feature: Add ctrl-w and ctrl-h support in the search (#409)

Ctrl-w deletes one word backwards from the current cursor location. Ctrl-h is just an alias for backspace.

CHANGELOG.md

@@ -19,6 +19,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - [#406](https://github.com/ClementTsang/bottom/pull/406): Adds the Nord colour scheme, as well as a light variant.
 
+- [#409](https://github.com/ClementTsang/bottom/pull/409): Adds `Ctrl-w` and `Ctrl-h` shortcuts in search, to delete a word and delete a character respectively.
+
 ## Changes
 
 - [#372](https://github.com/ClementTsang/bottom/pull/372): Hides the SWAP graph and legend in normal mode if SWAP is 0.

README.md

@@ -333,6 +333,8 @@ Use `btm --help` for more information.
 | `Ctrl-a`      | Skip to the start of the search query        |
 | `Ctrl-e`      | Skip to the end of the search query          |
 | `Ctrl-u`      | Clear the current search query               |
+| `Ctrl-w`      | Delete a word behind the cursor              |
+| `Ctrl-h`      | Delete the character behind the cursor       |
 | `Backspace`   | Delete the character behind the cursor       |
 | `Delete`      | Delete the character at the cursor           |
 | `Alt-c`, `F1` | Toggle matching case                         |

src/app.rs

@@ -725,17 +725,22 @@ impl App {
                                 .current_search_query
                                 .len()
                     {
+                        let current_cursor = proc_widget_state.get_search_cursor_position();
                         proc_widget_state
+                            .search_walk_forward(proc_widget_state.get_search_cursor_position());
+
+                        let _removed_chars: String = proc_widget_state
                             .process_search_state
                             .search_state
                             .current_search_query
-                            .remove(proc_widget_state.get_search_cursor_position());
+                            .drain(current_cursor..proc_widget_state.get_search_cursor_position())
+                            .collect();
 
                         proc_widget_state
                             .process_search_state
                             .search_state
                             .grapheme_cursor = GraphemeCursor::new(
-                            proc_widget_state.get_search_cursor_position(),
+                            current_cursor,
                             proc_widget_state
                                 .process_search_state
                                 .search_state
@@ -769,14 +774,16 @@ impl App {
                         .is_enabled
                     && proc_widget_state.get_search_cursor_position() > 0
                 {
+                    let current_cursor = proc_widget_state.get_search_cursor_position();
                     proc_widget_state
                         .search_walk_back(proc_widget_state.get_search_cursor_position());
 
-                    let removed_char = proc_widget_state
+                    let removed_chars: String = proc_widget_state
                         .process_search_state
                         .search_state
                         .current_search_query
-                        .remove(proc_widget_state.get_search_cursor_position());
+                        .drain(proc_widget_state.get_search_cursor_position()..current_cursor)
+                        .collect();
 
                     proc_widget_state
                         .process_search_state
@@ -794,7 +801,8 @@ impl App {
                     proc_widget_state
                         .process_search_state
                         .search_state
-                        .char_cursor_position -= UnicodeWidthChar::width(removed_char).unwrap_or(0);
+                        .char_cursor_position -= UnicodeWidthStr::width(removed_chars.as_str());
+
                     proc_widget_state
                         .process_search_state
                         .search_state
@@ -1167,6 +1175,82 @@ impl App {
         }
     }
 
+    pub fn clear_previous_word(&mut self) {
+        if let BottomWidgetType::ProcSearch = self.current_widget.widget_type {
+            if let Some(proc_widget_state) = self
+                .proc_state
+                .widget_states
+                .get_mut(&(self.current_widget.widget_id - 1))
+            {
+                // Traverse backwards from the current cursor location until you hit non-whitespace characters,
+                // then continue to traverse (and delete) backwards until you hit a whitespace character.  Halt.
+
+                // So... first, let's get our current cursor position using graphemes...
+                let end_index = proc_widget_state.get_char_cursor_position();
+
+                // Then, let's crawl backwards until we hit our location, and store the "head"...
+                let query = proc_widget_state.get_current_search_query();
+                let mut start_index = 0;
+                let mut saw_non_whitespace = false;
+
+                for (itx, c) in query
+                    .chars()
+                    .rev()
+                    .enumerate()
+                    .skip(query.len() - end_index)
+                {
+                    if c.is_whitespace() {
+                        if saw_non_whitespace {
+                            start_index = query.len() - itx;
+                            break;
+                        }
+                    } else {
+                        saw_non_whitespace = true;
+                    }
+                }
+
+                let removed_chars: String = proc_widget_state
+                    .process_search_state
+                    .search_state
+                    .current_search_query
+                    .drain(start_index..end_index)
+                    .collect();
+
+                proc_widget_state
+                    .process_search_state
+                    .search_state
+                    .grapheme_cursor = GraphemeCursor::new(
+                    start_index,
+                    proc_widget_state
+                        .process_search_state
+                        .search_state
+                        .current_search_query
+                        .len(),
+                    true,
+                );
+
+                proc_widget_state
+                    .process_search_state
+                    .search_state
+                    .char_cursor_position -= UnicodeWidthStr::width(removed_chars.as_str());
+
+                proc_widget_state
+                    .process_search_state
+                    .search_state
+                    .cursor_direction = CursorDirection::Left;
+
+                proc_widget_state.update_query();
+                self.proc_state.force_update = Some(self.current_widget.widget_id - 1);
+
+                // Now, convert this range into a String-friendly range and remove it all at once!
+
+                // Now make sure to also update our current cursor positions...
+
+                self.proc_state.force_update = Some(self.current_widget.widget_id - 1);
+            }
+        }
+    }
+
     pub fn start_dd(&mut self) {
         self.reset_multi_tap_keys();
 

src/canvas/widgets/process_table.rs

@@ -549,7 +549,7 @@ impl ProcessTableWidget for Painter {
                     })
                     .collect::<Vec<_>>();
 
-                if cursor_position >= query.len() {
+                if cursor_position == query.len() {
                     res.push(Span::styled(" ", currently_selected_text_style))
                 }
 
@@ -558,17 +558,7 @@ impl ProcessTableWidget for Painter {
                 // This is easier - we just need to get a range of graphemes, rather than
                 // dealing with possibly inserting a cursor (as none is shown!)
 
-                grapheme_indices
+                vec![Span::styled(query.to_string(), text_style)]
-                    .filter_map(|grapheme| {
-                        current_grapheme_posn += UnicodeWidthStr::width(grapheme.1);
-                        if current_grapheme_posn <= start_position {
-                            None
-                        } else {
-                            let styled = Span::styled(grapheme.1, text_style);
-                            Some(styled)
-                        }
-                    })
-                    .collect::<Vec<_>>()
             }
         }
 
@@ -622,6 +612,7 @@ impl ProcessTableWidget for Painter {
                     },
                 )];
                 search_vec.extend(query_with_cursor);
+
                 search_vec
             })];
 

src/constants.rs

@@ -271,13 +271,15 @@ pub const PROCESS_HELP_TEXT: [&str; 14] = [
     "+, -, click      Collapse/expand a branch while in tree mode",
 ];
 
-pub const SEARCH_HELP_TEXT: [&str; 46] = [
+pub const SEARCH_HELP_TEXT: [&str; 48] = [
     "4 - Process search widget",
     "Tab              Toggle between searching for PID and name",
     "Esc              Close the search widget (retains the filter)",
     "Ctrl-a           Skip to the start of the search query",
     "Ctrl-e           Skip to the end of the search query",
     "Ctrl-u           Clear the current search query",
+    "Ctrl-w           Delete a word behind the cursor",
+    "Ctrl-h           Delete the character behind the cursor",
     "Backspace        Delete the character behind the cursor",
     "Delete           Delete the character at the cursor",
     "Alt-c, F1        Toggle matching case",

src/lib.rs

@@ -157,6 +157,8 @@ pub fn handle_key_event_or_break(
                 KeyCode::Char('a') => app.skip_cursor_beginning(),
                 KeyCode::Char('e') => app.skip_cursor_end(),
                 KeyCode::Char('u') => app.clear_search(),
+                KeyCode::Char('w') => app.clear_previous_word(),
+                KeyCode::Char('h') => app.on_backspace(),
                 // KeyCode::Char('j') => {}, // Move down
                 // KeyCode::Char('k') => {}, // Move up
                 // KeyCode::Char('h') => {}, // Move right