outlineView(_:isItemExpandable:)

Declaration

@MainActor optional func outlineView(_ outlineView: NSOutlineView, isItemExpandable item: Any) -> Bool

Parameters

• outlineView:

  The outline view that sent the message.

• item:

  An item in the data source.

Return Value

true if item can be expanded to display its children, otherwise false.

Discussion

This method may be called quite often, so it must be efficient.

See Also

Instance Methods

• outlineView(_:acceptDrop:item:childIndex:)
• outlineView(_:child:ofItem:)
• outlineView(_:draggingSession:endedAt:operation:)
• outlineView(_:draggingSession:willBeginAt:forItems:)
• outlineView(_:itemForPersistentObject:)
• outlineView(_:namesOfPromisedFilesDroppedAtDestination:forDraggedItems:)
• outlineView(_:numberOfChildrenOfItem:)
• outlineView(_:objectValueFor:byItem:)
• outlineView(_:pasteboardWriterForItem:)
• outlineView(_:persistentObjectForItem:)
• outlineView(_:setObjectValue:for:byItem:)
• outlineView(_:sortDescriptorsDidChange:)
• outlineView(_:updateDraggingItemsForDrag:)
• outlineView(_:validateDrop:proposedItem:proposedChildIndex:)
• outlineView(_:writeItems:to:)