Calculate a Label Size from its content and its position. It is useful when you want to adapt a UILabel size according to its x;y origin, its width and its content. It can then adapt a cell's height from a dynamic content.

UILabel+Size.h

//--------------------------------------------------------
// 
//--------------------------------------------------------
// Project     : 
// File        : UILabel+Size.h
// Created     : $ 04/05/12 $
// Maintainer  : $ Rémi LAVEDRINE $
//
// Copyright Rémi LAVEDRINE 2004-2012, All Rights Reserved
//
// This software is the confidential and proprietary
// information of Rémi LAVEDRINE.
// You shall not disclose such Confidential Information
// and shall use it only in accordance with the terms
// of the license agreement you entered into with
// Rémi LAVEDRINE.
//--------------------------------------------------------
// 
// @brief
// Calculate a Label Size from its content and its position.
// It is useful when you want to adapt a UILabel size according to its x;y origin, its width and its content.
// It can then adapt a cell's height from a dynamic content.
//

#import <UIKit/UIKit.h>


//! @brief Calculate a Label Size from its content and its position.
//! @class UILabel+Size
//! @ingroup Utilities
//! @author Rémi Lavedrine
@interface UILabel (Size)

//! Adjusts Adjusts UILabel's frame to begin at defined x and y position and have a dynamic height
//! @param[in] startX - value that the frames x coord to be
//! @param[in] startY - value that the frames y coord to be
-(void)setUpMultiLineFrameWithStartXPosition:(CGFloat)startX withStartYPosition:(CGFloat)startY;

//! Adjusts UILabel's frame to begin at defined x position, to maxiumum width and height, centered veritcally based on maxHeight and height of content
//! @param[in] width     : value that the frames width property will be
//! @param[in] startX    : value that the frames x coord to be
//! @param[in] maxHeight : value that the frames height property will be
-(void)setUpMultiLineFrameBasedOnWidth:(CGFloat)width withStartXPosition:(CGFloat)startX withHeight:(CGFloat)maxHeight; 

//! Adjusts UILabel's frame to begin at defined x and y position, to maxiumum width and have a dynamic height
//! @param[in] maxWidth : value that the frames width property will be
//! @param[in] startX   : value that the frames x coord to be
//! @param[in] startY   : value that the frames y coord to be
-(void)setUpMultiLineFrameBasedOnWidth:(CGFloat)maxWidth withStartXPosition:(CGFloat)startX withStartYPosition:(CGFloat)startY;

//! Adjusts UILabel's frame to begin at defined x position, to maximum width
//! @param[in] maxWidth : value that the frames width property will be
//! @param[in] startX   : value that the frames x coord to be
-(void)setUpMultiLineFrameBasedOnWidth:(CGFloat)maxWidth withStartXPosition:(CGFloat)startX;

//! Returns height value of UILabel based on content and max width
//! @param[in] width : max width of content
//! @return height of UILabel
-(CGFloat)getHeightBasedOnWidth:(CGFloat)width;

//! Returns size of UILabel based on content
//! @return Size of UILabel
-(CGSize)getSize;

@end

UILabel+Size.m

//
//  UILabel+Size.m
//  MobinilAndMe
//
//  Created by Rémi LAVEDRINE on 04/05/12.
//  Copyright (c) 2012 Rémi LAVEDRINE. All rights reserved.
//

#import "UILabel+Size.h"

@implementation UILabel (Size)

/**
 @brief Adjusts Adjusts UILabel's frame to begin at defined x and y position and have a dynamic height 
 @author : Rémi Lavedrine
 @date : 04/05/2012 (May the 4th be with you ^^) 
 @remarks : <#(optional)#>
 */
-(void)setUpMultiLineFrameWithStartXPosition:(CGFloat)startX withStartYPosition:(CGFloat)startY
{
	self.lineBreakMode = UILineBreakModeWordWrap;
	self.numberOfLines = 0;//instructs the label to contain any number of lines
	
	CGSize minSize = [self getSize];
	[self setFrame:CGRectMake(startX, startY, minSize.width, minSize.height)];
}

/**
 @brief Adjusts UILabel's frame to begin at defined x position, to maxiumum width and height, centered veritcally based on maxHeight and height of content 
 @author : Rémi Lavedrine
 @date : 04/05/2012 (May the 4th be with you ^^) 
 @remarks : <#(optional)#>
 */
-(void)setUpMultiLineFrameBasedOnWidth:(CGFloat)maxWidth withStartXPosition:(CGFloat)startX withHeight:(CGFloat)maxHeight{
	self.lineBreakMode = UILineBreakModeWordWrap;
	self.numberOfLines = 0; //instructs the label to contain any number of lines
	
	CGFloat labelHeight = [self getHeightBasedOnWidth:maxWidth];
	CGFloat padding = ((maxHeight - labelHeight)/2); //center label within maxHeight box
	[self setFrame:CGRectMake(startX, padding, maxWidth, labelHeight)];
}

/**
 @brief Adjusts UILabel's frame to begin at defined x and y position, to maxiumum width and have a dynamic height 
 @author : Rémi Lavedrine
 @date : 04/05/2012 (May the 4th be with you ^^) 
 @remarks : <#(optional)#>
 */
-(void)setUpMultiLineFrameBasedOnWidth:(CGFloat)maxWidth withStartXPosition:(CGFloat)startX withStartYPosition:(CGFloat)startY{
	
	self.lineBreakMode = UILineBreakModeWordWrap;
	self.numberOfLines = 0;//instructs the label to contain any number of lines
	
	CGFloat labelHeight = [self getHeightBasedOnWidth:maxWidth];
	[self setFrame:CGRectMake(startX, startY, maxWidth, labelHeight)];
}

/**
 @brief Adjusts UILabel's frame to begin at defined x position, to maximum width 
 @author : Rémi Lavedrine
 @date : 04/05/2012 (May the 4th be with you ^^) 
 @remarks : <#(optional)#>
 */
-(void)setUpMultiLineFrameBasedOnWidth:(CGFloat)maxWidth withStartXPosition:(CGFloat)startX{
	self.lineBreakMode = UILineBreakModeWordWrap;
	self.numberOfLines = 0;//instructs the label to contain any number of lines
	
	CGFloat labelHeight = [self getHeightBasedOnWidth:maxWidth];
	[self setFrame:CGRectMake(startX, 0, maxWidth, labelHeight)];
}

/**
 @brief Returns height value of UILabel based on content and max width 
 @author : Rémi Lavedrine
 @date : 04/05/2012 (May the 4th be with you ^^) 
 @remarks : <#(optional)#>
 */
-(CGFloat)getHeightBasedOnWidth:(CGFloat)maxWidth{
	
	CGSize size = [self.text sizeWithFont:self.font constrainedToSize:CGSizeMake(maxWidth, 9999) lineBreakMode:self.lineBreakMode];
	
	return size.height;
}

/**
 @brief Returns size of UILabel based on content 
 @author : Rémi Lavedrine
 @date : 04/05/2012 (May the 4th be with you ^^) 
 @remarks : <#(optional)#>
 */
-(CGSize)getSize{
	CGSize size = [self.text sizeWithFont:self.font constrainedToSize:CGSizeMake(9999, 9999) lineBreakMode:self.lineBreakMode];
	
	return size;
}

@end