/*

See LICENSE folder for this sample’s licensing information.

Abstract:

An example demonstrating adding accessibility to an NSView subclass that draws itself using two separate CALayers.

*/

import Cocoa

class ImageViewLayerView: NSView {

    // MARK: - Internals

    fileprivate struct LayoutInfo {

        static let ImageWidth = CGFloat(75.0)

        static let ImageHeight = ImageWidth

        static let FontSize = CGFloat(18.0)

        static let TextFrameHeight = CGFloat(25.0)

    }

    var imageLayer: CustomImageLayer!

    var textLayer: CustomTextLayer!

    // MARK: - View Lifecycle

    required override init(frame frameRect: NSRect) {

        super.init(frame: frameRect)

        commonInit()

    }

    required init?(coder aDecoder: NSCoder) {

        super.init(coder: aDecoder)

        commonInit()

    }

    func commonInit() {

        // Root layer will have a green background color.

        let rootLayer = CALayer()

        let colorSpace = CGColorSpace(name: CGColorSpace.sRGB)

        rootLayer.backgroundColor = CGColor(colorSpace: colorSpace!, components: [0.9, 1.0, 0.60, 1.0])

        layer = rootLayer

        // Sub image layer will have the RedDot image as it's content.

        let imageLayer = CustomImageLayer()

        let imageName = "RedDot"

        imageLayer.contents = NSImage(named: NSImage.Name(rawValue: imageName))

        imageLayer.parent = self

        let imageFrame = NSRect(x: (frame.size.width / 2) - LayoutInfo.ImageWidth,

                                y: (frame.size.height / 2) - LayoutInfo.ImageHeight + 8,

                                width: LayoutInfo.ImageWidth,

                                height: LayoutInfo.ImageHeight)

        imageLayer.frame = imageFrame

        imageLayer.anchorPoint = CGPoint()

        rootLayer.addSublayer(imageLayer)

        // Sub text layer will have a black label.

        let textLayer = CustomTextLayer()

        textLayer.string = NSLocalizedString("Red Dot", comment: "displayed text for the RedDot image")

        textLayer.parent = self

        textLayer.frame = CGRect(x: imageFrame.origin.x,

                                 y: imageFrame.origin.y,

                                 width: LayoutInfo.ImageWidth,

                                 height: LayoutInfo.TextFrameHeight)

        textLayer.anchorPoint = CGPoint()

        textLayer.fontSize = LayoutInfo.FontSize

        textLayer.alignmentMode = "center"

        textLayer.foregroundColor = NSColor.black.cgColor

        rootLayer.addSublayer(textLayer)

        wantsLayer = true

        imageLayer.titleElement = textLayer

        self.imageLayer = imageLayer

        self.textLayer = textLayer

    }

    override var wantsUpdateLayer: Bool {

        return true

    }

}

// MARK: -

extension ImageViewLayerView {

    // MARK: NSAccessibility

    override func accessibilityChildren() -> [Any]? {

        return [imageLayer, textLayer]

    }

    override func accessibilityHitTest(_ point: NSPoint) -> Any? {

        // Note: use Xcode's "Accessibility Inspector" to test this.

        let accessibilityContainer = NSAccessibilityUnignoredAncestor(self)

        let imageFrame = NSAccessibilityFrameInView(self, imageLayer.frame)

        let textFrame = NSAccessibilityFrameInView(self, textLayer.frame)

        var hitTestElement : Any

        if imageFrame.contains(point) {

            hitTestElement = imageLayer

        } else if textFrame.contains(point) {

            hitTestElement = textLayer

        } else {

            hitTestElement = accessibilityContainer!

        }

        return hitTestElement

    }

}