ESOUI SVN LibAddonMenu

--[[customData = {
        type = "custom",
        reference = "MyAddonCustomControl",     --(optional) unique name for your control to use as reference
        refreshFunc = function(customControl) end,      --(optional) function to call when panel/controls refresh
        width = "full", --or "half" (optional)
}       ]]

local widgetVersion = 4
local LAM = LibStub("LibAddonMenu-2.0")
if not LAM:RegisterWidget("custom", widgetVersion) then return end

local wm = WINDOW_MANAGER
local tinsert = table.insert

local function UpdateValue(control)
        if control.data.refreshFunc then
                control.data.refreshFunc(control)
        end
end

function LAMCreateControl.custom(parent, customData, controlName)
        local control = wm:CreateTopLevelWindow(controlName or customData.reference)
        control:SetResizeToFitDescendents(true)
        control:SetParent(parent.scroll or parent)
        
        local isHalfWidth = customData.width == "half"
        if isHalfWidth then     --note these restrictions
                control:SetDimensionConstraints(250, 55, 250, 100)
                control:SetDimensions(250, 55)
        else
                control:SetDimensionConstraints(510, 30, 510, 100)
                control:SetDimensions(510, 30)
        end
        
        control.panel = parent.panel or parent  --if this is in a submenu, panel is its parent
        control.data = customData
        
        control.UpdateValue = UpdateValue
        
        if control.panel.data.registerForRefresh or control.panel.data.registerForDefaults then --if our parent window wants to refresh controls, then add this to the list
                tinsert(control.panel.controlsToRefresh, control)
        end
        
        return control
end