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;
}
// Reparents a list of tracks to a new parent
// the new parent cannot be null (has to be track asset or sequence)
// the insertAfter can be null (will not reorder)
internal static bool ReparentTracks(List <TrackAsset> tracksToMove, PlayableAsset targetParent,
TrackAsset insertMarker = null, bool insertBefore = false)
{
var targetParentTrack = targetParent as TrackAsset;
var targetSequenceTrack = targetParent as TimelineAsset;
if (tracksToMove == null || tracksToMove.Count == 0 || (targetParentTrack == null && targetSequenceTrack == null))
{
return(false);
}
// invalid parent type on a track
if (targetParentTrack != null && tracksToMove.Any(x => !TimelineCreateUtilities.ValidateParentTrack(targetParentTrack, x.GetType())))
{
return(false);
}
// no valid tracks means this is simply a rearrangement
var validTracks = tracksToMove.Where(x => x.parent != targetParent).ToList();
if (insertMarker == null && !validTracks.Any())
{
return(false);
}
var parents = validTracks.Select(x => x.parent).Where(x => x != null).Distinct().ToList();
// push the current state of the tracks that will change
foreach (var p in parents)
{
TimelineUndo.PushUndo(p, "Reparent");
}
foreach (var t in validTracks)
{
TimelineUndo.PushUndo(t, "Reparent");
}
TimelineUndo.PushUndo(targetParent, "Reparent");
// need to reparent tracks first, before moving them.
foreach (var t in validTracks)
{
if (t.parent != targetParent)
{
TrackAsset toMoveParent = t.parent as TrackAsset;
TimelineAsset toMoveTimeline = t.parent as TimelineAsset;
if (toMoveTimeline != null)
{
toMoveTimeline.RemoveTrack(t);
}
else if (toMoveParent != null)
{
toMoveParent.RemoveSubTrack(t);
}
if (targetParentTrack != null)
{
targetParentTrack.AddChild(t);
targetParentTrack.SetCollapsed(false);
}
else
{
targetSequenceTrack.AddTrackInternal(t);
}
}
}
if (insertMarker != null)
{
// re-ordering track. This is using internal APIs, so invalidation of the tracks must be done manually to avoid
// cache mismatches
var children = targetParentTrack != null ? targetParentTrack.subTracksObjects : targetSequenceTrack.trackObjects;
TimelineUtility.ReorderTracks(children, tracksToMove, insertMarker, insertBefore);
if (targetParentTrack != null)
{
targetParentTrack.Invalidate();
}
if (insertMarker.timelineAsset != null)
{
insertMarker.timelineAsset.Invalidate();
}
}
return(true);
}