feat(mouse): double-click to mark word boundaries, triple-click to mark paragraph (#3996)

* double-triple click on word/line boundaries

* adjust snapshots

* style(fmt): rustfmt

9 files changed, 259 insertions, 17 deletions

diff --git a/zellij-server/src/os_input_output.rs b/zellij-server/src/os_input_output.rs
index e4263857..1ac4d64e 100644
--- a/zellij-server/src/os_input_output.rs
+++ b/zellij-server/src/os_input_output.rs
@@ -388,6 +388,7 @@ impl ClientSender {
                 sender.send(msg).with_context(err_context).non_fatal();
             }
             // If we're here, the message buffer is broken for some reason
+            log::error!("Client buffer overflow!");
             let _ = sender.send(ServerToClientMsg::Exit(ExitReason::Disconnect));
         });
         ClientSender {
diff --git a/zellij-server/src/panes/grid.rs b/zellij-server/src/panes/grid.rs
index 34f68986..4e0ba9b8 100644
--- a/zellij-server/src/panes/grid.rs
+++ b/zellij-server/src/panes/grid.rs
@@ -365,7 +365,47 @@ pub struct Grid {
     styled_underlines: bool,
     pub supports_kitty_keyboard_protocol: bool, // has the app requested kitty keyboard support?
     explicitly_disable_kitty_keyboard_protocol: bool, // has kitty keyboard support been explicitly
-                                                // disabled by user config?
+    // disabled by user config?
+    click: Click,
+}
+
+const CLICK_TIME_THRESHOLD: u128 = 400; // Doherty Threshold
+
+#[derive(Clone, Debug, Default)]
+struct Click {
+    position_and_time: Option<(Position, std::time::Instant)>,
+    count: usize,
+}
+
+impl Click {
+    pub fn record_click(&mut self, position: Position) {
+        let click_is_same_position_as_last_click = self
+            .position_and_time
+            .map(|(p, _t)| p == position)
+            .unwrap_or(false);
+        let click_is_within_time_threshold = self
+            .position_and_time
+            .map(|(_p, t)| t.elapsed().as_millis() <= CLICK_TIME_THRESHOLD)
+            .unwrap_or(false);
+        if click_is_same_position_as_last_click && click_is_within_time_threshold {
+            self.count += 1;
+        } else {
+            self.count = 1;
+        }
+        self.position_and_time = Some((position, std::time::Instant::now()));
+        if self.count == 4 {
+            self.reset();
+        }
+    }
+    pub fn is_double_click(&self) -> bool {
+        self.count == 2
+    }
+    pub fn is_triple_click(&self) -> bool {
+        self.count == 3
+    }
+    pub fn reset(&mut self) {
+        self.count = 0;
+    }
 }
 
 #[derive(Clone, Debug)]
@@ -513,6 +553,7 @@ impl Grid {
             lock_renders: false,
             supports_kitty_keyboard_protocol: false,
             explicitly_disable_kitty_keyboard_protocol,
+            click: Click::default(),
         }
     }
     pub fn render_full_viewport(&mut self) {
@@ -1478,6 +1519,8 @@ impl Grid {
                 let line_wrapped_row = Row::new();
                 self.viewport.push(line_wrapped_row);
                 self.output_buffer.update_line(self.cursor.y);
+            } else if let Some(current_line) = self.viewport.get_mut(self.cursor.y) {
+                current_line.is_canonical = false;
             }
         }
     }
@@ -1750,6 +1793,39 @@ impl Grid {
     }
     pub fn start_selection(&mut self, start: &Position) {
         let old_selection = self.selection;
+        self.click.record_click(*start);
+
+        if self.click.is_double_click() {
+            let Some((start_position, end_position)) = self.word_around_position(&start) else {
+                // no-op
+                return;
+            };
+            self.selection
+                .set_start_and_end_positions(start_position, end_position);
+            for i in std::cmp::min(start_position.line.0, end_position.line.0)
+                ..=std::cmp::max(start_position.line.0, end_position.line.0)
+            {
+                self.output_buffer.update_line(i as usize);
+            }
+            self.mark_for_rerender();
+            return;
+        } else if self.click.is_triple_click() {
+            let Some((start_position, end_position)) = self.canonical_line_around_position(&start)
+            else {
+                // no-op
+                return;
+            };
+            self.selection
+                .set_start_and_end_positions(start_position, end_position);
+            for i in std::cmp::min(start_position.line.0, end_position.line.0)
+                ..=std::cmp::max(start_position.line.0, end_position.line.0)
+            {
+                self.output_buffer.update_line(i as usize);
+            }
+            self.mark_for_rerender();
+            return;
+        }
+
         self.selection.start(*start);
         self.update_selected_lines(&old_selection, &self.selection.clone());
         self.mark_for_rerender();
@@ -1764,9 +1840,11 @@ impl Grid {
     }
 
     pub fn end_selection(&mut self, end: &Position) {
-        let old_selection = self.selection;
-        self.selection.end(*end);
-        self.update_selected_lines(&old_selection, &self.selection.clone());
+        if !self.click.is_double_click() && !self.click.is_triple_click() {
+            let old_selection = self.selection;
+            self.selection.end(*end);
+            self.update_selected_lines(&old_selection, &self.selection.clone());
+        }
         self.mark_for_rerender();
     }
 
@@ -1860,6 +1938,87 @@ impl Grid {
     pub fn absolute_position_in_scrollback(&self) -> usize {
         self.lines_above.len() + self.cursor.y
     }
+    pub fn word_around_position(&self, position: &Position) -> Option<(Position, Position)> {
+        let position_row = self.viewport.get(position.line.0 as usize)?;
+        let (index_start, index_end) =
+            position_row.word_indices_around_character_index(position.column.0)?;
+
+        let mut position_start = Position::new(position.line.0 as i32, index_start as u16);
+        let mut position_end = Position::new(position.line.0 as i32, index_end as u16);
+        let mut position_row_is_canonical = position_row.is_canonical;
+
+        while !position_row_is_canonical && position_start.column.0 == 0 {
+            if let Some(position_row_above) = self
+                .viewport
+                .get(position_start.line.0.saturating_sub(1) as usize)
+            {
+                let new_start_index = position_row_above.word_start_index_of_last_character();
+                position_start = Position::new(
+                    position_start.line.0.saturating_sub(1) as i32,
+                    new_start_index as u16,
+                );
+                position_row_is_canonical = position_row_above.is_canonical;
+            } else {
+                break;
+            }
+        }
+
+        let mut column_count_in_row = position_row.columns.len();
+        while position_end.column.0 == column_count_in_row {
+            if let Some(position_row_below) = self.viewport.get(position_end.line.0 as usize + 1) {
+                if position_row_below.is_canonical {
+                    break;
+                }
+                let new_end_index = position_row_below.word_end_index_of_first_character();
+                position_end = Position::new(position_end.line.0 as i32 + 1, new_end_index as u16);
+                column_count_in_row = position_row_below.columns.len();
+            } else {
+                break;
+            }
+        }
+
+        Some((position_start, position_end))
+    }
+    pub fn canonical_line_around_position(
+        &self,
+        position: &Position,
+    ) -> Option<(Position, Position)> {
+        let position_row = self.viewport.get(position.line.0 as usize)?;
+
+        let mut position_start = Position::new(position.line.0 as i32, 0);
+        let mut position_end =
+            Position::new(position.line.0 as i32, position_row.columns.len() as u16);
+
+        let mut found_canonical_row_start = position_row.is_canonical;
+        while !found_canonical_row_start {
+            if let Some(row_above) = self
+                .viewport
+                .get(position_start.line.0.saturating_sub(1) as usize)
+            {
+                position_start.line.0 = position_start.line.0.saturating_sub(1);
+                found_canonical_row_start = row_above.is_canonical;
+            } else {
+                break;
+            }
+        }
+
+        let mut found_canonical_row_end = false;
+        while !found_canonical_row_end {
+            if let Some(row_below) = self.viewport.get(position_end.line.0 as usize + 1) {
+                if row_below.is_canonical {
+                    found_canonical_row_end = true;
+                } else {
+                    position_end = Position::new(
+                        position_end.line.0 as i32 + 1,
+                        row_below.columns.len() as u16,
+                    );
+                }
+            } else {
+                break;
+            }
+        }
+        Some((position_start, position_end))
+    }
 
     fn update_selected_lines(&mut self, old_selection: &Selection, new_selection: &Selection) {
         for l in old_selection.diff(new_selection, self.height) {
@@ -3644,6 +3803,83 @@ impl Row {
         self.width = None;
         parts
     }
+    pub fn word_indices_around_character_index(&self, index: usize) -> Option<(usize, usize)> {
+        let character_at_index = self.columns.get(index)?;
+        if is_selection_boundary_character(character_at_index.character) {
+            return Some((index, index + 1));
+        }
+        let mut end_position = self
+            .columns
+            .iter()
+            .enumerate()
+            .skip(index)
+            .find_map(|(i, t_c)| {
+                if is_selection_boundary_character(t_c.character) {
+                    Some(i)
+                } else {
+                    None
+                }
+            })
+            .unwrap_or_else(|| self.columns.len());
+        let start_position = self
+            .columns
+            .iter()
+            .enumerate()
+            .take(index)
+            .rev()
+            .find_map(|(i, t_c)| {
+                if is_selection_boundary_character(t_c.character) {
+                    Some(i + 1)
+                } else {
+                    None
+                }
+            })
+            .unwrap_or(0);
+        if start_position == end_position {
+            // so that if this is only one character, it'll still be marked
+            end_position += 1;
+        }
+        Some((start_position, end_position))
+    }
+    pub fn word_start_index_of_last_character(&self) -> usize {
+        self.columns
+            .iter()
+            .enumerate()
+            .rev()
+            .find_map(|(i, t_c)| {
+                if is_selection_boundary_character(t_c.character) {
+                    Some(i + 1)
+                } else {
+                    None
+                }
+            })
+            .unwrap_or(0)
+    }
+    pub fn word_end_index_of_first_character(&self) -> usize {
+        self.columns
+            .iter()
+            .enumerate()
+            .find_map(|(i, t_c)| {
+                if is_selection_boundary_character(t_c.character) {
+                    Some(i)
+                } else {
+                    None
+                }
+            })
+            .unwrap_or_else(|| self.columns.len())
+    }
+}
+
+fn is_selection_boundary_character(character: char) -> bool {
+    character.is_ascii_whitespace()
+        || character == '['
+        || character == ']'
+        || character == '{'
+        || character == '}'
+        || character == '<'
+        || character == '>'
+        || character == '('
+        || character == ')'
 }
 
 #[cfg(test)]
diff --git a/zellij-server/src/panes/selection.rs b/zellij-server/src/panes/selection.rs
index cfe10c5c..cc0fa675 100644
--- a/zellij-server/src/panes/selection.rs
+++ b/zellij-server/src/panes/selection.rs
@@ -37,6 +37,11 @@ impl Selection {
         self.end = end;
     }
 
+    pub fn set_start_and_end_positions(&mut self, start: Position, end: Position) {
+        self.start = start;
+        self.end = end;
+    }
+
     pub fn contains(&self, row: usize, col: usize) -> bool {
         let row = row as isize;
         let (start, end) = if self.start <= self.end {
diff --git a/zellij-server/src/panes/terminal_pane.rs b/zellij-server/src/panes/terminal_pane.rs
index 3ad21ddc..186b8ac5 100644
--- a/zellij-server/src/panes/terminal_pane.rs
+++ b/zellij-server/src/panes/terminal_pane.rs
@@ -220,6 +220,7 @@ impl Pane for TerminalPane {
         // here we match against those cases - if need be, we adjust the input and if not
         // we send back the original input
 
+        self.reset_selection();
         if !self.grid.bracketed_paste_mode {
             // Zellij itself operates in bracketed paste mode, so the terminal sends these
             // instructions (bracketed paste start and bracketed paste end respectively)
diff --git a/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest1_3.snap b/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest1_3.snap
index f33ce414..1052e377 100644
--- a/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest1_3.snap
+++ b/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest1_3.snap
@@ -1,28 +1,28 @@
 ---
 source: zellij-server/src/panes/./unit/grid_tests.rs
+assertion_line: 148
 expression: "format!(\"{:?}\", grid)"
-
 ---
 00 (C): Test of autowrap, mixing control and print characters.                                                        
 01 (C): The left/right margins should have letters in order:                                                          
 02 (C): I                                                                                                            i
-03 (C): J                                                                                                            j
+03 (W): J                                                                                                            j
 04 (C): K                                                                                                            k
 05 (C): L                                                                                                            l
 06 (C): M                                                                                                            m
-07 (C): N                                                                                                            n
+07 (W): N                                                                                                            n
 08 (C): O                                                                                                            o
 09 (C): P                                                                                                            p
 10 (C): Q                                                                                                            q
-11 (C): R                                                                                                            r
+11 (W): R                                                                                                            r
 12 (C): S                                                                                                            s
 13 (C): T                                                                                                            t
 14 (C): U                                                                                                            u
-15 (C): V                                                                                                            v
+15 (W): V                                                                                                            v
 16 (C): W                                                                                                            w
 17 (C): X                                                                                                            x
 18 (C): Y                                                                                                            y
-19 (C): Z                                                                                                            z
+19 (W): Z                                                                                                            z
 20 (C):                                                                                                               
 21 (C): Push <RETURN>                                                                                                 
 22 (C):                                                                                                               
diff --git a/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest2_0.snap b/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest2_0.snap
index a8250e29..408dbb32 100644
--- a/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest2_0.snap
+++ b/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest2_0.snap
@@ -1,10 +1,10 @@
 ---
 source: zellij-server/src/panes/./unit/grid_tests.rs
+assertion_line: 241
 expression: "format!(\"{:?}\", grid)"
-
 ---
 00 (C): **************************************************************************************************************
-01 (C): **************************************************                                                            
+01 (W): **************************************************                                                            
 02 (C): **************************************************************************************************************
 03 (C):                                                                                                               
 04 (C): This should be three identical lines of *'s completely filling                                                
diff --git a/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest2_2.snap b/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest2_2.snap
index d751b7b5..10c900a8 100644
--- a/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest2_2.snap
+++ b/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest2_2.snap
@@ -1,10 +1,10 @@
 ---
 source: zellij-server/src/panes/./unit/grid_tests.rs
+assertion_line: 303
 expression: "format!(\"{:?}\", grid)"
-
 ---
 00 (C): 12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
-01 (C): 123456789012345678901                                                                                         
+01 (W): 123456789012345678901                                                                                         
 02 (C):   This is 132 column mode, light background.                                                                  
 03 (C):    This is 132 column mode, light background.                                                                 
 04 (C):     This is 132 column mode, light background.                                                                
diff --git a/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest2_4.snap b/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest2_4.snap
index 7c819279..8d9822c2 100644
--- a/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest2_4.snap
+++ b/zellij-server/src/panes/unit/snapshots/zellij_server__panes__grid__grid_tests__vttest2_4.snap
@@ -1,10 +1,10 @@
 ---
 source: zellij-server/src/panes/./unit/grid_tests.rs
+assertion_line: 365
 expression: "format!(\"{:?}\", grid)"
-
 ---
 00 (C): 12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
-01 (C): 123456789012345678901                                                                                         
+01 (W): 123456789012345678901                                                                                         
 02 (C):   This is 132 column mode, dark background.                                                                   
 03 (C):    This is 132 column mode, dark background.                                                                  
 04 (C):     This is 132 column mode, dark background.                                                                 
diff --git a/zellij-server/src/tab/mod.rs b/zellij-server/src/tab/mod.rs
index 8d94744c..e5a7e217 100644
--- a/zellij-server/src/tab/mod.rs
+++ b/zellij-server/src/tab/mod.rs
@@ -3587,7 +3587,6 @@ impl Tab {
                 if let PaneId::Terminal(_) = pane_with_selection.pid() {
                     if copy_on_release {
                         let selected_text = pane_with_selection.get_selected_text();
-                        pane_with_selection.reset_selection();
 
                         if let Some(selected_text) = selected_text {
                             self.write_selection_to_clipboard(&selected_text)