git.r.bdr.sh - rbdr/custom_event_support.lua/blob - lib/vendor/middleclass.lua

   1 -- middleclass.lua - v2.0 (2011-09)
   2 -- Copyright (c) 2011 Enrique García Cota
   3 -- Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
   4 -- The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
   5 -- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   6 -- Based on YaciCode, from Julien Patte and LuaObject, from Sebastien Rocca-Serra
   7
   8 local _classes = setmetatable({}, {__mode = "k"})
   9
  10 local function _setClassDictionariesMetatables(klass)
  11   local dict = klass.__instanceDict
  12   dict.__index = dict
  13
  14   local super = klass.super
  15   if super then
  16     local superStatic = super.static
  17     setmetatable(dict, super.__instanceDict)
  18     setmetatable(klass.static, { __index = function(_,k) return dict[k] or superStatic[k] end })
  19   else
  20     setmetatable(klass.static, { __index = function(_,k) return dict[k] end })
  21   end
  22 end
  23
  24 local function _setClassMetatable(klass)
  25   setmetatable(klass, {
  26     __tostring = function() return "class " .. klass.name end,
  27     __index    = klass.static,
  28     __newindex = klass.__instanceDict,
  29     __call     = function(self, ...) return self:new(...) end
  30   })
  31 end
  32
  33 local function _createClass(name, super)
  34   local klass = { name = name, super = super, static = {}, __mixins = {}, __instanceDict={} }
  35   klass.subclasses = setmetatable({}, {__mode = "k"})
  36
  37   _setClassDictionariesMetatables(klass)
  38   _setClassMetatable(klass)
  39   _classes[klass] = true
  40
  41   return klass
  42 end
  43
  44 local function _createLookupMetamethod(klass, name)
  45   return function(...)
  46     local method = klass.super[name]
  47     assert( type(method)=='function', tostring(klass) .. " doesn't implement metamethod '" .. name .. "'" )
  48     return method(...)
  49   end
  50 end
  51
  52 local function _setClassMetamethods(klass)
  53   for _,m in ipairs(klass.__metamethods) do
  54     klass[m]= _createLookupMetamethod(klass, m)
  55   end
  56 end
  57
  58 local function _setDefaultInitializeMethod(klass, super)
  59   klass.initialize = function(instance, ...)
  60     return super.initialize(instance, ...)
  61   end
  62 end
  63
  64 local function _includeMixin(klass, mixin)
  65   assert(type(mixin)=='table', "mixin must be a table")
  66   for name,method in pairs(mixin) do
  67     if name ~= "included" and name ~= "static" then klass[name] = method end
  68   end
  69   if mixin.static then
  70     for name,method in pairs(mixin.static) do
  71       klass.static[name] = method
  72     end
  73   end
  74   if type(mixin.included)=="function" then mixin:included(klass) end
  75   klass.__mixins[mixin] = true
  76 end
  77
  78 Object = _createClass("Object", nil)
  79
  80 Object.static.__metamethods = { '__add', '__call', '__concat', '__div', '__le', '__lt',
  81                                 '__mod', '__mul', '__pow', '__sub', '__tostring', '__unm' }
  82
  83 function Object.static:allocate()
  84   assert(_classes[self], "Make sure that you are using 'Class:allocate' instead of 'Class.allocate'")
  85   return setmetatable({ class = self }, self.__instanceDict)
  86 end
  87
  88 function Object.static:new(...)
  89   local instance = self:allocate()
  90   instance:initialize(...)
  91   return instance
  92 end
  93
  94 function Object.static:subclass(name)
  95   assert(_classes[self], "Make sure that you are using 'Class:subclass' instead of 'Class.subclass'")
  96   assert(type(name) == "string", "You must provide a name(string) for your class")
  97
  98   local subclass = _createClass(name, self)
  99   _setClassMetamethods(subclass)
 100   _setDefaultInitializeMethod(subclass, self)
 101   self.subclasses[subclass] = true
 102   self:subclassed(subclass)
 103
 104   return subclass
 105 end
 106
 107 function Object.static:subclassed(other) end
 108
 109 function Object.static:include( ... )
 110   assert(_classes[self], "Make sure you that you are using 'Class:include' instead of 'Class.include'")
 111   for _,mixin in ipairs({...}) do _includeMixin(self, mixin) end
 112   return self
 113 end
 114
 115 function Object:initialize() end
 116
 117 function Object:__tostring() return "instance of " .. tostring(self.class) end
 118
 119 function class(name, super, ...)
 120   super = super or Object
 121   return super:subclass(name, ...)
 122 end
 123
 124 function instanceOf(aClass, obj)
 125   if not _classes[aClass] or type(obj) ~= 'table' or not _classes[obj.class] then return false end
 126   if obj.class == aClass then return true end
 127   return subclassOf(aClass, obj.class)
 128 end
 129
 130 function subclassOf(other, aClass)
 131   if not _classes[aClass] or not _classes[other] or aClass.super == nil then return false end
 132   return aClass.super == other or subclassOf(other, aClass.super)
 133 end
 134
 135 function includes(mixin, aClass)
 136   if not _classes[aClass] then return false end
 137   if aClass.__mixins[mixin] then return true end
 138   return includes(mixin, aClass.super)
 139 end