How should I scroll the canvas, is there an API to generate a scroll canvas?

[HoChihchou]

I need to make an interface that can scroll up and down

[muescha]

for help you need provide more details - maybe show also your existing code.

[asmagill]

Generally speaking, hs.canvas objects don't scroll. You can mimic something similar programmatically by changing the ___location of objects within the canvas, and objects with positions outside of the canvas's frame (i.e. positions with negative numbers or positions greater than the height/width of the canvas) will "disappear" in the sense that they won't be displayed, but there is no mechanism for doing it automatically -- you have to move them programatically.

If you want a truly scrolling window in the traditional application style, most likely you need to be using hs.webview, which displays web pages (either remote or locally/programmatically generated). Full HTML and Javascript is supported... for the most part if Safari can render it, hs.webview can as well.

But as @muescha says, more details or seeing some of your existing code would help in determining what the best solution might be.