##############################################################################
##
## Select-GraphicalFilteredObject.ps1
##
## Adapted from Windows PowerShell Cookbook (O'Reilly)
## by Lee Holmes (http://www.leeholmes.com/guide)
##
## Display a Windows Form to help the user select a list of items piped in.
## Any selected items get passed along the pipeline.
##
## ie:
##
##      PS >dir | Select-GraphicalFilteredObject -Title "Select items to delete" | Delete-Item -Whatif
##
##############################################################################

param (
    [string]$title = "Select the list of objects you wish to pass down the pipeline",
    [Switch]$checkOnClick      # this is usually annoying 
)

$controlSpacing = 7

$objectArray = @($input)

## Ensure that they've piped information into the script
if($objectArray.Count -eq 0)
{
    Write-Error "This script requires pipeline input."
    return
}

function SelectAllCheckedListBoxItems(
    [Windows.Forms.CheckedListBox]$checkedListBox,
    [bool]$selected = $true
)
{
    for ($i = 0; $i -lt $checkedListBox.Items.Count; $i++) { 
        $checkedListBox.SetItemChecked( $i, $selected ) 
    } 
}

## Load the Windows Forms assembly
[void] [Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")

## Create the main form
$form = New-Object Windows.Forms.Form
$form.Size = New-Object Drawing.Size @(600,600)
$form.Padding = new Windows.Forms.Padding(4)

## Create the listbox to hold the items from the pipeline
$listbox = New-Object Windows.Forms.CheckedListBox
$listbox.CheckOnClick = $checkOnClick
$listbox.Dock = "Fill"
 
$form.Text = $title
$listBox.Items.AddRange($objectArray)

## Create the button panel to hold the OK and Cancel buttons
$buttonPanel = New-Object Windows.Forms.Panel
$buttonPanel.Size = New-Object Drawing.Size @(600,30)
$buttonPanel.Dock = "Bottom"

## Create the Cancel button, which will anchor to the bottom right
$cancelButton = New-Object Windows.Forms.Button
$cancelButton.Text = "Cancel"
$cancelButton.DialogResult = "Cancel"
$cancelButton.Top = $buttonPanel.Height - $cancelButton.Height - $controlSpacing
$cancelButton.Left = $buttonPanel.Width - $cancelButton.Width - $controlSpacing - $controlSpacing
$cancelButton.Anchor = "Right"

## Create the OK button, which will anchor to the left of Cancel
$okButton = New-Object Windows.Forms.Button
$okButton.Text = "Ok"
$okButton.DialogResult = "Ok"
$okButton.Top = $cancelButton.Top
$okButton.Left = $cancelButton.Left - $okButton.Width - $controlSpacing
$okButton.Anchor = "Right"

## Create the None button, which will anchor to the left of OK
$noneButton = New-Object Windows.Forms.Button
$noneButton.Text = "&None"
$noneButton.Top = $cancelButton.Top
$noneButton.Left = $okButton.Left - $noneButton.Width - $controlSpacing
$noneButton.Anchor = "Right"
$noneButton.add_Click( { SelectAllCheckedListBoxItems $listbox $false } )

## Create the All button, which will anchor to the left of None
$allButton = New-Object Windows.Forms.Button
$allButton.Text = "&All"
$allButton.Top = $cancelButton.Top
$allButton.Left = $noneButton.Left - $allButton.Width - $controlSpacing
$allButton.Anchor = "Right"
$allButton.add_Click( { SelectAllCheckedListBoxItems $listbox $true } )

## Add the buttons to the button panel
$buttonPanel.Controls.Add($noneButton)
$buttonPanel.Controls.Add($allButton)
$buttonPanel.Controls.Add($okButton)
$buttonPanel.Controls.Add($cancelButton)

## Add the button panel and list box to the form, and also set
## the actions for the buttons
$form.Controls.Add($listBox)
$form.Controls.Add($buttonPanel)
$form.AcceptButton = $okButton
$form.CancelButton = $cancelButton
$form.Add_Shown( { $form.Activate() } )

## Show the form, and wait for the response
$result = $form.ShowDialog()

## If they pressed OK (or Enter,) go through all the
## checked items and send the corresponding object down the pipeline
if($result -eq "OK")
{
    foreach($index in $listBox.CheckedIndices)
    {
        $objectArray[$index]
    }
}