[Help] dx calculation

[Snow-Man]

Hello everybody,

i have started on new script but faced some troubles on showing data through index of the tables, didnt know the right calculation for that and trying to make it only shows 8 data at once here part of my code where i found ther problem on it

 

if i ~= index then
            dxDrawBorderedText(1," "..skinTable[index].name.."  "..skinTable[index].price.." $", (985/x)*sx, ((356*y)/sy)*((index*52)/#skinTable), (1258/x)*sx, (646*y)/sy, tocolor(255, 255, 255, 255), 1.00, "bankgothic", "left", "top", false, false, false, false, false)
        else
            iprint(((356*y)/sy)*((index*30)/#skinTable))
            dxDrawBorderedText(1," "..skinTable[index].name.."  "..skinTable[index].price.." $", (985/x)*sx,  ((356*y)/sy)*((index*52)/#skinTable), (1258/x)*sx, (646*y)/sy, tocolor(255, 255, 0, 255), 1.2, "bankgothic", "left", "top", false, false, false, false, false)
        end

explaining some variables 

i = 1

index starts from 1 and follow i but that works fine

and #skinTable, the result for that is 385 its a long table 

this is the result of my code https://imgur.com/Ly2OqZW

and what i expected to have https://imgur.com/yFAw6or

Edited September 24, 2022 by Snow-Man

[Tails]

Hi Snow-Man,

 

Just do something like this:

local startIndex = 1
local maxShownItems = 3

addEventHandler('onClientRender', root, function()
    for i=startIndex, startIndex+maxShownItems do
        local y = (i-startIndex)*20
        dxDrawText(skinTable[i].name, 0, y, 100, 100)
    end
end)

And then add or subtract 1 to the startIndex on a key press

addEventHandler('onClientKey', root, function(key, p)
    if key == 'arrow_u' and p then
        if startIndex > 1 then
            startIndex = startIndex - 1
        end
    elseif key == 'arrow_d' and p then
        if startIndex+maxShownItems < #skinTable then
            startIndex = startIndex + 1
        end
    end
end)

Hope this helps.

[Snow-Man]

Thank you it's works but had another problem it doesn't select last 8 data from the table

It selects only lower than #skinTable-maxShownItem

In my case local maxShownItem = 8

[Tails]

Maybe use + in your calculation instead. Or paste your loop here so we can look at it.

[Snow-Man]

I have changed from the code that you already posted to

local maxShownItem = 8

And table contains almost 385 data 

 

 

 

[Snow-Man]

this is the part of the loop

and now i have an error when i reach the end of the table

this error attempt to index field "?" (a nil value )

exactly the error comes from "i" this one -> for i=startIndex, startIndex+maxShownItems do

 

local startIndex = 1
local maxShownItems = 8
addEventHandler("onClientRender", root,
    function()
    for i=startIndex, startIndex+maxShownItems do
        local xy = (i-startIndex)*29
            if i ~= startIndex then
                dxDrawBorderedText(1,(" "..skinTable[i].name.."  "..skinTable[i].price.."$"), (985/x)*sx, (sy*0.40)+xy, (1258/x)*sx, (646*y)/sy, tocolor(255, 255, 255, 255), scale, "bankgothic", "left", "top", false, false, false, false, false)
            else
               
               dxDrawBorderedText(1,(" "..skinTable[i].name.."  "..skinTable[i].price.."$"), (985/x)*sx,  (sy*0.40)+xy, (1258/x)*sx, (646*y)/sy, tocolor(255, 255, 0, 255), scale, "bankgothic", "left", "top", false, false, false, false, false)
            end
        end
end
)

i have changed this part and it works better and having the result what i wanted for 

addEventHandler( "onClientKey", root, function(b, state)
    if b and validKeys[b] then
        if b == "arrow_u" and state then
            if startIndex-1 > 0 then
                startIndex = startIndex - 1
            else
                startIndex = #skinTable
            end
            playSoundFrontEnd(1)
        elseif b == "arrow_d" and state then
            if startIndex+1 <= #skinTable then
                startIndex = startIndex + 1
            else
                startIndex = 1
            end
            playSoundFrontEnd(1)
        end
    end
end
)

[Tails]

I think what you're looking for is a continuous list

addEventHandler( "onClientKey", root, function(b, state)
        if b == "arrow_u" and state then
            table.insert(skinTable, 1, table.remove(skinTable))
            playSoundFrontEnd(1)
        elseif b == "arrow_d" and state then
            table.insert(skinTable, table.remove(skinTable, 1))
            playSoundFrontEnd(1)
        end
end)

 

local x,y = 0, 0
local sx, sy = guiGetScreenSize()


local maxShownItems = 7
local selectedItem = 4 --use middle item as the current selected item

addEventHandler("onClientRender", root, function()
    for i=1, maxShownItems do
        local xy = (i)*55

        -- draw rectangle behind text
        dxDrawRectangle(x, y+xy, 200, 50, tocolor(0, 0, 0, 125))

        if i == 4 then
            -- selected item
            dxDrawRectangle(x, y+xy, 200, 50, tocolor(255, 0, 0, 125))
            dxDrawText(" "..skinTable[i].name.."  "..skinTable[i].price.."$", x, y+xy, x+200, y+xy+50, tocolor(255, 255, 255, 255), 1.5, 'default', 'center', 'center', false, false, true, true)
        else
            -- the other items
            dxDrawText(" "..skinTable[i].name.."  "..skinTable[i].price.."$", x, y+xy, x+200, y+xy+50, tocolor(255, 255, 255, 255), 1, 'default', 'center', 'center', false, false, true, true)
        end
    end
end)

This is pretty standard for these types of lists (ignore the styling)

[Snow-Man]

thank you so much for helping, i have changed a lot on the code and mixed between what you write here and my code and works well even selectedItem = 1 

now it works on continuous list

[Tails]

You're welcome!