/*

 Copyright (C) 2016 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 The CanvasView is a basic NSView subclass that demonstrates using updateLayer/wantsUpdateLayer by adding a drop shadow and a simple white fill color.

 */

import Cocoa

class CanvasView: NSView {

    override init(frame frameRect: NSRect) {

        super.init(frame: frameRect)

        commonSetup()

    }

    required init?(coder: NSCoder) {

        super.init(coder: coder)

        commonSetup()

    }

    private func commonSetup() {

        wantsLayer = true

        layerContentsRedrawPolicy = .onSetNeedsDisplay

        let shadow = NSShadow()

        shadow.shadowColor = NSColor(calibratedWhite: 0.0, alpha: 0.66)

        shadow.shadowBlurRadius = 4.0

        shadow.shadowOffset = NSSize(width: 0.0, height: 2.0)

        self.shadow = shadow

    }

    // Make the origin be the top left

    override var isFlipped: Bool {

        return true

    }

    override var isOpaque: Bool {

        return true

    }

    override var wantsUpdateLayer: Bool {

        return true

    }

    override func updateLayer() {

        layer?.backgroundColor = NSColor.white.cgColor

    }

}