Make UIButtons from images with a single line

SPAppearance.h

@interface SPAppearance : NSObject
+(id)sharedAppearance;

/** return a button with [name].png for normal, [name]-highlighted.png for highlight state,
    [name]-selected.png for selected and [name]-disabled.png for disabled, and combinations thereof.
    If the image conforms to configuredImageNamed, its 9-part configuration will be used for the button,
    and its title insets configured appropriately.
*/
-(UIButton*)buttonWithImageNamed:(NSString*)name;

/** If there is a [name].9edge.plist or [name.plist] file in the bundle, it will be used to make a stretched
    or tiled image from the image with the given name. Otherwise [UIImage imageNamed:] is used unmodified
*/
-(UIImage*)configuredImageNamed:(NSString*)name;
-(UIImage*)configuredImageNamed:(NSString*)name configName:(NSString*)configName; // if different from image name
@end

SPAppearance.m

#import "SPAppearance.h"

@implementation SPAppearance
+(id)sharedAppearance;
{
	static SPAppearance *g_singleton;
	static dispatch_once_t onceToken;
	dispatch_once(&onceToken, ^{
		g_singleton = [SPAppearance new];
	});
	return g_singleton;
}

-(UIButton*)buttonWithImageNamed:(NSString*)name;
{
	UIButton *b = [UIButton buttonWithType:UIButtonTypeCustom];
	
	UIImage *normal = [self configuredImageNamed:$sprintf(@"%@", name) configName:name];
	UIImage *highlighted = [self configuredImageNamed:$sprintf(@"%@-highlighted", name) configName:name];
	UIImage *selected = [self configuredImageNamed:$sprintf(@"%@-selected", name) configName:name];
	UIImage *highlightedSelected = [self configuredImageNamed:$sprintf(@"%@-highlighted+selected", name) configName:name];
	UIImage *disabled = [self configuredImageNamed:$sprintf(@"%@-disabled", name) configName:name];
	
	if(normal)
		[b setBackgroundImage:normal forState:UIControlStateNormal];
	if(highlighted)
		[b setBackgroundImage:highlighted forState:UIControlStateHighlighted];
	if(selected)
		[b setBackgroundImage:selected forState:UIControlStateSelected];
	if(highlightedSelected)
		[b setBackgroundImage:highlightedSelected forState:UIControlStateHighlighted|UIControlStateSelected];
	if(disabled)
		[b setBackgroundImage:disabled forState:UIControlStateDisabled];
	
    b.titleEdgeInsets = normal.capInsets;
    
	return b;
}

-(UIImage*)configuredImageNamed:(NSString*)name configName:(NSString*)configName;
{
	UIImage *img = [UIImage imageNamed:name];
	NSDictionary *settings = [NSDictionary dictionaryWithContentsOfFile:[[NSBundle mainBundle] pathForResource:configName ofType:@"9edge.plist"]];
	if(!settings)
		settings = [NSDictionary dictionaryWithContentsOfFile:[[NSBundle mainBundle] pathForResource:configName ofType:@"plist"]];
	if(!img || !settings)
		return img;
		
	NSNumber *left = [settings objectForKey:@"left"];
	NSNumber *top = [settings objectForKey:@"top"];
	NSNumber *bottom = [settings objectForKey:@"bottom"];
	NSNumber *right = [settings objectForKey:@"right"];
	
	if([[settings objectForKey:@"type"] isEqual:@"strech"])
		return [img stretchableImageWithLeftCapWidth:left.floatValue topCapHeight:top.floatValue];
	else if([[settings objectForKey:@"type"] isEqual:@"tile"])
		return [img resizableImageWithCapInsets:UIEdgeInsetsMake(top.floatValue, left.floatValue, bottom.floatValue, right.floatValue)];
	else
		NSLog(@"Unknown image configuration type %@", [settings objectForKey:@"type"]);
	
	return img;
}
-(UIImage*)configuredImageNamed:(NSString *)name;
{
	return [self configuredImageNamed:name configName:name];
}
@end