1 files changed, 137 insertions, 0 deletions
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Editor/Manipulators/Utils/EditModeMixUtils.cs b/Library/PackageCache/com.unity.timeline@1.2.13/Editor/Manipulators/Utils/EditModeMixUtils.cs
new file mode 100644
index 0000000..ca34f4b
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Editor/Manipulators/Utils/EditModeMixUtils.cs
@@ -0,0 +1,137 @@
+using System.Collections.Generic;
+using System.Linq;
+using UnityEngine.Timeline;
+
+namespace UnityEditor.Timeline
+{
+    static class EditModeMixUtils
+    {
+        static readonly List<PlacementValidity> k_UnrecoverablePlacements = new List<PlacementValidity>
+        {
+            PlacementValidity.InvalidIsWithin,
+            PlacementValidity.InvalidStartsInBlend,
+            PlacementValidity.InvalidContainsBlend
+        };
+
+        public static bool CanInsert(IEnumerable<ItemsPerTrack> itemsGroups)
+        {
+            foreach (var itemsGroup in itemsGroups)
+            {
+                var siblings = ItemsUtils.GetItemsExcept(itemsGroup.targetTrack, itemsGroup.items);
+                foreach (var item in itemsGroup.items)
+                {
+                    var placementValidity = GetPlacementValidity(item, siblings);
+
+                    if (k_UnrecoverablePlacements.Contains(placementValidity))
+                    {
+                        return false;
+                    }
+                }
+            }
+
+            return true;
+        }
+
+        //Corrects clips durations to fit at insertion point, if needed
+        public static void PrepareItemsForInsertion(IEnumerable<ItemsPerTrack> itemsGroups)
+        {
+            foreach (var itemsGroup in itemsGroups)
+            {
+                var siblings = ItemsUtils.GetItemsExcept(itemsGroup.targetTrack, itemsGroup.items);
+                foreach (var item in itemsGroup.items.OfType<ITrimmable>())
+                {
+                    var eatenItems = siblings.Where(c => EditModeUtils.IsItemWithinRange(c, item.start, item.end)).ToList();
+
+                    var intersectedItem = EditModeUtils.GetFirstIntersectedItem(siblings, item.end);
+                    if (intersectedItem != null)
+                        eatenItems.Add(intersectedItem);
+
+                    var blendableItems = eatenItems.OfType<IBlendable>();
+                    if (blendableItems.Any())
+                    {
+                        var minTime = blendableItems.Min(c => c.end - c.rightBlendDuration);
+
+                        if (item.end > minTime)
+                            item.SetEnd(minTime, false);
+                    }
+                }
+            }
+        }
+
+        public static PlacementValidity GetPlacementValidity(ITimelineItem item, IEnumerable<ITimelineItem> otherItems)
+        {
+            if (item.duration <= 0.0)
+                return PlacementValidity.Valid;  //items without any duration can always be placed
+
+            var sortedItems = otherItems.Where(i => i.duration > 0.0).OrderBy(c => c.start);
+            var candidates = new List<ITimelineItem>();
+            foreach (var sortedItem in sortedItems)
+            {
+                if ((DiscreteTime)sortedItem.start >= (DiscreteTime)item.end)
+                {
+                    // No need to process further
+                    break;
+                }
+
+                if ((DiscreteTime)sortedItem.end <= (DiscreteTime)item.start)
+                {
+                    // Skip
+                    continue;
+                }
+
+                candidates.Add(sortedItem);
+            }
+
+            var discreteStart = (DiscreteTime)item.start;
+            var discreteEnd = (DiscreteTime)item.end;
+
+            // Note: Order of tests matters
+            for (int i = 0, n = candidates.Count; i < n; i++)
+            {
+                var candidate = candidates[i];
+
+                var blendItem = item as IBlendable;
+                if (blendItem != null && blendItem.supportsBlending)
+                {
+                    if (EditModeUtils.Contains(candidate.start, candidate.end, item))
+                        return PlacementValidity.InvalidIsWithin;
+
+                    if (i < n - 1)
+                    {
+                        var nextCandidate = candidates[i + 1];
+
+                        var discreteNextCandidateStart = (DiscreteTime)nextCandidate.start;
+                        var discreteCandidateEnd = (DiscreteTime)candidate.end;
+
+                        if (discreteCandidateEnd > discreteNextCandidateStart)
+                        {
+                            if (discreteStart >= discreteNextCandidateStart)
+                            {
+                                // Note: In case the placement is fully within a blend,
+                                // InvalidStartsInBlend MUST have priority
+                                return PlacementValidity.InvalidStartsInBlend;
+                            }
+
+                            if (discreteEnd > discreteNextCandidateStart && discreteEnd <= discreteCandidateEnd)
+                                return PlacementValidity.InvalidEndsInBlend;
+
+                            if (discreteStart < discreteNextCandidateStart && discreteEnd > discreteCandidateEnd)
+                                return PlacementValidity.InvalidContainsBlend;
+                        }
+                    }
+
+                    if (EditModeUtils.Contains(item.start, item.end, candidate))
+                        return PlacementValidity.InvalidContains;
+                }
+                else
+                {
+                    if (EditModeUtils.Overlaps(item, candidate.start, candidate.end)
+                        || EditModeUtils.Overlaps(candidate, item.start, item.end))
+                        return PlacementValidity.InvalidOverlapWithNonBlendableClip;
+                }
+            }
+
+            return PlacementValidity.Valid;
+        }
+    }
+}