ShadowView.swift

//
//  ShadowView.swift
//

import UIKit

@IBDesignable
class ShadowView: UIView {
	
	@IBInspectable var startAlpha: CGFloat = 90 {
		didSet {
			setNeedsDisplay()
		}
	}
	
	@IBInspectable var midAlpha: CGFloat = 45 {
		didSet {
			setNeedsDisplay()
		}
	}
	
	@IBInspectable var midPosPercent: CGFloat = 50 {
		didSet {
			setNeedsDisplay()
		}
	}
	
	@IBInspectable var endAlpha: CGFloat = 0 {
		didSet {
			setNeedsDisplay()
		}
	}
	
	override func drawRect(rect: CGRect) {
		
		let ctx = UIGraphicsGetCurrentContext()
		let colorSpace = CGColorSpaceCreateDeviceRGB()
		//	let scaleFactor: CGFloat = 1
		let rectangle = CGRectMake( 0, 0, self.bounds.width, self.bounds.height )
		
		CGContextSaveGState( ctx )
		CGContextAddRect( ctx, rectangle )
		CGContextClip( ctx )
		
		let gradientColors: [CGFloat] = [
			0, 0, 0, self.startAlpha / 100,
			0, 0, 0, self.midAlpha / 100,
			0, 0, 0, self.endAlpha / 100 ]
		
		let gradientLocations: [CGFloat] = [ 0, self.midPosPercent / 100, 0.9 ]
		
		let gradientRef = CGGradientCreateWithColorComponents( colorSpace, gradientColors, gradientLocations, 3 )
		
		//	CGContextDrawLinearGradient( ctx, gradientRef, CGPoint(x: 0, y: 0), CGPoint(x: 0, y: self.bounds.height), CGGradientDrawingOptions(CGGradientDrawingOptions.DrawsBeforeStartLocation | CGGradientDrawingOptions.DrawsAfterEndLocation) )
		
		CGContextDrawLinearGradient( ctx, gradientRef, CGPoint(x: 0, y: 0), CGPoint(x: 0, y: self.bounds.height), CGGradientDrawingOptions([.DrawsBeforeStartLocation, .DrawsAfterEndLocation]) )
		
		CGContextRestoreGState( ctx )
		
	}
	
}