Skip to content

Refactor draw_legend() #463

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
vincentarelbundock merged 7 commits into from
Sep 9, 2025
Merged

Refactor draw_legend() #463

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
6807dbd
swap utility
vincentarelbundock Sep 8, 2025
6fdd941
Merge branch 'main' into tinyplot_main_refactor
vincentarelbundock Sep 8, 2025
559fa64
restore_margin_inner()
vincentarelbundock Sep 8, 2025
012f6ec
compute_legend_args()
vincentarelbundock Sep 8, 2025
20a1ad9
more compute_legend_args()
vincentarelbundock Sep 8, 2025
c961d5c
hardcoded variables
vincentarelbundock Sep 8, 2025
50d6008
style: <- vs =
vincentarelbundock Sep 9, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
182 changes: 36 additions & 146 deletions R/draw_legend.R
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -129,119 +129,47 @@ draw_legend = function(

#
## legend args ----

legend_args = sanitize_legend(legend, legend_args)

## Use `!exists` rather than `is.null` for title in case user specified no title
if (!exists("title", where = legend_args)) legend_args[["title"]] = by_dep

legend_args[["pch"]] = legend_args[["pch"]] %||% pch
legend_args[["lty"]] = legend_args[["lty"]] %||% lty
legend_args[["col"]] = legend_args[["col"]] %||% col
legend_args[["bty"]] = legend_args[["bty"]] %||% "n"
legend_args[["horiz"]] = legend_args[["horiz"]] %||% FALSE
legend_args[["xpd"]] = legend_args[["xpd"]] %||% NA

if (!isTRUE(type %in% c("p", "ribbon", "polygon", "polypath"))) {
legend_args[["lwd"]] = legend_args[["lwd"]] %||% lwd
}

if (is.null(type) || type %in% c("p", "pointrange", "errorbar", "text")) {
legend_args[["pt.cex"]] = legend_args[["pt.cex"]] %||% (cex %||% par("cex"))
}

# turn off inner line for "barplot" type
if (identical(type, "barplot")) {
legend_args[["lty"]] = 0
}

if (isTRUE(type %in% c("rect", "ribbon", "polygon", "polypath", "boxplot", "hist", "histogram", "spineplot", "ridge", "barplot", "violin")) || gradient) {
legend_args[["pch"]] = 22
legend_args[["pt.cex"]] = legend_args[["pt.cex"]] %||% 3.5
legend_args[["y.intersp"]] = legend_args[["y.intersp"]] %||% 1.25
legend_args[["seg.len"]] = legend_args[["seg.len"]] %||% 1.25
}

if (isTRUE(type %in% c("ribbon", "hist", "histogram", "spineplot"))) {
legend_args[["pt.lwd"]] = legend_args[["pt.lwd"]] %||% 0
}

if (identical(type, "p")) {
legend_args[["pt.lwd"]] = legend_args[["pt.lwd"]] %||% lwd
}

if (identical(type, "n") && isFALSE(gradient)) {
legend_args[["pch"]] = legend_args[["pch"]] %||% par("pch")
}

if (identical(type, "spineplot")) {
legend_args[["pt.bg"]] = legend_args[["pt.bg"]] %||% legend_args[["col"]]
}

if (identical(type, "ridge") && isFALSE(gradient)) {
legend_args[["pt.bg"]] = legend_args[["pt.bg"]] %||% sapply(legend_args[["col"]], function(ccol) seq_palette(ccol, n = 2)[2])
}

legend_args[["pt.bg"]] = legend_args[["pt.bg"]] %||% bg

legend_args[["legend"]] = legend_args[["legend"]] %||% lgnd_labs
if (length(lgnd_labs) != length(eval(legend_args[["legend"]]))) {
warning(
"\nUser-supplied legend labels do not match the number of groups.\n",
"Defaulting to automatic labels determined by the group splits in `by`,\n"
)
legend_args[["legend"]] = lgnd_labs
}

if (isTRUE(gradient)) {
legend_args[["ncol"]] = NULL
}
# flag for multicolumn legend
mcol_flag = !is.null(legend_args[["ncol"]]) && legend_args[["ncol"]] > 1

# flag for (extra) user inset (also used for dual legends)
user_inset = !is.null(legend_args[["inset"]])

outer_side = outer_end = outer_right = outer_bottom = FALSE
list2env(
compute_legend_args(
legend = legend,
legend_args = legend_args,
by_dep = by_dep,
lgnd_labs = lgnd_labs,
type = type,
pch = pch,
lty = lty,
lwd = lwd,
col = col,
bg = bg,
cex = cex,
gradient = gradient
),
environment()
)

#
## legend placement ----

# Note: "side" = left/right ; "end" = top/bottom
outer_side = outer_end = outer_right = outer_bottom = FALSE ## placeholders

ooma = par("oma")
omar = par("mar")
topmar_epsilon = 0.1

# Catch to avoid recursive offsets, e.g. repeated tinyplot calls with
# "bottom!" legend position.

## restore inner margin defaults
## (in case the plot region/margins were affected by the preceding tinyplot call)
dynmar = isTRUE(.tpar[["dynmar"]])
if (any(ooma != 0) && !dynmar) {
if ( ooma[1] != 0 & omar[1] == par("mgp")[1] + 1*par("cex.lab") ) omar[1] = 5.1
if ( ooma[2] != 0 & omar[2] == par("mgp")[1] + 1*par("cex.lab") ) omar[2] = 4.1
if ( ooma[3] == topmar_epsilon & omar[3] != 4.1 ) omar[3] = 4.1
if ( ooma[4] != 0 & omar[4] == 0 ) omar[4] = 2.1
par(mar = omar)
}
## restore outer margin defaults
par(omd = c(0,1,0,1))

# flag for (extra) user inset (also used for dual legends)
user_inset = !is.null(legend_args[["inset"]])

## restore margin defaults
## (in case the plot region/margins were affected by the preceding tinyplot call)
topmar_epsilon = 0.1
restore_margin_outer()
if (!dynmar) restore_margin_inner(ooma, topmar_epsilon = topmar_epsilon)

ooma = par("oma")
omar = par("mar")

## Legend to outer side (either right or left) of plot
if (grepl("right!$|left!$", legend_args[["x"]])) {

outer_side = TRUE
outer_right = grepl("right!$", legend_args[["x"]])

if (outer_side) {
# extra bump for spineplot if outer_right legend (to accommodate secondary y-axis)
if (identical(type, "spineplot")) lmar[1] = lmar[1] + 1.1

## Switch position anchor (we'll adjust relative to the _opposite_ side below)
if (outer_right) legend_args[["x"]] = gsub("right!$", "left", legend_args[["x"]])
if (!outer_right) legend_args[["x"]] = gsub("left!$", "right", legend_args[["x"]])

## We have to set the inner margins of the plot before the (fake) legend is
## drawn, otherwise the inset calculation---which is based in the legend
## width---will be off the first time.
Expand Down Expand Up @@ -271,24 +199,17 @@ draw_legend = function(
}
}

legend_args[["horiz"]] = FALSE

## Legend at the outer top or bottom of plot
} else if (grepl("bottom!$|top!$", legend_args[["x"]])) {

outer_end = TRUE
outer_bottom = grepl("bottom!$", legend_args[["x"]])

## Switch position anchor (we'll adjust relative to the _opposite_ side below)
if (outer_bottom) legend_args[["x"]] = gsub("bottom!$", "top", legend_args[["x"]])
if (!outer_bottom) legend_args[["x"]] = gsub("top!$", "bottom", legend_args[["x"]])
} else if (outer_end) {

## We have to set the inner margins of the plot before the (fake) legend is
## drawn, otherwise the inset calculation---which is based in the legend
## width---will be off the first time.
if (outer_bottom) {
omar[1] = par("mgp")[1] + 1*par("cex.lab")
if (has_sub && (is.null(.tpar[["side.sub"]]) || .tpar[["side.sub"]]==1)) omar[1] = omar[1] + 1*par("cex.sub")
if (has_sub && (is.null(.tpar[["side.sub"]]) || .tpar[["side.sub"]]==1)) {
omar[1] = omar[1] + 1*par("cex.sub")
}
} else {
## For "top!", the logic is slightly different: We don't expand the outer
## margin b/c we need the legend to come underneath the main title. So
Expand Down Expand Up @@ -318,42 +239,11 @@ draw_legend = function(
}
}

# enforce horizontal legend if user hasn't specified ncol arg
# (exception: gradient legends at bottom/top are always horizontal)
if (is.null(legend_args[["ncol"]]) || gradient) legend_args[["horiz"]] = TRUE

} else {

legend_args[["inset"]] = 0
# if (new_plot && draw) plot.new()
if (new_plot) plot.new()

}

# Additional tweaks for horiz and/or multi-column legends
if (isTRUE(legend_args[["horiz"]]) || mcol_flag) {
# tighter horizontal labelling
# See: https://github.com/grantmcdermott/tinyplot/issues/434
if (!gradient) {
legend_args[["text.width"]] = NA
# Add a space to all labs except the outer most right ones
nlabs = length(legend_args[["legend"]])
nidx = nlabs
if (mcol_flag) nidx = tail(1:nlabs, (nlabs %/% legend_args[["ncol"]]))
legend_args[["legend"]][-nidx] = paste(legend_args[["legend"]][-nidx], " ")
}
# catch for horizontal ribbon legend spacing
if (type=="ribbon") {
if (legend_args[["pt.lwd"]] == 1) {
legend_args[["x.intersp"]] = 1
} else {
legend_args[["x.intersp"]] = 0.5
}
} else if (gradient) {
legend_args[["x.intersp"]] = 0.5
}
}

#
## draw the legend ----
# Legend drawing is handled by the internal `tinylegend()` function, which:
Expand Down Expand Up @@ -736,4 +626,4 @@ sanitize_legend = function(legend, legend_args) {
}
}
return(legend_args)
}
}
Loading