[tui] Allow saving file with CTRL+S.

+ Improved event handling in general.

src/tui/app.rs

@@ -17,10 +17,14 @@ pub struct App<'a> {
 
 impl<'a> App<'a> {
     pub(crate) fn new(root_path: std::path::PathBuf) -> Self {
-        Self {
+        let mut app = Self {
-            explorer: Explorer::new(root_path),
+            explorer: Explorer::new(&root_path),
             editor: Editor::new(),
-        }
+        };
+        app.editor
+            .set_contents(&root_path.join("src/tui/app.rs"))
+            .expect("Failed to set editor contents.");
+        app
     }
 
     fn get_event(&mut self) -> Option<Event> {
@@ -33,19 +37,18 @@ impl<'a> App<'a> {
 
     pub fn run(mut self, mut terminal: DefaultTerminal) -> anyhow::Result<()> {
         loop {
+            // TODO: Handle events based on which component is active.
             terminal.draw(|f| {
                 f.render_widget(&mut self, f.area());
             })?;
 
-            // TODO: Handle events based on which component is active.
             if let Some(event) = self.get_event() {
-                self.editor
-                    .event_handler
-                    .on_event(event.clone(), &mut self.editor.state);
                 match self.handle_event(event) {
-                    Action::Noop => {}
                     Action::Quit => break,
-                    Action::Pass => {}
+                    Action::Handled => {}
+                    _ => {
+                        // panic!("Unhandled event: {:?}", event);
+                    }
                 }
             }
         }
@@ -131,6 +134,43 @@ impl<'a> Widget for &mut App<'a> {
 }
 
 impl<'a> Component for App<'a> {
+    fn id(&self) -> &str {
+        "app"
+    }
+
+    /// TODO: Get active widget with some Component trait function helper?
+    /// trait Component { fn get_state() -> ComponentState; }
+    /// if component.get_state() = ComponentState::Active { component.handle_event(); }
+    ///
+    /// App could then provide helpers for altering Component state based on TUI grouping..
+    ///    (such as editor tabs, file explorer, status bars, etc..)
+    fn handle_event(&mut self, event: Event) -> Action {
+        // Handle events in the primary application.
+        if let Some(key_event) = event.as_key_event() {
+            match self.handle_key_events(key_event) {
+                Action::Quit => return Action::Quit,
+                Action::Handled => {
+                    dbg!(format!("Handled event: {:?}", self.id()));
+                    return Action::Handled;
+                }
+                _ => {}
+            }
+        }
+        self.editor.handle_event(event);
+
+        // Handle events for all components.
+        // for component in &mut self.components {
+        //     dbg!(format!("Handling event: {:?}", component.id()));
+        //     // Actions returned here abort the input handling iteration.
+        //     match component.handle_event(event.clone()) {
+        //         Action::Quit => return Action::Quit,
+        //         Action::Handled => return Action::Handled,
+        //         _ => continue,
+        //     }
+        // }
+        Action::Noop
+    }
+
     fn handle_key_events(&mut self, key: KeyEvent) -> Action {
         match key {
             KeyEvent {

src/tui/component.rs

@@ -3,12 +3,28 @@
 use ratatui::crossterm::event::{Event, KeyEvent, MouseEvent};
 
 pub enum Action {
-    Noop,
+    /// Exit the application.
     Quit,
-    Pass, // Pass input to another component.
+
+    /// The input was checked by the Component and had no effect.
+    Noop,
+
+    /// Pass input to another component or external handler.
+    /// Similar to Noop with the added context that externally handled input may have had an impact.
+    Pass,
+
+    /// Save the current file.
+    Save,
+
+    /// The input was handled by a Component and should not be passed to the next component.
+    Handled,
 }
 
 pub trait Component {
+    /// Returns a unique identifier for the component.
+    /// This is used for lookup in a container of Components.
+    fn id(&self) -> &str;
+
     fn handle_event(&mut self, event: Event) -> Action {
         match event {
             Event::Key(key_event) => self.handle_key_events(key_event),

src/tui/editor.rs

@@ -1,9 +1,11 @@
 use crate::tui::component::{Action, Component};
+
+use anyhow::Result;
 use edtui::{
-    EditorEventHandler, EditorState, EditorTheme, EditorView, LineNumbers, SyntaxHighlighter,
+    EditorEventHandler, EditorState, EditorTheme, EditorView, LineNumbers, Lines, SyntaxHighlighter,
 };
 use ratatui::buffer::Buffer;
-use ratatui::crossterm::event::KeyEvent;
+use ratatui::crossterm::event::{Event, KeyCode, KeyEvent, KeyModifiers};
 use ratatui::layout::{Alignment, Rect};
 use ratatui::prelude::{Color, Style};
 use ratatui::widgets::{Block, Borders, Padding, Widget};
@@ -15,6 +17,7 @@ use ratatui::widgets::{Block, Borders, Padding, Widget};
 pub struct Editor {
     pub state: EditorState,
     pub event_handler: EditorEventHandler,
+    file_path: Option<std::path::PathBuf>,
 }
 
 impl Editor {
@@ -22,15 +25,32 @@ impl Editor {
         Editor {
             state: EditorState::default(),
             event_handler: EditorEventHandler::default(),
+            file_path: None,
         }
     }
+
+    pub fn set_contents(&mut self, path: &std::path::PathBuf) -> Result<()> {
+        let contents = std::fs::read_to_string(path)
+            .expect(&format!("Failed to read file contents: {}", path.display()));
+        let lines: Vec<_> = contents
+            .lines()
+            .map(|line| line.chars().collect::<Vec<char>>())
+            .collect();
+        self.file_path = Some(path.clone());
+        self.state.lines = Lines::new(lines);
+        Ok(())
+    }
+
+    pub fn save(&self) -> Result<()> {
+        if let Some(path) = &self.file_path {
+            return std::fs::write(path, self.state.lines.to_string()).map_err(|e| e.into());
+        };
+        Err(anyhow::anyhow!("File not saved. No file path set."))
+    }
 }
 
 impl Widget for &mut Editor {
-    fn render(self, area: Rect, buf: &mut Buffer)
+    fn render(self, area: Rect, buf: &mut Buffer) {
-    where
-        Self: Sized,
-    {
         // TODO: Use current file extension for syntax highlighting here.
         EditorView::new(&mut self.state)
             .wrap(true)
@@ -52,8 +72,36 @@ impl Widget for &mut Editor {
 }
 
 impl Component for Editor {
-    fn handle_key_events(&mut self, key: KeyEvent) -> Action {
+    fn id(&self) -> &str {
-        self.event_handler.on_key_event(key, &mut self.state);
+        "editor"
+    }
+
+    fn handle_event(&mut self, event: Event) -> Action {
+        if let Some(key_event) = event.as_key_event() {
+            // Handle events here that should not be passed on to the vim emulation handler.
+            match self.handle_key_events(key_event) {
+                Action::Handled => return Action::Handled,
+                _ => {}
+            }
+        }
+        self.event_handler.on_event(event, &mut self.state);
         Action::Pass
     }
+
+    /// The events for the vim emulation should be handled by EditorEventHandler::on_event.
+    /// These events are custom to the clide application.
+    fn handle_key_events(&mut self, key: KeyEvent) -> Action {
+        match key {
+            KeyEvent {
+                code: KeyCode::Char('s'),
+                modifiers: KeyModifiers::CONTROL,
+                ..
+            } => {
+                self.save().expect("Failed to save file.");
+                Action::Handled
+            }
+            // For other events not handled here, pass to the vim emulation handler.
+            _ => Action::Noop,
+        }
+    }
 }

src/tui/explorer.rs

@@ -16,10 +16,10 @@ pub struct Explorer<'a> {
 }
 
 impl<'a> Explorer<'a> {
-    pub fn new(path: std::path::PathBuf) -> Self {
+    pub fn new(path: &std::path::PathBuf) -> Self {
         let explorer = Explorer {
             root_path: path.to_owned(),
-            tree_items: Self::build_tree_from_path(path),
+            tree_items: Self::build_tree_from_path(path.to_owned()),
         };
         explorer
     }
@@ -80,4 +80,8 @@ impl<'a> Widget for &Explorer<'a> {
     }
 }
 
-impl<'a> Component for Explorer<'a> {}
+impl<'a> Component for Explorer<'a> {
+    fn id(&self) -> &str {
+        "explorer"
+    }
+}