helium/core/input.lua

local path   = string.sub(..., 1, string.len(...) - string.len(".core.input"))
local helium = require(path .. ".dummy")

local input={
	eventHandlers = {},
	subscriptions = {},
	activeEvents  = {}
}

---@class subscription
local subscription   = {}
subscription.__index = subscription

---@class inputContext
local context   = {}
context.__index = context

local activeContext

--[[Event types
	###SIMPLE EVENTS###
	mousepressed,--press started
	mousereleased,--press released after an event inside started

	mousepressed_outside --mousepressed outside of the subscription
	mousereleased_outside --mousereleased outside of the subscription

	keypressed,--key pressed
	keyreleased,--key released

	###COMPLEX EVENTS###
		dragged,
		clicked,
		hover,


]]
function input.newContext(element)
	local ctx = setmetatable({view = element.view, subs = {}}, context)

	return ctx
end

function context:set()
	if activeContext then
		self.parentCtx = activeContext
		self.absX      = self.parentCtx.absX + self.view.x
		self.absY      = self.parentCtx.absY + self.view.y
		activeContext  = self
	else
		self.absX     = self.view.x
		self.absY     = self.view.y
		activeContext = self
	end
end

function context:unset()
	if self.parentCtx then
		activeContext = self.parentCtx
	else
		activeContext = nil
	end
end

function context:destroy()
	for i, e in ipairs(self.subs) do
		self.subs:destroy()
	end
end

---@param x number
---@param y number
---@param w number
---@param h number
---@param eventType string
---@param callback function
---@param doff boolean
---@return subscription
function subscription.create(x, y, w, h, eventType, callback, doff)
	local sub
	if activeContext then
		sub = setmetatable({
			x         = activeContext.absX + x,
			y         = activeContext.absY + y,
			w         = w,
			h         = h,
			eventType = eventType,
			active    = doff or true,
			callback  = callback
		},subscription)
	else
		sub = setmetatable({
			x         = x,
			y         = y,
			w         = w,
			h         = h,
			eventType = eventType,
			active    = doff or true,
			callback  = callback
		},subscription)
	end

	if not input.subscriptions[eventType] then
		input.subscriptions[eventType] = {}
	end

	table.insert(input.subscriptions[eventType],sub)

	return sub
end

function subscription:off()
	self.active = false
end

function subscription:on()
	self.active = true
end

function subscription:destroy()
	self.destroy = true
	self.active = false
end

function subscription:update(x, y, w, h)
	self.x = x or self.x
	self.y = y or self.y
	self.w = w or self.w
	self.h = h or self.h
end

function subscription:emit(...)
	return self.callback(...)
end

function subscription:checkInside(x, y)
	if x>self.x and x<self.x+self.w and y>self.y and y<self.y+self.h then
		return true
	else
		return false
	end
end

function subscription:checkOutside(x, y)
	if x>self.x and x<self.x+self.w and y>self.y and y<self.y+self.h then
		return false
	else
		return true
	end
end

input.subscribe = function(...)
	return subscription.create(...)
end


function input.eventHandlers.mousereleased(x, y, btn)
	local captured = false
	if input.subscriptions.mousereleased then
		for index, sub in ipairs(input.subscriptions.mousereleased) do
			local succ = sub:checkInside(x, y)

			if  succ and sub.active  then
				sub:emit(x, y, btn)
				captured = true
			end

		end
	end
	if input.subscriptions.mousereleased_outside then
		for index, sub in ipairs(input.subscriptions.mousereleased_outside) do
			local succ = sub:checkOutside(x, y)

			if  succ and sub.active  then
				sub:emit(x, y, btn)
				captured = true
			end

		end
	end

	if input.subscriptions.clicked then
		for index, sub in ipairs(input.subscriptions.clicked) do
			if sub.currentEvent then
				sub.currentEvent = false
				captured         = true
				if sub.cleanUp then
					sub.cleanUp(x, y, btn)
				end
			end
		end
	end

	return captured
end


function input.eventHandlers.mousepressed(x, y, btn)
	local captured = false
	if input.subscriptions.mousepressed then
		for index, sub in ipairs(input.subscriptions.mousepressed) do
			local succ = sub:checkInside(x, y)

			if  succ and sub.active  then
				sub:emit(x, y, btn)
				captured = true
			end

		end
	end
	if input.subscriptions.mousepressed_outside then
		for index, sub in ipairs(input.subscriptions.mousepressed_outside) do
			local succ = sub:checkOutside(x, y)

			if succ and sub.active then
				sub:emit(x, y, btn)
				captured = true
			end

		end
	end
	if input.subscriptions.clicked then
		for index, sub in ipairs(input.subscriptions.clicked) do
			local succ = sub:checkInside(x, y)

			if succ and sub.active then
				sub.cleanUp      = sub:emit(x, y, btn)
				sub.currentEvent = true
				captured         = true
			end

		end
	end

	return captured
end

function input.eventHandlers.keypressed(btn)
	local captured = false
	if input.subscriptions.keypressed then
		for index, sub in ipairs(input.subscriptions.keypressed) do
			if sub.active ==true then
				sub:emit( btn)
				captured = true
			end

		end
	end

	return captured
end

function input.eventHandlers.keyreleased(btn)
	local captured = false
	if input.subscriptions.keyreleased then
		for index, sub in ipairs(input.subscriptions.keyreleased) do
			if sub.active then
				sub:emit(btn)
				captured = true
			end
		end
	end

	return captured
end

function input.eventHandlers.mousemoved(x, y)
	local captured = false

	if input.subscriptions.hover then
		for index, sub in ipairs(input.subscriptions.hover) do
			local succ = sub:checkInside(x, y)

			if succ and sub.active and not sub.currentEvent then
				sub.cleanUp      = sub:emit(x, y)
				sub.currentEvent = true
				captured         = true
			elseif sub.currentEvent and not sub:checkInside(x, y) then
				sub.currentEvent = false
				captured         = true
				if sub.cleanUp then
					sub.cleanUp(x, y)
				end
			end
		end
	end

	return captured
end

return input