function widget:GetInfo()
  return {
    name      = "attack warning",
    desc      = "warns if stuff gets attacked",
    author    = "knorke",
    date      = "Oct 2011",
    license   = "GNU GPL, v2 or later or horse",
    layer     = 0,
    enabled   = true,
  }
end

local warningDelay = 30 * 5     --in frames
local lastWarning = 0           --in frames
local localTeamID = Spring.GetLocalTeamID ()

function widget:UnitDamaged (unitID, unitDefID, unitTeam, damage, paralyzer, weaponID, attackerID, attackerDefID, attackerTeam)
    local currentFrame = Spring.GetGameFrame ()
    if (lastWarning+warningDelay > currentFrame) then
        return
    end
    if (localTeamID==unitTeam and not Spring.IsUnitInView (unitID)) then
        lastWarning = currentFrame
        local attackedUnit = unitName (unitID) or "Unit"
        Spring.Echo ("-> " .. attackedUnit  .." is being attacked!")
        --Spring.PlaySoundFile (blabla attack.wav, ... "userinterface")
        local x,y,z = Spring.GetUnitPosition (unitID)
        if (x and y and z) then Spring.SetLastMessagePosition (x,y,z) end
    end
end

function unitName (unitID)
    if (not unitID) then return nil end
    local unitDefID = Spring.GetUnitDefID(unitID)
    if (unitDefID) then
        local unitDef = UnitDefs[unitDefID]
        if (unitDef) then
            return unitDef.humanName
        end
    end
    return nil
end

--changing teams, rejoin, becoming spec etc
function widget:PlayerChanged (playerID)
    localTeamID = Spring.GetLocalTeamID ()
end