# CTFramesetterSuggestFrameSizeWithConstraints(_:_:_:_:_:) Determines the frame size needed for a string range. ``` func CTFramesetterSuggestFrameSizeWithConstraints(_ framesetter: CTFramesetter, _ stringRange: CFRange, _ frameAttributes: CFDictionary?, _ constraints: CGSize, _ fitRange: UnsafeMutablePointer?) -> CGSize ``` ## Parameters `framesetter` The framesetter used for measuring the frame size. `stringRange` The string range to which the frame size applies. The string range is a range over the string used to create the framesetter. If the length portion of the range is set to `0`, then the framesetter continues to add lines until it runs out of text or space. `frameAttributes` Additional attributes that control the frame filling process, or `NULL` if there are no such attributes. `constraints` The width and height to which the frame size is constrained. A value of for either dimension indicates that it should be treated as unconstrained. `fitRange` On return, contains the range of the string that actually fit in the constrained size. ## Return Value The actual dimensions for the given string range and constraints. ## Discussion This function can be used to determine how much space is needed to display a string, optionally by constraining the space along either dimension. --- 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)