scrap widget inheritance

luigi/event.lua

@@ -3,26 +3,22 @@ local ROOT = (...):gsub('[^.]*$', '')
 local Base = require(ROOT .. 'base')
 local Hooker = require(ROOT .. 'hooker')
 
-local Event = Base:extend { name = 'Event' }
+local Event = Base:extend({ name = 'Event' })
 
 function Event:emit (target, data, defaultAction)
-    while target do
-        local handlers = rawget(target, 'eventHandlers')
-        local callbacks = handlers and handlers[self.name]
-        if callbacks then
-            local result = callbacks(data or {})
-            if result ~= nil then return result end
-        end
-        target = target.widgetClass
+    local callbacks = self.registry[target]
+    if not callbacks then
+        if defaultAction then defaultAction() end
+        return
     end
+    local result = callbacks(data or {})
+    if result ~= nil then return result end
     if defaultAction then defaultAction() end
 end
 
 function Event:bind (target, callback)
-    if not rawget(target, 'eventHandlers') then
-        target.eventHandlers = {}
-    end
-    return Hooker.hook(target.eventHandlers, self.name, callback)
+    local registry = self.registry
+    return Hooker.hook(registry, target, callback)
 end
 
 local eventNames = {
@@ -34,7 +30,10 @@ local eventNames = {
 local weakKeyMeta = { __mode = 'k' }
 
 for i, name in ipairs(eventNames) do
-    Event[name] = Event:extend { name = name }
+    Event[name] = Event:extend({
+        name = name,
+        registry = setmetatable({}, weakKeyMeta),
+    })
 end
 
 function Event.injectBinders (t)