feat: ring terminal bell on blocked edge-scroll

CHANGELOG.md

@@ -7,6 +7,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- Vim-style edge bell: scrolling past the top or bottom now emits a
+  terminal BEL. The visible effect (audible beep, title-bar 🔔, dock
+  bounce) is up to the terminal emulator — e.g. Ghostty surfaces a 🔔
+  in the window title via its default `bell-features`. Triggers on
+  `j`/`k`, `d`/`u`, `f`/`b`/`Space`/`PgUp`/`PgDn`; explicit jumps
+  (`gg`, `G`, `]`, `[`) stay silent. Disable with `--no-bell` or
+  `bell = false` in `~/.termdown/config.toml`.
+
 ### Changed
 - Removed the 4-column outer margin that cat mode and TUI body rows
   shared, plus the additional 2-column inset on cat-mode table rows.

README.md

@@ -99,6 +99,9 @@ termdown README.md | less
 # Use a specific theme instead of auto-detect
 termdown --theme light README.md
 
+# Disable the edge-scroll bell (also configurable via `bell = false`)
+termdown --no-bell README.md
+
 # View help
 termdown --help
 termdown --version
@@ -143,6 +146,12 @@ termdown reads configuration from `~/.termdown/config.toml`.
 # Auto-detection queries the terminal background color via OSC 11.
 theme = "auto"
 
+# Vim-style edge bell: emit a terminal BEL when you scroll past the
+# top/bottom of the document. The terminal emulator decides the visible
+# effect (audible beep, title-bar 🔔, dock bounce, …). Default true.
+# CLI: `--no-bell`.
+bell = true
+
 [font.heading]
 # English heading font (sans-serif recommended)
 latin = "Inter"

README_CN.md

@@ -92,6 +92,9 @@ termdown README.md | less
 # 指定主题（不使用终端亮色、暗色主题自动检测）
 termdown --theme light README.md
 
+# 关闭文档到顶/到底时的提示铃声（也可在配置中设 `bell = false`）
+termdown --no-bell README.md
+
 # 查看帮助
 termdown --help
 termdown --version
@@ -135,6 +138,10 @@ TUI 模式需要指定文件路径，不支持从 stdin 读取。
 # 自动检测通过 OSC 11 查询终端背景色。
 theme = "auto"
 
+# 文档到顶/到底时向终端发一次 BEL。具体表现（响铃、标题栏 🔔、
+# dock 弹跳等）由终端模拟器决定。默认 true，命令行可用 `--no-bell` 关闭。
+bell = true
+
 [font.heading]
 # 英文标题字体（推荐无衬线字体）
 latin = "Inter"

TODO.md

@@ -7,3 +7,5 @@
   - 在 `.github/workflows/ci.yml` 加一个 `msrv` job(`cargo check --all-targets` on pinned toolchain),防止以后 PR 悄悄抬高 MSRV
 - [ ] 测试 markdown metadata 支持
 - [ ] 检测文件变化
+- [x] 文件到顶、末尾时，播放声音提示，增加喇叭icon
+- [ ] t 开启目录时，支持左右等方向键在目录和内容之间切换，并可以有一些界面上的 focus 提示

src/config.rs

@@ -9,6 +9,13 @@ pub struct Config {
 
     /// Theme override: "dark", "light", or "auto" (default).
     pub theme: Option<String>,
+
+    /// Vim-style edge bell: emit a terminal BEL when the user tries to scroll
+    /// past the top or bottom of the document. The terminal emulator decides
+    /// the visible effect (audible beep, title-bar 🔔, dock bounce, …) — see
+    /// e.g. Ghostty's `bell-features`. `None` means default (on). CLI
+    /// `--no-bell` overrides to `Some(false)`.
+    pub bell: Option<bool>,
 }
 
 #[derive(Deserialize, Default, Clone)]

src/main.rs

@@ -31,6 +31,7 @@ fn main() {
         println!("  -V, --version             Show version");
         println!("  --theme <auto|dark|light>  Color theme (default: auto-detect)");
         println!("  --cat                     Force non-interactive cat-style output");
+        println!("  --no-bell                 Disable the edge-scroll terminal bell");
         println!();
         println!("By default, passing FILE opens it in the interactive TUI.");
         println!("Piped/redirected stdout and stdin input automatically use cat mode.");
@@ -45,10 +46,14 @@ fn main() {
     }
 
     let cat_flag = args.iter().any(|a| a == "--cat");
+    let no_bell_flag = args.iter().any(|a| a == "--no-bell");
 
     check_terminal_support();
 
-    let config = config::load();
+    let mut config = config::load();
+    if no_bell_flag {
+        config.bell = Some(false);
+    }
 
     // Parse --theme flag (takes precedence over config).
     let cli_theme = args

src/tui/mod.rs

@@ -357,6 +357,34 @@ fn event_loop<B: Backend>(terminal: &mut Terminal<B>, app: &mut App) -> io::Resu
     }
 }
 
+/// Apply a scroll delta and ring the edge bell if the viewport didn't budge.
+/// Detection lives here (not in `Viewport`) so the data layer stays free of
+/// `App`/`Config`/audio coupling and `gg`/`G`/`]`/`[` — which bypass this
+/// helper — silently stay non-belling, matching the chosen scope.
+fn perform_scroll(app: &mut App, delta: i32) {
+    if delta == 0 {
+        return;
+    }
+    let before = app.active().viewport.top;
+    app.active_mut().viewport.scroll_by(delta);
+    if app.active().viewport.top == before {
+        ring_bell(&app.config);
+    }
+}
+
+/// Emit a terminal BEL on blocked edge-scroll. No-op when the user has
+/// disabled bells via config or `--no-bell`. Writes to stderr (which is
+/// unbuffered, so no manual flush) so the byte does not enter the
+/// alternate-screen buffer. The visible "🔔 in the title bar" effect is the
+/// terminal emulator's own response to BEL (e.g. Ghostty's `bell-features`
+/// defaults include `title`), not something termdown paints.
+fn ring_bell(config: &Config) {
+    if !config.bell.unwrap_or(true) {
+        return;
+    }
+    let _ = io::stderr().write_all(b"\x07");
+}
+
 fn handle_normal_key(app: &mut App, ev: &Event) -> io::Result<()> {
     if let Event::Key(key) = ev {
         if key.kind != event::KeyEventKind::Press {
@@ -381,16 +409,14 @@ fn handle_normal_key(app: &mut App, ev: &Event) -> io::Result<()> {
             input::Action::Quit => {
                 app.should_quit = true;
             }
-            input::Action::ScrollLines(d) => app.active_mut().viewport.scroll_by(d),
+            input::Action::ScrollLines(d) => perform_scroll(app, d),
             input::Action::ScrollHalfPage(s) => {
-                let active = app.active_mut();
-                let delta = (active.viewport.height as i32 / 2) * s;
-                active.viewport.scroll_by(delta);
+                let delta = (app.active().viewport.height as i32 / 2) * s;
+                perform_scroll(app, delta);
             }
             input::Action::ScrollPage(s) => {
-                let active = app.active_mut();
-                let delta = active.viewport.height as i32 * s;
-                active.viewport.scroll_by(delta);
+                let delta = app.active().viewport.height as i32 * s;
+                perform_scroll(app, delta);
             }
             input::Action::JumpStart => app.active_mut().viewport.top = 0,
             input::Action::JumpEnd => {