Is there an easy way to move the legend to the right using ComplexHeatmap, so that it doesn't overlap with the row names? I have read the documentation, but am struggling to find the appropriate argument. The main heatmap code is below, along with a plot example.

annotation_col <- HeatmapAnnotation(
    Timepoint = metadata$timepoint, 
    col = list(Timepoint = time_cols), 
    show_legend = TRUE, 
    show_annotation_name = FALSE, 
    simple_anno_size = unit(4, "mm"), 
    annotation_name_gp = gpar(fontsize = 11))

my_heatmap <- Heatmap(
    my_matrix, 
    col = colorRampPalette(rev(
        RColorBrewer::brewer.pal(n = 7, name = "RdYlBu")))(100), 
    show_column_names = FALSE, 
    top_annotation = annotation_col, 
    row_names_gp = gpar(fontsize = 10, fontface = 1), 
    column_title_gp = gpar(fontsize = 14), 
    heatmap_legend_param = list(
        title = "Activity", 
        title_gp = gpar(fontsize = 11), 
        labels_gp = gpar(fontsize = 11)),  
    split = 3, 
    row_title = NULL)

There is a default "maximal length of row names". You can set the argument row_names_max_width to a larger value:

Heatmap(..., row_names_max_width = unit(10, "cm"))

If you want to set such max width programmatically, you can do

max_width = grobWidth(textGrob(rownames(my_matrix), gpar(fontsize = 10, fontface = 1)))

You can also explicitly convert it to mm or inche since the current max_width object might be large.

max_width = convertWidth(max_width, "mm")

then

Heatmap(..., row_names_max_width = max_width)

There is an argument to specify which side to put the legend on.