Swift Playground to measure how much pressure you are putting on your trackpad

PressurePoint.swift

// A Cocoa based Playground to show how to use pressure events in a macOS application.

import AppKit
import PlaygroundSupport

class PressureView: NSView {
    private let pressureLabel = NSTextField(labelWithString: "Pressure: 0.0")

    override init(frame frameRect: NSRect) {
        super.init(frame: frameRect)
        pressureLabel.frame = NSRect(x: 20, y: 20, width: 200, height: 40)
        pressureLabel.font = NSFont.systemFont(ofSize: 24)
        addSubview(pressureLabel)
        wantsLayer = true
        layer?.backgroundColor = NSColor.white.cgColor
    }

    // We miss you Interface Builder... :(
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    // Override to handle pressure changes. Pressure is shown as a value between 0.0 and 1.0.
    override func pressureChange(with event: NSEvent) {
        super.pressureChange(with: event)
        let pressure = event.pressure
        pressureLabel.stringValue = String(format: "Pressure: %.2f", pressure)
    }
}

// Make our view. You need to press in the view to see pressure changes.
let view = PressureView(frame: NSRect(x: 0, y: 0, width: 300, height: 100))
PlaygroundPage.current.liveView = view

Demo of the PressurePoint playground.

PressurePoint.mov