Add plot nchar function

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: aleksandeR
 Title: Aleksander Bang-Larsen's personal convenience functions
-Version: 0.0.0.9002
+Version: 0.0.0.9003
 Date: 2024-11-3
 Authors@R: 
     person("Aleksander", "Bang-Larsen", , "contact@aleksanderbl.dk", role = c("aut", "cre", "cph"),

NAMESPACE

@@ -3,6 +3,7 @@
 export(format_num)
 export(install_basic_packages)
 export(pkg_bib)
+export(plot_nchar)
 export(prepare_classes)
 export(project_init)
 export(theme_map)

R/plot_nchar.R

@@ -0,0 +1,55 @@
+#' Get character count from `ggplot2` object.
+#'
+#' @param plot Input a `ggplot2` object
+#'
+#' @returns Returns a integer with the amount of characters in the plot
+#' @export
+#'
+#' @examples
+#' plot <- data.frame(
+#'   x = seq(1, 10),
+#'   y = seq(10, 1),
+#'   label = rep(seq(1, 10, 2), 2)
+#'   ) |>
+#'   ggplot2::ggplot(ggplot2::aes(x = x, y = y, label = label)) +
+#'   ggplot2::geom_text(nudge_y = 3)
+#'
+#' plot_nchar(plot)
+plot_nchar <- function(plot) {
+  # Extract built plot
+  built_plot <- ggplot2::ggplot_build(plot)
+
+  # Get text from geom_text/geom_label layers
+  text_layers <- lapply(built_plot$data, function(layer) {
+    if("label" %in% names(layer)) {
+      return(layer$label)
+    }
+    NULL
+  }) |> unique()
+
+  text_layers <- unlist(text_layers[!sapply(text_layers, is.null)])
+
+  # Get plot labels (title, axis labels, etc)
+  labels <- plot$labels
+
+  # Get axis text
+  x_text <- built_plot$layout$panel_params[[1]]$x$get_labels()
+  y_text <- built_plot$layout$panel_params[[1]]$y$get_labels()
+
+  # Combine all text elements
+  all_text <- list(
+    geom_text = text_layers,
+    title = labels$title,
+    subtitle = labels$subtitle,
+    x_label = labels$x,
+    y_label = labels$y,
+    caption = labels$caption,
+    x_axis_text = x_text,
+    y_axis_text = y_text
+  ) |>
+    unlist() |>
+    nchar() |>
+    sum(na.rm = TRUE)
+
+  return(all_text)
+}

tests/testthat/test-plot_nchar.R

@@ -0,0 +1,21 @@
+test_that("plot_nchar correctly extracts text", {
+  df_1 <- data.frame(
+    x = seq(20, 11),
+    y = seq(11, 20),
+    label = rep(seq(11, 15), 2)
+  )
+
+  plot <- data.frame(
+    x = seq(1, 10),
+    y = seq(10, 1),
+    label = rep(seq(1, 10, 2), 2)
+  ) |>
+    ggplot2::ggplot(ggplot2::aes(x = x, y = y, label = label)) +
+    ggplot2::geom_point() +
+    ggplot2::geom_line() +
+    ggplot2::geom_text(nudge_y = 3) +
+    ggplot2::geom_text(data = df_1) +
+    ggplot2::annotate("text", x = c(3, 8), y = c(3, 8),
+                      label = c("Hej", "Farvel til dig"))
+  expect_equal(63, plot_nchar(plot))
+})