Storyboard extra

function storyboard.goBack()
    local prev = storyboard.prevName
    if prev then
        storyboard.gotoScene(prev, {effect = 'slideRight', time = 400, params = storyboard.prevParams, back = true})
        return true
    else
        return false
    end
end

storyboard._gotoScene = storyboard.gotoScene
function storyboard.gotoScene(name, params)
    if not params then
        storyboard.prevName = storyboard.getCurrentSceneName()
        storyboard.prevParams = storyboard.currentParams
        storyboard.currentParams = nil
        storyboard._gotoScene(name)
    elseif params then
        storyboard.prevName = storyboard.getCurrentSceneName()
        storyboard.prevParams = storyboard.currentParams
        if params.back then
            storyboard.prevName = nil
            storyboard.prevParams = nil
        end
        storyboard.currentParams = params.params
        storyboard._gotoScene(name, params)
    end
end

function storyboard.getCurrentScene()
    return storyboard.getScene(storyboard.getCurrentSceneName())
end