buflist: Add support for clicks to switch buffers

src/action.rs

@@ -20,7 +20,9 @@ pub enum Action {
   Error(String),
   PreviousBuffer,
   NextBuffer,
+  ToBuffer(isize),
   RunCommand(String),
+  MouseEvent(crossterm::event::MouseEvent),
   Help,
 }
 

src/app.rs

@@ -147,8 +147,8 @@ impl App {
 
     let mut tui = tui::Tui::new()?
       .tick_rate(self.tick_rate)
-      .frame_rate(self.frame_rate);
-    // tui.mouse(true);
+      .frame_rate(self.frame_rate)
+      .mouse(self.config.mouse.enable);
     tui.enter()?;
 
     for component in self.components.iter_mut() {
@@ -255,6 +255,10 @@ impl App {
               .buffers
               .set_active_index(self.buffers.active_index() as isize - 1)
           },
+          Action::ToBuffer(buffer_index) => {
+            changes_since_last_render = true;
+            self.buffers.set_active_index(buffer_index)
+          },
           Action::Resize(w, h) => {
             changes_since_last_render = true;
             tui.resize(Rect::new(0, 0, w, h))?;
@@ -306,8 +310,8 @@ impl App {
         action_tx.send(Action::Resume)?;
         tui = tui::Tui::new()?
           .tick_rate(self.tick_rate)
-          .frame_rate(self.frame_rate);
-        // tui.mouse(true);
+          .frame_rate(self.frame_rate)
+          .mouse(self.config.mouse.enable);
         tui.enter()?;
       } else if self.should_quit.load(Ordering::Acquire) {
         tui.stop()?;
@@ -319,7 +323,7 @@ impl App {
   }
 
   fn handle_tui_event(
-    &self,
+    &mut self,
     action_tx: &mpsc::UnboundedSender<Action>,
     e: tui::Event,
   ) -> Result<()> {
@@ -328,6 +332,15 @@ impl App {
       tui::Event::Tick => action_tx.send(Action::Tick)?,
       tui::Event::Render => action_tx.send(Action::Render)?,
       tui::Event::Resize(x, y) => action_tx.send(Action::Resize(x, y))?,
+      tui::Event::Mouse(event) => {
+        // Don't go through the action queue, we need to process mouse events immediately
+        // or stuff may move on screen before we process the click
+        for component in &mut self.components {
+          if let Some(action) = component.handle_mouse_events(event)? {
+            action_tx.send(action)?;
+          }
+        }
+      },
       tui::Event::Key(key) => {
         if let Some(keymap) = self.config.keybindings.get(&self.mode) {
           if let Some(command_line) = keymap.get(&vec![key]) {

src/components/buflist.rs

@@ -15,6 +15,7 @@
  */
 
 use color_eyre::eyre::{Result, WrapErr};
+use crossterm::event::{MouseEvent, MouseEventKind};
 use ratatui::{prelude::*, widgets::*};
 use tokio::sync::mpsc::UnboundedSender;
 use tokio::sync::OnceCell;
@@ -28,12 +29,18 @@ use crate::{
 pub struct Buflist {
   command_tx: Option<UnboundedSender<Action>>,
   config: Config,
+
+  /// Updated by [`draw`], used by [`handle_mouse_events`] to find which buffer was clicked.
+  last_area: Option<Rect>,
+  last_num_buffers: Option<usize>,
 }
 impl Buflist {
   pub fn new(config: Config) -> Self {
     Buflist {
       command_tx: None,
       config,
+      last_area: None,
+      last_num_buffers: None,
     }
   }
 
@@ -57,6 +64,53 @@ impl Component for Buflist {
     Ok(())
   }
 
+  fn handle_mouse_events(&mut self, mouse: MouseEvent) -> Result<Option<Action>> {
+    match mouse {
+      MouseEvent {
+        kind: MouseEventKind::Up(_),
+        column: x,
+        row: y,
+        modifiers: _,
+      } => {
+        let Some(last_area) = self.last_area else {
+          return Ok(None);
+        };
+        if !last_area.intersects(Rect {
+          x,
+          y,
+          height: 1,
+          width: 1,
+        }) {
+          // Clicked outside the buflist (or on the border)
+          return Ok(None);
+        }
+        let Some(last_num_buffers) = self.last_num_buffers else {
+          return Ok(None);
+        };
+        let column = (x - last_area.x) / self.config.layout.buflist.column_width;
+        let mut buffer_id: isize =
+          (column as isize) * (last_area.height as isize) + ((y as isize) - (last_area.y as isize));
+        let buffer_id_usize: usize = buffer_id.try_into().expect("negative buffer_id");
+        if buffer_id_usize >= last_num_buffers {
+          if self.config.layout.buflist.penultimate_right_overflow {
+            // Clicked on the overflow of the last-but-one column
+            buffer_id -= last_area.height as isize;
+          } else {
+            // Clicked past the last buffer
+            return Ok(None);
+          }
+        }
+        let buffer_id_usize: usize = buffer_id.try_into().expect("negative buffer_id");
+        if buffer_id_usize >= last_num_buffers {
+          tracing::error!("[BUG] Unexpected click past the last buffer");
+          return Ok(None);
+        }
+        Ok(Some(Action::ToBuffer(buffer_id)))
+      },
+      _ => Ok(None),
+    }
+  }
+
   fn update(&mut self, action: &Action) -> Result<Option<Action>> {
     Ok(None)
   }
@@ -72,6 +126,8 @@ impl Component for Buflist {
     block.render(area, frame.buffer_mut());
 
     let area = inner_area;
+    self.last_area = Some(area);
+    self.last_num_buffers = buffers.len().try_into().ok();
 
     let num_digits = u32::min(5, buffers.len().ilog10() + 1) as usize;
     let right_pad = " ".repeat(area.width.into());
@@ -92,7 +148,7 @@ impl Component for Buflist {
       } else {
         false
       };
-      for y in area.x..(area.x + area.height) {
+      for y in area.top()..area.bottom() {
         let Some((i, buf)) = buffers_iter.next() else {
           return Ok(());
         };

src/components/home.rs

@@ -105,6 +105,10 @@ impl Component for Home {
     }
   }
 
+  fn handle_mouse_events(&mut self, mouse: crossterm::event::MouseEvent) -> Result<Option<Action>> {
+    self.buflist.handle_mouse_events(mouse)
+  }
+
   fn update(&mut self, action: &Action) -> Result<Option<Action>> {
     self.buflist.update(action)?;
     Ok(None)

src/config.rs

@@ -40,6 +40,11 @@ fn default_device_name() -> String {
   }
 }
 
+#[derive(Clone, Debug, Deserialize)]
+pub struct MouseConfig {
+  pub enable: bool,
+}
+
 #[derive(Clone, Debug, Deserialize)]
 pub struct BuflistLayoutConfig {
   pub column_width: u16,
@@ -65,6 +70,7 @@ pub struct Config {
   pub accounts: nonempty::NonEmpty<AccountConfig>,
   #[serde(default)]
   pub keybindings: KeyBindings,
+  pub mouse: MouseConfig,
   pub layout: LayoutConfig,
   #[serde(default)]
   pub styles: Styles,

src/default_config.toml

@@ -6,6 +6,9 @@
 "<Alt-left>" = "/previous"
 "<Alt-right>" = "/next"
 
+[mouse]
+enable = true
+
 # Configuration for the list of rooms on the right.
 [layout.buflist]
 # How long room names can be before being truncated.