feat: select and copy rectangular row ranges

TODO.md

@@ -1,4 +1,4 @@
-- [ ] add selection + copy support in the rows panel.
+- [x] add selection + copy support in the rows panel.
     - should be able to select/highlight an arbitrary rectangle (like vim visual block basically)
     - should be able to copy selection
     - copied data should be formatted nicely before inserting into the clipboard (system clipboard)

src/app.rs

@@ -29,6 +29,9 @@ pub struct App {
     page: Page,
     page_index: usize,
     rows_state: TableState,
+    selection_anchor: Option<(usize, usize)>,
+    copy_headers: Option<bool>,
+    copy_status: Option<String>,
     schema_state: TableState,
     column_offset: usize,
     show_schema: bool,
@@ -55,6 +58,9 @@ impl App {
             },
             page_index: 0,
             rows_state: TableState::default(),
+            selection_anchor: None,
+            copy_headers: None,
+            copy_status: None,
             schema_state: TableState::default(),
             column_offset: 0,
             show_schema: false,
@@ -94,13 +100,127 @@ impl App {
         self.query.position()
     }
 
+    pub(crate) fn handle_rows_command(&mut self, key: KeyEvent) -> bool {
+        let pending = self.copy_headers.take();
+        if self.show_schema {
+            return false;
+        }
+        if key.modifiers.intersects(KeyModifiers::CONTROL | KeyModifiers::ALT)
+            && !(key.code == KeyCode::Char('v') && key.modifiers == KeyModifiers::CONTROL)
+        {
+            return false;
+        }
+        if let Some(headers) = pending {
+            match key.code {
+                KeyCode::Char(format @ ('m' | 'c')) => {
+                    if let Some(text) = self.selection_text(headers, format == 'm') {
+                        match copy_to_clipboard(&text) {
+                            Ok(()) => {
+                                self.error = None;
+                                self.copy_status = Some(format!(
+                                    " Copied {} {} headers ",
+                                    if format == 'm' { "Markdown" } else { "CSV" },
+                                    if headers { "with" } else { "without" },
+                                ));
+                            }
+                            Err(error) => {
+                                self.error = Some(format!("Clipboard: {}", error_text(error.as_ref())));
+                            }
+                        }
+                    }
+                    return true;
+                }
+                KeyCode::Esc => return true,
+                _ => {}
+            }
+        }
+        match key.code {
+            KeyCode::Char('v') => {
+                self.copy_status = None;
+                self.selection_anchor = if self.selection_anchor.is_some() {
+                    None
+                } else {
+                    self.rows_state.selected_cell()
+                };
+                true
+            }
+            KeyCode::Char(character @ ('y' | 'Y')) => {
+                self.copy_status = None;
+                if self.selection_bounds().is_some() {
+                    self.copy_headers = Some(character == 'y');
+                }
+                true
+            }
+            KeyCode::Esc if self.selection_anchor.is_some() => {
+                self.selection_anchor = None;
+                self.copy_status = None;
+                true
+            }
+            _ => false,
+        }
+    }
+
+    fn clear_selection(&mut self) {
+        self.selection_anchor = None;
+        self.copy_headers = None;
+        self.copy_status = None;
+    }
+
+    fn selection_bounds(&self) -> Option<(usize, usize, usize, usize)> {
+        if self.show_schema {
+            return None;
+        }
+        let (row, column) = self.rows_state.selected_cell()?;
+        let (anchor_row, anchor_column) = self.selection_anchor.unwrap_or((row, column));
+        Some((
+            row.min(anchor_row),
+            row.max(anchor_row),
+            column.min(anchor_column),
+            column.max(anchor_column),
+        ))
+    }
+
+    fn selection_text(&self, headers: bool, markdown: bool) -> Option<String> {
+        let (top, bottom, left, right) = self.selection_bounds()?;
+        let page = self.query_result.as_ref().map_or(&self.page, |result| &result.page);
+        let rows = page.rows.get(top..=bottom)?;
+        let mut output = String::new();
+        if headers {
+            append_record(
+                &mut output,
+                (left..=right).map(|column| {
+                    self.query_result.as_ref().map_or_else(
+                        || self.columns[column].label.as_str(),
+                        |result| result.headers[column].as_str(),
+                    )
+                }),
+                markdown,
+            );
+        } else if markdown {
+            append_record(&mut output, (left..=right).map(|_| ""), true);
+        }
+        if markdown {
+            append_record(&mut output, (left..=right).map(|_| "---"), true);
+        }
+        for row in rows {
+            append_record(
+                &mut output,
+                row.get(left..=right)?.iter().map(|value| value.as_deref().unwrap_or("NULL")),
+                markdown,
+            );
+        }
+        Some(output)
+    }
+
     pub(crate) fn handle_key(&mut self, key: KeyEvent) {
+        self.copy_status = None;
         match key.code {
             KeyCode::Down | KeyCode::Char('j') => self.move_selection(1),
             KeyCode::Up | KeyCode::Char('k') => self.move_selection(-1),
             KeyCode::Home | KeyCode::Char('g') => self.move_selection(isize::MIN),
             KeyCode::End | KeyCode::Char('G') => self.move_selection(isize::MAX),
             KeyCode::Char('s') if self.query_result.is_none() => {
+                self.clear_selection();
                 self.show_schema = !self.show_schema;
                 self.column_offset = 0;
             }
@@ -204,6 +324,7 @@ impl App {
     fn execute_query(&mut self) {
         match self.db.query(&self.query.value) {
             Ok(result) => {
+                self.clear_selection();
                 self.error = None;
                 if self.db.access_mode() == crate::db::AccessMode::ReadWrite {
                     self.refresh();
@@ -254,6 +375,7 @@ impl App {
     }
 
     pub(crate) fn open_relation(&mut self, index: Option<usize>) {
+        self.clear_selection();
         self.active = index;
         self.query_result = None;
         self.columns.clear();
@@ -286,6 +408,7 @@ impl App {
             // ponytail: synchronous reads block input; use a worker if responsiveness matters.
             match self.db.page(&self.relations[active], &self.columns, index) {
                 Ok(page) => {
+                    self.clear_selection();
                     self.rows_state = TableState::default()
                         .with_selected((!page.rows.is_empty()).then_some(0))
                         .with_selected_column(
@@ -340,7 +463,14 @@ impl App {
             focus == Focus::Query,
             Some(sql::text(&self.query.value, &self.query_highlights)),
         );
-        let title = if self.query_result.is_some() {
+        let title = if let Some(headers) = self.copy_headers {
+            if headers { " Copy with headers · m Markdown / c CSV " }
+            else { " Copy without headers · m Markdown / c CSV " }
+        } else if self.selection_anchor.is_some() {
+            " VISUAL BLOCK · ym/yc with headers · Ym/Yc without "
+        } else if let Some(status) = &self.copy_status {
+            status.as_str()
+        } else if self.query_result.is_some() {
             " Results "
         } else if self.show_schema {
             " Schema · s for rows "
@@ -474,18 +604,30 @@ impl App {
                     |result| result.headers[index].as_str(),
                 )
             });
-            let rows = page.rows.iter().map(|row| {
+            let bounds = self.selection_anchor.and_then(|_| self.selection_bounds());
+            let rows = page.rows.iter().enumerate().map(|(row_index, row)| {
                 Row::new(
                     row.iter()
+                        .enumerate()
                         .skip(self.column_offset)
                         .take(visible)
-                        .map(|value| match value {
+                        .map(|(column_index, value)| {
+                            let cell = match value {
                                 Some(value) => Cell::from(value.as_str()),
                                 None => Cell::from("NULL").style(
                                     Style::default()
                                         .fg(Color::DarkGray)
                                         .add_modifier(Modifier::ITALIC),
                                 ),
+                            };
+                            if bounds.is_some_and(|(top, bottom, left, right)| {
+                                (top..=bottom).contains(&row_index)
+                                    && (left..=right).contains(&column_index)
+                            }) {
+                                cell.style(selected_style())
+                            } else {
+                                cell
+                            }
                         }),
                 )
             });
@@ -507,6 +649,76 @@ impl App {
     }
 }
 
+fn append_record<'a>(
+    output: &mut String,
+    values: impl Iterator<Item = &'a str>,
+    markdown: bool,
+) {
+    if markdown {
+        output.push('|');
+    }
+    for (index, value) in values.enumerate() {
+        if markdown {
+            output.push(' ');
+            for character in value.chars() {
+                match character {
+                    '&' => output.push_str("&amp;"),
+                    '<' => output.push_str("&lt;"),
+                    '>' => output.push_str("&gt;"),
+                    '\\' | '|' | '`' | '*' | '_' | '[' | ']' => {
+                        output.push('\\');
+                        output.push(character);
+                    }
+                    _ => output.push(character),
+                }
+            }
+            output.push_str(" |");
+        } else {
+            if index > 0 {
+                output.push(',');
+            }
+            output.push('"');
+            for character in value.chars() {
+                if character == '"' {
+                    output.push('"');
+                }
+                output.push(character);
+            }
+            output.push('"');
+        }
+    }
+    output.push_str(if markdown { "\n" } else { "\r\n" });
+}
+
+fn copy_to_clipboard(text: &str) -> Result<()> {
+    use std::{io::Write, process::{Command, Stdio}};
+
+    let (program, args): (&str, &[&str]) = if cfg!(target_os = "macos") {
+        ("pbcopy", &[])
+    } else if cfg!(target_os = "windows") {
+        ("powershell.exe", &["-NoProfile", "-Command",
+            "[Console]::InputEncoding = [System.Text.UTF8Encoding]::new(); Set-Clipboard -Value ([Console]::In.ReadToEnd())"])
+    } else if std::env::var_os("WAYLAND_DISPLAY").is_some() {
+        ("wl-copy", &[])
+    } else {
+        ("xclip", &["-selection", "clipboard"])
+    };
+    let mut child = Command::new(program)
+        .args(args)
+        .stdin(Stdio::piped())
+        .stdout(Stdio::null())
+        .stderr(Stdio::null())
+        .spawn()
+        .map_err(|error| format!("could not start {program}: {error}"))?;
+    let written = child.stdin.take().unwrap().write_all(text.as_bytes());
+    let status = child.wait()?;
+    if !status.success() {
+        return Err(format!("{program} failed ({status})").into());
+    }
+    written?;
+    Ok(())
+}
+
 fn panel(title: &str, focused: bool) -> Block<'_> {
     Block::bordered()
         .title(title)
@@ -543,6 +755,90 @@ fn moved_index(selected: Option<usize>, count: usize, delta: isize) -> Option<us
 mod tests {
     use super::moved_index;
 
+    #[test]
+    fn rectangular_selection_copies_full_cells_and_resets_on_data_changes() -> crate::Result<()> {
+        use super::{App, Focus};
+        use crossterm::event::{KeyCode, KeyEvent, KeyModifiers};
+        use ratatui::{Terminal, backend::TestBackend, style::Color};
+
+        let file = tempfile::NamedTempFile::new()?;
+        rusqlite::Connection::open(file.path())?.execute_batch(
+            "CREATE TABLE cells (a, b, c, d);
+             INSERT INTO cells VALUES
+             ('outside', 'a|b', 'say \"hi\",界', 'outside'),
+             ('outside', NULL, '<&>\\tail', 'outside'),
+             ('outside', 'outside', 'outside', 'outside');
+             WITH RECURSIVE n(x) AS (VALUES(4) UNION ALL SELECT x+1 FROM n WHERE x<101)
+             INSERT INTO cells SELECT x,x,x,x FROM n;",
+        )?;
+        let mut app = App::new(crate::db::Database::open_sqlite(file.path(), Default::default())?)?;
+        let key = |character| KeyEvent::new(KeyCode::Char(character), KeyModifiers::NONE);
+        // Anchor at the bottom right, extend up and left across a scrolled viewport.
+        for character in ['j', 'l', 'l'] {
+            app.handle_key(key(character));
+        }
+        let mut terminal = Terminal::new(TestBackend::new(60, 20))?;
+        terminal.draw(|frame| app.draw(frame, frame.area(), Focus::Rows))?;
+        assert!(app.handle_rows_command(KeyEvent::new(KeyCode::Char('v'), KeyModifiers::CONTROL)));
+        app.handle_key(key('k'));
+        app.handle_key(key('h'));
+        terminal.draw(|frame| app.draw(frame, frame.area(), Focus::Rows))?;
+        let buffer = terminal.backend().buffer();
+        assert_eq!(app.column_offset, 1);
+        for position in [(1, 12), (22, 12), (1, 13), (22, 13)] {
+            assert_eq!(buffer[position].bg, Color::Blue);
+        }
+        assert_ne!(buffer[(1, 14)].bg, Color::Blue);
+        assert_eq!(
+            app.selection_text(true, true).as_deref(),
+            Some("| b | c |\n| --- | --- |\n| a\\|b | say \"hi\",界 |\n| NULL | &lt;&amp;&gt;\\\\tail |\n")
+        );
+        assert_eq!(
+            app.selection_text(false, true).as_deref(),
+            Some("|  |  |\n| --- | --- |\n| a\\|b | say \"hi\",界 |\n| NULL | &lt;&amp;&gt;\\\\tail |\n")
+        );
+        assert_eq!(
+            app.selection_text(true, false).as_deref(),
+            Some("\"b\",\"c\"\r\n\"a|b\",\"say \"\"hi\"\",界\"\r\n\"NULL\",\"<&>\\tail\"\r\n")
+        );
+        assert_eq!(
+            app.selection_text(false, false).as_deref(),
+            Some("\"a|b\",\"say \"\"hi\"\",界\"\r\n\"NULL\",\"<&>\\tail\"\r\n")
+        );
+        assert!(app.handle_rows_command(KeyEvent::new(KeyCode::Esc, KeyModifiers::NONE)));
+        assert_eq!(app.selection_text(false, false).as_deref(), Some("\"a|b\"\r\n"));
+        // A prefix cancels on focus changes rather than capturing a later key.
+        app.handle_rows_command(key('y'));
+        assert!(!app.handle_rows_command(KeyEvent::new(KeyCode::Tab, KeyModifiers::NONE)));
+        assert!(app.copy_headers.is_none());
+        app.handle_rows_command(key('v'));
+        app.handle_key(key('n'));
+        assert!(app.selection_anchor.is_none());
+        assert_eq!(app.selection_text(false, false).as_deref(), Some("\"101\"\r\n"));
+        app.handle_rows_command(key('v'));
+        app.handle_key(key('s'));
+        assert!(app.selection_anchor.is_none());
+        assert!(app.selection_text(true, true).is_none());
+        app.handle_key(key('s'));
+        app.handle_rows_command(key('v'));
+        app.query.value = "SELECT 42 AS answer".into();
+        app.execute_query();
+        assert!(app.selection_anchor.is_none());
+        assert_eq!(app.selection_text(true, false).as_deref(), Some("\"answer\"\r\n\"42\"\r\n"));
+        app.handle_rows_command(key('v'));
+        app.query.value = "SELECT missing FROM nowhere".into();
+        app.execute_query();
+        assert_eq!(app.selection_text(false, false).as_deref(), Some("\"42\"\r\n"));
+        assert!(app.selection_anchor.is_some());
+        app.open_relation(Some(0));
+        assert!(app.selection_anchor.is_none());
+        app.query.value = "SELECT * FROM cells WHERE 0".into();
+        app.execute_query();
+        app.handle_rows_command(key('v'));
+        assert!(app.selection_text(true, true).is_none());
+        Ok(())
+    }
+
     #[test]
     fn navigation_clamps_to_available_items() {
         assert_eq!(moved_index(None, 0, 1), None);

src/connection.rs

@@ -221,6 +221,8 @@ pub fn run(terminal: &mut DefaultTerminal, initial: Option<Database>) -> Result<
                     }
                 } else {
                     match key.code {
+                        _ if focus == Focus::Rows
+                            && browser.as_mut().is_some_and(|app| app.handle_rows_command(key)) => {}
                         KeyCode::Char('?')
                             if focus != Focus::Query
                                 || !browser.as_ref().is_some_and(App::query_insert_mode) =>
@@ -423,6 +425,16 @@ fn draw_help(frame: &mut Frame, screen: Rect, offset: &mut u16) {
          s                    Toggle rows / column schema\n\
          n/p, PgDn/PgUp       Next / previous 100-row relation page\n\
          r                    Refresh relations and active relation\n\n\
+         Rows / query results\n\
+         v / Ctrl-V           Toggle rectangular block; hjkl/arrows extend it\n\
+         ym / yc              Copy Markdown / CSV with column headers\n\
+         Ym / Yc              Copy Markdown / CSV without column names\n\
+         Esc                  Cancel pending copy or block before leaving rows\n\
+         With no block, copy uses the current cell. Blocks stay within the loaded page.\n\
+         Paging, refresh, schema/relation changes, and successful queries clear blocks.\n\
+         Copy uses full displayed values; NULL/control escapes are preserved.\n\
+         Headerless Markdown has blank headings. CSV quotes fields with CRLF endings.\n\
+         Clipboard: macOS pbcopy; Windows PowerShell; Wayland wl-copy; X11 xclip.\n\n\
          Query editor\n\
          i/a/I/A              Enter Insert mode (at/after/start/end)\n\
          hjkl / arrows        Move cursor in Normal mode\n\

src/main.rs

@@ -72,6 +72,16 @@ Navigation:
   s             Toggle rows and column schema
   Left/Right    Collapse/expand in explorer; select cells in rows/schema (h/l too)
   n/p, PgDn/Up  Next / previous 100-row relation page
+  v / Ctrl-V    Toggle rectangular selection in rows/results; move with hjkl/arrows
+  ym / yc       Copy the block (or current cell) as Markdown / CSV with column headers
+  Ym / Yc       Copy as Markdown / CSV without column names
+  Esc           Cancel a pending copy or block selection before returning to explorer
+  Blocks cover the current loaded page, including cells scrolled out of view.
+  Paging, refreshing, opening a relation, schema changes, and successful queries clear blocks.
+  Copies use full displayed cell values (NULL and escaped control characters included).
+  Headerless Markdown uses blank headings; CSV quotes fields and uses CRLF line endings.
+  Clipboard tools: pbcopy on macOS, PowerShell on Windows, wl-copy on Wayland,
+  or xclip on X11. A missing/failing tool reports an error without clearing the block.
   c             Add a configured database in a floating window
   i             Show configured database info (Esc/Enter closes; passwords omitted)
   Works on a saved database entry or any of its table/view children.