The default tilesize on macos

I really like to maintain defaults on a system, including preferences. This means I like to keep my MacOS's dock tile size to the default size.

I used to grep my shell history for this command defaults delete com.apple.dock "tilesize" && killall Dock and re-run it every time the dock got resized.

I thought it'd be fun to try to use Swift do to this instead.

The approach suggested by ChatGPT is to use the NSScreen API.

  if let screen = NSScreen.main {
      let fullFrame = screen.frame
      let visibleFrame = screen.visibleFrame
      dump(fullFrame)
      dump(visibleFrame)
  }

When I dump the NSScreen.frame, I get this:

▿ (0.0, 0.0, 3840.0, 1600.0)
  ▿ origin: (0.0, 0.0)
    - x: 0.0
    - y: 0.0
  ▿ size: (3840.0, 1600.0)
    - width: 3840.0
    - height: 1600.0

And when I dump the NSScreen.visibleFrame, I get this:

▿ (0.0, 85.0, 3840.0, 1490.0)
  ▿ origin: (0.0, 85.0)
    - x: 0.0
    - y: 85.0
  ▿ size: (3840.0, 1490.0)
    - width: 3840.0
    - height: 1490.0

I'm on a Dell U3818DW, which has a resolution of 3840 x 1600.

So the difference between the frame and visibleFrame is a height of 110 pixels, which should be pixel of height of the dock and menu bar combined.

The menu bar size can be calculated by substracting the maxY's of the frames:

  let menuBarHeight = fullFrame.maxY - visibleFrame.maxY

And finally, the dock height will be what remains:

  let dockHeight = fullFrame.height - visibleFrame.height - menuBarHeight

On my MacOS, I've customized the dock height a little bit just to have some values in the defaults:

  defaults read com.apple.dock tilesize # 29

When I use swift to calculate the pixels:

  if let screen = NSScreen.main {
      let fullFrame = screen.frame
      let visibleFrame = screen.visibleFrame
      let menuBarHeight = fullFrame.maxY - visibleFrame.maxY
      let dockHeight = fullFrame.height - visibleFrame.height - menuBarHeight
      print(dockHeight) // 46.0
  }

There seems to be difference! Why? Aha, an adventure for another time.

Whops, I confused two projects in one. The swift implementation of defaults delete com.apple.dock "tilesize" && killall Dock is actually this:

  if let defaults = UserDefaults(suiteName: "com.apple.dock") {
      let key = "tilesize"
      let tilesize = defaults.object(forKey: key)
      if tilesize != nil {
          defaults.removeObject(forKey: key)
          defaults.synchronize()

          if let dock = NSRunningApplication.runningApplications(
               withBundleIdentifier: "com.apple.dock"
             ).first {
              dock.terminate()
          }
      }
  }

The dock height is for another project. Fooled ya!