Get selected text from TextInput #514

I need to find one of several urls in a TextInput (say with a double-click) so I can open it in a browser.
I've tried

self.recTxt = gui.TextInput(single_line=False, margin='10px')
self.recTxt.ondblclick.connect(self.onDblClick)
self.recTxt.onmousemove.connect(self.onMouseMove)

def onDblClick(self,obj):
    print(obj.children['text'])

I can get all the text, but not find the particular url that was clicked on.
Or I can get the mouse position in x,y coordinates.

How do I get the text?