I have a label (NSTextField) with text aligned right. When the text becomes too large to display, the end of the text is truncated (at the right edge of the label).
NSTextField
What you're looking for is
[[myTextField cell] setLineBreakMode: NSLineBreakByTruncatingHead];
Swift:
myTextField.cell.lineBreakMode = NSLineBreakMode.ByTruncatingHead