99fbf8eb28
The matrix.eventable module/function returns a table with a pair of functions
which can be used to connect event handlers to events, and to generate them.
Basic usage is as follows:
obj = eventable()
obj.hook("event-name", print) -- Handle the event with "print"
obj.fire("event-name", "Hello, world") -- Prints "Hello, world"
This initial implementation has the following limitations:
* Event handlers are always invoked in the same order in which they have been
connected using the .hook() function.
* Individual event handlers cannot be disconnected. Only disconnecting all
handlers for en event at once is possible via .hook("event", nil).
53 lines
1.3 KiB
Lua
53 lines
1.3 KiB
Lua
#! /usr/bin/env lua
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--
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-- eventable.lua
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-- Copyright (C) 2016 Adrian Perez <aperez@igalia.com>
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--
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-- Distributed under terms of the MIT license.
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--
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local eventable = require "matrix.eventable"
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do -- Simple event
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local ev = assert(eventable())
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local flag = false
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ev.hook("foo", function () flag = true end)
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ev.fire("foo")
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assert(flag)
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end
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do -- Stop at first handler that returns some value
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local ev = assert(eventable())
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local flag1, flag2, flag3 = false, false, false
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ev.hook("foo", function () flag1 = true end)
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ev.hook("foo", function () flag2 = true ; return 42 end)
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ev.hook("foo", function () flag3 = true ; return 0 end)
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assert(ev.fire("foo") == 42)
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assert(flag1 == true)
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assert(flag2 == true)
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assert(flag3 == false)
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end
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do -- Arguments to eventable() are passed to handlers
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local obj = { answer = 42 }
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local ev = assert(eventable(obj))
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ev.hook("foo", function (o)
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assert(o == obj)
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assert(o.answer == 42)
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o.answer = 0 -- Mutate
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end)
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ev.fire("foo")
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assert(obj.answer == 0)
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end
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do -- Multiple arguments passed to eventable
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local ev = assert(eventable(42, "bar", nil, { v=10 }))
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ev.hook("foo", function (a, s, n, o)
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assert(a == 42)
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assert(s == "bar")
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assert(n == nil)
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assert(o.v == 10)
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end)
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ev.fire("foo")
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end
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