Internal function.
.identifyGrobToPlot(toPlot, sGrob, takeFromPlotObj)# S4 method for ANY,.quickPlotGrob
.identifyGrobToPlot(toPlot, sGrob, takeFromPlotObj)
The object to plot. Should be a single layer if from a multi-layer
object such as a RasterStack.
quickPlot grob object
Logical. Should the data come from the argument passed
into Plot (TRUE), or from the (.quickPlotEnv) (FALSE).
Eliot McIntire
Because the Plot function can use the global environment as a source of
objects to plot, not just the call itself, this function identifies where the
data for the grob should come from, the current call or the global environment.