applescript - jxa - Getting NSAttributedString font metrics in JavaScript for Automation -

in macos sierra javascript automation, can write:

// helvetica12width :: string -> num function helvetica12width(str) {     return $.nsattributedstring.alloc.init.initwithstring(             str         )         .size.width; } 

to metrics particular string in default helvetica 12. haven't yet managed pass in attributes other fonts , font sizes, , corresponding metrics those.

has discovered idiom/syntax works here jxa or applescript ?

update: kind of thing have experimented – off mark though, variation in font size/name values doesn't affect return value:

(() => {     'use strict';      objc.import('appkit');      return $.nsattributedstring.alloc.init.initwithstringattributes(             "substantiation", {                 'nsfontattributename': $.nsfont.fontwithnamesize('helvetica', 24)             }         )         .size.width })(); 

ah ... seems it:

(function () {     'use strict';      objc.import('appkit');      // show :: -> string     const show = x => json.stringify(x, null, 2);      // stringsizeinfontatpointsize :: string -> string -> num     //                                  -> {width:num, height:num}     function stringsizeinfontatpointsize(str, fontname, points) {         return $.nsattributedstring.alloc.init.initwithstringattributes(             str, $({                 'nsfont': $.nsfont.fontwithnamesize(fontname, points)             })         )         .size;     }      // test -------------------------------------------------------------------     return show([         stringsizeinfontatpointsize("hello world", "geneva", 32),         stringsizeinfontatpointsize("hello world", "geneva", 64),         stringsizeinfontatpointsize("hello world", "helvetica", 64),     ]); })();