OC/context

local e = require "event"
local unicode = require "unicode"

--local context = {}
local g = require ("component").gpu
local s = require "serialization"

function createContext(context_content, gpu, x, y, design)
    local self = {}
    self.pixels_under_context = {}
    self.content = context_content
    self.draw_point = {['x'] = x, ['y'] = y}
    self.gpu = gpu

    self.default_design = {}
    self.default_design.width, self.default_design.height = 10, 10
    self.default_design.horizontal_indents = 2
    self.default_design.shadow = true
    self.default_design.blink_time = 0.2

    self.default_design.enabled_background = 0xffffff
    self.default_design.enabled_foreground = 0x000000

    self.default_design.disabled_background = 0xffffff
    self.default_design.disabled_foreground = 0xaaaaaa

    self.default_design.selected_background = 0x0000ff
    self.default_design.selected_foreground = 0x000000

    self.default_design.shadow_background = 0xaaaaaa
    self.default_design.delim_char = '—'

    if ( design ) then
        self.default_design = design
    end

    local maxLength = 0
    for _, item in pairs(context_content) do
        if ( item ) then
            maxLength = math.max( maxLength, unicode.len(item.name) )
        end
    end
    self.default_design.width, self.default_design.height = maxLength+self.default_design.horizontal_indents*2, #context_content

    function self.copyPixelsUnderContext(self)
        for y=self.draw_point.y, self.default_design.height+self.draw_point.y+1 do
            self.pixels_under_context[y] = {}
            for x=self.draw_point.x, self.default_design.width+self.draw_point.x+1 do
                self.pixels_under_context[y][x] = { self.gpu.get(x, y) }
            end
        end
    end

    function self.drawPixelsUnderContext(self)
        for y=self.draw_point.y, self.default_design.height+self.draw_point.y+1 do
            for x=self.draw_point.x, self.default_design.width+self.draw_point.x+1 do
                self.gpu.setBackground( self.pixels_under_context[y][x][3] )
                self.gpu.setForeground( self.pixels_under_context[y][x][2] )
                self.gpu.set( x, y, self.pixels_under_context[y][x][1] )
            end
        end
    end

    function self.drawShadow(self)
        self.gpu.setBackground(self.default_design.shadow_background)
        self.gpu.fill(self.draw_point.x+1, self.draw_point.y+self.default_design.height, self.default_design.width, 1, ' ')
        self.gpu.fill(self.draw_point.x+self.default_design.width, self.draw_point.y+1, 1, self.default_design.height, ' ')
    end

    function self.drawItem(self, num_item, item)
        if ( not item ) then
            self.gpu.setBackground( self.default_design.disabled_background )
            self.gpu.setForeground( self.default_design.disabled_foreground )
            self.gpu.fill(self.draw_point.x, self.draw_point.y+num_item, self.default_design.width, 1, self.default_design.delim_char)
        else
            if ( item.active ) then
                self.gpu.setBackground( self.default_design.enabled_background )
                self.gpu.setForeground( self.default_design.enabled_foreground )
            else
                self.gpu.setBackground( self.default_design.disabled_background )
                self.gpu.setForeground( self.default_design.disabled_foreground )
            end
            self.gpu.fill(self.draw_point.x, self.draw_point.y+num_item, self.default_design.width, 1, ' ')
            self.gpu.set(self.draw_point.x, self.draw_point.y+num_item, string.rep(' ', self.default_design.horizontal_indents) .. item.name)
        end
    end

    function self.blinkItem(self, selected_item, touch_y)
        self.gpu.setBackground( self.default_design.selected_background )
        self.gpu.setForeground( self.default_design.selected_foreground )
        self.gpu.fill(x, touch_y, self.default_design.width, 1, ' ')
        self.gpu.set(x, touch_y, string.rep(' ', self.default_design.horizontal_indents) .. selected_item.name)

        os.sleep( self.default_design.blink_time )

        self.gpu.setBackground( self.default_design.enabled_background )
        self.gpu.setForeground( self.default_design.enabled_foreground )
        self.gpu.fill(x, touch_y, self.default_design.width, 1, ' ')
        self.gpu.set(x, touch_y, string.rep(' ', self.default_design.horizontal_indents) .. selected_item.name)
    end

    function self.openContext(self)
        self:copyPixelsUnderContext()
        self:drawShadow()

        for numItem, item in pairs(self.content) do
            self:drawItem(numItem-1, item)
        end
    end

    function self.checkTouch(self, event)
        local numSelectedItem = event[4]-self.draw_point.y+1

        local selectedItem = self.content[numSelectedItem]
        local isEnabledItem = ( selectedItem ) and ( selectedItem.active == true )
        local clickOnContextFrame = ( event[3] > self.draw_point.x-1 ) and ( event[3] < self.draw_point.x+self.default_design.width )

        if ( event[1] == "touch" ) then
            if ( isEnabledItem and clickOnContextFrame ) then
                self:blinkItem(selectedItem, event[4])

                --Call function
                local calledFunction = selectedItem["function"]
                if ( calledFunction ) then
                    calledFunction()
                end
            end
        end
    end

    function self.closeContext(self)
        self:drawPixelsUnderContext()
    end

    return self
end

--Example
local function pr()
    print("Opened!")
end

local content = {}
content[1] = {["name"] = "Open", ["function"] = pr, ["active"] = true}
content[2] = {["name"] = "Close", ["function"] = nil, ["active"] = true}
content[3] = false
content[4] = {["name"] = "Delete", ["function"] = nil, ["active"] = false}
content[5] = false

local t = { e.pull("touch") }

local menu = createContext(content, g, t[3], t[4])
menu:openContext()
menu:checkTouch({ e.pull() } )
menu:closeContext()

--return context