Change legend tick length inheritance (#5652)

* `legend.ticks.length` inherits from `legend.key.size`

* set `legend.ticks.length` defaults in theme

* remove `legend.ticks.length` defaults from guides

Author: teunbrand

R/guide-bins.R

@@ -114,7 +114,6 @@ GuideBins <- ggproto(
     theme = NULL,
     default_axis = element_line("black", linewidth = (0.5 / .pt)),
     default_ticks = element_line(inherit.blank = TRUE),
-    default_tick_length = unit(0.2, "npc"),
 
     direction = NULL,
     override.aes = list(),
@@ -228,7 +227,6 @@ GuideBins <- ggproto(
     theme <- replace_null(
       theme,
       legend.text.position = valid_position[1],
-      legend.ticks.length  = params$default_tick_length,
       legend.axis.line     = params$default_axis,
       legend.ticks         = params$default_ticks
     )

R/guide-colorbar.R

@@ -179,7 +179,6 @@ GuideColourbar <- ggproto(
     theme = NULL,
     default_ticks = element_line(colour = "white", linewidth = 0.5 / .pt),
     default_frame = element_blank(),
-    default_tick_length = unit(0.2, "npc"),
 
     # bar
     nbin = 300,
@@ -291,7 +290,6 @@ GuideColourbar <- ggproto(
     theme <- replace_null(
       theme,
       legend.text.position = valid_position[1],
-      legend.ticks.length  = params$default_tick_length,
       legend.ticks         = params$default_ticks,
       legend.frame         = params$default_frame
     )

R/theme-defaults.R

@@ -179,6 +179,7 @@ theme_grey <- function(base_size = 11, base_family = "",
     legend.key.spacing = unit(half_line, "pt"),
     legend.text =        element_text(size = rel(0.8)),
     legend.title =       element_text(hjust = 0),
+    legend.ticks.length = rel(0.2),
     legend.position =    "right",
     legend.direction =   NULL,
     legend.justification = "center",
@@ -476,6 +477,7 @@ theme_void <- function(base_size = 11, base_family = "",
     legend.text =        element_text(size = rel(0.8)),
     legend.title =       element_text(hjust = 0),
     legend.key.spacing = unit(half_line, "pt"),
+    legend.ticks.length = rel(0.2),
     strip.clip =         "inherit",
     strip.text =         element_text(size = rel(0.8)),
     strip.switch.pad.grid = unit(half_line / 2, "pt"),
@@ -586,6 +588,7 @@ theme_test <- function(base_size = 11, base_family = "",
     legend.key.spacing.y = NULL,
     legend.text =        element_text(size = rel(0.8)),
     legend.title =       element_text(hjust = 0),
+    legend.ticks.length = rel(0.2),
     legend.position =    "right",
     legend.direction =   NULL,
     legend.justification = "center",

R/theme-elements.R

@@ -506,7 +506,7 @@ el_def <- function(class = NULL, inherit = NULL, description = NULL) {
   legend.frame        = el_def("element_rect", "rect"),
   legend.axis.line    = el_def("element_line", "line"),
   legend.ticks        = el_def("element_line", "legend.axis.line"),
-  legend.ticks.length = el_def("unit"),
+  legend.ticks.length = el_def(c("rel", "unit"), "legend.key.size"),
   legend.text         = el_def("element_text", "text"),
   legend.text.position = el_def("character"),
   legend.title        = el_def("element_text", "title"),