R/viewscales.R

In teunbrand/ggvctrcoords: Coordinates and scales for ggplot2 using the vctrs package

# This is just a near-copy of the ggplot one except it calls
# expand_limits_scale_vctr instead of expand_limits_scale
view_scales_from_scale_vctr <- function(scale, coord_limits = NULL,
                                        expand = TRUE) {
  if (!inherits(scale, "ScaleContinuousVctr")) {
    .int$view_scales_from_scale(scale, coord_limits = coord_limits,
                                     expand = expand)
  } else {
    expansion <- .int$default_expansion(scale, expand = expand)
    limits <- scale$get_limits()
    newrange <- expand_limits_scale_vctr(scale, expansion, limits,
                                         coord_limits = coord_limits)
    aesthetic <- scale$aesthetics[1]

    view_scales <- list(
      .int$view_scale_primary(scale, limits, newrange),
      sec = .int$view_scale_secondary(scale, limits, newrange),
      arrange = scale$axis_order(),
      range = newrange
    )
    names(view_scales) <- c(aesthetic, paste0(aesthetic, ".",
                                              names(view_scales)[-1]))
    view_scales
  }
}

# This does a similar job as expand_limits_continuous_trans, but leaves the
# implementation details to the class of the limits.
expand_limits_scale_vctr <- function(scale, expand = expansion(0, 0),
                                     limits = waiver(),
                                     coord_limits = NULL) {
  if (!inherits(scale, "ScaleContinuousVctr")) {
    .int$expand_limits_scale(scale = scale, expand = expand,
                                  limits = limits, coord_limits = coord_limits)
  } else {
    limits <- limits %|W|% scale$get_limits()
    if (is.null(limits)) {
      return()
    }
    if (!(is.numeric(expand) && length(expand) %in% c(2,4))) {
      rlang::abort("`expand` must be a numeric vector with 1 or 2 elements")
    }
    if (length(expand) == 2) {
      expand <- c(expand, expand)
    }
    if (is.null(coord_limits)) {
      coord_limits <- vec_cast(NA, limits)
      coord_limits <- vec_recycle(coord_limits, vec_size(limits))
    }
    vec_expand_limits(limits, expand = expand, coord_limits = coord_limits)
  }
}