Manage-WindowFollower.ps1

param(
  [Parameter(Mandatory = $true)]
  [ValidateSet("Install", "Start", "Stop", "Disable")]
  [string]$Action
)

$BaseDir = Split-Path -Parent $MyInvocation.MyCommand.Path
$TaskName = "WindowFollower"
$CorePath = Join-Path $BaseDir "WindowFollower.ps1"
function Start-Direct {
  $command = 'powershell.exe -NoProfile -ExecutionPolicy Bypass -File "' + $CorePath + '" -Mode Move -BaseDir "' + $BaseDir + '"'
  $shell = New-Object -ComObject WScript.Shell
  [void]$shell.Run($command, 0, $false)
}

switch ($Action) {
  "Install" {
    $taskRun = 'powershell.exe -NoProfile -WindowStyle Hidden -ExecutionPolicy Bypass -File "' + $CorePath + '" -Mode Move -BaseDir "' + $BaseDir + '"'
    schtasks.exe /Create /TN $TaskName /SC ONLOGON /TR $taskRun /RL HIGHEST /F
    if ($LASTEXITCODE -ne 0) { exit 1 }
    schtasks.exe /Run /TN $TaskName | Out-Null
    if ($LASTEXITCODE -ne 0) { exit 1 }
  }
  "Start" {
    schtasks.exe /Query /TN $TaskName 2>$null | Out-Null
    if ($LASTEXITCODE -eq 0) { schtasks.exe /Run /TN $TaskName | Out-Null }
    else { Start-Direct }
  }
  "Stop" {
    try {
      $stopEvent = [System.Threading.EventWaitHandle]::OpenExisting("Global\WindowFollowerStop")
      [void]$stopEvent.Set()
      $stopEvent.Dispose()
      Start-Sleep -Milliseconds 500
    } catch { }
    schtasks.exe /End /TN $TaskName 2>$null | Out-Null
  }
  "Disable" {
    schtasks.exe /Delete /TN $TaskName /F 2>$null | Out-Null
  }
}