Source code for numlockicon.ps

param (

	[parameter( Mandatory = $False, ValueFromPipeline = $True )]

	[string] $text

)

if ( $text -eq "/?" ) {

	Clear-Host

	Write-Host "`nNumLockIcon.ps1,  Version 1.00 for Windows"

	Write-Host "NumLock key indicator in the System tray`n"

	Write-Host "Usage:`t. './NumLockIcon.ps1' [text]`n"

	Write-Host "Where:`ttext`tis the text on the indicator"

	Write-Host "`t`t(default: `"N`"; maximum length: 2)`n"

	Write-Host "Credit:`tCode to dynamically generate icons by Joshua Flanagan"

	Write-Host "`thttps://www.codeproject.com/Articles/7122/Dynamically-Generating-Icons-safely`n"

	Write-Host "Written by Rob van der Woude"

	Write-Host "https://www.robvanderwoude.com`n"

	exit

} else {

	# Remove whitespace and special characters

	$text = $text -replace '\W', ''

	# Use no more than 2 characters

	if ( $text.Length -gt 2 )

	{

		$text = $text.Substring( 0, 2 )

	}

}

# Use default in case no valid text was supplied

if ( [string]::IsNullOrWhiteSpace( $text ) ) {

	$text = "N"

}

[void] [System.Reflection.Assembly]::LoadWithPartialName( "System.Drawing" )

[void] [System.Reflection.Assembly]::LoadWithPartialName( "System.Windows.Forms" )

# Create bitmap

$bitmap = [System.Drawing.Bitmap]::new( 16, 16 )

# Define font

$fontfamily = [System.Drawing.FontFamily]::GenericSansSerif

$fontstyle = [System.Drawing.FontStyle]::Bold

$font = [System.Drawing.Font]::new( $fontfamily, 8, $fontstyle )

# Create graphic from bitmap

$graphic = [System.Drawing.Graphics]::FromImage( $bitmap )

# Create a circle in the graphic, fill this circle with color

$blackbrush = [System.Drawing.Brushes]::Black

$redbrush = [System.Drawing.Brushes]::Red

$graphic.FillEllipse( $redbrush, 0, 0, 16, 16 )

# Center text in circle

$textsize = $graphic.MeasureString( $text, $font )

# Resize font if text is too large to fit in icon

if ( $textsize.Width -gt 14 ) {

	$font = [System.Drawing.Font]::new( $fontfamily, $font.Size * 0.8, $fontstyle )

	$textsize = $graphic.MeasureString( $text, $font )

}

$x = [Math]::Max( 0, [Math]::Floor( ( $bitmap.Width - $textsize.Width ) / 2 ) )

$y = [Math]::Max( 0, [Math]::Ceiling( ( $bitmap.Height - $textsize.Height ) / 2 ) )

$stringformat = [System.Drawing.StringFormat]::GenericDefault

$graphic.DrawString( $text, $font, $blackbrush, $x, $y, $stringformat )

# Create icon from graphic

$icon = [System.Drawing.Icon]::FromHandle( $bitmap.GetHicon( ) )

# Cleanup

$graphic.Dispose( )

$bitmap.Dispose( )

# Create new System Tray icon

[void] [System.Reflection.Assembly]::LoadWithPartialName( "System.Windows.Forms" )

$notifyIcon = New-Object System.Windows.Forms.NotifyIcon

$notifyIcon.Icon = $icon

# Explain how to break free from the endless loop

Write-Host "`nPress any key to stop monitoring NumLock . . .  " -NoNewline

# Monitor NumLock until a key is pressed in this console

while ( !$Host.UI.RawUI.KeyAvailable ) {

	Start-Sleep -Seconds 1

	# Show System Tray icon only if NumLock is ON

	$notifyIcon.Visible = [System.Windows.Forms.Control]::IsKeyLocked( [System.Windows.Forms.Keys]::NumLock )

}

# Remove the key from the keyboard buffer . . .

[void] $Host.UI.RawUI.ReadKey( )

# . . .  and wipe it from the screen

Write-Host "`b `n"

# Cleanup

$notifyIcon.Visible = $False

# Only if variable "$icon" is of type "Icon" it should be disposed of

if ( $icon.GetType( ) -eq [System.Drawing.Icon] ) {

	$icon.Dispose( )

}

$notifyIcon.Dispose( )