CPArrayController was erroneously using canRemove to determine whether explicit removal could take place, when in fact the documentation for [NSObjectController canRemove] (NSArrayController does not override canRemove) states that it returns "YES if an object can be removed from the receiver using remove:, otherwise NO", implying that it should only be used to check whether there is a selected element that can be removed (for example, to bind the enabled state of a toolbar button to a CPArrayController's canRemove property). It should not be used to decide whether a specific object can be removed or not.
When initializing a CPArrayController with a value that is not an array setContent: would make it an array by replacing value with [value]. This is consistent with how Cocoa does it, but it should first check to make sure that the content is not nil. If it is, the sensible thing to do (and what Cocoa does) is to replace it with an empty array.
This commit also includes a missing import to make CPArrayControllerTest run without error.
It is crucial that we send notification only before and after complete changes. In the middle notifications might cause observers to see or react to inconsistent data (e.g. selection indexes pointing to rows no longer present). Added some unit tests - more might be needed in the future. Fixed: before and after values when observing array controller key paths during content changes or rearranges were wrong. Fixed: the array controller sent out multiple redundant change notifications.
Brian Donovan
Ross Boucher
Klaas Pieter Annema
Alexander Ljungberg