropVisualMode HandleTrackDrop(TreeViewItem parentItem, TreeViewItem targetItem, bool perform, DropPosition dropPos)
-        {
-            ((TimelineTreeView)m_Window.treeView.gui).showInsertionMarker = false;
-            var trackDragData = (TimelineDragData)DragAndDrop.GetGenericData(k_GenericDragId);
-            bool validDrag = ValidDrag(targetItem, trackDragData.draggedItems);
-            if (!validDrag)
-                return DragAndDropVisualMode.None;
-
-
-            var draggedTracks = trackDragData.draggedItems.OfType<TimelineGroupGUI>().Select(x => x.track).ToList();
-            if (draggedTracks.Count == 0)
-                return DragAndDropVisualMode.None;
-
-            if (parentItem != null)
-            {
-                var parentActor = parentItem as TimelineGroupGUI;
-                if (parentActor != null && parentActor.track != null)
-                {
-                    if (parentActor.track.lockedInHierarchy)
-                        return DragAndDropVisualMode.Rejected;
-
-                    if (draggedTracks.Any(x => !TimelineCreateUtilities.ValidateParentTrack(parentActor.track, x.GetType())))
-                        return DragAndDropVisualMode.Rejected;
-                }
-            }
-
-            var insertAfterItem = targetItem as TimelineGroupGUI;
-            if (insertAfterItem != null && insertAfterItem.track != null)
-            {
-                ((TimelineTreeView)m_Window.treeView.gui).showInsertionMarker = true;
-            }
-
-            if (dropPos == DropPosition.Upon)
-            {
-                var groupGUI = targetItem as TimelineGroupGUI;
-                if (groupGUI != null)
-                    groupGUI.isDropTarget = true;
-            }
-
-            if (perform)
-            {
-                PlayableAsset targetParent = m_Timeline;
-                var parentActor = parentItem as TimelineGroupGUI;
-
-                if (parentActor != null && parentActor.track != null)
-                    targetParent = parentActor.track;
-
-                TrackAsset siblingTrack = insertAfterItem != null ? insertAfterItem.track : null;
-
-                // where the user drops after the last track, make sure to place it after all the tracks
-                if (targetParent == m_Timeline && dropPos == DropPosition.Below && siblingTrack == null)
-                {
-                    siblingTrack = m_Timeline.GetRootTracks().LastOrDefault(x => !draggedTracks.Contains(x));
-                }
-
-                if (TrackExtensions.ReparentTracks(TrackExtensions.FilterTracks(draggedTracks).ToList(), targetParent, siblingTrack, dropPos == DropPosition.Above))
-                {
-                    m_Window.state.Refresh();
-                }
-            }
-
-            return DragAndDropVisualMode.Move;
-        }
-
-        public static void HandleBindingDragAndDrop(TrackAsset dropTarget, Type requiredBindingType)
-        {
-            var objectBeingDragged = DragAndDrop.objectReferences[0];
-
-            var action = BindingUtility.GetBindingAction(requiredBindingType, objectBeingDragged);
-            DragAndDrop.visualMode = action == BindingAction.DoNotBind
-                ? DragAndDropVisualMode.Rejected
-                : DragAndDropVisualMode.Link;
-
-            if (action == BindingAction.DoNotBind || Event.current.type != EventType.DragPerform)
-                return;
-
-            var director = TimelineEditor.inspectedDirector;
-
-            switch (action)
-            {
-                case BindingAction.BindDirectly:
-                {
-                    BindingUtility.Bind(director, dropTarget, objectBeingDragged);
-                    break;
-                }
-                case BindingAction.BindToExistingComponent:
-                {
-                    var gameObjectBeingDragged = objectBeingDragged as GameObject;
-                    Debug.Assert(gameObjectBeingDragged != null, "The object being dragged was detected as being a GameObject");
-
-                    BindingUtility.Bind(director, dropTarget, gameObjectBeingDragged.GetComponent(requiredBindingType));
-                    break;
-                }
-                case BindingAction.BindToMissingComponent:
-                {
-                    var gameObjectBeingDragged = objectBeingDragged as GameObject;
-                    Debug.Assert(gameObjectBeingDragged != null, "The object being dragged was detected as being a GameObject");
-
-                    var typeNameOfComponent = requiredBindingType.ToString().Split(".".ToCharArray()).Last();
-                    var bindMenu = new GenericMenu();
-
-                    bindMenu.AddItem(
-                        EditorGUIUtility.TextContent("Create " + typeNameOfComponent + " on " + gameObjectBeingDragged.name),
-                        false,
-                        nullParam => BindingUtility.Bind(director, dropTarget, Undo.AddComponent(gameObjectBeingDragged, requiredBindingType)),
-                        null);
-
-                    bindMenu.AddSeparator("");
-                    bindMenu.AddItem(EditorGUIUtility.TrTextContent("Cancel"), false, userData => {}, null);
-                    bindMenu.ShowAsContext();
-
-                    break;
-                }
-                default:
-                {
-                    //no-op
-                    return;
-                }
-            }
-
-            DragAndDrop.AcceptDrag();
-        }
-
-        static bool ValidDrag(TreeViewItem target, List<TreeViewItem> draggedItems)
-        {
-            TreeViewItem currentParent = target;
-            while (currentParent != null)
-            {
-                if (draggedItems.Contains(currentParent))
-                    return false;
-                currentParent = currentParent.parent;
-            }
-
-            // dragging into the sequence itself
-            return true;
-        }
-    }
-}