graphlog: load settings by caller

I'll make it error out if the style name is invalid.

cli/src/commands/evolog.rs

@@ -32,6 +32,7 @@ use crate::diff_util::DiffRenderer;
 use crate::formatter::Formatter;
 use crate::graphlog::get_graphlog;
 use crate::graphlog::Edge;
+use crate::graphlog::GraphStyle;
 use crate::ui::Ui;
 
 /// Show how a change has evolved over time
@@ -143,7 +144,8 @@ pub(crate) fn cmd_evolog(
         commits.truncate(n);
     }
     if !args.no_graph {
-        let mut graph = get_graphlog(command.settings(), formatter.raw());
+        let graph_style = GraphStyle::from_settings(command.settings());
+        let mut graph = get_graphlog(graph_style, formatter.raw());
         for commit in commits {
             let mut edges = vec![];
             for predecessor in commit.predecessors() {

cli/src/commands/log.rs

@@ -33,6 +33,7 @@ use crate::diff_util::DiffFormatArgs;
 use crate::graphlog::get_graphlog;
 use crate::graphlog::node_template_for_key;
 use crate::graphlog::Edge;
+use crate::graphlog::GraphStyle;
 use crate::ui::Ui;
 
 /// Show revision history
@@ -164,7 +165,8 @@ pub(crate) fn cmd_log(
         let limit = args.limit.or(args.deprecated_limit).unwrap_or(usize::MAX);
 
         if !args.no_graph {
-            let mut graph = get_graphlog(command.settings(), formatter.raw());
+            let graph_style = GraphStyle::from_settings(command.settings());
+            let mut graph = get_graphlog(graph_style, formatter.raw());
             let forward_iter = TopoGroupedGraphIterator::new(revset.iter_graph());
             let iter: Box<dyn Iterator<Item = _>> = if args.reversed {
                 Box::new(ReverseGraphIterator::new(forward_iter))

cli/src/commands/operation/diff.rs

@@ -47,6 +47,7 @@ use crate::diff_util::DiffRenderer;
 use crate::formatter::Formatter;
 use crate::graphlog::get_graphlog;
 use crate::graphlog::Edge;
+use crate::graphlog::GraphStyle;
 use crate::templater::TemplateRenderer;
 use crate::ui::Ui;
 
@@ -216,7 +217,8 @@ pub fn show_op_diff(
         writeln!(formatter)?;
         writeln!(formatter, "Changed commits:")?;
         if show_graph {
-            let mut graph = get_graphlog(command.settings(), formatter.raw());
+            let graph_style = GraphStyle::from_settings(command.settings());
+            let mut graph = get_graphlog(graph_style, formatter.raw());
 
             let graph_iter =
                 TopoGroupedGraphIterator::new(ordered_change_ids.iter().map(|change_id| {

cli/src/commands/operation/log.rs

@@ -24,6 +24,7 @@ use crate::command_error::CommandError;
 use crate::graphlog::get_graphlog;
 use crate::graphlog::node_template_for_key;
 use crate::graphlog::Edge;
+use crate::graphlog::GraphStyle;
 use crate::operation_templater::OperationTemplateLanguage;
 use crate::ui::Ui;
 
@@ -116,7 +117,8 @@ pub fn cmd_op_log(
     let limit = args.limit.or(args.deprecated_limit).unwrap_or(usize::MAX);
     let iter = op_walk::walk_ancestors(slice::from_ref(&current_op)).take(limit);
     if !args.no_graph {
-        let mut graph = get_graphlog(command.settings(), formatter.raw());
+        let graph_style = GraphStyle::from_settings(command.settings());
+        let mut graph = get_graphlog(graph_style, formatter.raw());
         for op in iter {
             let op = op?;
             let mut edges = vec![];

cli/src/graphlog.rs

@@ -142,11 +142,11 @@ pub fn node_template_for_key(
 }
 
 pub fn get_graphlog<'a, K: Clone + Eq + Hash + 'a>(
-    settings: &UserSettings,
+    style: GraphStyle,
     formatter: &'a mut dyn Write,
 ) -> Box<dyn GraphLog<K> + 'a> {
     let builder = GraphRowRenderer::new().output().with_min_row_height(0);
-    match GraphStyle::from_settings(settings) {
+    match style {
         GraphStyle::Ascii => SaplingGraphLog::create(builder.build_ascii(), formatter),
         GraphStyle::AsciiLarge => SaplingGraphLog::create(builder.build_ascii_large(), formatter),
         GraphStyle::Curved => SaplingGraphLog::create(builder.build_box_drawing(), formatter),