Input fields and KeyCodes

Cargo.lock

@@ -129,7 +129,7 @@ dependencies = [
 ]
 
 [[package]]
-name = "lemors"
+name = "lemurs"
 version = "0.1.0"
 dependencies = [
  "argh",

src/input_field.rs

@@ -0,0 +1,196 @@
+use crossterm::event::KeyCode;
+use tui::{
+    layout::{Alignment, Rect},
+    style::{Color, Style},
+    terminal::Frame,
+    text::{Span, Spans, Text},
+    widgets::{Block, Borders, Paragraph},
+};
+use unicode_width::UnicodeWidthStr;
+
+pub enum InputFieldDisplayType {
+    Echo,
+    Replace(char),
+}
+
+pub struct InputFieldWidget {
+    title: String,
+    content: String,
+    cursor: u16,
+    display_type: InputFieldDisplayType,
+}
+
+impl InputFieldWidget {
+    pub fn new(title: impl ToString, display_type: InputFieldDisplayType) -> Self {
+        let title = title.to_string();
+
+        Self {
+            title,
+            content: String::new(),
+            cursor: 0,
+            display_type,
+        }
+    }
+
+    #[inline]
+    fn len(&self) -> usize {
+        self.content.len()
+    }
+
+    fn show_string(&self) -> String {
+        use InputFieldDisplayType::{Echo, Replace};
+
+        match self.display_type {
+            Echo => self.content.clone(),
+            Replace(character) => character.to_string().repeat(self.len()),
+        }
+    }
+
+    fn backspace(&mut self) {
+        if self.cursor == 0 {
+            return;
+        }
+
+        debug_assert!(usize::from(self.cursor) <= self.len());
+        self.cursor -= 1;
+        self.content.remove(self.cursor.into());
+    }
+
+    fn delete(&mut self) {
+        if usize::from(self.cursor) == self.len() {
+            return;
+        }
+
+        debug_assert!(usize::from(self.cursor) <= self.len());
+        self.content.remove(self.cursor.into());
+    }
+
+    fn insert(&mut self, character: char) {
+        // Make sure the cursor doesn't overflow
+        if self.len() == usize::from(u16::MAX) {
+            return;
+        }
+
+        debug_assert!(usize::from(self.cursor) <= self.len());
+        self.content.insert(self.cursor.into(), character);
+        self.cursor += 1;
+    }
+
+    fn right(&mut self) {
+        if usize::from(self.cursor) == self.len() {
+            return;
+        }
+
+        self.cursor += 1;
+    }
+
+    fn left(&mut self) {
+        if self.cursor == 0 {
+            return;
+        }
+
+        self.cursor -= 1;
+    }
+
+    pub fn render(
+        &self,
+        frame: &mut Frame<impl tui::backend::Backend>,
+        area: Rect,
+        is_focused: bool,
+    ) {
+        let show_string = self.show_string();
+        let widget = Paragraph::new(show_string.as_ref())
+            .style(if is_focused {
+                Style::default().fg(Color::Yellow)
+            } else {
+                Style::default()
+            })
+            .block(
+                Block::default()
+                    .borders(Borders::ALL)
+                    .title(self.title.clone()),
+            );
+
+        frame.render_widget(widget, area);
+
+        if is_focused {
+            frame.set_cursor(area.x + self.content[..usize::from(self.cursor)].width() as u16 + 1, area.y + 1);
+        }
+    }
+
+    pub fn key_press(&mut self, key_code: KeyCode) {
+        match key_code {
+            KeyCode::Backspace => self.backspace(),
+            KeyCode::Delete => self.delete(),
+
+            KeyCode::Left => self.left(),
+            KeyCode::Right => self.right(),
+
+            KeyCode::Char(c) => self.insert(c),
+            _ => {}
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use InputFieldDisplayType::*;
+
+    #[test]
+    fn cursor_movement() {
+        // TODO: Verify Unicode behaviour
+        let mut input_field = InputFieldWidget::new("", Echo);
+        assert_eq!(input_field.cursor, 0);
+        input_field.insert('x');
+        assert_eq!(input_field.cursor, 1);
+        input_field.insert('x');
+        assert_eq!(input_field.cursor, 2);
+        input_field.insert('x');
+        assert_eq!(input_field.cursor, 3);
+        input_field.insert('x');
+        assert_eq!(input_field.cursor, 4);
+        input_field.right();
+        assert_eq!(input_field.cursor, 4);
+        input_field.left();
+        assert_eq!(input_field.cursor, 3);
+        input_field.left();
+        assert_eq!(input_field.cursor, 2);
+        input_field.left();
+        assert_eq!(input_field.cursor, 1);
+        input_field.left();
+        assert_eq!(input_field.cursor, 0);
+        input_field.left();
+        assert_eq!(input_field.cursor, 0);
+        input_field.right();
+        assert_eq!(input_field.cursor, 1);
+        input_field.backspace();
+        assert_eq!(input_field.cursor, 0);
+    }
+
+    #[test]
+    fn integration() {
+        let mut input_field = InputFieldWidget::new("", Echo);
+        assert_eq!(&input_field.show_string(), "");
+        input_field.backspace();
+        assert_eq!(&input_field.show_string(), "");
+        input_field.insert('x');
+        assert_eq!(&input_field.show_string(), "x");
+        input_field.insert('y');
+        assert_eq!(&input_field.show_string(), "xy");
+        input_field.backspace();
+        assert_eq!(&input_field.show_string(), "x");
+        input_field.insert('y');
+        assert_eq!(&input_field.show_string(), "xy");
+        input_field.left();
+        assert_eq!(&input_field.show_string(), "xy");
+        input_field.backspace();
+        assert_eq!(&input_field.show_string(), "y");
+        input_field.backspace();
+        assert_eq!(&input_field.show_string(), "y");
+        input_field.right();
+        assert_eq!(&input_field.show_string(), "y");
+        input_field.backspace();
+        assert_eq!(&input_field.show_string(), "");
+    }
+}

src/main.rs

@@ -1,5 +1,5 @@
 use crossterm::{
-    event::{self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode},
+    event::{self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode, KeyModifiers},
     execute,
     terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
 };
@@ -13,7 +13,9 @@ use tui::{
 };
 use unicode_width::UnicodeWidthStr;
 
+mod input_field;
 mod window_manager_selector;
+use input_field::{InputFieldDisplayType, InputFieldWidget};
 use window_manager_selector::{WindowManager, WindowManagerSelectorWidget};
 
 enum InputMode {
@@ -29,10 +31,10 @@ struct App {
     window_manager_widget: WindowManagerSelectorWidget,
 
     /// Current value of the Username
-    username: String,
+    username_widget: InputFieldWidget,
 
     /// Current value of the Password
-    password: String,
+    password_widget: InputFieldWidget,
 
     /// Current input mode
     input_mode: InputMode,
@@ -46,8 +48,8 @@ impl Default for App {
                 WindowManager::new("i3", "/usr/bin/i3"),
                 WindowManager::new("awesome", "/usr/bin/awesome"),
             ]),
-            username: String::new(),
-            password: String::new(),
+            username_widget: InputFieldWidget::new("Username", InputFieldDisplayType::Echo),
+            password_widget: InputFieldWidget::new("Password", InputFieldDisplayType::Replace('*')),
             input_mode: InputMode::Normal,
         }
     }
@@ -97,42 +99,55 @@ fn run_app<B: Backend>(terminal: &mut Terminal<B>, mut app: App) -> io::Result<(
                     _ => {}
                 },
                 InputMode::WindowManager => match key.code {
-                    KeyCode::Enter | KeyCode::Tab => {
+                    KeyCode::Enter | KeyCode::Tab | KeyCode::Down => {
                         app.input_mode = InputMode::Username;
                     }
                     KeyCode::Esc => {
                         app.input_mode = InputMode::Normal;
                     }
-                    KeyCode::Left => {
+                    KeyCode::Left | KeyCode::Char('h') => {
                         app.window_manager_widget.left();
                     }
-                    KeyCode::Right => {
+                    KeyCode::Right | KeyCode::Char('l') => {
                         app.window_manager_widget.right();
                     }
                     _ => {}
                 },
                 InputMode::Username => match key.code {
-                    KeyCode::Enter | KeyCode::Tab => {
+                    KeyCode::Enter | KeyCode::Down => {
                         app.input_mode = InputMode::Password;
                     }
+                    KeyCode::Tab => {
+                        if key.modifiers == KeyModifiers::SHIFT {
+                            app.input_mode = InputMode::WindowManager;
+                        } else {
+                            app.input_mode = InputMode::Password;
+                        }
+                    }
+                    KeyCode::Up => {
+                        app.input_mode = InputMode::WindowManager;
+                    }
                     KeyCode::Esc => {
                         app.input_mode = InputMode::Normal;
                     }
-                    KeyCode::Char(c) => {
-                        app.username.push(c);
-                    }
-                    _ => {}
+                    key_code => app.username_widget.key_press(key_code),
                 },
                 InputMode::Password => match key.code {
-                    KeyCode::Enter | KeyCode::Tab => {
+                    KeyCode::Enter => {
                         todo!()
                     }
+                    KeyCode::Tab => {
+                        if key.modifiers == KeyModifiers::SHIFT {
+                            app.input_mode = InputMode::Username;
+                        }
+                    }
+                    KeyCode::Up => {
+                        app.input_mode = InputMode::Username;
+                    }
                     KeyCode::Esc => {
                         app.input_mode = InputMode::Normal;
                     }
-                    KeyCode::Char(c) => {
-                        app.password.push(c);
-                    }
+                    key_code => app.password_widget.key_press(key_code),
                     _ => {}
                 },
             }
@@ -166,35 +181,9 @@ fn ui<B: Backend>(f: &mut Frame<B>, app: &App) {
         matches!(app.input_mode, InputMode::WindowManager),
     );
 
-    let username = Paragraph::new(app.username.as_ref())
-        .style(match app.input_mode {
-            InputMode::Normal => Style::default(),
-            InputMode::WindowManager => Style::default(),
-            InputMode::Username => Style::default().fg(Color::Yellow),
-            InputMode::Password => Style::default(),
-        })
-        .block(Block::default().borders(Borders::ALL).title("Input"));
-    f.render_widget(username, chunks[4]);
+    app.username_widget
+        .render(f, chunks[4], matches!(app.input_mode, InputMode::Username));
 
-    let password = Paragraph::new(app.password.as_ref())
-        .style(match app.input_mode {
-            InputMode::Normal => Style::default(),
-            InputMode::WindowManager => Style::default(),
-            InputMode::Username => Style::default(),
-            InputMode::Password => Style::default().fg(Color::Yellow),
-        })
-        .block(Block::default().borders(Borders::ALL).title("Password"));
-    f.render_widget(password, chunks[6]);
-
-    match app.input_mode {
-        InputMode::Normal | InputMode::WindowManager => {}
-        InputMode::Username => f.set_cursor(
-            chunks[4].x + app.username.width() as u16 + 1,
-            chunks[4].y + 1,
-        ),
-        InputMode::Password => f.set_cursor(
-            chunks[6].x + app.password.width() as u16 + 1,
-            chunks[6].y + 1,
-        ),
-    }
+    app.password_widget
+        .render(f, chunks[6], matches!(app.input_mode, InputMode::Password));
 }