Custom implementation of the OSX Yosemite close, miniaturize, zoom buttons.

WindowButtonBar.swift

class WindowButton: NSButton {
    private var _isMouseOver:Bool = false;
    private var useTrackingArea:Bool = true;
    
    var isMouseOver:Bool {
        set {
            self._isMouseOver = newValue;
            self.setNeedsDisplay();
        }
        get {
            return self._isMouseOver;
        }
    };
    
    var type:NSWindowButton = NSWindowButton.MiniaturizeButton;
    
    
    init(frame:NSRect, type:NSWindowButton, useTrackingArea:Bool = true) {
        super.init(frame: frame);
        
        self.type = type;
        self.target = self;
        self.action = "onClick";
        self.useTrackingArea = useTrackingArea;
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder);
        
        self.target = self;
        self.action = "onClick";
    }
    
    func onClick () {
        if (type == NSWindowButton.ZoomButton) {
            self.window?.zoom(self);
        } else if (type == NSWindowButton.MiniaturizeButton) {
            self.window?.miniaturize(self);
        } else if (type == NSWindowButton.CloseButton) {
            self.window?.close();
        }
    }
    
    override func updateTrackingAreas() {
        if (self.useTrackingArea) {
            let options:NSTrackingAreaOptions = NSTrackingAreaOptions.ActiveInActiveApp
                .union(NSTrackingAreaOptions.MouseEnteredAndExited)
                .union(NSTrackingAreaOptions.AssumeInside)
                .union(NSTrackingAreaOptions.InVisibleRect);
            
            let trackingArea = NSTrackingArea(rect: self.bounds, options:options, owner: self, userInfo: nil);
            self.addTrackingArea(trackingArea);
        }
    }
    
    override func mouseEntered(theEvent: NSEvent) {
        if (self.useTrackingArea) {
            self.isMouseOver = true;
        }
    }
    
    override func drawRect(dirtyRect: NSRect) {
        NSGraphicsContext.currentContext()?.saveGraphicsState();
        var backgroundGradient:NSGradient?;
        var strokeColor:NSColor?;
        var lineColor:NSColor?;
        
        if (type == NSWindowButton.ZoomButton) {
            backgroundGradient = NSGradient(
                startingColor: NSColor(red: 0.153, green: 0.788, blue: 0.247, alpha: 1),
                endingColor: NSColor(red: 0.153, green: 0.816, blue: 0.255, alpha: 1))!;

            lineColor = NSColor(red: 0.004, green: 0.392, blue: 0, alpha: 1);
            strokeColor = NSColor(red: 0.180, green: 0.690, blue: 0.235, alpha: 1);
        } else if (type == NSWindowButton.MiniaturizeButton) {
            backgroundGradient = NSGradient(
                startingColor: NSColor(red: 1, green: 0.741, blue: 0.180, alpha: 1),
                endingColor: NSColor(red: 1, green: 0.773, blue: 0.184, alpha: 1))!;

            lineColor = NSColor(red: 0.600, green: 0.345, blue: 0.004, alpha: 1);
            strokeColor = NSColor(red: 0.875, green: 0.616, blue: 0.094, alpha: 1);
        } else if (type == NSWindowButton.CloseButton) {
            backgroundGradient = NSGradient(
                startingColor: NSColor(red: 1, green: 0.373, blue: 0.337, alpha: 1),
                endingColor: NSColor(red: 1, green: 0.388, blue: 0.357, alpha: 1))!;

            lineColor = NSColor(red: 0.302, green: 0, blue: 0, alpha: 1);
            strokeColor = NSColor(red: 0.886, green: 0.243, blue: 0.216, alpha: 1);
        }
        
        // draw background
        var path = NSBezierPath();
        
        path.appendBezierPathWithOvalInRect(NSMakeRect(self.bounds.origin.x + 0.5, self.bounds.origin.y + 0.5, self.bounds.width - 1, self.bounds.height - 1));
        
        backgroundGradient?.drawInBezierPath(path, relativeCenterPosition: NSMakePoint(0, 0));
        strokeColor?.setStroke();
        path.lineWidth = 0.5;
        path.stroke();
        
        if (self.highlighted) {
            NSColor(calibratedRed: 0, green: 0, blue: 0, alpha: 0.2).setFill();
            path.fill();
        }
        
        // draw contents
        if (self.isMouseOver) {
            path = NSBezierPath();
            
            if (type == NSWindowButton.ZoomButton) {
                NSGraphicsContext.currentContext()?.shouldAntialias = false;
                path.moveToPoint(NSMakePoint(self.bounds.width / 2, self.bounds.height * 0.20));
                path.lineToPoint(NSMakePoint(self.bounds.width / 2, self.bounds.height * 0.80));
                
                path.moveToPoint(NSMakePoint(self.bounds.width * 0.80, self.bounds.height / 2));
                path.lineToPoint(NSMakePoint(self.bounds.width * 0.20, self.bounds.height / 2));
                path.lineWidth = 0.75;
            } else if (type == NSWindowButton.MiniaturizeButton) {
                NSGraphicsContext.currentContext()?.shouldAntialias = false;
                
                path.moveToPoint(NSMakePoint(self.bounds.width * 0.80, self.bounds.height / 2));
                path.lineToPoint(NSMakePoint(self.bounds.width * 0.20, self.bounds.height / 2));
                path.lineWidth = 0.75;
            } else if (type == NSWindowButton.CloseButton) {
                path.moveToPoint(NSMakePoint(self.bounds.width * 0.30, self.bounds.height * 0.30));
                path.lineToPoint(NSMakePoint(self.bounds.width * 0.70, self.bounds.height * 0.70));
                
                path.moveToPoint(NSMakePoint(self.bounds.width * 0.70, self.bounds.height * 0.30));
                path.lineToPoint(NSMakePoint(self.bounds.width * 0.30, self.bounds.height * 0.70));
                path.lineWidth = 1;
            }
            

            lineColor?.setStroke();
            path.stroke();
        }
        
        NSGraphicsContext.currentContext()?.restoreGraphicsState();
    }
}

public class WindowButtonBar:NSView {
    var closeButton:WindowButton?;
    var miniaturizeButton:WindowButton?;
    var zoomButton:WindowButton?;
    
    required public init?(coder: NSCoder) {
        super.init(coder: coder);
        self.setupViews();
    }
    
    override init (frame:NSRect) {
        super.init(frame: frame);
        self.setupViews();
    }
    
    func setupViews () {
        self.closeButton = WindowButton(frame: NSMakeRect(0, 0, 13, 13), type: NSWindowButton.CloseButton, useTrackingArea: false);
        self.miniaturizeButton = WindowButton(frame: NSMakeRect(20, 0, 13, 13), type: NSWindowButton.MiniaturizeButton, useTrackingArea: false);
        self.zoomButton = WindowButton(frame: NSMakeRect(40, 0, 13, 13), type: NSWindowButton.ZoomButton, useTrackingArea: false);
        
        self.addSubview(self.closeButton!);
        self.addSubview(self.miniaturizeButton!);
        self.addSubview(self.zoomButton!);
        
        let trackingArea = NSTrackingArea(rect: self.bounds, options: NSTrackingAreaOptions.MouseEnteredAndExited.union(NSTrackingAreaOptions.MouseMoved).union(NSTrackingAreaOptions.ActiveAlways), owner: self, userInfo: nil);
        self.addTrackingArea(trackingArea);
    }
    
    override public func mouseEntered(theEvent: NSEvent) {
        self.closeButton?.isMouseOver = true;
        self.miniaturizeButton?.isMouseOver = true;
        self.zoomButton?.isMouseOver = true;
    }
    
    override public func mouseExited(theEvent: NSEvent) {
        self.closeButton?.isMouseOver = false;
        self.miniaturizeButton?.isMouseOver = false;
        self.zoomButton?.isMouseOver = false;
    }
}