Instance Method

rulerView(_:shouldAdd:)

Returns whether a new marker can be added.

Declaration

func rulerView(_ ruler: NSRulerView, shouldAdd marker: NSRulerMarker) -> Bool

Parameters

aRulerView

The ruler view sending the message.

aMarker

The marker to be added.

Return Value

true if aMarker can be added, false otherwise.

Discussion

The receiver checks for permission to make the change by invoking shouldChangeText(in:replacementString:) and returning the return value of that message. If the change is allowed, the receiver is then sent a rulerView(_:didAdd:) message.

See Also

NSRulerView Client Methods

func rulerView(NSRulerView, didMove: NSRulerMarker)

Modifies the paragraph style of the paragraphs containing the selection to record the new location of the marker.

func rulerView(NSRulerView, willMove: NSRulerMarker, toLocation: CGFloat) -> CGFloat

Returns a potentially modified location to which the marker should be moved.

func rulerView(NSRulerView, shouldMove: NSRulerMarker) -> Bool

Returns whether the marker should be moved.

func rulerView(NSRulerView, didRemove: NSRulerMarker)

Modifies the paragraph style of the paragraphs containing the selection—if possible—by removing the specified marker.

func rulerView(NSRulerView, shouldRemove: NSRulerMarker) -> Bool

Returns whether the marker should be removed.

func rulerView(NSRulerView, didAdd: NSRulerMarker)

Modifies the paragraph style of the paragraphs containing the selection to accommodate a new marker.

func rulerView(NSRulerView, willAdd: NSRulerMarker, atLocation: CGFloat) -> CGFloat

Returns a potentially modified location to which the marker should be added.

func rulerView(NSRulerView, handleMouseDownWith: NSEvent)

Adds a left tab marker to the ruler at the location clicked.