Codea button creation following the model of the built-in ellipse and rect functions

SuperSimpleButtons.txt

--# Main
-- SimpleButton

displayMode(OVERLAY)

-- Use this function to perform your initial setup
function setup()
    -- Uncomment to run super simple tests:
    --tests()
end

function draw()
    background(255, 177, 0, 255)
    --to show a button just add a button(name) statement to draw()
    button("hello world")
    --you don't need to do anything else
    --the button will start in a random position 
    --which is fine because you can manually position it while the project runs
    --and the project will save your positioning so the buttons stay in place
    --buttons act like all other Codea drawing shapes
    --they simply use all the currently defined styles
    pushStyle()
    stroke(224, 18, 18, 255)
    fill(26, 153, 95, 255)
    strokeWidth(8)
    font("AmericanTypewriter-Bold")
    fontSize(15)
    button("I use custom styles")
    popStyle()
    --to specify a button action, just add a function after the button name
    local tapResponse = function() print("you tapped me!") end
    button("tap me", tapResponse)
    --buttons use a default font color or a passed-in font color parameter
    button("font color customized", nil, color(255,180,80,255))
    --buttons use a default width and height or passed-in parameters
    button("size customized", nil, nil, 300, 30)
    --buttons choose initial random positions or can be positioned in code
    button("positioned in code", nil, nil, nil, nil, WIDTH-200, 80)
    --here's a fully customized button
    pushStyle()  
    stroke(253, 0, 198, 255)
    fill(223, 168, 159, 255)
    strokeWidth(3)
    font("Zapfino")
    fontSize(35)
    button("Fully custom, yo!", function() print("I've got my own response!") end, color(253, 0, 198, 255), 400, 150, WIDTH/2, HEIGHT/2)
    popStyle()  
end


--# SimpleButton
button = function(name, action, textColor, width, height, x, y)
    if buttonHandler.configured == false then
        buttonHandler.configure()
    end
    if buttonHandler.buttons[name] == nil then
        buttonHandler.buttons[name] = {}
    end
    if action ~= nil and buttonHandler.buttons[name].action == nil then
        buttonHandler.buttons[name].action = action
    end
    buttonHandler.positionByTouchIfTouched(name)
    buttonHandler.buttons[name].x = x or buttonHandler.buttons[name].x or buttonHandler.randomX(name)
    buttonHandler.buttons[name].y = y or buttonHandler.buttons[name].y or buttonHandler.randomY(name)
    buttonHandler.buttons[name].width = width or buttonHandler.buttons[name].width or buttonHandler.defaultWidth
    buttonHandler.buttons[name].height = height or buttonHandler.buttons[name].height or buttonHandler.defaultHeight
    buttonTable = buttonHandler.buttons[name]
    local wordColor = textColor or color(215, 221, 231, 255)
    rectMode(CENTER)
    rect(buttonTable.x,buttonTable.y,buttonTable.width,buttonTable.height)
    pushStyle()
    fill(wordColor)
    text(name, buttonTable.x, buttonTable.y)
    popStyle()
end

-- buttonHandler setup
buttonHandler = {}
buttonHandler.defaultWidth = 190
buttonHandler.defaultHeight = 65
buttonHandler.buttons = {}
buttonHandler.configured = false
buttonHandler.configure = function ()
    parameter.boolean("buttons_can_be_dragged", false)
    buttonHandler.configured = true
end

buttonHandler.randomX = function(name)
    print("button '"..name.."' is using a random x value")
    return math.random(WIDTH)
end

buttonHandler.randomY = function(name)
    print("button '"..name.."' is using a random y value")
    return math.random(HEIGHT)
end

buttonHandler.doAction = function(name)
    if buttonHandler.buttons[name].action == nil then
        print("Specify a function after the button's name to define an action for the button '"..name.."'")
        return
    else
        buttonHandler.buttons[name].action()
    end
end

buttonHandler.touchIsInside = function(name)
    insideX = math.abs(CurrentTouch.prevX-buttonHandler.buttons[name].x) < buttonHandler.buttons[name].width /2
    insideY = math.abs(CurrentTouch.prevY-buttonHandler.buttons[name].y) < buttonHandler.buttons[name].height /2
    if insideX and insideY then
        return true
    end
    return false
end

buttonHandler.positionByTouchIfTouched = function(name)
    if CurrentTouch.state ==  BEGAN and buttonHandler.touchIsInside(name) then
        activatedButton = name
    end
    if activatedButton == name then
        if buttons_can_be_dragged then
            if CurrentTouch.state == MOVING then
                buttonHandler.dragButton(name, vec2( CurrentTouch.x, CurrentTouch.y))
            elseif CurrentTouch.state == ENDED then
                buttonHandler.savePositions()
                activatedButton = nil
            end
        elseif CurrentTouch.state == ENDED then
            buttonHandler.doAction(name)
            activatedButton = nil
        end
    end
end

buttonHandler.dragButton = function (name, touch)
    buttonHandler.buttons[name].x = touch.x
    buttonHandler.buttons[name].y = touch.y
end

buttonHandler.positionOf = function (name)
    return buttonHandler.buttons[name]
end

buttonHandler.savePositions = function ()
    dataString = "--delete this tab to erase positions created by dragging\n"
    for name, buttonValues in pairs(buttonHandler.buttons) do
        dataString = dataString.."buttonHandler.buttons['"..name.."'] = {x = "..buttonValues.x
        dataString = dataString..", y = "..buttonValues.y
        dataString = dataString..", width = "..buttonValues.width..", height = "..buttonValues.height.."}\n"
    end
    saveProjectTab("ButtonTables",dataString)
end

--# Tests
function tests()
    testButtonName = "hello world"
    button(testButtonName)
    local touch = {x=10,y=19}      
    buttonHandler.savePositions(testButtonName, touch)
    print("saved position")
    buttonHandler.dragButton(testButtonName, touch)
    print("dragged button")
    loadedPosition = buttonHandler.positionOf(testButtonName)
    print("loaded position is", loadedPosition.x, loadedPosition.y)
    print("TESTS SUCCEEDED")
end