t9cdmtBX

1local event, handlers, interruptingKeysDown, lastInterrupt = {
2	interruptingEnabled = true,
3	interruptingDelay = 1,
4	interruptingKeyCodes = {
5		[29] = true,
6		[46] = true,
7		[56] = true
8	},
9	push = computer.pushSignal
10}, {}, {}, 0
11
12local computerPullSignal, computerUptime, mathHuge, mathMin, skipSignalType = computer.pullSignal, computer.uptime, math.huge, math.min
13
14--------------------------------------------------------------------------------------------------------
15
16function event.addHandler(callback, interval, times)
17	checkArg(1, callback, "function")
18	checkArg(2, interval, "number", "nil")
19	checkArg(3, times, "number", "nil")
20
21	local handler = {
22		callback = callback,
23		times = times or mathHuge,
24		interval = interval,
25		nextTriggerTime = interval and computerUptime() + interval or 0
26	}
27
28	handlers[handler] = true
29
30	return handler
31end
32
33function event.removeHandler(handler)
34	checkArg(1, handler, "table")
35
36	if handlers[handler] then
37		handlers[handler] = nil
38
39		return true
40	else
41		return false, "Handler with given table is not registered"
42	end
43end
44
45function event.getHandlers()
46	return handlers
47end
48
49function event.skip(signalType)
50	skipSignalType = signalType
51end
52
53function event.pull(preferredTimeout)	
54	local uptime, signalData = computerUptime()
55	local deadline = uptime + (preferredTimeout or mathHuge)
56	
57	repeat
58		-- Determining pullSignal timeout
59		timeout = deadline
60		for handler in pairs(handlers) do
61			if handler.nextTriggerTime > 0 then
62				timeout = mathMin(timeout, handler.nextTriggerTime)
63			end
64		end
65
66		-- Pulling signal data
67		signalData = { computerPullSignal(timeout - computerUptime()) }
68				
69		-- Handlers processing
70		for handler in pairs(handlers) do
71			if handler.times > 0 then
72				uptime = computerUptime()
73
74				if
75					handler.nextTriggerTime <= uptime
76				then
77					handler.times = handler.times - 1
78					if handler.nextTriggerTime > 0 then
79						handler.nextTriggerTime = uptime + handler.interval
80					end
81
82					-- Callback running
83					handler.callback(table.unpack(signalData))
84				end
85			else
86				handlers[handler] = nil
87			end
88		end
89
90		-- Program interruption support. It's faster to do it here instead of registering handlers
91		if signalData[1] == "key_down" or signalData[1] == "key_up" and event.interruptingEnabled then
92			-- Analysing for which interrupting key is pressed - we don't need keyboard API for this
93			if event.interruptingKeyCodes[signalData[4]] then
94				interruptingKeysDown[signalData[4]] = signalData[1] == "key_down" and true or nil
95			end
96
97			local shouldInterrupt = true
98			for keyCode in pairs(event.interruptingKeyCodes) do
99				if not interruptingKeysDown[keyCode] then
100					shouldInterrupt = false
101				end
102			end
103			
104			if shouldInterrupt and uptime - lastInterrupt > event.interruptingDelay then
105				lastInterrupt = uptime
106				error("interrupted", 0)
107			end
108		end
109		
110		-- Loop-breaking condition
111		if signalData[1] then
112			if signalData[1] == skipSignalType then
113				skipSignalType = nil
114			else
115				return table.unpack(signalData)
116			end
117		end
118	until uptime >= deadline
119end
120
121-- Sleeps "time" of seconds via "busy-wait" concept
122function event.sleep(time)
123	checkArg(1, time, "number", "nil")
124
125	local deadline = computerUptime() + (time or 0)
126	repeat
127		event.pull(deadline - computerUptime())
128	until computerUptime() >= deadline
129end
130
131--------------------------------------------------------------------------------------------------------
132
133return event