BNRBlockView: Add custom-drawn views to the Cocoa view hierarchy without subclassing.

BNRBlockView.h

@class BNRBlockView;

typedef void(^BNRBlockViewDrawer)(BNRBlockView *view, NSRect dirtyRect);

@interface BNRBlockView : NSView {
	BNRBlockViewDrawer drawBlock;
	BOOL opaque;
}

+ (BNRBlockView *)viewWithFrame:(NSRect)frame
                         opaque:(BOOL)opaque
                drawnUsingBlock:(BNRBlockViewDrawer)drawBlock;

@property (nonatomic, copy) BNRBlockViewDrawer drawBlock;
@property (nonatomic, assign) BOOL opaque;
@end

BNRBlockView.m

#import "BNRBlockView.h"

@implementation BNRBlockView

@synthesize drawBlock, opaque;

+ (BNRBlockView *)viewWithFrame:(NSRect)frame
                         opaque:(BOOL)opaque
                drawnUsingBlock:(BNRBlockViewDrawer)theDrawBlock
{
	__typeof__(self) view = [[BNRBlockView alloc] initWithFrame:frame];
	[view setDrawBlock:theDrawBlock];
	[view setOpaque:opaque];
	return [view autorelease];
}

- (void)dealloc
{
	[drawBlock release];
	[super dealloc];
}

- (void)drawRect:(NSRect)dirtyRect {
	if (drawBlock)
		drawBlock(self, dirtyRect);
}

- (BOOL)isOpaque {
	return opaque;
}

@end