Event-driven UI

local character = require "characters.character"
local sprite = require "sprite"

-- these should probably be moved into a new module
local function trackButton(event)
    local button = event.target
    if event.phase == "began" then
        display.getCurrentStage():setFocus(button)
        button._isFocused = true
        button._down = true
        button:dispatchEvent{name='Button.State'; target=button, down=true}
    elseif button._isFocused then
        if event.phase == "moved" then
            local bounds = button.contentBounds
            local isWithinBounds = bounds.xMin <= event.x and bounds.xMax >= event.x and bounds.yMin <= event.y and bounds.yMax >= event.y
            if isWithinBounds ~= button._down then
                button._down = isWithinBounds
                button:dispatchEvent{name='Button.State'; target=button, down=button._down}
            end
        elseif event.phase == "ended" or event.phase == "cancelled" then
            button:dispatchEvent{name='Button.State'; target=button, down=false}
            button:dispatchEvent{name='Button'; target=button, activate=button._down and event.phase == "ended"}
            display.getCurrentStage():setFocus(button, nil)
            button._down = nil
            button._isFocused = nil
        end
    end
    return true
end

end
local button = {}
function button.new(object)
    object:addEventListener('touch', trackButton)
end

local resistance = {}

local menuSheet = sprite.newSpriteSheet("visuals/resistance_buttons.png", 60, 20)
local menuButtonMove = sprite.newSpriteSet(menuSheet, 1, 2)
local menuButtonAttack = sprite.newSpriteSet(menuSheet, 3, 2)
local menuButtonDone = sprite.newSpriteSet(menuSheet, 5, 2)

function resistance.ToggleMenu(group, self)
    group.isVisible = not group.isVisible
    if group.isVisible then
        self:prepare("Selected")
    else
        self:prepare("Stationary")
    end
    self:play()
end

local function triggerMenu(event)
    event.target.menu:Open()
    return true
end

local function monitorMenu(self, event)
    local sequence = "Stationary"
    if event.action == "open" then
        sequence = "Selected"
    end
    if self.sequence ~= sequence then
        self:prepare(sequence)
        self:play()
    end
end

local function animateButton(event)
    event.target.currentFrame = event.down and 2 or 1
end

local function newMenuButton(parent, spriteSet, x, y)
    local self = sprite.newSprite(spriteSet)
    parent:insert(self)
    self:setReferencePoint(display.TopLeftReferencePoint)
    self.x, self = x, y
    self:addEventListener('Button.State', animateButton)
    self:addEventListener('Button', parent)
    self:addEventListener('Button', self)
    return self
end

local menuFunctions = {}

function menuFunctions:Open(event)
    self.isVisible = true
    self:dispatchEvent{name='Menu'; target=self, action='open'}
end

function menuFunctions:Close(event)
    self.isVisible = false
    self:dispatchEvent{name='Menu'; target=self, action='close'}
end

function menuFunctions:Button(event)
    if event.activate then
        self:Close()
    end
end

function resistance.Create(spritesheet, size, health, move, attack, defense, xTile, yTile)
    local self = character.Create(spritesheet, size, health, move, attack, defense, xTile, yTile)
        self:addEventListener("tap", triggerMenu)
    self.menu = display.newGroup() do local menu = self.menu
        menu.owner = self
        menu.x, menu.y = 145, 173
        menu.Block = display.newRect(0, 0, display.contentWidth, display.contentHeight)
            menu:insert(menu.Block)
            menu.Block:setFillColor(0, 0)
            menu.Block:addEventListener("tap", function() return true end)
        menu.Background = display.newImage("visuals/resistance_background.png", 0, 0)
            menu.Background:setReferencePoint(display.CenterReferencePoint)
            menu.Background.x, menu.Background.y = display.contentWidth / 2, display.contentHeight / 2
            menu:insert(menu.Background)
        menu.Icon = display.newImage(menu, ("visuals/character_" .. spritesheet .. "icon.png"), 0, -45)
        menu.ButtonMove = newMenuButton(menu, menuButtonMove, 0, 0)
            function menu.ButtonMove:Button(event)
                if event.activate then
                    character.Move(self, 30, math.random(0, 15), math.random(0, 9))
                end
            end
        menu.ButtonAttack = newMenuButton(menu, menuButtonAttack, 65, 0)
        menu.ButtonDone = newMenuButton(menu, menuButtonDone, 130, 0)

        for name, method in pairs(menuFunctions) do
            menu[name] = method
        end

        menu.isVisible = false
    end
    self.Menu = monitorMenu
    self.menu:addEventListener('Menu', self)
    return self
end

return resistance