ExperimentalGear/scripts/components/pager/pageview.lua

require("common.class")

---@class PageView
---@field pageStack Page[]
local PageView = {
    __tostring = function () return "PageView" end
}

local function pushStack(t, o)
    table.insert(t, 1, o)
end

local function popStack(t)
    return table.remove(t, 1)
end

---Create a new PageView instance
---@param rootPage Page
---@return PageView
function PageView:new(rootPage)
    local o = Base(self)

    --set viewHandler as this instance for rootPage

    rootPage.viewHandler = o

    --set instance members

    o.pageStack = {}
    pushStack(o.pageStack, rootPage)

    return o
end

---Navigate to page
---@param page Page
function PageView:navigate(page)
    page.viewHandler = self
    pushStack(self.pageStack, page)
end

---Replace the current pageStack with a new root page
---@param page Page
function PageView:replace(page)
    --clear pageStack
    while self.pageStack[1] do
        self:back()
    end

    self:navigate(page)
end

---Navigate to the previous page
function PageView:back()
    if not self.pageStack[1] then
        game.Log("PageView:back() : pageStack empty, cannot go back", game.LOGGER_WARNING)
        return
    end

    self.pageStack[1].viewHandler = nil
    popStack(self.pageStack)
end

function PageView:render(deltaTime)
    if not self.pageStack[1] then
        -- pageStack empty, cannot render, but do not error out, also do not log every frame
        return
    else
        self.pageStack[1]:render(deltaTime)
    end
end

return PageView