tell application "Pixelmator Pro"
    activate
	tell its front document
		
        -- prompt for settings
        set _r to text returned of ¬
			(display dialog "Roundness? (0..100):" default answer "50" buttons {"Cancel", "OK"} default button "OK")
		set _r to _r as number

        set _s to text returned of ¬
			(display dialog "Softness? (0..100):" default answer "50" buttons {"Cancel", "OK"} default button "OK")
		set _s to _s as number

        set _e to text returned of ¬
			(display dialog "Expand? (-100..100):" default answer "-20" buttons {"Cancel", "OK"} default button "OK")
		set _e to _e as number

        -- cache selected layers
        set selected_layers to selected layers
		
        -- Process each layer
		repeat with l in selected_layers
			deselect
			unmask l
			load selection of the l mode add selection
			refine selection roundness _r softness _s expand _e
			mask l
		end repeat

        -- restore selected layers
		set selected layers to selected_layers
	end tell
end tell

Download AppleScript file

Suggest an improvement  ·  How to install scripts