Draw formatted text labels
This grob acts mostly as a drop-in replacement for grid::textGrob()
but provides more sophisticated formatting. The grob can handle basic
markdown and HTML formatting directives, and it can also draw
boxes around each piece of text. Note that this grob does not draw
plotmath expressions.
richtext_grob( text, x = unit(0.5, "npc"), y = unit(0.5, "npc"), hjust = 0.5, vjust = 0.5, halign = hjust, valign = vjust, rot = 0, default.units = "npc", margin = unit(c(0, 0, 0, 0), "pt"), padding = unit(c(0, 0, 0, 0), "pt"), r = unit(0, "pt"), align_widths = FALSE, align_heights = FALSE, name = NULL, gp = gpar(), box_gp = gpar(col = NA), vp = NULL, use_markdown = TRUE, debug = FALSE )
text |
Character vector containing Markdown/HTML strings to draw. |
x, y |
Unit objects specifying the location of the reference point. |
hjust, vjust |
Numerical values specifying the justification
of the text boxes relative to |
halign, valign |
Numerical values specifying the text justification
inside the text boxes. If not specified, these default to |
rot |
Angle of rotation for text, in degrees. |
default.units |
Units of |
margin, padding |
Unit vectors of four elements each indicating the margin and padding around each text label in the order top, right, bottom, left. Margins are drawn outside the enclosing box (if any), and padding is drawn inside. To avoid rendering artifacts, it is best to specify these values in absolute units (such as points, mm, or inch) rather than in relative units (such as npc). |
r |
The radius of the rounded corners. To avoid rendering artifacts, it is best to specify this in absolute units (such as points, mm, or inch) rather than in relative units (such as npc). |
align_widths, align_heights |
Should the widths and heights of all the text boxes be aligned? Default is no. |
name |
Name of the grob. |
gp |
Other graphical parameters for drawing. |
box_gp |
Graphical parameters for the enclosing box around each text label. |
vp |
Viewport. |
use_markdown |
Should the |
debug |
Should debugging info be drawn? Default is no. |
A grid grob that represents the formatted text.
library(grid)
text <- c(
"Some text **in bold.**", "Linebreaks<br>Linebreaks<br>Linebreaks",
"*x*<sup>2</sup> + 5*x* + *C*<sub>*i*</sub>",
"Some <span style='color:blue'>blue text **in bold.**</span><br>And *italics text.*<br>
And some <span style='font-size:18pt; color:black'>large</span> text."
)
x <- c(.2, .1, .7, .9)
y <- c(.8, .4, .1, .5)
rot <- c(0, 0, 45, -45)
gp = gpar(col = c("black", "red"), fontfamily = c("Palatino", "Courier", "Times", "Helvetica"))
box_gp = gpar(col = "black", fill = c("cornsilk", NA, "lightblue1", NA), lty = c(0, 1, 1, 1))
hjust <- c(0.5, 0, 0, 1)
vjust <- c(0.5, 1, 0, 0.5)
g <- richtext_grob(
text, x, y, hjust = hjust, vjust = vjust, rot = rot,
padding = unit(c(6, 6, 4, 6), "pt"),
r = unit(c(0, 2, 4, 8), "pt"),
gp = gp, box_gp = box_gp
)
grid.newpage()
grid.draw(g)
grid.points(x, y, default.units = "npc", pch = 19, size = unit(5, "pt"))
# multiple text labels with aligned boxes
text <- c("January", "February", "March", "April", "May")
x <- (1:5)/6 + 1/24
y <- rep(0.8, 5)
g <- richtext_grob(
text, x, y, halign = 0, hjust = 1,
rot = 45,
padding = unit(c(3, 6, 1, 3), "pt"),
r = unit(4, "pt"),
align_widths = TRUE,
box_gp = gpar(col = "black", fill = "cornsilk")
)
grid.newpage()
grid.draw(g)
grid.points(x, y, default.units = "npc", pch = 19, size = unit(5, "pt"))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.