Beat Wolf has made good progress this week on improving the MacOS Dashboard widget support in Plasma. We now have the full widget API implemented (though some of the methods are just stubs as they don't really make sense for Plasma) so Dashboard widgets can now store and retrieve their settings, get notification of being closed, etc. We don't yet have the "flip" animation bit there, but that leads us to the current state of affairs:
So first things first, Beat put a little trick into the Dashboard installer that replaces the requests for Apple's files with requests for our own files when the widget is installed. So now installed Dashboard widgets will actually load our own JavaSript files.
Only .. we don't have those files .... yet! You see,the ones that Apple ships are not freely redistributable unless you include them with a widget that you write for MacOS. Uh-oh.
The answer? Reverse engineering, of course!