PowerShell :: Console input with search list by typed letters, tab cycling, etc.

GetPickListChoice.ps1

function GetPickListChoice {
    param (
        [Parameter(Mandatory=$true)]
        [string[]]$PickList,
        [string]$Prompt = 'Type to search, Tab to cycle matches, Backspace to reset, ''?'' for a list: ',
        [switch]$PromptNoNewLine
    )

    function ClearCurrentChoice {
        for ($i = $origCursorPos.X; $i -lt $endPos; $i++) {
            $currentCursorPos.X = $i
            $Host.UI.RawUI.CursorPosition = $currentCursorPos
            Write-Host ' ' -NoNewLine
            $Host.UI.RawUI.CursorPosition = $origCursorPos
        }
    }

    # Alphabetize pick list.
    $PickList = $PickList | Sort-Object

    # Init result.
    $result = ''
    $searchTerm = ''

    # Display prompt.
    Write-Host $Prompt -NoNewLine:$PromptNoNewLine

    # Get current cursor position as a starting point.
    $origCursorPos = New-Object System.Management.Automation.Host.Coordinates
    $origCursorPos.X = $Host.UI.RawUI.CursorPosition.X
    $origCursorPos.Y = $Host.UI.RawUI.CursorPosition.Y

    do {
        # Get current cursor position
        $currentCursorPos = New-Object System.Management.Automation.Host.Coordinates
        $currentCursorPos.X = $Host.UI.RawUI.CursorPosition.X
        $currentCursorPos.Y = $Host.UI.RawUI.CursorPosition.Y
        $endPos = $currentCursorPos.X

        # Process one key at a time. Don't echo the character back.
        $key = $Host.UI.RawUI.ReadKey('NoEcho, IncludeKeyDown')

        switch ($key.VirtualKeyCode) {
            191 {
                $searchTerm = ''
                Write-Host
                Write-Host
                Write-Host ' Available Choices'
                Write-Host '.=================.'
                Write-Host
                $PickList | ForEach-Object { Write-Host "- $_" }
                Write-Host
                Write-Host $Prompt -NoNewLine:$PromptNoNewLine
                break
            } # '?' (191)
            13 {
                break
            } # Enter (13)
            9 {
                ClearCurrentChoice
                [string[]]$matches = $PickList | Where-Object { $_.StartsWith($searchTerm, "CurrentCultureIgnoreCase") }
                if ($matches) {
                    $Host.UI.RawUI.CursorPosition = $origCursorPos
                    $lastMatch++
                    if ($lastMatch -gt ($matches.Count-1)) {
                        $lastMatch = 0
                    }
                    $result = $matches[$lastMatch].Trim()

                    Write-Host $result -NoNewline
                }
                break
            } # Tab (9)
            8 {
                ClearCurrentChoice
                $searchTerm = ''
                $result = ''
                break
            } # Backspace (8)
            default {
                $lastChar = $key.Character
                if ($key.VirtualKeyCode -ne 8) {
                    $searchTerm += $lastChar
                }

                [string[]]$matches = $PickList | Where-Object { $_.StartsWith($searchTerm, "CurrentCultureIgnoreCase") }
                if ($matches) {
                    ClearCurrentChoice
                    $lastMatch = 0
                    $result = $matches[$lastMatch].Trim()

                    Write-Host $result -NoNewline
                } else {
                    if ($searchTerm.Length -gt 1) {
                        $searchTerm = $searchTerm.Substring(0,$searchTerm.Length-1)
                    } else {
                        $searchTerm = ''
                        $result = ''
                    }
                }
            } # default
        }

    } until (($key.VirtualKeyCode -eq 13) -and $result)

    Write-Host
    return $result
}


# Example
$choices = @('Fart', 'Farted', 'Frat', 'Fred', 'John', 'Car', 'Jack', 'Zed', 'Cow', 'Container99')
Write-Host ('Choice: {0}' -f $(GetPickListChoice -PickList $choices -PromptNoNewLine))