How to change desktop background in AppleScript in 10.7?

Maybe you might want to try the following script as a starting point.

The script assumes that the keyboard shortcuts ^1, ^2, ^3, ^4, etc. (for switching to the corresponding desktop) are activated in the Keyboard Shortcut pane of the Keyboard System Preferences.

set N to 4 -- number of desktops

set theFile to POSIX file "/Library/Desktop Pictures/Isles.jpg" -- just an example

repeat with k from 18 to (18 + N - 1) -- 18 is the key code for "1"

tell application "System Events" to key code k using {control down}

delay 1

tell application "Finder" to set desktop picture to theFile

delay 1

end repeat

Here's a somewhat more sophisticated version of the preceding script. However, this version requires that you first enable access for assistive devices in the Universal Access System Preference pane.

set theFile to POSIX file "/Library/Desktop Pictures/Isles.jpg" -- just an example

-- Find out how many desktops you have:

tell application "System Preferences"

reveal anchor "shortcutsTab" of pane id "com.apple.preference.keyboard"

tell application "System Events" to tell window "Keyboard" of process "System Preferences"

set N to count (UI elements of rows of outline 1 of scroll area 2 of splitter group 1 of tab group 1 whose name begins with "Switch to Desktop")

end tell

quit

end tell

-- Loop through the desktops, setting each of their backgrounds in turn:

repeat with k from 18 to (18 + N - 1) -- 18 is the key code for "1"

tell application "System Events" to key code k using {control down}

delay 1

tell application "Finder" to set desktop picture to theFile

delay 1

end repeat

Message was edited by: Pierre L.

Actually, “repeat with k from 18 to (18 + N - 1)” was not a good idea, since it works only with N < 5, as I discovered after posting the script.

So here's an improved version of the previous script that should work with any number of desktops:

set theFile to POSIX file "/Library/Desktop Pictures/Isles.jpg" -- just an example

-- Find out how many desktops you have:

tell application "System Preferences"

reveal anchor "shortcutsTab" of pane id "com.apple.preference.keyboard"

tell application "System Events" to tell window "Keyboard" of process "System Preferences"

set N to count (UI elements of rows of outline 1 of scroll area 2 of splitter group 1 of tab group 1 whose name begins with "Switch to Desktop")

end tell

quit

end tell

-- Loop through the desktops, setting each of their backgrounds in turn:

tell application "System Events" to key code 18 using {control down}-- Desktop 1

tell application "Finder" to set desktop picture to theFile

repeat (N - 1) times

delay 1

tell application "System Events" to key code 124 using {control down} -- ⌘→

delay 1

tell application "Finder" to set desktop picture to theFile

end repeat

I'd love to know a good reference for AppleScript that explains some of this stuff; I find Apple's documentation on this point to lack some of the details that I'd need explained.

If you're a novice in AppleScript, I would suggest this learning path:

1. Go to this Web page and from there to the Beginner's Tutorial.

2. After that, you might want to have a look at the AppleScript Language Guide.

3. You might also want to have a look at GUI Scripting.

Hope it can help.

RCobbe wrote:

osascript -e "tell application \"System Events\" to set picture of every desktop to \"<path>\""

Unfortunately, that also changes only the current desktop's picture.

Imho there is only one desktop (for each connected monitor).

It sounds confusing since Mission Control shows several "desktops". But the internal name for them is still "spaces".

The larger script is in Perl, so I'd prefer a technology that works well with that language, but if I have to change to a different scripting language, that's not the end of the world.

How about a shell script? This one works with only one monitor connected:

defaults write com.apple.desktop Background '{default = {ImageFilePath = "/path/to/your/image"; }; }'; killAll Dock;

Spazek

I know this is an old question, but:

tell application "Finder" to set desktop picture to POSIX file "/Library/Desktop Pictures/Ducks on a misty pond.jpg"