add line numbers (#109)

* add line numbers

add command to change line numbers displaying

* refactor line numbering code

* add navigating by line numbers

add NumberedExecute trait for Command

* fix line numbering margin bug

* add documentation for numbered commands

2 files changed, 29 insertions, 1 deletions

diff --git a/src/config/general/display_crude.rs b/src/config/general/display_crude.rs
index ba3c307..26473ae 100644
--- a/src/config/general/display_crude.rs
+++ b/src/config/general/display_crude.rs
@@ -3,7 +3,7 @@ use std::convert::From;
 use serde_derive::Deserialize;
 use tui::layout::Constraint;
 
-use crate::config::option::DisplayOption;
+use crate::config::option::{DisplayOption, LineNumberStyle};
 
 use super::sort_crude::SortOptionCrude;
 
@@ -50,6 +50,9 @@ pub struct DisplayOptionCrude {
 
     #[serde(default, rename = "sort")]
     pub sort_options: SortOptionCrude,
+
+    #[serde(default)]
+    pub line_number_style: String,
 }
 
 impl std::default::Default for DisplayOptionCrude {
@@ -65,6 +68,7 @@ impl std::default::Default for DisplayOptionCrude {
             show_preview: true,
             sort_options: SortOptionCrude::default(),
             tilde_in_titlebar: true,
+            line_number_style: "none".to_string(),
         }
     }
 }
@@ -89,6 +93,12 @@ impl From<DisplayOptionCrude> for DisplayOption {
             Constraint::Ratio(0, total),
         ];
 
+        let _line_nums = match crude.line_number_style.as_ref() {
+            "absolute" => LineNumberStyle::Absolute,
+            "relative" => LineNumberStyle::Relative,
+            _ => LineNumberStyle::None,
+        };
+
         Self {
             _automatically_count_files: crude.automatically_count_files,
             _collapse_preview: crude.collapse_preview,
@@ -99,6 +109,7 @@ impl From<DisplayOptionCrude> for DisplayOption {
             _show_preview: crude.show_preview,
             _sort_options: crude.sort_options.into(),
             _tilde_in_titlebar: crude.tilde_in_titlebar,
+            _line_nums,
 
             column_ratio,
             default_layout,
diff --git a/src/config/option/display_option.rs b/src/config/option/display_option.rs
index 304ddf7..6454a1b 100644
--- a/src/config/option/display_option.rs
+++ b/src/config/option/display_option.rs
@@ -19,11 +19,19 @@ pub struct DisplayOption {
     pub _show_preview: bool,
     pub _sort_options: SortOption,
     pub _tilde_in_titlebar: bool,
+    pub _line_nums: LineNumberStyle,
     pub column_ratio: (usize, usize, usize),
     pub default_layout: [Constraint; 3],
     pub no_preview_layout: [Constraint; 3],
 }
 
+#[derive(Clone, Copy, Debug)]
+pub enum LineNumberStyle {
+    None,
+    Relative,
+    Absolute,
+}
+
 impl DisplayOption {
     pub fn automatically_count_files(&self) -> bool {
         self._automatically_count_files
@@ -69,6 +77,14 @@ impl DisplayOption {
         self._tilde_in_titlebar
     }
 
+    pub fn line_nums(&self) -> LineNumberStyle {
+        self._line_nums
+    }
+
+    pub fn set_line_nums(&mut self, style: LineNumberStyle) {
+        self._line_nums = style;
+    }
+
     pub fn filter_func(&self) -> fn(&Result<fs::DirEntry, std::io::Error>) -> bool {
         if self.show_hidden() {
             no_filter
@@ -105,6 +121,7 @@ impl std::default::Default for DisplayOption {
             _show_preview: true,
             _sort_options: SortOption::default(),
             _tilde_in_titlebar: true,
+            _line_nums: LineNumberStyle::None,
             default_layout,
             no_preview_layout,
         }