AppleScript: Finder: How can I tell if the Desktop has focus?

Question

• window of the desktop is rather crippled. Can't get its index.
• Finder windows does not include the desktop window, so I can't check that the it's the first there.
• index of the first Finder window is 1 regardless of the desktop having focus. (as long as other Finder windows exist, otherwise it'll fail.)

Answer 1

Looks like the insertion location property comes close, maybe close enough.

insertion location (specifier, r/o) : the container in which a new folder would appear if “New Folder” was selected

tell application "Finder"
    get insertion location
end tell

Result:
folder "Desktop" of folder "nad" of folder "Users" of startup disk of application "Finder"

There's an ambiguity, though, if the focus is on a Finder window opened to the Desktop folder; that gives the same result as if the focus is on the Desktop background. But maybe that doesn't matter for what you want to do.

Answer 2

It looks like you can just check the selection...

set desktopIsFrontmost to false
tell application "Finder"
    if selection is {} then set desktopIsFrontmost to true
end tell
return desktopIsFrontmost

Answer 3

Using Ned's answer, here's what I came up with (in rb-appscript):

#!/usr/bin/env ruby
# encoding: UTF-8
require 'pathname'
require 'appscript'
include Appscript

path_to_desktop             = Pathname.new "#{ENV['HOME']}/Desktop"
path_of_insertion_location  = Pathname.new app("Finder").insertion_location.get(:result_type => :file_ref).get(:result_type => :alias).path
path_of_first_finder_window = Pathname.new app("Finder").Finder_windows.first.target.get(:result_type => :alias).path rescue nil
is_desktop_the_active_view  = path_to_desktop == path_of_insertion_location && path_of_first_finder_window != path_to_desktop