Getting the POSIX path of the Finder's front window

Question

Hi,

How can I get the POSIX path of the Finder window that is currently at the top of its window list? Preferably with some kind of Cocoa framework but I am open for anything.

Background: I would need this because I want to make a selection of files matching a regex pattern, starting recursively from this path. The idea is to use

[[NSWorkspace sharedWorkspace] subpathsAtPath:thePath]

method to get all the descendants of this path, use "grep" in an NSTask (to avoid packaging a regex support framework) and use

[[NSWorkspace sharedWorkspace] selectFile:aFile inFileViewerRootedAtPath:thePath]

in a loop looping through an NSArray made from the entries returned by grep.

So far, I have looked at NSWorkspace, NSFileManager and NSApplication plus other keyword searches within the Xcode Documentation.

Thanks for checking out my question!

Andre

PS: I am not sure about the grep part, maybe I'll just slap RegexKit Lite in there...

Answer 1

You can probably ask the Finder this via an AppleScript.

This* one-liner works for me:

osascript -e 'tell application "Finder" to set myname to POSIX path of (target of window 1 as alias)'

*a modified version of this.

Answer 2

Getting the POSIX path represented by the frontmost window in the Finder is going to involve sending Apple Events to the Finder in one way or another.

Your choices include:

• Using the Apple Event Manager (or NSAppleEventDescriptor and friends) directly.
• Using NSAppleScript or OSAScript objects.
• Using ScriptingBridge.

If you are building a Cocoa app, OSAScript is probably the most natural choice.

Answer 3

I'm developing an commercial application that does exactly what you describe and I've been messing with different ways of doing this for over a year now. I'm a newbie developer, so I'm totally open to the idea that there may be a much better way of doing it than my way, but it seems to be stable and work.

I use Apple Script

I get the path of the active document every 3 seconds, but if the active application is the Finder, I get the path of the active window. I do this using Apple Script as described by the accepted answer.

Getting Window List using Carbon

To get the window list of all processes to get the window ID (something Apple Script can't do), I use CGWindowListCopyWindowInfo as detailed in this question:

http://stackoverflow.com/questions/311956/getting-a-unique-id-for-a-window-of-another-application

This presents me an array with all the windows of all processes ordered by which is frontmost. So all I need to do is pluck the first entry from the array. This can also be used to get a screengrab of the front window, if that's helpful to you, as shown in the Son of Grab sample application, which has been invaluable to me as a working example.

Sending Apple Script from Cocoa

When it comes to Apple Script, I've experimented with all 3 that Jim suggests and my conclusion is that each has it's issues, both in terms of stability and flexibility.

1. Apple Event Manager relies on you sending raw Apple Events. For me, this was too much like hard work and too low level.

2. Using NSAppleScript I found to be slow and error prone. It's also pretty clumsy when you want to send a whole variety of Apple Script messages as I do.

3. When reading about Scripting Bridge, I got very excited, only to try it out and be very disappointed. For the attributes of the windows I was trying to grab, it didn't even recognise them as existing. It seemed to me to be buggy and weird. I expect if the commands you're sending are supported by SB, it would be the best option.

A Fourth Option

I now rely on a fabulous Objective C wrapper around Apple Script called AppScript. It's been around for many, many years, it's stable, the developer is great and most of all it just works.

It has rock solid methods which allow you to send Apple Script and it'll even return errors for you neatly without a whole load of potentially buggy and messy code needing to check for them.

I've been using it for a year now with no problems. If you have any other questions about how to do this, please don't hesitate to comment and I'll try my best to answer them.