Calculate density ranges based on treatment name and based on AVICI…

…TCD for density plot (#308)

Fixes insightsengineering/goshawk#192

For proper density calculations, you need to calculate ranges within
groups inside the plot. Groups are created based on treatment variable
and based on AVICITCD plot. So the max ranges need to be calculated in
each group, and the max needs to be extracted.

> Set filters to: ADSL -> SEX -> Male, ADSL -> AGE -> 31.41, 35

# How it looked before

<img width="665" alt="image"
src="https://github.com/user-attachments/assets/344d408e-5357-4ebc-b037-7fa483b0e052">


# How it looks now

<img width="664" alt="image"
src="https://github.com/user-attachments/assets/d84fd7b1-6a06-43f9-8ff4-97310dcc629a">

# Example code

<details><summary> Example from `?tm_g_gh_density_distribution_plot`
</summary>

```r
pkgload::load_all("../teal.widgets")
pkgload::load_all("../teal")
pkgload::load_all(".")

data <- teal_data()
data <- within(data, {
  library(dplyr)
  library(stringr)
  
  # original ARM value = dose value
  arm_mapping <- list(
    "A: Drug X" = "150mg QD",
    "B: Placebo" = "Placebo",
    "C: Combination" = "Combination"
  )
  ADSL <- rADSL
  ADLB <- rADLB
  var_labels <- lapply(ADLB, function(x) attributes(x)$label)
  ADLB <- ADLB %>%
    mutate(
      AVISITCD = case_when(
        AVISIT == "SCREENING" ~ "SCR",
        AVISIT == "BASELINE" ~ "BL",
        grepl("WEEK", AVISIT) ~ paste("W", str_extract(AVISIT, "(?<=(WEEK ))[0-9]+")),
        TRUE ~ as.character(NA)
      ),
      AVISITCDN = case_when(
        AVISITCD == "SCR" ~ -2,
        AVISITCD == "BL" ~ 0,
        grepl("W", AVISITCD) ~ as.numeric(gsub("[^0-9]*", "", AVISITCD)),
        TRUE ~ as.numeric(NA)
      ),
      AVISITCD = factor(AVISITCD) %>% reorder(AVISITCDN),
      TRTORD = case_when(
        ARMCD == "ARM C" ~ 1,
        ARMCD == "ARM B" ~ 2,
        ARMCD == "ARM A" ~ 3
      ),
      ARM = as.character(arm_mapping[match(ARM, names(arm_mapping))]),
      ARM = factor(ARM) %>% reorder(TRTORD),
      ACTARM = as.character(arm_mapping[match(ACTARM, names(arm_mapping))]),
      ACTARM = factor(ACTARM) %>% reorder(TRTORD)
    )
  
  attr(ADLB[["ARM"]], "label") <- var_labels[["ARM"]]
  attr(ADLB[["ACTARM"]], "label") <- var_labels[["ACTARM"]]
})

datanames <- c("ADSL", "ADLB")
datanames(data) <- datanames
join_keys(data) <- default_cdisc_join_keys[datanames]

app <- init(
  data = data,
  modules = modules(
    tm_g_gh_density_distribution_plot(
      label = "Density Distribution Plot",
      dataname = "ADLB",
      param_var = "PARAMCD",
      param = choices_selected(c("ALT", "CRP", "IGA"), "ALT"),
      xaxis_var = choices_selected(c("AVAL", "BASE", "CHG", "PCHG"), "AVAL"),
      trt_group = choices_selected(c("ARM", "ACTARM"), "ARM"),
      color_manual = c(
        "150mg QD" = "#000000",
        "Placebo" = "#3498DB",
        "Combination" = "#E74C3C"
      ),
      color_comb = "#39ff14",
      comb_line = TRUE,
      plot_height = c(500, 200, 2000),
      font_size = c(12, 8, 20),
      line_size = c(1, .25, 3),
      hline_arb = c(.02, .05),
      hline_arb_color = c("red", "black"),
      hline_arb_label = c("Horizontal Line A", "Horizontal Line B")
    )
  )
)
if (interactive()) {
  shinyApp(app$ui, app$server)
}


```


</details>

R/tm_g_gh_density_distribution_plot.R

@@ -300,7 +300,8 @@ srv_g_density_distribution_plot <- function(id, # nolint
       "xaxis_var",
       "xaxis_param",
       anl_q,
-      is_density = TRUE
+      is_density = TRUE,
+      "trt_group"
     )
     keep_data_const_opts_updated(session, input, anl_q, "xaxis_param")
 

R/utils-keep_range_slider_updated.r

@@ -4,7 +4,8 @@ keep_range_slider_updated <- function(session,
                                       id_var,
                                       id_param_var,
                                       reactive_ANL, # nolint
-                                      is_density = FALSE) {
+                                      is_density = FALSE,
+                                      id_trt_group) {
   stopifnot(is.function(update_slider_fcn))
 
   observe({
@@ -25,8 +26,14 @@ keep_range_slider_updated <- function(session,
     step <- NULL
 
     if (isTRUE(is_density)) {
-      minmax <- c(0, round(max(stats::density(stats::na.omit(ANL[[varname]]))$y) * 1.5, 5))
-      step <- round(max(stats::density(stats::na.omit(ANL[[varname]]))$y) / 100, 5)
+      treatname <- input[[id_trt_group]]
+      ANL_split <- ANL %>% split(f = factor(paste0(ANL[["AVISITCD"]], ANL[[treatname]]))) # nolint
+      density_maxes <- lapply(ANL_split, function(x) {
+        max(stats::density(stats::na.omit(x[[varname]]))$y)
+      })
+      dmax <- max(unlist(density_maxes))
+      minmax <- c(0, round(dmax * 1.2, 5))
+      step <- round(dmax / 100, 5)
     }
 
     isolate(update_slider_fcn(