I have a map with four layers, and I want to have one legend for all the layers. If I add a legend to each layer, then when all four layers are visible, there will be four of the same legend. And if I add a legend to only one layer, say layer 1, then when layer 1 is hidden, so is the legend. Is it possible to create a legend associate with layer 1 and have it visible in other layers even if layer 1 is hidden?
Why not make a legend on a 5th layer called 'legend' that contained no data? That way the user would be able to leave the legend on with any combination (or actually toggle it of just like another layer!).