From 8121b5fe85fdaad7674101b3196d771538d50c5f Mon Sep 17 00:00:00 2001
From: Julio Biason <j.biason@engys.com>
Date: Tue, 22 Aug 2023 10:58:58 -0300
Subject: [PATCH] Selecte elements, return selected elements

---
 ratatuitest/src/main.rs | 142 +++++++++++++++++++++++++++++++++-------
 1 file changed, 117 insertions(+), 25 deletions(-)

diff --git a/ratatuitest/src/main.rs b/ratatuitest/src/main.rs
index f865668..df27525 100644
--- a/ratatuitest/src/main.rs
+++ b/ratatuitest/src/main.rs
@@ -3,40 +3,129 @@ use crossterm::event::KeyEventKind;
 use crossterm::terminal::disable_raw_mode;
 use crossterm::terminal::enable_raw_mode;
 use ratatui::prelude::Backend;
-use ratatui::prelude::Constraint;
 use ratatui::prelude::CrosstermBackend;
-use ratatui::prelude::Direction;
-use ratatui::prelude::Layout;
-use ratatui::style::Color;
+use ratatui::prelude::Rect;
 use ratatui::style::Modifier;
 use ratatui::style::Style;
 use ratatui::widgets::List;
 use ratatui::widgets::ListItem;
+use ratatui::widgets::ListState;
 use ratatui::Frame;
 use ratatui::Terminal;
 use std::error::Error;
 
+struct Cursor {
+    pub state: ListState,
+    pub values: Vec<String>,
+    pub selected: Vec<usize>,
+}
+
+impl Cursor {
+    pub fn new(values: Vec<String>) -> Self {
+        Self {
+            state: ListState::default().with_selected(Some(0)),
+            values,
+            selected: Vec::new(),
+        }
+    }
+
+    pub fn down(&mut self) {
+        let current_selected = self.selected();
+        if current_selected >= self.values.len() - 1 {
+            self.state.select(Some(0))
+        } else {
+            self.state.select(Some(current_selected + 1));
+        }
+    }
+
+    pub fn up(&mut self) {
+        let current_selected = self.selected();
+        if current_selected <= 0 {
+            self.state.select(Some(self.values.len() - 1));
+        } else {
+            self.state.select(Some(current_selected - 1))
+        }
+    }
+
+    fn selected(&self) -> usize {
+        match self.state.selected() {
+            Some(i) => i,
+            None => 0,
+        }
+    }
+
+    fn mark(&mut self) {
+        let current_selected = self.selected();
+        match self
+            .selected
+            .iter()
+            .position(|&value| value == current_selected)
+        {
+            Some(x) => _ = self.selected.remove(x),
+            None => self.selected.push(current_selected),
+        };
+    }
+
+    fn marked(&self) -> Vec<&str> {
+        self.selected
+            .iter()
+            .map(|p| self.values[*p].as_str())
+            .collect()
+    }
+}
+
 fn main() -> Result<(), Box<dyn Error>> {
     enable_raw_mode()?;
-    let mut stdout = std::io::stdout();
+    let stdout = std::io::stdout();
     let backend = CrosstermBackend::new(stdout);
     let mut terminal = Terminal::new(backend)?;
-    let res = run_app(&mut terminal);
+
+    let terminal_rect = terminal.size().unwrap();
+
+    println!("---");
+    // since we need 5 lines...
+    for _ in 0..5 {
+        println!("");
+    }
+    let cursor_pos = terminal.get_cursor().unwrap();
+
+    let mut options = Cursor::new(vec![
+        "Option 1".into(),
+        "Option 2".into(),
+        "Option 3".into(),
+        "Option 4".into(),
+        "Option 5".into(),
+        "Option 6".into(),
+    ]);
+    let lower_rect = Rect::new(0, cursor_pos.1 - 5, terminal_rect.width, 5);
+    run_app(&mut terminal, &lower_rect, &mut options)?;
+
+    terminal.set_cursor(0, cursor_pos.1)?;
 
     // finish
     disable_raw_mode()?;
+
+    println!("Selected: {:?}", options.marked());
     Ok(())
 }
 
-fn run_app<B: Backend>(terminal: &mut Terminal<B>) -> std::io::Result<()> {
+fn run_app<B: Backend>(
+    terminal: &mut Terminal<B>,
+    pos: &Rect,
+    values: &mut Cursor,
+) -> std::io::Result<()> {
     loop {
-        terminal.draw(|f| ui(f))?;
+        terminal.draw(|f| ui(f, pos, values))?;
 
         match crossterm::event::read()? {
             crossterm::event::Event::Key(key) => {
                 if key.kind == KeyEventKind::Press {
                     match key.code {
                         KeyCode::Esc => break,
+                        KeyCode::Enter => break,
+                        KeyCode::Down => values.down(),
+                        KeyCode::Up => values.up(),
+                        KeyCode::Char(' ') => values.mark(),
                         _ => (),
                     }
                 }
@@ -47,23 +136,26 @@ fn run_app<B: Backend>(terminal: &mut Terminal<B>) -> std::io::Result<()> {
     Ok(())
 }
 
-fn ui<B: Backend>(f: &mut Frame<B>) {
-    let items = [
-        ListItem::new("Item 1"),
-        ListItem::new("Item 2"),
-        ListItem::new("Item 3"),
-    ];
-    let block = Layout::default()
-        .direction(Direction::Horizontal)
-        .constraints([Constraint::Percentage(50), Constraint::Percentage(50)].as_ref())
-        .split(f.size());
-
+fn ui<B: Backend>(f: &mut Frame<B>, pos: &Rect, cursor: &mut Cursor) {
+    let items = cursor
+        .values
+        .iter()
+        .enumerate()
+        .map(|(pos, desc)| {
+            ListItem::new(format!(
+                "{} {}",
+                if cursor.selected.contains(&pos) {
+                    "✔"
+                } else {
+                    "✕"
+                },
+                desc.to_string()
+            ))
+        })
+        .collect::<Vec<ListItem>>();
     let list = List::new(items)
-        .highlight_style(
-            Style::default()
-                .bg(Color::LightGreen)
-                .add_modifier(Modifier::BOLD),
-        )
+        // .block(Block::default().borders(Borders::ALL))
+        .highlight_style(Style::default().add_modifier(Modifier::BOLD))
         .highlight_symbol("> ");
-    f.render_widget(list, block[0]);
+    f.render_stateful_widget(list, *pos, &mut cursor.state);
 }