implement dynamic shortcut list sizing (#668)

* implement dynamic shortcut list sizing

* Remove all dynamic allocations from shortcut creation

tui/src/float.rs

@@ -4,13 +4,13 @@ use ratatui::{
     Frame,
 };
 
-use crate::hint::ShortcutList;
+use crate::hint::Shortcut;
 
 pub trait FloatContent {
     fn draw(&mut self, frame: &mut Frame, area: Rect);
     fn handle_key_event(&mut self, key: &KeyEvent) -> bool;
     fn is_finished(&self) -> bool;
-    fn get_shortcut_list(&self) -> ShortcutList;
+    fn get_shortcut_list(&self) -> (&str, Box<[Shortcut]>);
 }
 
 pub struct Float {
@@ -69,7 +69,7 @@ impl Float {
         }
     }
 
-    pub fn get_shortcut_list(&self) -> ShortcutList {
+    pub fn get_shortcut_list(&self) -> (&str, Box<[Shortcut]>) {
         self.content.get_shortcut_list()
     }
 }

tui/src/floating_text.rs

@@ -4,10 +4,7 @@ use std::{
     io::{Cursor, Read as _, Seek, SeekFrom, Write as _},
 };
 
-use crate::{
+use crate::{float::FloatContent, hint::Shortcut};
-    float::FloatContent,
-    hint::{Shortcut, ShortcutList},
-};
 
 use linutil_core::Command;
 
@@ -293,16 +290,16 @@ impl FloatContent for FloatingText {
         true
     }
 
-    fn get_shortcut_list(&self) -> ShortcutList {
+    fn get_shortcut_list(&self) -> (&str, Box<[Shortcut]>) {
-        ShortcutList {
+        (
-            scope_name: self.mode_title,
+            self.mode_title,
-            hints: vec![
+            Box::new([
-                Shortcut::new(vec!["j", "Down"], "Scroll down"),
+                Shortcut::new("Scroll down", ["j", "Down"]),
-                Shortcut::new(vec!["k", "Up"], "Scroll up"),
+                Shortcut::new("Scroll up", ["k", "Up"]),
-                Shortcut::new(vec!["h", "Left"], "Scroll left"),
+                Shortcut::new("Scroll left", ["h", "Left"]),
-                Shortcut::new(vec!["l", "Right"], "Scroll right"),
+                Shortcut::new("Scroll right", ["l", "Right"]),
-                Shortcut::new(vec!["Enter", "p", "d", "g"], "Close window"),
+                Shortcut::new("Close window", ["Enter", "p", "d", "g"]),
-            ],
+            ]),
-        }
+        )
     }
 }

tui/src/hint.rs

@@ -1,20 +1,10 @@
+use std::borrow::Cow;
+
 use ratatui::{
-    layout::{Margin, Rect},
     style::{Style, Stylize},
     text::{Line, Span},
-    widgets::{Block, Borders, Paragraph},
-    Frame,
 };
 
-use crate::state::{AppState, Focus};
-
-pub const SHORTCUT_LINES: usize = 2;
-
-pub struct ShortcutList {
-    pub scope_name: &'static str,
-    pub hints: Vec<Shortcut>,
-}
-
 pub struct Shortcut {
     pub key_sequences: Vec<Span<'static>>,
     pub desc: &'static str,
@@ -32,54 +22,63 @@ fn add_spacing(list: Vec<Vec<Span>>) -> Line {
 pub fn span_vec_len(span_vec: &[Span]) -> usize {
     span_vec.iter().rfold(0, |init, s| init + s.width())
 }
-impl ShortcutList {
-    pub fn draw(&self, frame: &mut Frame, area: Rect) {
-        let block = Block::default()
-            .title(format!(" {} ", self.scope_name))
-            .borders(Borders::all());
-        let inner_area = area.inner(Margin::new(1, 1));
-        let shortcut_spans: Vec<Vec<Span>> = self.hints.iter().map(|h| h.to_spans()).collect();
 
-        let mut lines: Vec<Line> = Vec::with_capacity(SHORTCUT_LINES);
+pub fn create_shortcut_list(
+    shortcuts: impl IntoIterator<Item = Shortcut>,
+    render_width: u16,
+) -> Box<[Line<'static>]> {
+    let hints = shortcuts.into_iter().collect::<Box<[Shortcut]>>();
 
-        let shortcut_list = (0..SHORTCUT_LINES - 1).fold(shortcut_spans, |mut acc, _| {
+    let mut shortcut_spans: Vec<Vec<Span<'static>>> = hints.iter().map(|h| h.to_spans()).collect();
-            let split_idx = acc
+
-                .iter()
+    let mut lines: Vec<Line<'static>> = vec![];
-                .scan(0_usize, |total_len, s| {
+
+    loop {
+        let split_idx = shortcut_spans
+            .iter()
+            .scan(0usize, |total_len, s| {
+                // take at least one so that we guarantee that we drain the list
+                // otherwise, this might lock up if there's a shortcut that exceeds the window width
+                if *total_len == 0 {
+                    *total_len += span_vec_len(s) + 4;
+                    Some(())
+                } else {
                     *total_len += span_vec_len(s);
-                    if *total_len > inner_area.width as usize {
+                    if *total_len > render_width as usize {
                         None
                     } else {
                         *total_len += 4;
-                        Some(1)
+                        Some(())
                     }
-                })
+                }
-                .count();
+            })
+            .count();
 
-            let new_shortcut_list = acc.split_off(split_idx);
+        let rest = shortcut_spans.split_off(split_idx);
-            lines.push(add_spacing(acc));
+        lines.push(add_spacing(shortcut_spans));
 
-            new_shortcut_list
+        if rest.is_empty() {
-        });
+            break;
-        lines.push(add_spacing(shortcut_list));
+        } else {
-
+            shortcut_spans = rest;
-        let p = Paragraph::new(lines).block(block);
+        }
-        frame.render_widget(p, area);
     }
+
+    lines.into_boxed_slice()
 }
 
 impl Shortcut {
-    pub fn new(key_sequences: Vec<&'static str>, desc: &'static str) -> Self {
+    pub fn new<const N: usize>(desc: &'static str, key_sequences: [&'static str; N]) -> Self {
         Self {
             key_sequences: key_sequences
                 .iter()
-                .map(|s| Span::styled(*s, Style::default().bold()))
+                .map(|s| Span::styled(Cow::<'static, str>::Borrowed(s), Style::default().bold()))
                 .collect(),
             desc,
         }
     }
 
-    fn to_spans(&self) -> Vec<Span> {
+    fn to_spans(&self) -> Vec<Span<'static>> {
         let mut ret: Vec<_> = self
             .key_sequences
             .iter()
@@ -95,77 +94,3 @@ impl Shortcut {
         ret
     }
 }
-
-fn get_list_item_shortcut(state: &AppState) -> Vec<Shortcut> {
-    if state.selected_item_is_dir() {
-        vec![Shortcut::new(
-            vec!["l", "Right", "Enter"],
-            "Go to selected dir",
-        )]
-    } else {
-        vec![
-            Shortcut::new(vec!["l", "Right", "Enter"], "Run selected command"),
-            Shortcut::new(vec!["p"], "Enable preview"),
-            Shortcut::new(vec!["d"], "Command Description"),
-        ]
-    }
-}
-
-pub fn draw_shortcuts(state: &AppState, frame: &mut Frame, area: Rect) {
-    match state.focus {
-        Focus::Search => ShortcutList {
-            scope_name: "Search bar",
-            hints: vec![Shortcut::new(vec!["Enter"], "Finish search")],
-        },
-
-        Focus::List => {
-            let mut hints = Vec::new();
-            hints.push(Shortcut::new(vec!["q", "CTRL-c"], "Exit linutil"));
-
-            if state.at_root() {
-                hints.push(Shortcut::new(vec!["h", "Left"], "Focus tab list"));
-                hints.extend(get_list_item_shortcut(state));
-            } else if state.selected_item_is_up_dir() {
-                hints.push(Shortcut::new(
-                    vec!["l", "Right", "Enter", "h", "Left"],
-                    "Go to parent directory",
-                ));
-            } else {
-                hints.push(Shortcut::new(vec!["h", "Left"], "Go to parent directory"));
-                hints.extend(get_list_item_shortcut(state));
-            }
-            hints.push(Shortcut::new(vec!["k", "Up"], "Select item above"));
-            hints.push(Shortcut::new(vec!["j", "Down"], "Select item below"));
-            hints.push(Shortcut::new(vec!["t"], "Next theme"));
-            hints.push(Shortcut::new(vec!["T"], "Previous theme"));
-            if state.is_current_tab_multi_selectable() {
-                hints.push(Shortcut::new(vec!["v"], "Toggle multi-selection mode"));
-                hints.push(Shortcut::new(vec!["Space"], "Select multiple commands"));
-            }
-            hints.push(Shortcut::new(vec!["Tab"], "Next tab"));
-            hints.push(Shortcut::new(vec!["Shift-Tab"], "Previous tab"));
-            hints.push(Shortcut::new(vec!["g"], "Important actions guide"));
-            ShortcutList {
-                scope_name: "Command list",
-                hints,
-            }
-        }
-
-        Focus::TabList => ShortcutList {
-            scope_name: "Tab list",
-            hints: vec![
-                Shortcut::new(vec!["q", "CTRL-c"], "Exit linutil"),
-                Shortcut::new(vec!["l", "Right", "Enter"], "Focus action list"),
-                Shortcut::new(vec!["k", "Up"], "Select item above"),
-                Shortcut::new(vec!["j", "Down"], "Select item below"),
-                Shortcut::new(vec!["t"], "Next theme"),
-                Shortcut::new(vec!["T"], "Previous theme"),
-                Shortcut::new(vec!["Tab"], "Next tab"),
-                Shortcut::new(vec!["Shift-Tab"], "Previous tab"),
-            ],
-        },
-
-        Focus::FloatingWindow(ref float) => float.get_shortcut_list(),
-    }
-    .draw(frame, area);
-}

tui/src/running_command.rs

@@ -1,7 +1,4 @@
-use crate::{
+use crate::{float::FloatContent, hint::Shortcut};
-    float::FloatContent,
-    hint::{Shortcut, ShortcutList},
-};
 use crossterm::event::{KeyCode, KeyEvent, KeyModifiers};
 use linutil_core::Command;
 use oneshot::{channel, Receiver};
@@ -120,17 +117,17 @@ impl FloatContent for RunningCommand {
         }
     }
 
-    fn get_shortcut_list(&self) -> ShortcutList {
+    fn get_shortcut_list(&self) -> (&str, Box<[Shortcut]>) {
         if self.is_finished() {
-            ShortcutList {
+            (
-                scope_name: "Finished command",
+                "Finished command",
-                hints: vec![Shortcut::new(vec!["Enter", "q"], "Close window")],
+                Box::new([Shortcut::new("Close window", ["Enter", "q"])]),
-            }
+            )
         } else {
-            ShortcutList {
+            (
-                scope_name: "Running command",
+                "Running command",
-                hints: vec![Shortcut::new(vec!["CTRL-c"], "Kill the command")],
+                Box::new([Shortcut::new("Kill the command", ["CTRL-c"])]),
-            }
+            )
         }
     }
 }

tui/src/state.rs

@@ -2,7 +2,7 @@ use crate::{
     filter::{Filter, SearchAction},
     float::{Float, FloatContent},
     floating_text::{FloatingText, FloatingTextMode},
-    hint::{draw_shortcuts, SHORTCUT_LINES},
+    hint::{create_shortcut_list, Shortcut},
     running_command::RunningCommand,
     theme::Theme,
 };
@@ -12,9 +12,9 @@ use linutil_core::{Command, ListNode, Tab};
 #[cfg(feature = "tips")]
 use rand::Rng;
 use ratatui::{
-    layout::{Alignment, Constraint, Direction, Layout},
+    layout::{Alignment, Constraint, Direction, Flex, Layout},
     style::{Style, Stylize},
-    text::{Line, Span},
+    text::{Line, Span, Text},
     widgets::{Block, Borders, List, ListState, Paragraph},
     Frame,
 };
@@ -76,6 +76,7 @@ impl AppState {
     pub fn new(theme: Theme, override_validation: bool) -> Self {
         let tabs = linutil_core::get_tabs(!override_validation);
         let root_id = tabs[0].tree.root().id();
+
         let mut state = Self {
             theme,
             focus: Focus::List,
@@ -90,9 +91,82 @@ impl AppState {
             #[cfg(feature = "tips")]
             tip: get_random_tip(),
         };
+
         state.update_items();
         state
     }
+
+    fn get_list_item_shortcut(&self) -> Box<[Shortcut]> {
+        if self.selected_item_is_dir() {
+            Box::new([Shortcut::new("Go to selected dir", ["l", "Right", "Enter"])])
+        } else {
+            Box::new([
+                Shortcut::new("Run selected command", ["l", "Right", "Enter"]),
+                Shortcut::new("Enable preview", ["p"]),
+                Shortcut::new("Command Description", ["d"]),
+            ])
+        }
+    }
+
+    pub fn get_keybinds(&self) -> (&str, Box<[Shortcut]>) {
+        match self.focus {
+            Focus::Search => (
+                "Search bar",
+                Box::new([Shortcut::new("Finish search", ["Enter"])]),
+            ),
+
+            Focus::List => {
+                let mut hints = Vec::new();
+                hints.push(Shortcut::new("Exit linutil", ["q", "CTRL-c"]));
+
+                if self.at_root() {
+                    hints.push(Shortcut::new("Focus tab list", ["h", "Left"]));
+                    hints.extend(self.get_list_item_shortcut());
+                } else if self.selected_item_is_up_dir() {
+                    hints.push(Shortcut::new(
+                        "Go to parent directory",
+                        ["l", "Right", "Enter", "h", "Left"],
+                    ));
+                } else {
+                    hints.push(Shortcut::new("Go to parent directory", ["h", "Left"]));
+                    hints.extend(self.get_list_item_shortcut());
+                }
+
+                hints.push(Shortcut::new("Select item above", ["k", "Up"]));
+                hints.push(Shortcut::new("Select item below", ["j", "Down"]));
+                hints.push(Shortcut::new("Next theme", ["t"]));
+                hints.push(Shortcut::new("Previous theme", ["T"]));
+
+                if self.is_current_tab_multi_selectable() {
+                    hints.push(Shortcut::new("Toggle multi-selection mode", ["v"]));
+                    hints.push(Shortcut::new("Select multiple commands", ["Space"]));
+                }
+
+                hints.push(Shortcut::new("Next tab", ["Tab"]));
+                hints.push(Shortcut::new("Previous tab", ["Shift-Tab"]));
+                hints.push(Shortcut::new("Important actions guide", ["g"]));
+
+                ("Command list", hints.into_boxed_slice())
+            }
+
+            Focus::TabList => (
+                "Tab list",
+                Box::new([
+                    Shortcut::new("Exit linutil", ["q", "CTRL-c"]),
+                    Shortcut::new("Focus action list", ["l", "Right", "Enter"]),
+                    Shortcut::new("Select item above", ["k", "Up"]),
+                    Shortcut::new("Select item below", ["j", "Down"]),
+                    Shortcut::new("Next theme", ["t"]),
+                    Shortcut::new("Previous theme", ["T"]),
+                    Shortcut::new("Next tab", ["Tab"]),
+                    Shortcut::new("Previous tab", ["Shift-Tab"]),
+                ]),
+            ),
+
+            Focus::FloatingWindow(ref float) => float.get_shortcut_list(),
+        }
+    }
+
     pub fn draw(&mut self, frame: &mut Frame) {
         let terminal_size = frame.area();
 
@@ -153,12 +227,26 @@ impl AppState {
             .unwrap_or(0)
             .max(str1.len() + str2.len());
 
+        let (keybind_scope, shortcuts) = self.get_keybinds();
+
+        let keybind_render_width = terminal_size.width - 2;
+
+        let keybinds_block = Block::default()
+            .title(format!(" {} ", keybind_scope))
+            .borders(Borders::all());
+
+        let keybinds = create_shortcut_list(shortcuts, keybind_render_width);
+        let n_lines = keybinds.len() as u16;
+
+        let keybind_para = Paragraph::new(Text::from_iter(keybinds)).block(keybinds_block);
+
         let vertical = Layout::default()
             .direction(Direction::Vertical)
             .constraints([
-                Constraint::Percentage(100),
+                Constraint::Percentage(0),
-                Constraint::Min(2 + SHORTCUT_LINES as u16),
+                Constraint::Max(n_lines as u16 + 2),
             ])
+            .flex(Flex::Legacy)
             .margin(0)
             .split(frame.area());
 
@@ -305,7 +393,7 @@ impl AppState {
             float.draw(frame, chunks[1]);
         }
 
-        draw_shortcuts(self, frame, vertical[1]);
+        frame.render_widget(keybind_para, vertical[1]);
     }
 
     pub fn handle_key(&mut self, key: &KeyEvent) -> bool {
@@ -355,11 +443,13 @@ impl AppState {
                     self.focus = Focus::List;
                 }
             }
+
             Focus::Search => match self.filter.handle_key(key) {
                 SearchAction::Exit => self.exit_search(),
                 SearchAction::Update => self.update_items(),
                 SearchAction::None => {}
             },
+
             Focus::TabList => match key.code {
                 KeyCode::Enter | KeyCode::Char('l') | KeyCode::Right => self.focus = Focus::List,
 
@@ -381,19 +471,14 @@ impl AppState {
                 KeyCode::Char('g') => self.toggle_task_list_guide(),
                 _ => {}
             },
+
             Focus::List if key.kind != KeyEventKind::Release => match key.code {
                 KeyCode::Char('j') | KeyCode::Down => self.selection.select_next(),
                 KeyCode::Char('k') | KeyCode::Up => self.selection.select_previous(),
                 KeyCode::Char('p') | KeyCode::Char('P') => self.enable_preview(),
                 KeyCode::Char('d') | KeyCode::Char('D') => self.enable_description(),
                 KeyCode::Enter | KeyCode::Char('l') | KeyCode::Right => self.handle_enter(),
-                KeyCode::Char('h') | KeyCode::Left => {
+                KeyCode::Char('h') | KeyCode::Left => self.go_back(),
-                    if self.at_root() {
-                        self.focus = Focus::TabList;
-                    } else {
-                        self.enter_parent_directory();
-                    }
-                }
                 KeyCode::Char('/') => self.enter_search(),
                 KeyCode::Char('t') => self.theme.next(),
                 KeyCode::Char('T') => self.theme.prev(),
@@ -402,10 +487,12 @@ impl AppState {
                 KeyCode::Char(' ') if self.multi_select => self.toggle_selection(),
                 _ => {}
             },
+
             _ => (),
         };
         true
     }
+
     fn toggle_multi_select(&mut self) {
         if self.is_current_tab_multi_selectable() {
             self.multi_select = !self.multi_select;
@@ -414,6 +501,7 @@ impl AppState {
             }
         }
     }
+
     fn toggle_selection(&mut self) {
         if let Some(command) = self.get_selected_command() {
             if self.selected_commands.contains(&command) {
@@ -423,12 +511,14 @@ impl AppState {
             }
         }
     }
+
     pub fn is_current_tab_multi_selectable(&self) -> bool {
         let index = self.current_tab.selected().unwrap_or(0);
         self.tabs
             .get(index)
             .map_or(false, |tab| tab.multi_selectable)
     }
+
     fn update_items(&mut self) {
         self.filter.update_items(
             &self.tabs,
@@ -448,11 +538,20 @@ impl AppState {
         self.visit_stack.len() == 1
     }
 
+    fn go_back(&mut self) {
+        if self.at_root() {
+            self.focus = Focus::TabList;
+        } else {
+            self.enter_parent_directory();
+        }
+    }
+
     fn enter_parent_directory(&mut self) {
         self.visit_stack.pop();
         self.selection.select(Some(0));
         self.update_items();
     }
+
     fn get_selected_node(&self) -> Option<&ListNode> {
         let mut selected_index = self.selection.selected().unwrap_or(0);