OnMouseWheel

The mouse wheel turned while the player’s cursor is up.

One call a notch: 1 when the wheel turned away from the player (up), -1 towards them (down), with the pointer’s place in the UI space - for a list or a text that scrolls. The wheel is only observed - it also scrolls a page of the server’s interface under the pointer - unless the script holds the mouse with SetMouseCapture. While the cursor is down the wheel is the game’s and nothing is reported.

Syntax

function OnMouseWheel(delta, x, y)
  -- ...
end

Parameter	Type
delta	number	1 a notch up, -1 a notch down
x	number	the pointer’s place across, in the UI space
y	number	the pointer’s place down, in the UI space

Returns

nothing

Example

local first = 1   -- the first line of a list shown 10 lines at a time
function OnMouseWheel(delta, x, y)
  first = math.max(1, first - delta)
  drawList(first)
end

See also

OnMouseButton · SetMouseCapture · the The game’s UI for a script group of the index