#requires -pssnapin pseventing

# http://www.codeplex.com/pseventing (1.0 or 1.1)

param([string[]]$choices = $(throw "please supply a string array of choices"))

if ($choices.length -eq 0) {
    Write-Warning "cannot be a zero length array."
    return
}

# initialize form
$form = new-object windows.forms.form
$form.Text = "Choose..."
$form.MinimizeBox = $false
$form.MaximizeBox = $false
$form.AutoSize = $true
$form.AutoSizeMode = "GrowAndShrink"

# initialize listbox
$listbox = new-object windows.forms.listbox
$choices | % { [void]$listbox.items.add($_) }

$form.controls.Add($listbox)

# catch a choice in the listbox (remove -verbose for quiet mode)
Connect-EventListener -VariableName listbox -EventName SelectedIndexChanged -Verbose

# catch someone closing the form (remove -verbose for quiet mode)
Connect-EventListener -VariableName form -EventName Closed -Verbose

$form.Show()

# wait for an event while performing sendmessage pumping (or ctrl+c to exit)
$event = Get-Event -Wait

# don't pollute pipeline (remove in production)
write-host ($event | ft -auto | out-string)

$form.Dispose()

$choice = $listbox.SelectedItem

# clean up; event listeners will be automatically unhooked ;-)
$form = $null
$listbox = $null

# return chosen item, or $null if the form was closed
if ($event.Name -eq "SelectedIndexChanged") {
    $choice
} else {
    $null # cancelled
}