A simple category for Sparrow that allows one to auto size an SPTextField.

SPTextField+AutoSize.h

//
//  SPTextField+AutoSize.h
//  Sparrow
//
//  Created by Shilo White on 9/17/11.
//  Copyright 2011 Shilocity Productions. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface SPTextField (AutoSize)
- (SPRectangle *)textBounds;
- (void)autoSizeBounds;
- (void)autoSizeWidth;
- (void)autoSizeHeight;
@end

SPTextField+AutoSize.m

//
//  SPTextField+AutoSize.m
//  Sparrow
//
//  Created by Shilo White on 9/17/11.
//  Copyright 2011 Shilocity Productions. All rights reserved.
//

#import "SPTextField+AutoSize.h"

@implementation SPTextField (AutoSize)
- (SPRectangle *)textBounds {
    CGSize textSize = [self.text sizeWithFont:[UIFont fontWithName:self.fontName size:self.fontSize] constrainedToSize:CGSizeMake(self.width, self.height) lineBreakMode:UILineBreakModeTailTruncation];
    return [SPRectangle rectangleWithX:0 y:0 width:textSize.width height:textSize.height];
}
- (void)autoSizeBounds {
    SPRectangle *textBounds = [self textBounds];
    self.width = textBounds.width;
    self.height = textBounds.height;
}

- (void)autoSizeWidth {
    SPRectangle *textBounds = [self textBounds];
    self.width = textBounds.width;
}

- (void)autoSizeHeight {
    SPRectangle *textBounds = [self textBounds];
    self.height = textBounds.height;
}
@end