/*

    Copyright (C) 2017 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    DrawingView is a helper for the sample code. Your app can draw however it wants since alignment is independent of the view hierarchy. Here, we're using bezier paths.

*/

import Cocoa

class DrawingView: NSView {

    override func draw(_ dirtyRect: NSRect) {

        NSColor(deviceRed: 0.95, green: 0.95, blue: 0.9, alpha: 1.0).set()

        NSRectFill(bounds)

        NSColor.black.set()

        NSFrameRect(bounds)

    }

    func drawBox(_ frame: NSRect, drawCenterAlignmentGuides: Bool) {

        NSColor(deviceRed: 0.78, green: 0.78, blue: 0.78, alpha: 1.0).set()

        NSRectFill(frame)

        NSColor.black.set()

        NSFrameRectWithWidth(frame, 1.0)

        if drawCenterAlignmentGuides {

            let path = NSBezierPath()

            path.move(to: NSPoint(x: frame.minX, y: frame.midY))

            path.line(to: NSPoint(x: frame.maxX, y: frame.midY))

            path.move(to: NSPoint(x: frame.midX, y: frame.minY))

            path.line(to: NSPoint(x: frame.midX, y: frame.maxY))

            path.stroke()

        }

    }

    func drawHorizontalGuide(_ yCoordinate: CGFloat, holdingItem: Bool) {

        let path = NSBezierPath()

        NSColor(deviceRed: 0.0, green: 0.0, blue: 1.0, alpha: (holdingItem ? 0.8 : 0.2)).set()

        path.move(to: NSPoint(x: 0.0, y: yCoordinate))

        path.line(to: NSPoint(x: bounds.width, y: yCoordinate))

        path.stroke()

    }

    func drawVerticalGuide(_ xCoordinate: CGFloat, holdingItem: Bool) {

        let path = NSBezierPath()

        NSColor(deviceRed: 0.0, green: 0.0, blue: 1.0, alpha: (holdingItem ? 0.8 : 0.2)).set()

        path.move(to: NSPoint(x: xCoordinate, y: 0.0))

        path.line(to: NSPoint(x: xCoordinate, y: bounds.height))

        path.stroke()

    }

    func constrainRectToBounds(_ rect: NSRect) -> NSRect {

        var result = rect

        if rect.origin.x < 0.0 {

            result.origin.x = 0.0

        }

        if rect.origin.y < 0.0 {

            result.origin.y = 0.0

        }

        if rect.maxX > bounds.width {

            result.origin.x = bounds.width - rect.width

        }

        if rect.maxY > bounds.height {

            result.origin.y = bounds.height - rect.height

        }

        return result

    }

}