A simple overflow text extension for Sparrow.

SHOverflowTextField.h

//
//  SHOverflowTextField.h
//  Sparrow
//
//  Created by Shilo White on 9/14/11.
//  Copyright 2011 Shilocity Productions. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "SPTextField.h"

@interface SHOverflowTextField : SPTextField {
    SHOverflowTextField *mLinkedTextField;
}

@property (nonatomic, retain) SHOverflowTextField *linkedTextField;

+ (SHOverflowTextField *)overflowTextFieldWithWidth:(float)width height:(float)height text:(NSString *)text fontName:(NSString *)name fontSize:(float)size color:(uint)color;
+ (SHOverflowTextField *)overflowTextFieldWithWidth:(float)width height:(float)height text:(NSString *)text;
+ (SHOverflowTextField *)overflowTextFieldWithText:(NSString *)text;
+ (SHOverflowTextField *)overflowTextField;
@end

SHOverflowTextField.m

//
//  SHOverflowTextField.m
//  Sparrow
//
//  Created by Shilo White on 9/14/11.
//  Copyright 2011 Shilocity Productions. All rights reserved.
//

#import "SHOverflowTextField.h"
#import <CoreText/CoreText.h>

@interface SPTextField (RequiresRedraw)
@property (nonatomic, assign) BOOL requiresRedraw;
@property (nonatomic, readonly) SPQuad *hitArea;
@property (nonatomic, readonly) SPQuad *textArea;
@end

@implementation SPTextField (RequiresRedraw)
- (void)setRequiresRedraw:(BOOL)requiresRedraw {
    mRequiresRedraw = requiresRedraw;
}

- (BOOL)requiresRedraw {
    return mRequiresRedraw;
}

- (SPQuad *)hitArea {
    return mHitArea;
}

- (SPQuad *)textArea {
    return mTextArea;
}
@end

@implementation SHOverflowTextField

@synthesize linkedTextField = mLinkedTextField;

+ (SHOverflowTextField *)overflowTextFieldWithWidth:(float)width height:(float)height text:(NSString *)text fontName:(NSString *)name fontSize:(float)size color:(uint)color {
    return [[[self alloc] initWithWidth:width height:height text:text fontName:name fontSize:size color:color] autorelease];
}

+ (SHOverflowTextField *)overflowTextFieldWithWidth:(float)width height:(float)height text:(NSString *)text {
    return [[[self alloc] initWithWidth:width height:height text:text] autorelease];
}

+ (SHOverflowTextField *)overflowTextFieldWithText:(NSString *)text {
    return [[[self alloc] initWithText:text] autorelease];
}

+ (SHOverflowTextField *)overflowTextField {
    return [[[self alloc] initWithText:@""] autorelease];
}

- (SPDisplayObject *)createRenderedContents
{
    float width = self.hitArea.width;
    float height = self.hitArea.height;    
    float fontSize = self.fontSize == SP_NATIVE_FONT_SIZE ? SP_DEFAULT_FONT_SIZE : self.fontSize;
    
    UILineBreakMode lbm = (mLinkedTextField)?UILineBreakModeWordWrap:UILineBreakModeTailTruncation;
    CGSize textSize = [self.text sizeWithFont:[UIFont fontWithName:self.fontName size:fontSize] 
                        constrainedToSize:CGSizeMake(width, height) lineBreakMode:lbm];
    
    float xOffset = 0;
    if (self.hAlign == SPHAlignCenter)      xOffset = (width - textSize.width) / 2.0f;
    else if (self.hAlign == SPHAlignRight)  xOffset =  width - textSize.width;
    
    float yOffset = 0;
    if (self.vAlign == SPVAlignCenter)      yOffset = (height - textSize.height) / 2.0f;
    else if (self.vAlign == SPVAlignBottom) yOffset =  height - textSize.height;
    
    self.textArea.x = xOffset; 
    self.textArea.y = yOffset;
    self.textArea.width = textSize.width; 
    self.textArea.height = textSize.height;
    
    SPTexture *texture = [[SPTexture alloc] initWithWidth:width height:height
                                                    scale:[SPStage contentScaleFactor]
                                               colorSpace:SPColorSpaceAlpha
                                                     draw:^(CGContextRef context)
                          {
                              if (self.border)
                              {
                                  CGContextSetGrayStrokeColor(context, 1.0f, 1.0f);
                                  CGContextSetLineWidth(context, 1.0f);
                                  CGContextStrokeRect(context, CGRectMake(0.5f, 0.5f, width-1, height-1));
                              }
                              
                              CGContextSetGrayFillColor(context, 1.0f, 1.0f);        
                              
                              [self.text drawInRect:CGRectMake(0, yOffset, width, height)
                                       withFont:[UIFont fontWithName:self.fontName size:fontSize] 
                                  lineBreakMode:lbm alignment:self.hAlign];
                              
                              if (mLinkedTextField) {
                                  //CTParagraphStyleRef paragraphStyle = CTParagraphStyleCreate((CTParagraphStyleSetting[1]){{.spec = kCTParagraphStyleSpecifierLineBreakMode, .valueSize = sizeof(CTLineBreakMode), .value = (const void*)&lbm}}, 1);
                                  CTFontRef fontAttribute = CTFontCreateWithName((CFStringRef)self.fontName, self.fontSize, NULL);
                                  NSDictionary *attributes = [NSDictionary dictionaryWithObjectsAndKeys:(id)fontAttribute, (NSString *)kCTFontAttributeName, nil]; //(id)paragraphStyle, (NSString *)kCTParagraphStyleAttributeName, nil];
                                  CFRelease(fontAttribute);
                                  NSAttributedString *attributedText = [[NSAttributedString alloc] initWithString:self.text attributes:attributes];
                                  
                                  CGMutablePathRef framePath = CGPathCreateMutable();
                                  CGPathAddRect(framePath, NULL, CGRectMake(0, yOffset, width, height));
                                  CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)attributedText);
                                  CTFrameRef frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, 0), framePath, NULL);
                                  CGPathRelease(framePath);
                                  CFRelease(framesetter);
                                  
                                  int visibleLength = CTFrameGetVisibleStringRange(frame).length;
                                  CFRelease(frame);
                                  if (visibleLength<self.text.length) {
                                      NSString *overflowString = [[attributedText string] substringFromIndex:MAX(visibleLength, 0)];
                                      if (![overflowString isEqualToString:@""]) mLinkedTextField.text = overflowString;
                                  }
                                  
                                  [attributedText release];
                              }
                          }];
    
    SPImage *image = [SPImage imageWithTexture:texture];
    image.color = self.color;
    [texture release];
    
    return image;
}

- (void)setLinkedTextField:(SHOverflowTextField *)linkedTextField {
    if (linkedTextField != mLinkedTextField) {
        [mLinkedTextField autorelease];
        mLinkedTextField = [linkedTextField retain];
        self.requiresRedraw = YES;
    }
}

- (void)dealloc {
    [mLinkedTextField release];
    [super dealloc];
}
@end