initial commit

luigi/event.lua

@@ -0,0 +1,49 @@
+local ROOT = (...):gsub('[^.]*$', '')
+
+local Base = require(ROOT .. 'base')
+
+local Event = Base:extend({ name = 'Event' })
+
+function Event:emit (observer, data, defaultAction)
+    local callbacks = self.registry[observer]
+    if not callbacks then
+        if defaultAction then defaultAction() end
+        return
+    end
+    for i, callback in ipairs(callbacks) do
+        local result = callback(data or {})
+        if result ~= nil then return result end
+    end
+    if defaultAction then defaultAction() end
+end
+
+function Event:bind (observer, callback)
+    local registry = self.registry
+    if not registry[observer] then
+        registry[observer] = {}
+    end
+    table.insert(registry[observer], callback)
+end
+
+local eventNames = {
+    'Display', 'Keyboard', 'Motion', 'Mouse', 'Reshape', 'Enter', 'Leave',
+    'Press', 'PressStart', 'PressDrag', 'PressMove', 'PressLeave', 'PressEnter',
+    'PressEnd'
+}
+
+local weakKeyMeta = { __mode = 'k' }
+
+for i, name in ipairs(eventNames) do
+    Event[name] = Event:extend({
+        name = name,
+        registry = setmetatable({}, weakKeyMeta),
+    })
+end
+
+function Event.injectBinders (t)
+    for i, name in ipairs(eventNames) do
+        t['on' .. name] = function (...) return Event[name]:bind(...) end
+    end
+end
+
+return Event