objective c - How can I get all supported screen resolutions on mac OSX Swift

Question

I want a code that

1)grabs my current screen resolution, (solved).

For example : to get current screen display code is :

system_profiler SPDisplaysDataType |grep Resolution

2)grabs all supported resolution as shown in picture below (unsolved).

or any Objective C code will be also useful

Answer 1

Xcode 11 ? Swift 5.1

extension CGDirectDisplayID  {
    var displayMode: CGDisplayMode? { CGDisplayCopyDisplayMode(self) }
    func allDisplayModes(options: CFDictionary? = nil) -> [CGDisplayMode] { CGDisplayCopyAllDisplayModes(self, options) as? [CGDisplayMode] ?? [] }
}

---

extension CGDisplayMode {
    var resolution: String { .init(width) + " x " + .init(height) }
}

---

struct Display {
    static var main: CGDirectDisplayID { CGMainDisplayID() }
    static var mode: CGDisplayMode? { main.displayMode }
    static func allModes(for directDisplayID: CGDirectDisplayID = main) -> [CGDisplayMode] { directDisplayID.allDisplayModes() }
}

Usage:

if let resolution = Display.mode?.resolution {
    print("Resolution:", resolution)
}
for mode in Display.allModes() {
    print(mode.resolution)
}