Builder adds handlers ('on_touch_down', 'on_touch_up', etc) to widgets, disregarding if the method is called on the widget

[fscz]

I think in kivy/kivy/lang.py

if rule.handlers:                                                                                                                                                                    
    rctx['hdl'].append((widget.proxy_ref, rule.handlers)) 

shoule be replaced by

    for handler in rule.handlers:
        idmap = copy(global_idmap)
        idmap.update(rctx['ids'])
        idmap['self'] = widget.proxy_ref
        if hasattr(widget.proxy_ref, handler.name):
    method = getattr(widget.proxy_ref, handler.name)
            def new_method(*args):
                method(*args)
                exec handler.value in idmap
            setattr(widget.proxy_ref, handler.name, new_method)
        else:
            def new_method(*args):
                exec handler.value in idmap
            setattr(widget.proxy_ref, handler.name, new_method)