Make changing command more discoverable and UI friendly.

README.md

@@ -23,7 +23,7 @@ The default configuration tends to be as minimal as possible, visually speaking,
 
 The initial prompt container will be 80 column wide. You may change this with `--width` in case you need more space (for example, to account for large PAM challenge messages).
 
-You may change the command that will be executed after opening a session by prefixing it with `!` in the username input box, for example `!bash`.
+You may change the command that will be executed after opening a session by huttint `F2` and amending the command.
 
 ## Install
 

src/config.rs

@@ -27,9 +27,11 @@ impl Display for AuthStatus {
 
 impl Error for AuthStatus {}
 
+#[derive(Copy, Clone, PartialEq)]
 pub enum Mode {
   Username,
   Password,
+  Command,
 }
 
 impl Default for Mode {
@@ -43,11 +45,13 @@ pub struct Greeter {
   pub config: Option<Matches>,
   pub stream: Option<UnixStream>,
   pub command: Option<String>,
+  pub previous_mode: Mode,
   pub mode: Mode,
   pub request: Option<Request>,
   pub cursor_offset: i16,
   pub username: String,
   pub answer: String,
+  pub new_command: String,
   pub secret: bool,
   pub prompt: String,
   pub greeting: Option<String>,

src/keyboard.rs

@@ -11,41 +11,51 @@ use crate::{
 pub fn handle(greeter: &mut Greeter, events: &Events) -> Result<(), Box<dyn Error>> {
   if let Event::Input(input) = events.next()? {
     match input {
-      Key::Esc => crate::exit(greeter, AuthStatus::Cancel)?,
+      Key::Esc => {
+        if let Mode::Command = greeter.mode {
+          greeter.mode = greeter.previous_mode;
+        } else {
+          crate::exit(greeter, AuthStatus::Cancel)?;
+        }
+      }
 
       Key::Left => greeter.cursor_offset -= 1,
       Key::Right => greeter.cursor_offset += 1,
 
+      Key::F(2) => {
+        greeter.new_command = greeter.command.clone().unwrap_or_else(String::new);
+        greeter.previous_mode = greeter.mode;
+        greeter.mode = Mode::Command;
+      }
+
       Key::Ctrl('a') => greeter.cursor_offset = -(greeter.username.len() as i16),
       Key::Ctrl('e') => greeter.cursor_offset = 0,
 
-      Key::Char('\n') | Key::Char('\t') => {
+      Key::Char('\n') | Key::Char('\t') => match greeter.mode {
+        Mode::Username => {
           greeter.working = true;
           greeter.message = None;
-
-        match greeter.mode {
-          Mode::Username => {
-            if greeter.username.starts_with('!') {
-              greeter.command = Some(greeter.username.trim_start_matches('!').to_string());
-              greeter.username = String::new();
-              greeter.working = false;
-
-              return Ok(());
-            }
-
           greeter.request = Some(Request::CreateSession { username: greeter.username.clone() });
+          greeter.answer = String::new();
         }
 
         Mode::Password => {
+          greeter.working = true;
+          greeter.message = None;
+
           greeter.request = Some(Request::PostAuthMessageResponse {
             response: Some(greeter.answer.clone()),
-            })
-          }
-        }
+          });
 
           greeter.answer = String::new();
         }
 
+        Mode::Command => {
+          greeter.command = Some(greeter.new_command.clone());
+          greeter.mode = greeter.previous_mode;
+        }
+      },
+
       Key::Char(c) => insert_key(greeter, c),
 
       Key::Backspace | Key::Delete => delete_key(greeter, input),
@@ -61,6 +71,7 @@ fn insert_key(greeter: &mut Greeter, c: char) {
   let value = match greeter.mode {
     Mode::Username => &mut greeter.username,
     Mode::Password => &mut greeter.answer,
+    Mode::Command => &mut greeter.new_command,
   };
 
   let index = value.len() as i16 + greeter.cursor_offset;
@@ -72,6 +83,7 @@ fn delete_key(greeter: &mut Greeter, key: Key) {
   let value = match greeter.mode {
     Mode::Username => &mut greeter.username,
     Mode::Password => &mut greeter.answer,
+    Mode::Command => &mut greeter.new_command,
   };
 
   let index = match key {

src/ui/mod.rs

@@ -18,6 +18,7 @@ use tui::{
 use crate::Greeter;
 
 const EXIT: &str = "Exit";
+const CHANGE_COMMAND: &str = "Change command";
 const COMMAND: &str = "COMMAND";
 
 pub fn draw(terminal: &mut Terminal<TermionBackend<RawTerminal<io::Stdout>>>, greeter: &mut Greeter) -> Result<(), Box<dyn Error>> {
@@ -50,7 +51,14 @@ pub fn draw(terminal: &mut Terminal<TermionBackend<RawTerminal<io::Stdout>>>, gr
     }
 
     let command = greeter.command.clone().unwrap_or_else(|| "-".to_string());
-    let status_text = [status_label("ESC"), status_value(format!(" {} ", EXIT)), status_label(COMMAND), status_value(format!(" {} ", command))];
+    let status_text = [
+      status_label("ESC"),
+      status_value(EXIT),
+      status_label("F2"),
+      status_value(CHANGE_COMMAND),
+      status_label(COMMAND),
+      status_value(command),
+    ];
     let status = Paragraph::new(status_text.iter());
 
     f.render_widget(status, chunks[2]);
@@ -82,5 +90,12 @@ fn status_value<'s, S>(text: S) -> Text<'s>
 where
   S: Into<String>,
 {
-  Text::raw(text.into())
+  Text::raw(format!(" {} ", text.into()))
+}
+
+fn prompt_value<'s, S>(text: S) -> Text<'s>
+where
+  S: Into<String>,
+{
+  Text::styled(text.into(), Style::default().modifier(Modifier::BOLD))
 }

src/ui/prompt.rs

@@ -4,11 +4,11 @@ use termion::raw::RawTerminal;
 use tui::{
   backend::TermionBackend,
   layout::{Alignment, Constraint, Direction, Layout, Rect},
-  style::{Modifier, Style},
   widgets::{Block, BorderType, Borders, Paragraph, Text},
   Frame,
 };
 
+use super::prompt_value;
 use crate::{info::get_hostname, Greeter, Mode};
 
 const PADDING: u16 = 2;
@@ -20,6 +20,7 @@ const MESSAGE_INDEX: usize = 3;
 
 const TITLE: &str = "Authenticate into";
 const USERNAME: &str = "Username:";
+const COMMAND: &str = "New command:";
 const WORKING: &str = "Please wait...";
 
 pub fn draw(greeter: &mut Greeter, f: &mut Frame<TermionBackend<RawTerminal<io::Stdout>>>) -> Result<(u16, u16), Box<dyn Error>> {
@@ -59,26 +60,37 @@ pub fn draw(greeter: &mut Greeter, f: &mut Frame<TermionBackend<RawTerminal<io::
     f.render_widget(greeting_label, chunks[GREETING_INDEX]);
   }
 
-  let username_text = [Text::styled(USERNAME, Style::default().modifier(Modifier::BOLD))];
+  let username_text = [prompt_value(USERNAME)];
   let username_label = Paragraph::new(username_text.iter());
 
   let username_value_text = [Text::raw(&greeter.username)];
   let username_value = Paragraph::new(username_value_text.iter());
 
+  match greeter.mode {
+    Mode::Command => {
+      let command_label_text = [prompt_value(COMMAND)];
+      let command_label = Paragraph::new(command_label_text.iter());
+      let command_value_text = [Text::raw(&greeter.new_command)];
+      let command_value = Paragraph::new(command_value_text.iter());
+
+      f.render_widget(command_label, chunks[USERNAME_INDEX]);
+      f.render_widget(
+        command_value,
+        Rect::new(1 + chunks[USERNAME_INDEX].x + COMMAND.len() as u16, chunks[USERNAME_INDEX].y, get_input_width(greeter, COMMAND), 1),
+      );
+    }
+
+    Mode::Username | Mode::Password => {
       f.render_widget(username_label, chunks[USERNAME_INDEX]);
       f.render_widget(
         username_value,
         Rect::new(1 + chunks[USERNAME_INDEX].x + USERNAME.len() as u16, chunks[USERNAME_INDEX].y, get_input_width(greeter, USERNAME), 1),
       );
 
-  let answer_text = if greeter.working {
-    [Text::raw(WORKING)]
-  } else {
-    [Text::styled(&greeter.prompt, Style::default().modifier(Modifier::BOLD))]
-  };
+      let answer_text = if greeter.working { [Text::raw(WORKING)] } else { [prompt_value(&greeter.prompt)] };
       let answer_label = Paragraph::new(answer_text.iter());
 
-  if let Mode::Password = greeter.mode {
+      if greeter.mode == Mode::Password || greeter.previous_mode == Mode::Password {
         f.render_widget(answer_label, chunks[ANSWER_INDEX]);
 
         if !greeter.secret {
@@ -104,6 +116,9 @@ pub fn draw(greeter: &mut Greeter, f: &mut Frame<TermionBackend<RawTerminal<io::
         match greeter.mode {
           Mode::Username => f.render_widget(message, chunks[ANSWER_INDEX]),
           Mode::Password => f.render_widget(message, chunks[MESSAGE_INDEX]),
+          Mode::Command => {}
+        }
+      }
     }
   }
 
@@ -123,6 +138,12 @@ pub fn draw(greeter: &mut Greeter, f: &mut Frame<TermionBackend<RawTerminal<io::
         Ok((1 + cursor.x + greeter.prompt.len() as u16 + offset as u16, 3 + cursor.y))
       }
     }
+
+    Mode::Command => {
+      let offset = get_cursor_offset(greeter, greeter.new_command.len());
+
+      Ok((2 + cursor.x + COMMAND.len() as u16 + offset as u16, 1 + cursor.y))
+    }
   }
 }
 
@@ -131,11 +152,14 @@ fn get_height(greeter: &Greeter) -> u16 {
   let (_, greeting_height) = get_greeting_height(greeter, 1, 0);
 
   let initial = match greeter.mode {
-    Mode::Username => 5,
+    Mode::Username | Mode::Command => 5,
     Mode::Password => 7,
   };
 
-  initial + greeting_height + message_height
+  match greeter.mode {
+    Mode::Command => initial + greeting_height,
+    _ => initial + greeting_height + message_height,
+  }
 }
 
 fn get_greeting_height(greeter: &Greeter, padding: u16, fallback: u16) -> (Option<String>, u16) {