✨ Ability to get screen size in inches

Loop/Extensions/NSScreen+Extensions.swift

@@ -77,3 +77,41 @@ extension NSScreen {
         frame.maxY - visibleFrame.maxY
     }
 }
+
+// MARK: - Calculate physical screen size
+
+extension NSScreen {
+    // Returns diagonal size in inches
+    var diagonalSize: CGFloat {
+        let unitsPerInch = unitsPerInch
+        let screenSizeInInches = CGSize(
+            width: frame.width / unitsPerInch.width,
+            height: frame.height / unitsPerInch.height
+        )
+
+        // Just the pythagorean theorem
+        let diagonalSize = sqrt(pow(screenSizeInInches.width, 2) + pow(screenSizeInInches.height, 2))
+
+        return diagonalSize
+    }
+
+    private var unitsPerInch: CGSize {
+        // We need to convert from mm to inch because CGDisplayScreenSize returns units in mm.
+        let millimetersPerInch: CGFloat = 25.4
+
+        let screenDescription = deviceDescription
+        if let displayUnitSize = (screenDescription[NSDeviceDescriptionKey.size] as? NSValue)?.sizeValue,
+           let screenNumber = (screenDescription[NSDeviceDescriptionKey("NSScreenNumber")] as? NSNumber)?.uint32Value {
+            let displayPhysicalSize = CGDisplayScreenSize(screenNumber)
+
+            return CGSize(
+                width: millimetersPerInch * displayUnitSize.width / displayPhysicalSize.width,
+                height: millimetersPerInch * displayUnitSize.height / displayPhysicalSize.height
+            )
+        } else {
+            // this is the same as what CoreGraphics assumes if no EDID data is available from the display device
+            // https://developer.apple.com/documentation/coregraphics/1456599-cgdisplayscreensize?language=objc
+            return CGSize(width: 72.0, height: 72.0)
+        }
+    }
+}