Each Geom has an associated function that draws the key when the geom needs to be displayed in a legend. These are the options built into ggplot2.
draw_key_crosshair_tern(data, params, size)draw_key_Tmark(data, params, size)
draw_key_Lmark(data, params, size)
draw_key_Rmark(data, params, size)
draw_key_Tline(data, params, size)
draw_key_Lline(data, params, size)
draw_key_Rline(data, params, size)
draw_key_Tiso(data, params, size)
draw_key_Liso(data, params, size)
draw_key_Riso(data, params, size)
draw_key_point_swap(data, params, size)
A grid grob.
A single row data frame containing the scaled aesthetics to display in this key
A list of additional parameters supplied to the geom.
Width and height of key in mm.
Nicholas Hamilton