BubbleView.h

//
//  BubbleView.h
//
//  Created by Josh Kendall on 12/28/10.
//  Copyright 2010 JoshuaKendall.com. All rights reserved.
//

#import <UIKit/UIKit.h>
#import <QuartzCore/QuartzCore.h>

@interface BubbleView : NSObject {
	int maxWidth, x, s, i, count, totalWidth;
	CGPoint p;
}

@property (nonatomic, retain) UIView *bubble;
@property (nonatomic, retain) CAGradientLayer *gradient;

- (UIView *)createTokensFrom:(NSString *)label withPosition:(CGPoint)point withMaxWidth:(int)width;
- (UIView *)createTokensFrom:(NSString *)label withPosition:(CGPoint)point;
- (void)createTokens:(NSString *)string;
- (UIView *)createBubbleWithString:(NSString *)token;

@end

BubbleView.m

//
//  BubbleView.m
//
//  Created by Josh Kendall on 12/28/10.
//  Copyright 2010 JoshuaKendall.com. All rights reserved.
//

#import "BubbleView.h"

@interface BubbleView ()
@property (nonatomic,retain) NSArray *tokens;
@end


@implementation BubbleView

@synthesize bubble;
@synthesize gradient;
@synthesize tokens;

- (id)init {
  self = [super init];
  if (self != nil) {
    bubble = [[UIView alloc] init];
    maxWidth = 0;
    totalWidth = 0;
    x = 0;
    s = 0;
    i = 0;
    count = 0;
  }

	return self;
}

- (UIView *)createTokensFrom:(NSString *)label withPosition:(CGPoint)point withMaxWidth:(int)width; {
	p = point;
	maxWidth = width;
	[self createTokens:label];
	for(NSString *token in tokens){
		if(totalWidth < maxWidth){
			UIView *b = [self createBubbleWithString:token];
			[bubble addSubview:b];
		}
	}
	if(count > 0){
		CGSize sizeOfLabel = [[NSString stringWithFormat:@"& %d More", count] sizeWithFont:[UIFont systemFontOfSize:11]];
		UILabel *title = [[UILabel alloc] initWithFrame:CGRectMake((p.x + s), point.y, (sizeOfLabel.width + 16), (sizeOfLabel.height + 5))];
		[title setText:[NSString stringWithFormat:@"& %d More", count]];
		[title setFont:[UIFont systemFontOfSize:11]];
		title.textAlignment = UITextAlignmentCenter;
		title.textColor = [UIColor blackColor];
		[bubble addSubview:title];
		[title release];
		title = nil;
	}
	return bubble;
}

- (UIView *)createTokensFrom:(NSString *)label withPosition:(CGPoint)point; {
	p = point;
	[self createTokens:label];
	for(NSString *token in tokens){
		[bubble addSubview:[self createBubbleWithString:token]];
	}
	return bubble;
}

- (void)createTokens:(NSString *)string; {
	tokens = [string componentsSeparatedByString: @","];
	count = [tokens count];
}

- (UIView *)createBubbleWithString:(NSString *)token; {
	CGSize sizeOfLabel = [token sizeWithFont:[UIFont systemFontOfSize:11]];
	p.x = (p.x + s);
	s = (sizeOfLabel.width + 20);
	totalWidth = totalWidth + s;
	CGRect rect = CGRectMake(p.x, p.y, (sizeOfLabel.width + 16), (sizeOfLabel.height + 5));

	UILabel *title = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, (sizeOfLabel.width + 16), (sizeOfLabel.height + 5))];
	UIView *container = [[[UIView alloc] initWithFrame:rect] autorelease];

	[title setFont:[UIFont systemFontOfSize:11]];
	title.textAlignment = UITextAlignmentCenter;
	title.textColor = [UIColor blackColor];
	title.layer.cornerRadius = 10;
	title.layer.borderColor = [UIColor colorWithRed:0.678 green:0.733 blue:0.847 alpha:1].CGColor;
	title.layer.borderWidth = .5;
	title.backgroundColor = [UIColor clearColor];
	[title setText:token];
	
	gradient = [CAGradientLayer layer];
	gradient.frame = container.bounds;
	gradient.colors = [NSArray arrayWithObjects:(id)[[UIColor colorWithRed:0.847 green:0.898 blue:1 alpha:1] CGColor], (id)[[UIColor colorWithRed:0.741 green:0.796 blue:1 alpha:1] CGColor], nil];
	gradient.cornerRadius = 10;

	[container.layer insertSublayer:gradient atIndex:0];
	[container addSubview:title];
	[title release];
	title = nil;
	i = i + 1;
	count--;
	return container;
}

- (void)dealloc {
  [gradient release];
  [bubble release];
  [tokens release];
	[super dealloc];
}

@end

Usage

# Show all bubbles.
BubbleView *bv = [[BubbleView alloc] init];
UIView *tags = [bv createTokensFrom:@"PHP,MySQL,iOS" withPosition:CGPointMake(90, 12)];
[self.view addSubview:bubble];

# Show only the bubbles that fit in the specified width.
BubbleView *bv = [[BubbleView alloc] init];
UIView *tags = [bv createTokensFrom:@"PHP,MySQL,iOS,C++,AJAX,ASP.NET,SQLite,Ruby" withPosition:CGPointMake(90, 12) withMaxWidth:100];
[self.view addSubview:bubble];