Yes, it is possible to use Objective-C with AppleScript. The program AppleScriptObjC allows you to use both Objective-C code along AppleScript to add things like loading bars and more.
"AppleScriptObjC was introduced largely as a replacement for AppleScript Studio, as a way to develop AppleScript-based applications with a rich interface in Xcode. Subsequent releases have made it increasingly more accessible to regular scripters.
Not every script needs a complex interface, and not every scripter wants to master the complications of Xcode. AppleScriptObjC offers abilities most scripters want in their standard AppleScript applets or scripts. 'Everyday AppleScriptObjC' looks at AppleScriptObjC from this perspective: how to take advantage of this great resource in your everyday scripts." - Their website
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