Switch between views Mobile Safari-style

//
//  LSDotLayer.m
//  ViewSwitcher
//
//  Created by Le Son on 6/10/10.
//  Copyright 2010 __MyCompanyName__. All rights reserved.
//

#import "LSDotLayer.h"

@implementation LSDotLayer

@dynamic numberOfDots;
@dynamic activeDot;

- (NSUInteger)numberOfDots
{
	return numberOfDots;
}

- (void)setNumberOfDots:(NSUInteger)n
{
	numberOfDots = n;
	[self setNeedsDisplay];
}

- (NSUInteger)activeDot
{
	return activeDot;
}

- (void)setActiveDot:(NSUInteger)n
{
	activeDot = n;
	[self setNeedsDisplay];
}

- (void)drawInContext:(CGContextRef)ctx
{
	if (numberOfDots > 1)
	{
		// Diameter = height of this layer
		float diameter = self.bounds.size.height;
		
		// Get center point
		CGPoint center = CGPointMake(CGRectGetMidX(self.bounds), CGRectGetMidY(self.bounds));
		
		// Get point of first dot
		float x = center.x - (diameter + 10.0f) * self.numberOfDots/2 + 10.0f;
	
		float y = center.y;
		CGPoint pos = CGPointMake(x, y);
	
		for (int i = 0; i < self.numberOfDots; i++)
		{
			// Referenced from http://alanduncan.net/old/index.php?q=node/4
			
			// Draw the dot
			CGContextSetRGBFillColor(ctx, 1.0f, 1.0f, 1.0f, (i == self.activeDot ? 1.0f : 0.5f));
			float radius = diameter * 0.5;
			CGRect myOval = CGRectMake(pos.x - radius, pos.y - radius, diameter, diameter);
			CGContextAddEllipseInRect(ctx, myOval);
			CGContextFillPath(ctx);
			CGContextStrokePath(ctx);
			
			// Increase pos
			pos.x += diameter + 10.0f;
		}
	}
}

@end