Swift scripted mouse movement unreliable inside scheduledTimer - swift

Question

I'm trying to write a piece of code that moves the mouse cursor on the screen to a specified location. Here are some ways I've tried to accomplish that:
Code below is used in all attempts (sandboxing disabled):
let mouseCursorPosition = CGPoint.zero;
CGAssociateMouseAndMouseCursorPosition(1)
Attempt 1:
CGWarpMouseCursorPosition(mouseCursorPosition)
Attempt 2:
CGDisplayMoveCursorToPoint(CGMainDisplayID(), CGPoint.zero)
Attempt 3:
let moveEvent = CGEvent(mouseEventSource: nil, mouseType: CGEventType.mouseMoved, mouseCursorPosition: mouseCursorPosition,
mouseButton: CGMouseButton.left)
moveEvent?.post(tap: CGEventTapLocation.cghidEventTap)
Expected behavior: update the mouse position along with the cursor on screen.
Every attempt so far works as expected if called directly inside viewDidLoad(). The cursor moves to the requested screen location as soon as the application loads. However, things get a bit weird when called inside a scheduledTimer. Using the code below:
class ViewController: NSViewController {
var mouseTimer: Timer!
override func viewDidLoad() {
super.viewDidLoad()
mouseTimer = Timer.scheduledTimer(timeInterval: 5, target: self, selector: #selector(moveCursor), userInfo: nil, repeats: true)
}
#objc func moveCursor() {
print(NSDate().timeIntervalSince1970)
let mouseCursorPosition = CGPoint.zero;
CGAssociateMouseAndMouseCursorPosition(1)
//insert attempt code here
}
}
The moveCursor method is called every 5 seconds (the timestamp appears every time), however the cursor does not move on the screen as long I don't move the physical mouse. However, when I move the mouse, the cursor first snaps to the last scripted position. What seems to happen is that the scripted location is registered, however it is not updated on screen until some sort of refresh event is triggered.
Any thoughts on the matter are greatly appreciated.

Answer 1

I cannot reproduce this problem on macOS 11.14. I created a new Cocoa app, using Storyboards, and edited ViewController.swift to the following:
import Cocoa
class ViewController: NSViewController {
var mouseTimer: Timer!
override func viewDidLoad() {
super.viewDidLoad()
mouseTimer = Timer.scheduledTimer(timeInterval: 5, target: self, selector: #selector(moveCursor), userInfo: nil, repeats: true)
}
#objc func moveCursor() {
print(NSDate().timeIntervalSince1970)
let mouseCursorPosition = CGPoint.zero;
CGAssociateMouseAndMouseCursorPosition(1)
CGWarpMouseCursorPosition(mouseCursorPosition)
}
}
I then ran it under Xcode. After 5 seconds (and every 5 seconds after) a timestamp is printed and the cursor jumps to the upper-left corner. I can move the cursor elsewhere and it jumps again.
I have the same behavior with or without calling CGAssociateMouseAndMouseCursorPosition. (I'm not sure why you're calling this in the test; 1 is the default value.)
Updated based on your comments and I still can't reproduce:
import Cocoa
class ViewController: NSViewController {
var mouseTimer: Timer!
override func viewDidLoad() {
super.viewDidLoad()
mouseTimer = Timer.scheduledTimer(timeInterval: 5, target: self, selector: #selector(moveCursor), userInfo: nil, repeats: true)
}
#objc func moveCursor() {
let mouseCursorPosition = CGPoint(x: Int.random(in: 0...500), y: Int.random(in: 0...500))
print("\(Date().timeIntervalSince1970): \(mouseCursorPosition)")
CGWarpMouseCursorPosition(mouseCursorPosition)
}
}
Every 5 seconds this causes the mouse pointer to jump to a new location, whether I move the mouse pointer or not. Is this identical to your code?