[signal,timer,init] Add customized versions of signal and timer from vrld/hump.

signal.lua

@@ -0,0 +1,90 @@
+--- Timer utilities.
+--
+-- This is a reworked implementation of the original signal module
+-- from the hump library (https://github.com/vrld/hump).
+-- See README.ACKNOWLEDGEMENT for detailed information.
+--
+-- It offers functionality to register for and publish signals.
+-- Implements the Observer pattern.
+--
+-- @module gear.timer
+-- @copyright 2010-2013 Matthias Richter
+-- @copyright 2022 The DoubleFourteen Code Forge
+-- @author Matthias Richter, Lorenzo Cogotti
+
+local Signal = {}
+Signal.__index = function(self, key)
+    return Signal[key] or (function()
+        local t = {}
+        rawset(self, key, t)
+        return t
+    end)()
+end
+
+function Signal:register(s, f)
+    self[s][f] = f
+    return f
+end
+
+function Signal:emit(s, ...)
+    for f in pairs(self[s]) do
+        f(...)
+    end
+end
+
+function Signal:remove(s, ...)
+    local f = {...}
+    for i = 1,select('#', ...) do
+        self[s][f[i]] = nil
+    end
+end
+
+function Signal:clear(...)
+    local s = {...}
+    for i = 1,select('#', ...) do
+        self[s[i]] = {}
+    end
+end
+
+function Signal:emitPattern(p, ...)
+    for s in pairs(self) do
+        if s:match(p) then self:emit(s, ...) end
+    end
+end
+
+function Signal:registerPattern(p, f)
+    for s in pairs(self) do
+        if s:match(p) then self:register(s, f) end
+    end
+    return f
+end
+
+function Signal:removePattern(p, ...)
+    for s in pairs(self) do
+        if s:match(p) then self:remove(s, ...) end
+    end
+end
+
+function Signal:clearPattern(p)
+    for s in pairs(self) do
+        if s:match(p) then self[s] = {} end
+    end
+end
+
+-- instancing
+function Signal.new()
+    return setmetatable({}, Signal)
+end
+
+-- default instance
+local default = Signal.new()
+
+-- module forwards calls to default instance
+local module = {}
+for k in pairs(Signal) do
+    if k ~= "__index" then
+        module[k] = function(...) return default[k](default, ...) end
+    end
+end
+
+return Signal