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mirror of https://github.com/koreader/koreader synced 2024-10-31 21:20:20 +00:00
koreader/frontend/ui/hook_container.lua
NiLuJe 03e9fac156
Input: Process input events in batches (#7483)
Requires https://github.com/koreader/koreader-base/pull/1344 & https://github.com/koreader/koreader-base/pull/1346 (fix #7485)

Assorted input fixes:

* Actually handle errors in the "there's a callback timer" input polling loop.
* Don't break timerfd when the clock probe was inconclusive.

Not directly related, but noticed because of duplicate onInputEvent handlers:

* HookContainer: Fix deregistration to actually deregister properly. "Regression" extant since its inception in #2933 (!).
* Made sure the three plugins (basically the trio of AutoThingies ;p) that were using HookContainer actually unschedule their task on teardown.
2021-04-03 01:48:35 +02:00

104 lines
3.3 KiB
Lua

--[[--
HookContainer allows listeners to register and unregister a hook for speakers to execute.
It's an experimental feature: use with cautions, it can easily pin an object in memory and unblock
GC from recycling the memory.
]]
local HookContainer = {}
function HookContainer:new(o)
o = o or {}
setmetatable(o, self)
self.__index = self
return o
end
function HookContainer:_assertIsValidName(name)
assert(self ~= nil)
assert(type(name) == "string")
assert(string.len(name) > 0)
end
function HookContainer:_assertIsValidFunction(func)
assert(self ~= nil)
assert(type(func) == "function" or type(func) == "table")
end
function HookContainer:_assertIsValidFunctionOrNil(func)
assert(self ~= nil)
if func == nil then return end
self:_assertIsValidFunction(func)
end
--- Register a function to name. Must be called with self.
-- @tparam string name The name of the hook. Can only be an non-empty string.
-- @tparam function func The function to handle the hook. Can only be a function.
function HookContainer:register(name, func)
self:_assertIsValidName(name)
self:_assertIsValidFunction(func)
if self[name] == nil then
self[name] = {}
end
table.insert(self[name], func)
end
--- Register a widget to name. Must be called with self.
-- @tparam string name The name of the hook. Can only be an non-empty string.
-- @tparam table widget The widget to handle the hook. Can only be a table with required functions.
function HookContainer:registerWidget(name, widget)
self:_assertIsValidName(name)
assert(type(widget) == "table")
-- *That* is the function we actually register and need to unregister later, so keep a ref to it...
local hook_func = function(args)
local f = widget["on" .. name]
self:_assertIsValidFunction(f)
f(widget, args)
end
self:register(name, hook_func)
local original_close_widget = widget.onCloseWidget
self:_assertIsValidFunctionOrNil(original_close_widget)
widget.onCloseWidget = function()
if original_close_widget then original_close_widget(widget) end
self:unregister(name, hook_func)
end
end
--- Unregister a function from name. Must be called with self.
-- @tparam string name The name of the hook. Can only be an non-empty string.
-- @tparam function func The function to handle the hook. Can only be a function.
-- @treturn boolean Return true if the function is found and removed, otherwise false.
function HookContainer:unregister(name, func)
self:_assertIsValidName(name)
self:_assertIsValidFunction(func)
if self[name] == nil then
return false
end
for i, f in ipairs(self[name]) do
if f == func then
table.remove(self[name], i)
return true
end
end
return false
end
--- Execute all registered functions of name. Must be called with self.
-- @tparam string name The name of the hook. Can only be an non-empty string.
-- @param args Any kind of arguments sending to the functions.
-- @treturn number The number of functions have been executed.
function HookContainer:execute(name, args)
self:_assertIsValidName(name)
if self[name] == nil or #self[name] == 0 then
return 0
end
for _, f in ipairs(self[name]) do
f(args)
end
return #self[name]
end
return HookContainer