terminal_element.rs

  1use alacritty_terminal::{
  2    ansi::{Color as AnsiColor, Color::Named, CursorShape as AlacCursorShape, NamedColor},
  3    grid::Dimensions,
  4    index::Point,
  5    selection::SelectionRange,
  6    term::{
  7        cell::{Cell, Flags},
  8        TermMode,
  9    },
 10};
 11use editor::{Cursor, CursorShape, HighlightedRange, HighlightedRangeLine};
 12use gpui::{
 13    color::Color,
 14    fonts::{Properties, Style::Italic, TextStyle, Underline, Weight},
 15    geometry::{
 16        rect::RectF,
 17        vector::{vec2f, Vector2F},
 18    },
 19    serde_json::json,
 20    text_layout::{Line, RunStyle},
 21    Element, Event, EventContext, FontCache, KeyDownEvent, ModelContext, MouseButton,
 22    MouseButtonEvent, MouseRegion, PaintContext, Quad, TextLayoutCache, WeakModelHandle,
 23    WeakViewHandle,
 24};
 25use itertools::Itertools;
 26use ordered_float::OrderedFloat;
 27use settings::Settings;
 28use theme::TerminalStyle;
 29use util::ResultExt;
 30
 31use std::fmt::Debug;
 32use std::{
 33    mem,
 34    ops::{Deref, Range},
 35};
 36
 37use crate::{
 38    mappings::colors::convert_color,
 39    terminal_view::{DeployContextMenu, TerminalView},
 40    Terminal, TerminalSize,
 41};
 42
 43///The information generated during layout that is nescessary for painting
 44pub struct LayoutState {
 45    cells: Vec<LayoutCell>,
 46    rects: Vec<LayoutRect>,
 47    highlights: Vec<RelativeHighlightedRange>,
 48    cursor: Option<Cursor>,
 49    background_color: Color,
 50    selection_color: Color,
 51    size: TerminalSize,
 52    mode: TermMode,
 53}
 54
 55#[derive(Debug)]
 56struct IndexedCell {
 57    point: Point,
 58    cell: Cell,
 59}
 60
 61impl Deref for IndexedCell {
 62    type Target = Cell;
 63
 64    #[inline]
 65    fn deref(&self) -> &Cell {
 66        &self.cell
 67    }
 68}
 69
 70///Helper struct for converting data between alacritty's cursor points, and displayed cursor points
 71struct DisplayCursor {
 72    line: i32,
 73    col: usize,
 74}
 75
 76impl DisplayCursor {
 77    fn from(cursor_point: Point, display_offset: usize) -> Self {
 78        Self {
 79            line: cursor_point.line.0 + display_offset as i32,
 80            col: cursor_point.column.0,
 81        }
 82    }
 83
 84    pub fn line(&self) -> i32 {
 85        self.line
 86    }
 87
 88    pub fn col(&self) -> usize {
 89        self.col
 90    }
 91}
 92
 93#[derive(Clone, Debug, Default)]
 94struct LayoutCell {
 95    point: Point<i32, i32>,
 96    text: Line,
 97}
 98
 99impl LayoutCell {
100    fn new(point: Point<i32, i32>, text: Line) -> LayoutCell {
101        LayoutCell { point, text }
102    }
103
104    fn paint(
105        &self,
106        origin: Vector2F,
107        layout: &LayoutState,
108        visible_bounds: RectF,
109        cx: &mut PaintContext,
110    ) {
111        let pos = {
112            let point = self.point;
113            vec2f(
114                (origin.x() + point.column as f32 * layout.size.cell_width).floor(),
115                origin.y() + point.line as f32 * layout.size.line_height,
116            )
117        };
118
119        self.text
120            .paint(pos, visible_bounds, layout.size.line_height, cx);
121    }
122}
123
124#[derive(Clone, Debug, Default)]
125struct LayoutRect {
126    point: Point<i32, i32>,
127    num_of_cells: usize,
128    color: Color,
129}
130
131impl LayoutRect {
132    fn new(point: Point<i32, i32>, num_of_cells: usize, color: Color) -> LayoutRect {
133        LayoutRect {
134            point,
135            num_of_cells,
136            color,
137        }
138    }
139
140    fn extend(&self) -> Self {
141        LayoutRect {
142            point: self.point,
143            num_of_cells: self.num_of_cells + 1,
144            color: self.color,
145        }
146    }
147
148    fn paint(&self, origin: Vector2F, layout: &LayoutState, cx: &mut PaintContext) {
149        let position = {
150            let point = self.point;
151            vec2f(
152                (origin.x() + point.column as f32 * layout.size.cell_width).floor(),
153                origin.y() + point.line as f32 * layout.size.line_height,
154            )
155        };
156        let size = vec2f(
157            (layout.size.cell_width * self.num_of_cells as f32).ceil(),
158            layout.size.line_height,
159        );
160
161        cx.scene.push_quad(Quad {
162            bounds: RectF::new(position, size),
163            background: Some(self.color),
164            border: Default::default(),
165            corner_radius: 0.,
166        })
167    }
168}
169
170#[derive(Clone, Debug, Default)]
171struct RelativeHighlightedRange {
172    line_index: usize,
173    range: Range<usize>,
174}
175
176impl RelativeHighlightedRange {
177    fn new(line_index: usize, range: Range<usize>) -> Self {
178        RelativeHighlightedRange { line_index, range }
179    }
180
181    fn to_highlighted_range_line(
182        &self,
183        origin: Vector2F,
184        layout: &LayoutState,
185    ) -> HighlightedRangeLine {
186        let start_x = origin.x() + self.range.start as f32 * layout.size.cell_width;
187        let end_x =
188            origin.x() + self.range.end as f32 * layout.size.cell_width + layout.size.cell_width;
189
190        HighlightedRangeLine { start_x, end_x }
191    }
192}
193
194///The GPUI element that paints the terminal.
195///We need to keep a reference to the view for mouse events, do we need it for any other terminal stuff, or can we move that to connection?
196pub struct TerminalElement {
197    terminal: WeakModelHandle<Terminal>,
198    view: WeakViewHandle<TerminalView>,
199    modal: bool,
200    focused: bool,
201    cursor_visible: bool,
202}
203
204impl TerminalElement {
205    pub fn new(
206        view: WeakViewHandle<TerminalView>,
207        terminal: WeakModelHandle<Terminal>,
208        modal: bool,
209        focused: bool,
210        cursor_visible: bool,
211    ) -> TerminalElement {
212        TerminalElement {
213            view,
214            terminal,
215            modal,
216            focused,
217            cursor_visible,
218        }
219    }
220
221    fn layout_grid(
222        grid: Vec<IndexedCell>,
223        text_style: &TextStyle,
224        terminal_theme: &TerminalStyle,
225        text_layout_cache: &TextLayoutCache,
226        font_cache: &FontCache,
227        modal: bool,
228        selection_range: Option<SelectionRange>,
229    ) -> (
230        Vec<LayoutCell>,
231        Vec<LayoutRect>,
232        Vec<RelativeHighlightedRange>,
233    ) {
234        let mut cells = vec![];
235        let mut rects = vec![];
236        let mut highlight_ranges = vec![];
237
238        let mut cur_rect: Option<LayoutRect> = None;
239        let mut cur_alac_color = None;
240        let mut highlighted_range = None;
241
242        let linegroups = grid.into_iter().group_by(|i| i.point.line);
243        for (line_index, (_, line)) in linegroups.into_iter().enumerate() {
244            for (x_index, cell) in line.enumerate() {
245                let mut fg = cell.fg;
246                let mut bg = cell.bg;
247                if cell.flags.contains(Flags::INVERSE) {
248                    mem::swap(&mut fg, &mut bg);
249                }
250
251                //Increase selection range
252                {
253                    if selection_range
254                        .map(|range| range.contains(cell.point))
255                        .unwrap_or(false)
256                    {
257                        let mut range = highlighted_range.take().unwrap_or(x_index..x_index);
258                        range.end = range.end.max(x_index);
259                        highlighted_range = Some(range);
260                    }
261                }
262
263                //Expand background rect range
264                {
265                    if matches!(bg, Named(NamedColor::Background)) {
266                        //Continue to next cell, resetting variables if nescessary
267                        cur_alac_color = None;
268                        if let Some(rect) = cur_rect {
269                            rects.push(rect);
270                            cur_rect = None
271                        }
272                    } else {
273                        match cur_alac_color {
274                            Some(cur_color) => {
275                                if bg == cur_color {
276                                    cur_rect = cur_rect.take().map(|rect| rect.extend());
277                                } else {
278                                    cur_alac_color = Some(bg);
279                                    if cur_rect.is_some() {
280                                        rects.push(cur_rect.take().unwrap());
281                                    }
282                                    cur_rect = Some(LayoutRect::new(
283                                        Point::new(line_index as i32, cell.point.column.0 as i32),
284                                        1,
285                                        convert_color(&bg, &terminal_theme.colors, modal),
286                                    ));
287                                }
288                            }
289                            None => {
290                                cur_alac_color = Some(bg);
291                                cur_rect = Some(LayoutRect::new(
292                                    Point::new(line_index as i32, cell.point.column.0 as i32),
293                                    1,
294                                    convert_color(&bg, &terminal_theme.colors, modal),
295                                ));
296                            }
297                        }
298                    }
299                }
300
301                //Layout current cell text
302                {
303                    let cell_text = &cell.c.to_string();
304                    if cell_text != " " {
305                        let cell_style = TerminalElement::cell_style(
306                            &cell,
307                            fg,
308                            terminal_theme,
309                            text_style,
310                            font_cache,
311                            modal,
312                        );
313
314                        let layout_cell = text_layout_cache.layout_str(
315                            cell_text,
316                            text_style.font_size,
317                            &[(cell_text.len(), cell_style)],
318                        );
319
320                        cells.push(LayoutCell::new(
321                            Point::new(line_index as i32, cell.point.column.0 as i32),
322                            layout_cell,
323                        ))
324                    }
325                };
326            }
327
328            if highlighted_range.is_some() {
329                highlight_ranges.push(RelativeHighlightedRange::new(
330                    line_index,
331                    highlighted_range.take().unwrap(),
332                ))
333            }
334
335            if cur_rect.is_some() {
336                rects.push(cur_rect.take().unwrap());
337            }
338        }
339        (cells, rects, highlight_ranges)
340    }
341
342    // Compute the cursor position and expected block width, may return a zero width if x_for_index returns
343    // the same position for sequential indexes. Use em_width instead
344    fn shape_cursor(
345        cursor_point: DisplayCursor,
346        size: TerminalSize,
347        text_fragment: &Line,
348    ) -> Option<(Vector2F, f32)> {
349        if cursor_point.line() < size.total_lines() as i32 {
350            let cursor_width = if text_fragment.width() == 0. {
351                size.cell_width()
352            } else {
353                text_fragment.width()
354            };
355
356            //Cursor should always surround as much of the text as possible,
357            //hence when on pixel boundaries round the origin down and the width up
358            Some((
359                vec2f(
360                    (cursor_point.col() as f32 * size.cell_width()).floor(),
361                    (cursor_point.line() as f32 * size.line_height()).floor(),
362                ),
363                cursor_width.ceil(),
364            ))
365        } else {
366            None
367        }
368    }
369
370    ///Convert the Alacritty cell styles to GPUI text styles and background color
371    fn cell_style(
372        indexed: &IndexedCell,
373        fg: AnsiColor,
374        style: &TerminalStyle,
375        text_style: &TextStyle,
376        font_cache: &FontCache,
377        modal: bool,
378    ) -> RunStyle {
379        let flags = indexed.cell.flags;
380        let fg = convert_color(&fg, &style.colors, modal);
381
382        let underline = flags
383            .intersects(Flags::ALL_UNDERLINES)
384            .then(|| Underline {
385                color: Some(fg),
386                squiggly: flags.contains(Flags::UNDERCURL),
387                thickness: OrderedFloat(1.),
388            })
389            .unwrap_or_default();
390
391        let mut properties = Properties::new();
392        if indexed
393            .flags
394            .intersects(Flags::BOLD | Flags::BOLD_ITALIC | Flags::DIM_BOLD)
395        {
396            properties = *properties.weight(Weight::BOLD);
397        }
398        if indexed.flags.intersects(Flags::ITALIC | Flags::BOLD_ITALIC) {
399            properties = *properties.style(Italic);
400        }
401
402        let font_id = font_cache
403            .select_font(text_style.font_family_id, &properties)
404            .unwrap_or(text_style.font_id);
405
406        RunStyle {
407            color: fg,
408            font_id,
409            underline,
410        }
411    }
412
413    fn generic_button_handler(
414        connection: WeakModelHandle<Terminal>,
415        origin: Vector2F,
416        f: impl Fn(&mut Terminal, Vector2F, MouseButtonEvent, &mut ModelContext<Terminal>),
417    ) -> impl Fn(MouseButtonEvent, &mut EventContext) {
418        move |event, cx| {
419            cx.focus_parent_view();
420            if let Some(conn_handle) = connection.upgrade(cx.app) {
421                conn_handle.update(cx.app, |terminal, cx| {
422                    f(terminal, origin, event, cx);
423
424                    cx.notify();
425                })
426            }
427        }
428    }
429
430    fn attach_mouse_handlers(
431        &self,
432        origin: Vector2F,
433        view_id: usize,
434        visible_bounds: RectF,
435        mode: TermMode,
436        cx: &mut PaintContext,
437    ) {
438        let connection = self.terminal;
439
440        let mut region = MouseRegion::new(view_id, None, visible_bounds);
441
442        // Terminal Emulator controlled behavior:
443        region = region
444            // Start selections
445            .on_down(
446                MouseButton::Left,
447                TerminalElement::generic_button_handler(
448                    connection,
449                    origin,
450                    move |terminal, origin, e, _cx| {
451                        terminal.mouse_down(&e, origin);
452                    },
453                ),
454            )
455            // Update drag selections
456            .on_drag(MouseButton::Left, move |_prev, event, cx| {
457                if cx.is_parent_view_focused() {
458                    if let Some(conn_handle) = connection.upgrade(cx.app) {
459                        conn_handle.update(cx.app, |terminal, cx| {
460                            terminal.mouse_drag(event, origin);
461                            cx.notify();
462                        })
463                    }
464                }
465            })
466            // Copy on up behavior
467            .on_up(
468                MouseButton::Left,
469                TerminalElement::generic_button_handler(
470                    connection,
471                    origin,
472                    move |terminal, origin, e, _cx| {
473                        terminal.mouse_up(&e, origin);
474                    },
475                ),
476            )
477            // Handle click based selections
478            .on_click(
479                MouseButton::Left,
480                TerminalElement::generic_button_handler(
481                    connection,
482                    origin,
483                    move |terminal, origin, e, _cx| {
484                        terminal.left_click(&e, origin);
485                    },
486                ),
487            )
488            // Context menu
489            .on_click(
490                MouseButton::Right,
491                move |e @ MouseButtonEvent { position, .. }, cx| {
492                    let mouse_mode = if let Some(conn_handle) = connection.upgrade(cx.app) {
493                        conn_handle.update(cx.app, |terminal, _cx| terminal.mouse_mode(e.shift))
494                    } else {
495                        // If we can't get the model handle, probably can't deploy the context menu
496                        true
497                    };
498                    if !mouse_mode {
499                        cx.dispatch_action(DeployContextMenu { position });
500                    }
501                },
502            );
503
504        // Mouse mode handlers:
505        // All mouse modes need the extra click handlers
506        if mode.intersects(TermMode::MOUSE_MODE) {
507            region = region
508                .on_down(
509                    MouseButton::Right,
510                    TerminalElement::generic_button_handler(
511                        connection,
512                        origin,
513                        move |terminal, origin, e, _cx| {
514                            terminal.mouse_down(&e, origin);
515                        },
516                    ),
517                )
518                .on_down(
519                    MouseButton::Middle,
520                    TerminalElement::generic_button_handler(
521                        connection,
522                        origin,
523                        move |terminal, origin, e, _cx| {
524                            terminal.mouse_down(&e, origin);
525                        },
526                    ),
527                )
528                .on_up(
529                    MouseButton::Right,
530                    TerminalElement::generic_button_handler(
531                        connection,
532                        origin,
533                        move |terminal, origin, e, _cx| {
534                            terminal.mouse_up(&e, origin);
535                        },
536                    ),
537                )
538                .on_up(
539                    MouseButton::Middle,
540                    TerminalElement::generic_button_handler(
541                        connection,
542                        origin,
543                        move |terminal, origin, e, _cx| {
544                            terminal.mouse_up(&e, origin);
545                        },
546                    ),
547                )
548        }
549        //Mouse move manages both dragging and motion events
550        if mode.intersects(TermMode::MOUSE_DRAG | TermMode::MOUSE_MOTION) {
551            region = region
552                //TODO: This does not fire on right-mouse-down-move events.
553                .on_move(move |event, cx| {
554                    if cx.is_parent_view_focused() {
555                        if let Some(conn_handle) = connection.upgrade(cx.app) {
556                            conn_handle.update(cx.app, |terminal, cx| {
557                                terminal.mouse_move(&event, origin);
558                                cx.notify();
559                            })
560                        }
561                    }
562                })
563        }
564
565        cx.scene.push_mouse_region(region);
566    }
567
568    ///Configures a text style from the current settings.
569    pub fn make_text_style(font_cache: &FontCache, settings: &Settings) -> TextStyle {
570        // Pull the font family from settings properly overriding
571        let family_id = settings
572            .terminal_overrides
573            .font_family
574            .as_ref()
575            .or(settings.terminal_defaults.font_family.as_ref())
576            .and_then(|family_name| font_cache.load_family(&[family_name]).log_err())
577            .unwrap_or(settings.buffer_font_family);
578
579        let font_size = settings
580            .terminal_overrides
581            .font_size
582            .or(settings.terminal_defaults.font_size)
583            .unwrap_or(settings.buffer_font_size);
584
585        let font_id = font_cache
586            .select_font(family_id, &Default::default())
587            .unwrap();
588
589        TextStyle {
590            color: settings.theme.editor.text_color,
591            font_family_id: family_id,
592            font_family_name: font_cache.family_name(family_id).unwrap(),
593            font_id,
594            font_size,
595            font_properties: Default::default(),
596            underline: Default::default(),
597        }
598    }
599}
600
601impl Element for TerminalElement {
602    type LayoutState = LayoutState;
603    type PaintState = ();
604
605    fn layout(
606        &mut self,
607        constraint: gpui::SizeConstraint,
608        cx: &mut gpui::LayoutContext,
609    ) -> (gpui::geometry::vector::Vector2F, Self::LayoutState) {
610        let settings = cx.global::<Settings>();
611        let font_cache = cx.font_cache();
612
613        //Setup layout information
614        let terminal_theme = settings.theme.terminal.clone(); //TODO: Try to minimize this clone.
615        let text_style = TerminalElement::make_text_style(font_cache, settings);
616        let selection_color = settings.theme.editor.selection.selection;
617        let dimensions = {
618            let line_height = font_cache.line_height(text_style.font_size);
619            let cell_width = font_cache.em_advance(text_style.font_id, text_style.font_size);
620            TerminalSize::new(line_height, cell_width, constraint.max)
621        };
622
623        let background_color = if self.modal {
624            terminal_theme.colors.modal_background
625        } else {
626            terminal_theme.colors.background
627        };
628
629        let (cells, selection, cursor, display_offset, cursor_text, mode) = self
630            .terminal
631            .upgrade(cx)
632            .unwrap()
633            .update(cx.app, |terminal, mcx| {
634                terminal.set_size(dimensions);
635                terminal.render_lock(mcx, |content, cursor_text| {
636                    let mut cells = vec![];
637                    cells.extend(
638                        content
639                            .display_iter
640                            //TODO: Add this once there's a way to retain empty lines
641                            // .filter(|ic| {
642                            //     !ic.flags.contains(Flags::HIDDEN)
643                            //         && !(ic.bg == Named(NamedColor::Background)
644                            //             && ic.c == ' '
645                            //             && !ic.flags.contains(Flags::INVERSE))
646                            // })
647                            .map(|ic| IndexedCell {
648                                point: ic.point,
649                                cell: ic.cell.clone(),
650                            }),
651                    );
652                    (
653                        cells,
654                        content.selection,
655                        content.cursor,
656                        content.display_offset,
657                        cursor_text,
658                        content.mode,
659                    )
660                })
661            });
662
663        let (cells, rects, highlights) = TerminalElement::layout_grid(
664            cells,
665            &text_style,
666            &terminal_theme,
667            cx.text_layout_cache,
668            cx.font_cache(),
669            self.modal,
670            selection,
671        );
672
673        //Layout cursor. Rectangle is used for IME, so we should lay it out even
674        //if we don't end up showing it.
675        let cursor = if let AlacCursorShape::Hidden = cursor.shape {
676            None
677        } else {
678            let cursor_point = DisplayCursor::from(cursor.point, display_offset);
679            let cursor_text = {
680                let str_trxt = cursor_text.to_string();
681
682                let color = if self.focused {
683                    terminal_theme.colors.background
684                } else {
685                    terminal_theme.colors.foreground
686                };
687
688                cx.text_layout_cache.layout_str(
689                    &str_trxt,
690                    text_style.font_size,
691                    &[(
692                        str_trxt.len(),
693                        RunStyle {
694                            font_id: text_style.font_id,
695                            color,
696                            underline: Default::default(),
697                        },
698                    )],
699                )
700            };
701
702            TerminalElement::shape_cursor(cursor_point, dimensions, &cursor_text).map(
703                move |(cursor_position, block_width)| {
704                    let shape = match cursor.shape {
705                        AlacCursorShape::Block if !self.focused => CursorShape::Hollow,
706                        AlacCursorShape::Block => CursorShape::Block,
707                        AlacCursorShape::Underline => CursorShape::Underscore,
708                        AlacCursorShape::Beam => CursorShape::Bar,
709                        AlacCursorShape::HollowBlock => CursorShape::Hollow,
710                        //This case is handled in the if wrapping the whole cursor layout
711                        AlacCursorShape::Hidden => unreachable!(),
712                    };
713
714                    Cursor::new(
715                        cursor_position,
716                        block_width,
717                        dimensions.line_height,
718                        terminal_theme.colors.cursor,
719                        shape,
720                        Some(cursor_text),
721                    )
722                },
723            )
724        };
725
726        //Done!
727        (
728            constraint.max,
729            LayoutState {
730                cells,
731                cursor,
732                background_color,
733                selection_color,
734                size: dimensions,
735                rects,
736                highlights,
737                mode,
738            },
739        )
740    }
741
742    fn paint(
743        &mut self,
744        bounds: gpui::geometry::rect::RectF,
745        visible_bounds: gpui::geometry::rect::RectF,
746        layout: &mut Self::LayoutState,
747        cx: &mut gpui::PaintContext,
748    ) -> Self::PaintState {
749        //Setup element stuff
750        let clip_bounds = Some(visible_bounds);
751
752        cx.paint_layer(clip_bounds, |cx| {
753            let origin = bounds.origin() + vec2f(layout.size.cell_width, 0.);
754
755            //Elements are ephemeral, only at paint time do we know what could be clicked by a mouse
756            self.attach_mouse_handlers(origin, self.view.id(), visible_bounds, layout.mode, cx);
757
758            cx.paint_layer(clip_bounds, |cx| {
759                //Start with a background color
760                cx.scene.push_quad(Quad {
761                    bounds: RectF::new(bounds.origin(), bounds.size()),
762                    background: Some(layout.background_color),
763                    border: Default::default(),
764                    corner_radius: 0.,
765                });
766
767                for rect in &layout.rects {
768                    rect.paint(origin, layout, cx)
769                }
770            });
771
772            //Draw Selection
773            cx.paint_layer(clip_bounds, |cx| {
774                let start_y = layout.highlights.get(0).map(|highlight| {
775                    origin.y() + highlight.line_index as f32 * layout.size.line_height
776                });
777
778                if let Some(y) = start_y {
779                    let range_lines = layout
780                        .highlights
781                        .iter()
782                        .map(|relative_highlight| {
783                            relative_highlight.to_highlighted_range_line(origin, layout)
784                        })
785                        .collect::<Vec<HighlightedRangeLine>>();
786
787                    let hr = HighlightedRange {
788                        start_y: y, //Need to change this
789                        line_height: layout.size.line_height,
790                        lines: range_lines,
791                        color: layout.selection_color,
792                        //Copied from editor. TODO: move to theme or something
793                        corner_radius: 0.15 * layout.size.line_height,
794                    };
795                    hr.paint(bounds, cx.scene);
796                }
797            });
798
799            //Draw the text cells
800            cx.paint_layer(clip_bounds, |cx| {
801                for cell in &layout.cells {
802                    cell.paint(origin, layout, visible_bounds, cx);
803                }
804            });
805
806            //Draw cursor
807            if self.cursor_visible {
808                if let Some(cursor) = &layout.cursor {
809                    cx.paint_layer(clip_bounds, |cx| {
810                        cursor.paint(origin, cx);
811                    })
812                }
813            }
814        });
815    }
816
817    fn dispatch_event(
818        &mut self,
819        event: &gpui::Event,
820        bounds: gpui::geometry::rect::RectF,
821        visible_bounds: gpui::geometry::rect::RectF,
822        layout: &mut Self::LayoutState,
823        _paint: &mut Self::PaintState,
824        cx: &mut gpui::EventContext,
825    ) -> bool {
826        match event {
827            Event::ScrollWheel(e) => visible_bounds
828                .contains_point(e.position)
829                .then(|| {
830                    let origin = bounds.origin() + vec2f(layout.size.cell_width, 0.);
831
832                    if let Some(terminal) = self.terminal.upgrade(cx.app) {
833                        terminal.update(cx.app, |term, _| term.scroll(e, origin));
834                        cx.notify();
835                    }
836                })
837                .is_some(),
838            Event::KeyDown(KeyDownEvent { keystroke, .. }) => {
839                if !cx.is_parent_view_focused() {
840                    return false;
841                }
842
843                if let Some(view) = self.view.upgrade(cx.app) {
844                    view.update(cx.app, |view, cx| {
845                        view.clear_bel(cx);
846                        view.pause_cursor_blinking(cx);
847                    })
848                }
849
850                self.terminal
851                    .upgrade(cx.app)
852                    .map(|model_handle| {
853                        model_handle.update(cx.app, |term, _| term.try_keystroke(keystroke))
854                    })
855                    .unwrap_or(false)
856            }
857            _ => false,
858        }
859    }
860
861    fn metadata(&self) -> Option<&dyn std::any::Any> {
862        None
863    }
864
865    fn debug(
866        &self,
867        _bounds: gpui::geometry::rect::RectF,
868        _layout: &Self::LayoutState,
869        _paint: &Self::PaintState,
870        _cx: &gpui::DebugContext,
871    ) -> gpui::serde_json::Value {
872        json!({
873            "type": "TerminalElement",
874        })
875    }
876
877    fn rect_for_text_range(
878        &self,
879        _: Range<usize>,
880        bounds: RectF,
881        _: RectF,
882        layout: &Self::LayoutState,
883        _: &Self::PaintState,
884        _: &gpui::MeasurementContext,
885    ) -> Option<RectF> {
886        // Use the same origin that's passed to `Cursor::paint` in the paint
887        // method bove.
888        let mut origin = bounds.origin() + vec2f(layout.size.cell_width, 0.);
889
890        // TODO - Why is it necessary to move downward one line to get correct
891        // positioning? I would think that we'd want the same rect that is
892        // painted for the cursor.
893        origin += vec2f(0., layout.size.line_height);
894
895        Some(layout.cursor.as_ref()?.bounding_rect(origin))
896    }
897}