Category on NSTableView for animating rows, using old and new sorted arrays as input. Updated to support items having been removed or added.

NSTableView+Reordering.m

@implementation NSTableView (Reordering)


- (void) moveRowsWithOldObjects:(NSArray*)oldObjects newObjects:(NSArray*)newObjects
{
	NSMutableArray* oldSortedArray = [oldObjects mutableCopy];
	NSArray* newSortedArray = newObjects;
	
	[self beginUpdates];
	
	[newSortedArray enumerateObjectsUsingBlock:^(id obj, NSUInteger newIndex, BOOL *stop) {
		NSUInteger oldIndex = [oldSortedArray indexOfObject:obj];
		if( newIndex != oldIndex ) {
			if( oldIndex == NSNotFound ) {
				[oldSortedArray insertObject:obj atIndex:newIndex];
				[self insertRowsAtIndexes:[NSIndexSet indexSetWithIndex:newIndex]
					    withAnimation:NSTableViewAnimationEffectFade | NSTableViewAnimationSlideLeft];
			}
			else {
				[oldSortedArray removeObjectAtIndex:oldIndex];
				[oldSortedArray insertObject:obj atIndex:newIndex];
				[self moveRowAtIndex:oldIndex toIndex:newIndex];
			}
		}
	}];
	
	[oldSortedArray enumerateObjectsWithOptions:NSEnumerationReverse
					 usingBlock:^(id obj, NSUInteger oldIndex, BOOL *stop) {
		NSUInteger newIndex = [newSortedArray indexOfObject:obj];
		if( newIndex == NSNotFound ) {
			[oldSortedArray removeObject:obj];
			[self removeRowsAtIndexes:[NSIndexSet indexSetWithIndex:oldIndex]
				    withAnimation:NSTableViewAnimationEffectFade | NSTableViewAnimationSlideRight];
		}
	}];
	
	[self endUpdates];
}


@end

One might call it thusly:

NSArray* oldSortedArray = self.dataSource.arrangedObjects;
[self.dataSource arrangeObjects];
NSArray* newSortedArray = self.dataSource.arrangedObjects;
[self.tableView moveRowsWithOldObjects:oldSortedArray newObjects:newSortedArray];