use AppleScript
use framework "AppKit"
use framework "WebKit"

property NSURL : a reference to current application’s NSURL
property WebView : a reference to current application’s WebView
property NSScreen : a reference to current application’s NSScreen
property NSThread : a reference to current application’s NSThread
property NSWindow : a reference to current application’s NSWindow
property NSURLRequest : a reference to current application’s NSURLRequest
property NSMutableDictionary : a reference to current application’s NSMutableDictionary

on _DisplayWebWindowWithURL:theURLString windowSize:theWindowSize
　　— Create and display a horizontally centered window with a WebView
　　
　　set {thisWindowWidth, thisWindowHeight} to theWindowSize
　　set screenBounds to the NSScreen’s mainScreen’s visibleFrame as any
　　
　　if class of screenBounds = record then
　　　　set screenWidth to screenBounds’s |size|’s width
　　　　set screenHeight to screenBounds’s |size|’s height
　　　　set windowLeft to ((screenWidth – thisWindowWidth) / 2) + (screenBounds’s origin’s x)
　　　　set windowBottom to screenHeight – thisWindowHeight + (screenBounds’s origin’s y) – 40
　　else
　　　　copy screenBounds to {{originX, originY}, {screenWidth, screenHeight}}
　　　　set windowLeft to ((screenWidth – thisWindowWidth) / 2) + originX
　　　　set windowBottom to screenHeight – thisWindowHeight + originY – 40
　　end if
　　
　　set theStyleMask to (get current application’s NSTitledWindowMask) + (get current application’s NSClosableWindowMask) + (get current application’s NSMiniaturizableWindowMask) + (get current application’s NSResizableWindowMask)
　　set webWindow to NSWindow’s alloc()’s initWithContentRect:(current application’s NSMakeRect(windowLeft, windowBottom, thisWindowWidth, thisWindowHeight)) ¬
　　　　styleMask:theStyleMask backing:(current application’s NSBackingStoreBuffered) defer:false
　　— set webWindow’s title to "WebView Created with AppleScript – " & theURLString
　　
　　set theWebView to WebView’s alloc()’s initWithFrame:(current application’s NSMakeRect(0, 0, thisWindowWidth, thisWindowHeight)) ¬
　　　　frameName:"WebKit Frame" groupName:"WebKit Group"
　　set webWindow’s contentView to theWebView
　　
　　tell webWindow to makeKeyAndOrderFront:(missing value)
　　
　　— Start loading the URL
　　
　　set theURL to NSURL’s URLWithString:theURLString
　　set theURLRequest to NSURLRequest’s requestWithURL:theURL
　　tell theWebView’s mainFrame to loadRequest:theURLRequest
　　
　　webWindow
end _DisplayWebWindowWithURL:windowSize:

— The following two handlers exist to deal with running on a background thread.
— If we’re on a background thread, we have to run the UI code on the main thread.

on _DisplayWebWindowMainThread:parameterDictionary
　　try
　　　　set theURLString to parameterDictionary’s objectForKey:"url string"
　　　　set theWindowSize to parameterDictionary’s objectForKey:"window size"
　　　　
　　　　set webWindow to my _DisplayWebWindowWithURL:theURLString windowSize:theWindowSize
　　　　
　　　　tell parameterDictionary to setObject:webWindow forKey:"result"
　　on error errMsg number errNum
　　　　using terms from scripting additions
　　　　　　display alert "Error!" message errMsg & " (" & errNum & ")"
　　　　end using terms from
　　　　tell parameterDictionary to setObject:{errMsg, errNum} forKey:"error"
　　end try
end _DisplayWebWindowMainThread: