I am building a grid of geom_treemaps. There are 2 plots, side by side in one row. I want to have the legend (a continuous color gradient) span underneath the length of the entire window. To do this, I am extracting the legend from another geom with get_legend(plot) and drawing it in its own viewport. When I draw the legend, it shows no regard for the constraints of the viewport. I can adjust the legend.key.width parameter in the theme() of the plot I extracted the legend from, but that process is very manual. Is there a way to coerce this legend to fit (specifically lengthwise) into a viewport?
Thank you for any responses.