Support top-level las argument

NEWS.md

@@ -163,6 +163,12 @@ related to plot layering. See "Bug fixes" below.
     theme, since the plot margins are resized to fit the rotated labels. Also
     settable globally via `tpar(xaxr = <xaxr>, yaxr = <yaxr>)` and thus as part
     of a `tinytheme` too. (#717 @grantmcdermott)
+  - `las` does the same thing, but limited to the four right angles of base R's
+    `par(las=)` convention, having previously been settable only via `tpar()` or
+    a theme. Note that this top-level argument applies to a single plot only and
+    takes precedence over the active theme, so it can also be used to opt _out_
+    of a theme's `las`, e.g. `tinyplot(..., theme = "clean", las = 0)`.
+    (#353 @grantmcdermott)
   - (Experimental) `record` enables recording plots as replayable objects,
     closing another long-standing feature request (#121). Specifically, setting
     `record = TRUE` returns a `"recordedtinyplot"` object (see

R/sanitize_axes.R

@@ -1,6 +1,7 @@
 sanitize_axes = function(settings) {
   env2env(settings, environment(),
-          c("axes", "xaxt", "yaxt", "frame.plot", "xaxr", "yaxr", "xpad", "ypad"))
+          c("axes", "xaxt", "yaxt", "frame.plot", "xaxr", "yaxr", "xpad", "ypad",
+            "las"))
   ## handle defaults of axes, xaxt, yaxt, frame.plot
   ## - convert axes to character if necessary
   ## - set defaults of xaxt/yaxt (if these are NULL) based on axes
@@ -35,6 +36,16 @@ sanitize_axes = function(settings) {
   if (!is.null(xaxr) && (!is.finite(xaxr) || xaxr %% 360 == 0)) xaxr = NULL
   if (!is.null(yaxr) && (!is.finite(yaxr) || yaxr %% 360 == 0)) yaxr = NULL
 
+  ## tick label orientation. Unlike x/yaxr, not resolved against get_tpar():
+  ## that reads the global .tpar, which lacks the active theme's own las (queued
+  ## in a hook), so folding it in would overwrite a theme's las with 0.
+  ## one membership test, so NA/NaN/Inf and fractions all land on the same
+  ## message rather than tripping over a comparison that returns NA
+  assert_numeric(las, len = 1, null.ok = TRUE, name = "las")
+  if (!is.null(las) && !(las %in% 0:3)) {
+    stop("`las` must be one of 0, 1, 2, or 3", call. = FALSE)
+  }
+
   ## axis padding: an explicit x/ypad wins over the theme's tpar setting. This
   ## has to resolve here, before flip_datapoints() swaps the pair -- resolving
   ## it later would leave a tpar default attached to the axis rather than to
@@ -55,6 +66,6 @@ sanitize_axes = function(settings) {
     environment(),
     settings,
     c("axes", "xaxt", "yaxt", "frame.plot", "xaxr", "yaxr", "xpad", "ypad",
-      "xpad_user", "ypad_user")
+      "xpad_user", "ypad_user", "las")
   )
 }

R/tinyplot.R

@@ -303,6 +303,14 @@
 #'   documentation and examples. Note that this is a post-processing step that
 #'   affects the _appearance_ of the tick labels only; use in conjunction with
 #'   `x/yaxb` if you would like to adjust the position of the tick marks too.
+#' @param las numeric in `0:3` giving the orientation of the axis tick labels,
+#'   following the base \code{\link[graphics]{par}} convention: `0` (parallel
+#'   to the axis), `1` (always horizontal), `2` (perpendicular to the axis), or
+#'   `3` (always vertical). `NULL` (the default) defers to the active theme,
+#'   then to `par("las")`. Passing it here overrides both, but
+#'   only for this plot; unlike `tpar(las=)` or `tinytheme(las=)` it does not
+#'   persist. For rotations other than the four right angles, see `xaxr`/`yaxr`
+#'   below.
 #' @param xaxr,yaxr numeric giving the rotation of the x- or y-axis tick labels,
 #'   in degrees counter-clockwise; `NULL` (the default) leaves them unrotated.
 #'   Setting one overrides `las` for that axis alone, leaving the other axis
@@ -815,6 +823,7 @@ tinyplot.default = function(
     yaxl = NULL,
     xaxr = NULL,
     yaxr = NULL,
+    las = NULL,
     log = "",
     flip = FALSE,
     frame.plot = NULL,
@@ -1009,6 +1018,7 @@ tinyplot.default = function(
     yaxr          = yaxr,
     yaxs          = yaxs,
     ypad          = ypad,
+    las           = las,
     frame.plot    = frame.plot,
     xlim          = xlim,
     ylim          = ylim,
@@ -1235,6 +1245,27 @@ tinyplot.default = function(
 
   env2env(settings, environment())
 
+  #
+  ## per-call tick label orientation -----
+  #
+  # A theme sets its own las at plot.new(), so ours is appended after its hook
+  # (last appended runs last). The direct par() covers add = TRUE, which fires
+  # no plot.new(). Undone on exit, so the override stays per-call. (#353)
+  #
+  if (!is.null(las)) {
+    .las_old = par("las")
+    .las_hook = function() par(las = las)
+    setHook("before.plot.new", .las_hook, action = "append")
+    on.exit({
+      .hks = getHook("before.plot.new")
+      .keep = !vapply(.hks, identical, logical(1), .las_hook)
+      setHook("before.plot.new", .hks[.keep], action = "replace")
+      # par() would *open* a device if none is left (e.g. after `file=`)
+      if (!is.null(dev.list())) par(las = .las_old)
+    }, add = TRUE)
+    par(las = las)
+  }
+
   #
   ## dynmar: compute margins up front -----
   #
@@ -1267,6 +1298,8 @@ tinyplot.default = function(
       .bp = environment(.h)[["base_par"]]
       if (is.list(.bp)) .tpars = modifyList(.tpars, .bp)
     }
+    # runs before plot.new(), so the las hook hasn't fired and par() is stale
+    if (!is.null(las)) .tpars[["las"]] = las
     if (!is.null(.tpars[["mar"]])) .theme_mar = .tpars[["mar"]]
 
     # Tick-label cex is per-side (cex.xaxs/cex.yaxs), each falling back to the

inst/tinytest/test-tinyAxis.R

@@ -46,3 +46,19 @@ f = function() {
   plt(disp ~ mpg, data = mtcars, log = "y")
 }
 expect_silent(f())
+
+
+#
+## las as a per-call argument (#353)
+#
+
+# `las` was accepted by tpar()/tinytheme() but ignored as an argument.
+f = function() tinyplot(1:10, las = 1)
+expect_snapshot_plot(f, label = "axis_las1")
+
+# An explicit `las` must beat a theme's default, but dynmar still has to reserve
+# room for the rotated x labels.
+f = function() {
+  tinyplot(bill_len ~ species, data = penguins, las = 2, theme = "dynamic")
+}
+expect_snapshot_plot(f, label = "axis_las2_override")