# textView(_:willChangeSelectionFromCharacterRange:toCharacterRange:) Returns the actual range to select. ``` @MainActor optional func textView(_ textView: NSTextView, willChangeSelectionFromCharacterRange oldSelectedCharRange: NSRange, toCharacterRange newSelectedCharRange: NSRange) -> NSRange ``` ## Parameters `textView` The text view sending the message. This is the first text view in a series shared by a layout manager, not necessarily the text view displaying the selected text. `oldSelectedCharRange` The original range of the selection. `newSelectedCharRange` The proposed character range for the new selection. ## Return Value The actual character range for the new selection. ## Discussion This method is invoked before a text view finishes changing the selection—that is, when the last argument to a [`setSelectedRange(_:affinity:stillSelecting:)`](/documentation/AppKit/NSTextView/setSelectedRange(_:affinity:stillSelecting:)) message is . Non-selectable text views do not process any mouse events. If for some reason it is necessary to disallow user selection change in a text view that handles mouse events, this can be achieved by making the text view selectable but implementing this delegate method to disallow selection changes. ### Special Considerations In macOS 10.4 and later, if a delegate implements this delegate method and not its multiple-selection replacement, [`textView(_:willChangeSelectionFromCharacterRanges:toCharacterRanges:)`](/documentation/AppKit/NSTextViewDelegate/textView(_:willChangeSelectionFromCharacterRanges:toCharacterRanges:)), then multiple selection is effectively disallowed; attempts to set the selected ranges call the old delegate method with the first subrange, and afterwards only a single selected range is set. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)