I'm porting an NSView to Swift and I need to use Quartz CGContextAddPath.
import Cocoa
class MYView: NSView {
init(frame: NSRect) {
super.init(frame: frame)
}
override func drawRect(dirtyRect: NSRect) {
super.drawRect(dirtyRect)
NSColor .redColor() .set()
NSRectFill(self.bounds)
var p :CGMutablePathRef = CGPathCreateMutable()
var ctx = NSGraphicsContext.currentContext().graphicsPort()
CGContextAddPath(ctx, p) // compiler rejects this line
}
}
How do you understand this error message ?
Cannot convert the expression's type 'Void' to type 'CGContext!'
The Swift signature of CGContextAddPath is:
func CGContextAddPath(context: CGContext!, path: CGPath!)
What is my error ?
When I use this:
let context = UnsafePointer<CGContext>(ctx).memory
I now have a runtime error:
Jun 3 15:57:13 xxx.x SwiftTest[57092] <Error>: CGContextAddPath: invalid context 0x7fff73bd0060. This is a serious error. This application, or a library it uses, is using an invalid context and is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.
Here is the code that I'm currently using:
import Cocoa
class MYView: NSView {
init(frame: NSRect) {
super.init(frame: frame)
}
override func drawRect(dirtyRect: NSRect) {
super.drawRect(dirtyRect)
var p :CGMutablePathRef = CGPathCreateMutableCopy( CGPathCreateWithRoundedRect(self.bounds, 10, 10, nil))
var ctx = NSGraphicsContext.currentContext().graphicsPort()
let context = UnsafePointer<CGContext>(ctx).memory
CGContextAddPath(context, p) // compiler no longer rejects this line
var blueColor = NSColor.blueColor()
CGContextSetStrokeColorWithColor(context, NSColor.blueColor().CGColor)
CGContextSetLineWidth(context, 2)
CGContextStrokePath(context)
}
}