Detect screen idle time

Detecting screen idle time generally means tracking how long a user has been inactive on their device — no mouse movements, keyboard inputs, or touchscreen interactions. This can be useful in apps, websites, or system-level software to trigger screensavers, log out inactive users, or save power.

Here are common ways to detect screen idle time depending on platform and context:

1. In Web Browsers (JavaScript)

You can detect inactivity by tracking user events like mousemove, keydown, touchstart, and then measure the time since the last event.

js
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let idleTime = 0;

function resetIdleTime() {
  idleTime = 0;
}

document.onload = resetIdleTime;
document.onmousemove = resetIdleTime;
document.onkeydown = resetIdleTime;
document.ontouchstart = resetIdleTime;

setInterval(() => {
  idleTime++;
  console.log(`User idle for ${idleTime} seconds`);
  if (idleTime >= 300) { // 5 minutes
    console.log('User is idle, trigger action');
  }
}, 1000);

How it works:

• The idle timer resets on user interaction.

• If no interaction for 5 minutes, it triggers an action.

2. Windows (C# / WinAPI)

Windows provides system calls to get the last input time:

csharp
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using System;
using System.Runtime.InteropServices;

class IdleTimeDetector
{
    [StructLayout(LayoutKind.Sequential)]
    struct LASTINPUTINFO
    {
        public uint cbSize;
        public uint dwTime;
    }

    [DllImport("user32.dll")]
    static extern bool GetLastInputInfo(ref LASTINPUTINFO plii);

    public static uint GetIdleTime()
    {
        LASTINPUTINFO lastInputInfo = new LASTINPUTINFO();
        lastInputInfo.cbSize = (uint)Marshal.SizeOf(lastInputInfo);

        if (!GetLastInputInfo(ref lastInputInfo))
            return 0;

        return ((uint)Environment.TickCount - lastInputInfo.dwTime) / 1000; // idle time in seconds
    }
}

3. Linux (X11) Using Python

You can use xprintidle tool or interface with X11:

bash
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xprintidle

Returns idle time in milliseconds.

Python example calling xprintidle:

python
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import subprocess

def get_idle_time():
    idle_ms = int(subprocess.check_output(['xprintidle']))
    return idle_ms / 1000  # seconds

print(get_idle_time())

4. macOS (Swift)

macOS tracks idle time via IOKit:

swift
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import IOKit

func getIdleTime() -> Int {
    var iterator: io_iterator_t = 0
    let result = IOServiceGetMatchingServices(kIOMasterPortDefault, IOServiceMatching("IOHIDSystem"), &iterator)
    if result != KERN_SUCCESS { return -1 }

    let entry = IOIteratorNext(iterator)
    var dict: Unmanaged<CFMutableDictionary>? = nil
    IORegistryEntryCreateCFProperties(entry, &dict, kCFAllocatorDefault, 0)
    let dictRef = dict?.takeUnretainedValue()

    let idle = dictRef?[kIOHIDIdleTimeKey] as? Int64 ?? 0
    dict?.release()
    IOObjectRelease(entry)
    IOObjectRelease(iterator)

    // Idle time is in nanoseconds
    return Int(idle / 1000000000)
}

print("Idle time in seconds: (getIdleTime())")

5. Cross-platform Python (Using pyautogui and timers)

No direct idle timer in pure Python, but can track input events manually or use platform-specific libraries.

Summary

• Web: Detect by listening to input events and measuring inactivity.

• Windows: Use WinAPI GetLastInputInfo to get system idle time.

• Linux: Use xprintidle or X11 APIs.

• macOS: Use IOKit to fetch idle time.

If you want, I can provide a full example in a specific language or environment!