Added --theme option to select icon theme

Possible values are `default` and `unicode`.

src/app.rs

@@ -32,6 +32,15 @@ pub fn build() -> App<'static, 'static> {
                 .multiple(true)
                 .help("When to print the icons"),
         )
+        .arg(
+            Arg::with_name("theme")
+                .long("theme")
+                .possible_value("default")
+                .possible_value("unicode")
+                .default_value("default")
+                .multiple(true)
+                .help("Whether to use extended or unicode icons"),
+        )
         .arg(
             Arg::with_name("indicators")
                 .short("F")

src/core.rs

@@ -1,7 +1,7 @@
 use batch::Batch;
 use color::{self, Colors};
 use display::Display;
-use flags::{Flags, WhenFlag};
+use flags::{Flags, ThemeFlag, WhenFlag};
 use icon::{self, Icons};
 use meta::{FileType, Meta};
 use std::path::{Path, PathBuf};
@@ -28,12 +28,10 @@ impl Core {
             _ => color::Theme::Default,
         };
 
-        let icon_theme = match (tty_available, flags.icon) {
-            (true, WhenFlag::Never) => icon::Theme::NoIcon,
-            (false, WhenFlag::Never) => icon::Theme::NoIcon,
-            (false, WhenFlag::Auto) => icon::Theme::NoIcon,
-            (false, WhenFlag::Always) => icon::Theme::Default,
-            _ => icon::Theme::Default,
+        let icon_theme = match (tty_available, flags.icon, flags.icon_theme) {
+            (_, WhenFlag::Never, _) | (false, WhenFlag::Auto, _) => icon::Theme::NoIcon,
+            (_, _, ThemeFlag::Default) => icon::Theme::Default,
+            (_, _, ThemeFlag::Unicode) => icon::Theme::Unicode,
         };
 
         if !tty_available {

src/flags.rs

@@ -14,6 +14,7 @@ pub struct Flags {
     pub date: DateFlag,
     pub color: WhenFlag,
     pub icon: WhenFlag,
+    pub icon_theme: ThemeFlag,
     pub recursion_depth: usize,
 }
 
@@ -21,6 +22,7 @@ impl Flags {
     pub fn from_matches(matches: &ArgMatches) -> Result<Self, Error> {
         let color_inputs: Vec<&str> = matches.values_of("color").unwrap().collect();
         let icon_inputs: Vec<&str> = matches.values_of("icon").unwrap().collect();
+        let icon_theme_inputs: Vec<&str> = matches.values_of("theme").unwrap().collect();
         let date_inputs: Vec<&str> = matches.values_of("date").unwrap().collect();
         let dir_order_inputs: Vec<&str> = matches.values_of("group-dirs").unwrap().collect();
 
@@ -70,6 +72,7 @@ impl Flags {
             date: DateFlag::from(date_inputs[date_inputs.len() - 1]),
             color: WhenFlag::from(color_inputs[color_inputs.len() - 1]),
             icon: WhenFlag::from(icon_inputs[icon_inputs.len() - 1]),
+            icon_theme: ThemeFlag::from(icon_theme_inputs[icon_inputs.len() - 1]),
             directory_order: DirOrderFlag::from(dir_order_inputs[dir_order_inputs.len() - 1]),
         })
     }
@@ -91,6 +94,7 @@ impl Default for Flags {
             date: DateFlag::Date,
             color: WhenFlag::Auto,
             icon: WhenFlag::Auto,
+            icon_theme: ThemeFlag::Default,
         }
     }
 }
@@ -159,6 +163,22 @@ impl<'a> From<&'a str> for DirOrderFlag {
     }
 }
 
+#[derive(Clone, Debug, Copy, PartialEq, Eq)]
+pub enum ThemeFlag {
+    Unicode,
+    Default,
+}
+
+impl<'a> From<&'a str> for ThemeFlag {
+    fn from(theme: &'a str) -> Self {
+        match theme {
+            "default" => ThemeFlag::Default,
+            "unicode" => ThemeFlag::Unicode,
+            _ => panic!("invalid \"theme\" flag: {}", theme),
+        }
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::Flags;

src/icon.rs

@@ -24,7 +24,10 @@ impl Icons {
     pub fn new(theme: Theme) -> Self {
         let display_icons = theme == Theme::Default || theme == Theme::Unicode;
         let (icons_by_name, icons_by_extension) = if theme == Theme::Default {
-            (Self::get_default_icons_by_name(), Self::get_default_icons_by_extension())
+            (
+                Self::get_default_icons_by_name(),
+                Self::get_default_icons_by_extension(),
+            )
         } else {
             (HashMap::new(), HashMap::new())
         };

src/main.rs

@@ -1,9 +1,12 @@
-#![cfg_attr(feature = "cargo-clippy", allow(
-    clippy::cast_precision_loss,
-    clippy::cast_sign_loss,
-    clippy::match_same_arms,
-    clippy::cast_possible_wrap
-))]
+#![cfg_attr(
+    feature = "cargo-clippy",
+    allow(
+        clippy::cast_precision_loss,
+        clippy::cast_sign_loss,
+        clippy::match_same_arms,
+        clippy::cast_possible_wrap
+    )
+)]
 
 #[macro_use]
 extern crate clap;