Button API

--[[
    Project info:

    Name: Button API
    Creator: Jesusthekiller
    Language: Lua (CC)
    Website: None
    License: GNU GPL
        License file can be fount at www.jesusthekiller.com/license-gpl.html

    Version: 1.1
]]--

--[[
    Changelog:

    1.0:
      Initial release

    1.1:
      Added Single-Use buttons
]]--

--[[
    Usage:
      makeButton(localtionArray, buttonbTypeArray, callback, [callback_pressed])

        locationArray:
          Array, has to contain those keys:
            * xstart
            * ystart
            * xstop
            * ystop

        buttonbTypeArray:
          Array, has to contain those keys:
            * color_bkg
            * click_color_bkg
            * color_text
            * click_color_text
            * text
            * textStartPosX
            * textStartPosY
            * event_value

        callback:
          Function with code to be run in parallel with makeButton
          Button will terminate if this code ends.

        callback_pressed:
          Optional, function to be run when button is pressed.
          Don't make it infinite (it will freeze button pressed and unclickable until finished)

        makeButton will create "button" event with event_value as 1st value when button will be pressed.

      makeSingleUseButton(localtionArray, buttonbTypeArray, animationTime, callback, [callback_pressed])
        localtionArray, buttonbTypeArray, callback, callback_pressed same as in makeButton

        animatonTime:
          Controls for how long button has to be pressed after clicked. If set to >= 0 then animation will be disabled.

        callback_pressed is executed after animation, not in parallel with it.

      removeButton(event_value)
        Removes button
      !!By default this API will print to Terminal, if you want monitor output, do term.redirect()!!
]]--

-- Local API:
local function printButton(loc, btype, clicked)
    local bkg, text

    local x, y = term.getCursorPos()

    if clicked then
        bkg = btype.click_color_bkg
        text = btype.click_color_text
    else
        bkg = btype.color_bkg
        text = btype.color_text
    end

    term.setBackgroundColor(bkg)
    term.setTextColor(text)

    term.setCursorPos(loc.startx, loc.starty)  -- Write bkg

    for i = loc.starty, loc.stopy do
        term.setCursorPos(loc.startx, i)
        for j = loc.startx, loc.stopx do
            write(" ")
        end
    end

    term.setCursorPos(btype.textStartPosX, btype.textStartPosY) -- Write text
    write(btype.text)

    term.setCursorPos(x, y) -- Restore cursor xy
end

-- Global API:

function makeButton(loc, btype, callback, callback_pressed)
    printButton(loc, btype, false)

    local function wait_click()
        while true do
            local e, b, x, y = os.pullEvent("mouse_click")

            if x >= loc.startx and x <= loc.stopx and y >= loc.starty and y <= loc.stopy then
                os.queueEvent("button", btype.event_value)

                printButton(loc, btype, true)

                local function f1()
                    if callback_pressed then
                        callback_pressed()
                    end
                end

                local function f2()
                    sleep(0.2)
                end

                parallel.waitForAll(f1, f2)

                printButton(loc, btype, false)
            end
        end
    end

    local function wait_terminate()
        while true do
            local e, v = os.pullEvent("remove_button")
            if v == btype.event_value then
                return
            end
        end
    end

    parallel.waitForAny(wait_click, wait_terminate, callback)
end

function makeSingleUseButton(loc, btype, animation, callback, callback_pressed)
    printButton(loc, btype, false)

    local function wait_click()
        while true do
            local e, b, x, y = os.pullEvent("mouse_click")

            if x >= loc.startx and x <= loc.stopx and y >= loc.starty and y <= loc.stopy then
                os.queueEvent("button", btype.event_value)

                if animation > 0 then
                    printButton(loc, btype, true)
                    sleep(animation)
                    printButton(loc, btype, false)
                    sleep(0.1)
                end

                if callback_pressed then
                    callback_pressed()
                end

                return
            end
        end
    end

    local function wait_terminate()
        while true do
            local e, v = os.pullEvent("remove_button")
            if v == btype.event_value then
                return
            end
        end
    end

    parallel.waitForAny(wait_click, wait_terminate, callback)
end

function removeButton(event_value)
    os.queueEvent("remove_button", event_value)
end