terminal_element.rs

  1use alacritty_terminal::{
  2    ansi::{Color as AnsiColor, Color::Named, CursorShape as AlacCursorShape, NamedColor},
  3    grid::Dimensions,
  4    index::Point,
  5    term::{cell::Flags, TermMode},
  6};
  7use editor::{Cursor, CursorShape, HighlightedRange, HighlightedRangeLine};
  8use gpui::{
  9    color::Color,
 10    fonts::{Properties, Style::Italic, TextStyle, Underline, Weight},
 11    geometry::{
 12        rect::RectF,
 13        vector::{vec2f, Vector2F},
 14    },
 15    serde_json::json,
 16    text_layout::{Line, RunStyle},
 17    Element, Event, EventContext, FontCache, KeyDownEvent, ModelContext, MouseButton, MouseRegion,
 18    PaintContext, Quad, TextLayoutCache, WeakModelHandle, WeakViewHandle,
 19};
 20use itertools::Itertools;
 21use ordered_float::OrderedFloat;
 22use settings::Settings;
 23use theme::TerminalStyle;
 24use util::ResultExt;
 25
 26use std::{fmt::Debug, ops::RangeInclusive};
 27use std::{mem, ops::Range};
 28
 29use crate::{
 30    mappings::colors::convert_color,
 31    terminal_view::{DeployContextMenu, TerminalView},
 32    IndexedCell, Terminal, TerminalContent, TerminalSize,
 33};
 34
 35///The information generated during layout that is nescessary for painting
 36pub struct LayoutState {
 37    cells: Vec<LayoutCell>,
 38    rects: Vec<LayoutRect>,
 39    relative_highlighted_ranges: Vec<(RangeInclusive<Point>, Color)>,
 40    cursor: Option<Cursor>,
 41    background_color: Color,
 42    size: TerminalSize,
 43    mode: TermMode,
 44    display_offset: usize,
 45}
 46
 47///Helper struct for converting data between alacritty's cursor points, and displayed cursor points
 48struct DisplayCursor {
 49    line: i32,
 50    col: usize,
 51}
 52
 53impl DisplayCursor {
 54    fn from(cursor_point: Point, display_offset: usize) -> Self {
 55        Self {
 56            line: cursor_point.line.0 + display_offset as i32,
 57            col: cursor_point.column.0,
 58        }
 59    }
 60
 61    pub fn line(&self) -> i32 {
 62        self.line
 63    }
 64
 65    pub fn col(&self) -> usize {
 66        self.col
 67    }
 68}
 69
 70#[derive(Clone, Debug, Default)]
 71struct LayoutCell {
 72    point: Point<i32, i32>,
 73    text: Line,
 74}
 75
 76impl LayoutCell {
 77    fn new(point: Point<i32, i32>, text: Line) -> LayoutCell {
 78        LayoutCell { point, text }
 79    }
 80
 81    fn paint(
 82        &self,
 83        origin: Vector2F,
 84        layout: &LayoutState,
 85        visible_bounds: RectF,
 86        cx: &mut PaintContext,
 87    ) {
 88        let pos = {
 89            let point = self.point;
 90            vec2f(
 91                (origin.x() + point.column as f32 * layout.size.cell_width).floor(),
 92                origin.y() + point.line as f32 * layout.size.line_height,
 93            )
 94        };
 95
 96        self.text
 97            .paint(pos, visible_bounds, layout.size.line_height, cx);
 98    }
 99}
100
101#[derive(Clone, Debug, Default)]
102struct LayoutRect {
103    point: Point<i32, i32>,
104    num_of_cells: usize,
105    color: Color,
106}
107
108impl LayoutRect {
109    fn new(point: Point<i32, i32>, num_of_cells: usize, color: Color) -> LayoutRect {
110        LayoutRect {
111            point,
112            num_of_cells,
113            color,
114        }
115    }
116
117    fn extend(&self) -> Self {
118        LayoutRect {
119            point: self.point,
120            num_of_cells: self.num_of_cells + 1,
121            color: self.color,
122        }
123    }
124
125    fn paint(&self, origin: Vector2F, layout: &LayoutState, cx: &mut PaintContext) {
126        let position = {
127            let point = self.point;
128            vec2f(
129                (origin.x() + point.column as f32 * layout.size.cell_width).floor(),
130                origin.y() + point.line as f32 * layout.size.line_height,
131            )
132        };
133        let size = vec2f(
134            (layout.size.cell_width * self.num_of_cells as f32).ceil(),
135            layout.size.line_height,
136        );
137
138        cx.scene.push_quad(Quad {
139            bounds: RectF::new(position, size),
140            background: Some(self.color),
141            border: Default::default(),
142            corner_radius: 0.,
143        })
144    }
145}
146
147///The GPUI element that paints the terminal.
148///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?
149pub struct TerminalElement {
150    terminal: WeakModelHandle<Terminal>,
151    view: WeakViewHandle<TerminalView>,
152    modal: bool,
153    focused: bool,
154    cursor_visible: bool,
155}
156
157impl TerminalElement {
158    pub fn new(
159        view: WeakViewHandle<TerminalView>,
160        terminal: WeakModelHandle<Terminal>,
161        modal: bool,
162        focused: bool,
163        cursor_visible: bool,
164    ) -> TerminalElement {
165        TerminalElement {
166            view,
167            terminal,
168            modal,
169            focused,
170            cursor_visible,
171        }
172    }
173
174    //Vec<Range<Point>> -> Clip out the parts of the ranges
175
176    fn layout_grid(
177        grid: &Vec<IndexedCell>,
178        text_style: &TextStyle,
179        terminal_theme: &TerminalStyle,
180        text_layout_cache: &TextLayoutCache,
181        font_cache: &FontCache,
182        modal: bool,
183    ) -> (Vec<LayoutCell>, Vec<LayoutRect>) {
184        let mut cells = vec![];
185        let mut rects = vec![];
186
187        let mut cur_rect: Option<LayoutRect> = None;
188        let mut cur_alac_color = None;
189
190        let linegroups = grid.into_iter().group_by(|i| i.point.line);
191        for (line_index, (_, line)) in linegroups.into_iter().enumerate() {
192            for cell in line {
193                let mut fg = cell.fg;
194                let mut bg = cell.bg;
195                if cell.flags.contains(Flags::INVERSE) {
196                    mem::swap(&mut fg, &mut bg);
197                }
198
199                //Expand background rect range
200                {
201                    if matches!(bg, Named(NamedColor::Background)) {
202                        //Continue to next cell, resetting variables if nescessary
203                        cur_alac_color = None;
204                        if let Some(rect) = cur_rect {
205                            rects.push(rect);
206                            cur_rect = None
207                        }
208                    } else {
209                        match cur_alac_color {
210                            Some(cur_color) => {
211                                if bg == cur_color {
212                                    cur_rect = cur_rect.take().map(|rect| rect.extend());
213                                } else {
214                                    cur_alac_color = Some(bg);
215                                    if cur_rect.is_some() {
216                                        rects.push(cur_rect.take().unwrap());
217                                    }
218                                    cur_rect = Some(LayoutRect::new(
219                                        Point::new(line_index as i32, cell.point.column.0 as i32),
220                                        1,
221                                        convert_color(&bg, &terminal_theme.colors, modal),
222                                    ));
223                                }
224                            }
225                            None => {
226                                cur_alac_color = Some(bg);
227                                cur_rect = Some(LayoutRect::new(
228                                    Point::new(line_index as i32, cell.point.column.0 as i32),
229                                    1,
230                                    convert_color(&bg, &terminal_theme.colors, modal),
231                                ));
232                            }
233                        }
234                    }
235                }
236
237                //Layout current cell text
238                {
239                    let cell_text = &cell.c.to_string();
240                    if cell_text != " " {
241                        let cell_style = TerminalElement::cell_style(
242                            &cell,
243                            fg,
244                            terminal_theme,
245                            text_style,
246                            font_cache,
247                            modal,
248                        );
249
250                        let layout_cell = text_layout_cache.layout_str(
251                            cell_text,
252                            text_style.font_size,
253                            &[(cell_text.len(), cell_style)],
254                        );
255
256                        cells.push(LayoutCell::new(
257                            Point::new(line_index as i32, cell.point.column.0 as i32),
258                            layout_cell,
259                        ))
260                    }
261                };
262            }
263
264            if cur_rect.is_some() {
265                rects.push(cur_rect.take().unwrap());
266            }
267        }
268        (cells, rects)
269    }
270
271    // Compute the cursor position and expected block width, may return a zero width if x_for_index returns
272    // the same position for sequential indexes. Use em_width instead
273    fn shape_cursor(
274        cursor_point: DisplayCursor,
275        size: TerminalSize,
276        text_fragment: &Line,
277    ) -> Option<(Vector2F, f32)> {
278        if cursor_point.line() < size.total_lines() as i32 {
279            let cursor_width = if text_fragment.width() == 0. {
280                size.cell_width()
281            } else {
282                text_fragment.width()
283            };
284
285            //Cursor should always surround as much of the text as possible,
286            //hence when on pixel boundaries round the origin down and the width up
287            Some((
288                vec2f(
289                    (cursor_point.col() as f32 * size.cell_width()).floor(),
290                    (cursor_point.line() as f32 * size.line_height()).floor(),
291                ),
292                cursor_width.ceil(),
293            ))
294        } else {
295            None
296        }
297    }
298
299    ///Convert the Alacritty cell styles to GPUI text styles and background color
300    fn cell_style(
301        indexed: &IndexedCell,
302        fg: AnsiColor,
303        style: &TerminalStyle,
304        text_style: &TextStyle,
305        font_cache: &FontCache,
306        modal: bool,
307    ) -> RunStyle {
308        let flags = indexed.cell.flags;
309        let fg = convert_color(&fg, &style.colors, modal);
310
311        let underline = flags
312            .intersects(Flags::ALL_UNDERLINES)
313            .then(|| Underline {
314                color: Some(fg),
315                squiggly: flags.contains(Flags::UNDERCURL),
316                thickness: OrderedFloat(1.),
317            })
318            .unwrap_or_default();
319
320        let mut properties = Properties::new();
321        if indexed
322            .flags
323            .intersects(Flags::BOLD | Flags::BOLD_ITALIC | Flags::DIM_BOLD)
324        {
325            properties = *properties.weight(Weight::BOLD);
326        }
327        if indexed.flags.intersects(Flags::ITALIC | Flags::BOLD_ITALIC) {
328            properties = *properties.style(Italic);
329        }
330
331        let font_id = font_cache
332            .select_font(text_style.font_family_id, &properties)
333            .unwrap_or(text_style.font_id);
334
335        RunStyle {
336            color: fg,
337            font_id,
338            underline,
339        }
340    }
341
342    fn generic_button_handler<E>(
343        connection: WeakModelHandle<Terminal>,
344        origin: Vector2F,
345        f: impl Fn(&mut Terminal, Vector2F, E, &mut ModelContext<Terminal>),
346    ) -> impl Fn(E, &mut EventContext) {
347        move |event, cx| {
348            cx.focus_parent_view();
349            if let Some(conn_handle) = connection.upgrade(cx.app) {
350                conn_handle.update(cx.app, |terminal, cx| {
351                    f(terminal, origin, event, cx);
352
353                    cx.notify();
354                })
355            }
356        }
357    }
358
359    fn attach_mouse_handlers(
360        &self,
361        origin: Vector2F,
362        view_id: usize,
363        visible_bounds: RectF,
364        mode: TermMode,
365        cx: &mut PaintContext,
366    ) {
367        let connection = self.terminal;
368
369        let mut region = MouseRegion::new(view_id, None, visible_bounds);
370
371        // Terminal Emulator controlled behavior:
372        region = region
373            // Start selections
374            .on_down(
375                MouseButton::Left,
376                TerminalElement::generic_button_handler(
377                    connection,
378                    origin,
379                    move |terminal, origin, e, _cx| {
380                        terminal.mouse_down(&e, origin);
381                    },
382                ),
383            )
384            // Update drag selections
385            .on_drag(MouseButton::Left, move |event, cx| {
386                if cx.is_parent_view_focused() {
387                    if let Some(conn_handle) = connection.upgrade(cx.app) {
388                        conn_handle.update(cx.app, |terminal, cx| {
389                            terminal.mouse_drag(event, origin);
390                            cx.notify();
391                        })
392                    }
393                }
394            })
395            // Copy on up behavior
396            .on_up(
397                MouseButton::Left,
398                TerminalElement::generic_button_handler(
399                    connection,
400                    origin,
401                    move |terminal, origin, e, _cx| {
402                        terminal.mouse_up(&e, origin);
403                    },
404                ),
405            )
406            // Handle click based selections
407            .on_click(
408                MouseButton::Left,
409                TerminalElement::generic_button_handler(
410                    connection,
411                    origin,
412                    move |terminal, origin, e, _cx| {
413                        terminal.left_click(&e, origin);
414                    },
415                ),
416            )
417            // Context menu
418            .on_click(MouseButton::Right, move |e, cx| {
419                let mouse_mode = if let Some(conn_handle) = connection.upgrade(cx.app) {
420                    conn_handle.update(cx.app, |terminal, _cx| terminal.mouse_mode(e.shift))
421                } else {
422                    // If we can't get the model handle, probably can't deploy the context menu
423                    true
424                };
425                if !mouse_mode {
426                    cx.dispatch_action(DeployContextMenu {
427                        position: e.position,
428                    });
429                }
430            });
431
432        // Mouse mode handlers:
433        // All mouse modes need the extra click handlers
434        if mode.intersects(TermMode::MOUSE_MODE) {
435            region = region
436                .on_down(
437                    MouseButton::Right,
438                    TerminalElement::generic_button_handler(
439                        connection,
440                        origin,
441                        move |terminal, origin, e, _cx| {
442                            terminal.mouse_down(&e, origin);
443                        },
444                    ),
445                )
446                .on_down(
447                    MouseButton::Middle,
448                    TerminalElement::generic_button_handler(
449                        connection,
450                        origin,
451                        move |terminal, origin, e, _cx| {
452                            terminal.mouse_down(&e, origin);
453                        },
454                    ),
455                )
456                .on_up(
457                    MouseButton::Right,
458                    TerminalElement::generic_button_handler(
459                        connection,
460                        origin,
461                        move |terminal, origin, e, _cx| {
462                            terminal.mouse_up(&e, origin);
463                        },
464                    ),
465                )
466                .on_up(
467                    MouseButton::Middle,
468                    TerminalElement::generic_button_handler(
469                        connection,
470                        origin,
471                        move |terminal, origin, e, _cx| {
472                            terminal.mouse_up(&e, origin);
473                        },
474                    ),
475                )
476        }
477        //Mouse move manages both dragging and motion events
478        if mode.intersects(TermMode::MOUSE_DRAG | TermMode::MOUSE_MOTION) {
479            region = region
480                //TODO: This does not fire on right-mouse-down-move events.
481                .on_move(move |event, cx| {
482                    if cx.is_parent_view_focused() {
483                        if let Some(conn_handle) = connection.upgrade(cx.app) {
484                            conn_handle.update(cx.app, |terminal, cx| {
485                                terminal.mouse_move(&event, origin);
486                                cx.notify();
487                            })
488                        }
489                    }
490                })
491        }
492
493        cx.scene.push_mouse_region(region);
494    }
495
496    ///Configures a text style from the current settings.
497    pub fn make_text_style(font_cache: &FontCache, settings: &Settings) -> TextStyle {
498        // Pull the font family from settings properly overriding
499        let family_id = settings
500            .terminal_overrides
501            .font_family
502            .as_ref()
503            .or(settings.terminal_defaults.font_family.as_ref())
504            .and_then(|family_name| font_cache.load_family(&[family_name]).log_err())
505            .unwrap_or(settings.buffer_font_family);
506
507        let font_size = settings
508            .terminal_overrides
509            .font_size
510            .or(settings.terminal_defaults.font_size)
511            .unwrap_or(settings.buffer_font_size);
512
513        let font_id = font_cache
514            .select_font(family_id, &Default::default())
515            .unwrap();
516
517        TextStyle {
518            color: settings.theme.editor.text_color,
519            font_family_id: family_id,
520            font_family_name: font_cache.family_name(family_id).unwrap(),
521            font_id,
522            font_size,
523            font_properties: Default::default(),
524            underline: Default::default(),
525        }
526    }
527}
528
529impl Element for TerminalElement {
530    type LayoutState = LayoutState;
531    type PaintState = ();
532
533    fn layout(
534        &mut self,
535        constraint: gpui::SizeConstraint,
536        cx: &mut gpui::LayoutContext,
537    ) -> (gpui::geometry::vector::Vector2F, Self::LayoutState) {
538        let settings = cx.global::<Settings>();
539        let font_cache = cx.font_cache();
540
541        //Setup layout information
542        let terminal_theme = settings.theme.terminal.clone(); //TODO: Try to minimize this clone.
543        let text_style = TerminalElement::make_text_style(font_cache, settings);
544        let selection_color = settings.theme.editor.selection.selection;
545        let match_color = settings.theme.search.match_background;
546        let dimensions = {
547            let line_height = font_cache.line_height(text_style.font_size);
548            let cell_width = font_cache.em_advance(text_style.font_id, text_style.font_size);
549            TerminalSize::new(line_height, cell_width, constraint.max)
550        };
551
552        let search_matches = if let Some(terminal_model) = self.terminal.upgrade(cx) {
553            terminal_model.read(cx).matches.clone()
554        } else {
555            Default::default()
556        };
557
558        let background_color = if self.modal {
559            terminal_theme.colors.modal_background
560        } else {
561            terminal_theme.colors.background
562        };
563        let terminal_handle = self.terminal.upgrade(cx).unwrap();
564
565        terminal_handle.update(cx.app, |terminal, cx| {
566            terminal.set_size(dimensions);
567            terminal.try_sync(cx)
568        });
569
570        let TerminalContent {
571            cells,
572            mode,
573            display_offset,
574            cursor_char,
575            selection,
576            cursor,
577            ..
578        } = &terminal_handle.read(cx).last_content;
579
580        // searches, highlights to a single range representations
581        let mut relative_highlighted_ranges = Vec::new();
582        for search_match in search_matches {
583            relative_highlighted_ranges.push((search_match, match_color))
584        }
585        if let Some(selection) = selection {
586            relative_highlighted_ranges.push((selection.start..=selection.end, selection_color));
587        }
588
589        // then have that representation be converted to the appropriate highlight data structure
590
591        let (cells, rects) = TerminalElement::layout_grid(
592            cells,
593            &text_style,
594            &terminal_theme,
595            cx.text_layout_cache,
596            cx.font_cache(),
597            self.modal,
598        );
599
600        //Layout cursor. Rectangle is used for IME, so we should lay it out even
601        //if we don't end up showing it.
602        let cursor = if let AlacCursorShape::Hidden = cursor.shape {
603            None
604        } else {
605            let cursor_point = DisplayCursor::from(cursor.point, *display_offset);
606            let cursor_text = {
607                let str_trxt = cursor_char.to_string();
608
609                let color = if self.focused {
610                    terminal_theme.colors.background
611                } else {
612                    terminal_theme.colors.foreground
613                };
614
615                cx.text_layout_cache.layout_str(
616                    &str_trxt,
617                    text_style.font_size,
618                    &[(
619                        str_trxt.len(),
620                        RunStyle {
621                            font_id: text_style.font_id,
622                            color,
623                            underline: Default::default(),
624                        },
625                    )],
626                )
627            };
628
629            TerminalElement::shape_cursor(cursor_point, dimensions, &cursor_text).map(
630                move |(cursor_position, block_width)| {
631                    let shape = match cursor.shape {
632                        AlacCursorShape::Block if !self.focused => CursorShape::Hollow,
633                        AlacCursorShape::Block => CursorShape::Block,
634                        AlacCursorShape::Underline => CursorShape::Underscore,
635                        AlacCursorShape::Beam => CursorShape::Bar,
636                        AlacCursorShape::HollowBlock => CursorShape::Hollow,
637                        //This case is handled in the if wrapping the whole cursor layout
638                        AlacCursorShape::Hidden => unreachable!(),
639                    };
640
641                    Cursor::new(
642                        cursor_position,
643                        block_width,
644                        dimensions.line_height,
645                        terminal_theme.colors.cursor,
646                        shape,
647                        Some(cursor_text),
648                    )
649                },
650            )
651        };
652
653        //Done!
654        (
655            constraint.max,
656            LayoutState {
657                cells,
658                cursor,
659                background_color,
660                size: dimensions,
661                rects,
662                relative_highlighted_ranges,
663                mode: *mode,
664                display_offset: *display_offset,
665            },
666        )
667    }
668
669    fn paint(
670        &mut self,
671        bounds: gpui::geometry::rect::RectF,
672        visible_bounds: gpui::geometry::rect::RectF,
673        layout: &mut Self::LayoutState,
674        cx: &mut gpui::PaintContext,
675    ) -> Self::PaintState {
676        //Setup element stuff
677        let clip_bounds = Some(visible_bounds);
678
679        cx.paint_layer(clip_bounds, |cx| {
680            let origin = bounds.origin() + vec2f(layout.size.cell_width, 0.);
681
682            //Elements are ephemeral, only at paint time do we know what could be clicked by a mouse
683            self.attach_mouse_handlers(origin, self.view.id(), visible_bounds, layout.mode, cx);
684
685            cx.scene.push_cursor_region(gpui::CursorRegion {
686                bounds,
687                style: gpui::CursorStyle::IBeam,
688            });
689
690            cx.paint_layer(clip_bounds, |cx| {
691                //Start with a background color
692                cx.scene.push_quad(Quad {
693                    bounds: RectF::new(bounds.origin(), bounds.size()),
694                    background: Some(layout.background_color),
695                    border: Default::default(),
696                    corner_radius: 0.,
697                });
698
699                for rect in &layout.rects {
700                    rect.paint(origin, layout, cx)
701                }
702            });
703
704            //Draw Highlighted Backgrounds
705            cx.paint_layer(clip_bounds, |cx| {
706                for (relative_highlighted_range, color) in layout.relative_highlighted_ranges.iter()
707                {
708                    if let Some((start_y, highlighted_range_lines)) =
709                        to_highlighted_range_lines(relative_highlighted_range, layout, origin)
710                    {
711                        let hr = HighlightedRange {
712                            start_y, //Need to change this
713                            line_height: layout.size.line_height,
714                            lines: highlighted_range_lines,
715                            color: color.clone(),
716                            //Copied from editor. TODO: move to theme or something
717                            corner_radius: 0.15 * layout.size.line_height,
718                        };
719                        hr.paint(bounds, cx.scene);
720                    }
721                }
722            });
723
724            //Draw the text cells
725            cx.paint_layer(clip_bounds, |cx| {
726                for cell in &layout.cells {
727                    cell.paint(origin, layout, visible_bounds, cx);
728                }
729            });
730
731            //Draw cursor
732            if self.cursor_visible {
733                if let Some(cursor) = &layout.cursor {
734                    cx.paint_layer(clip_bounds, |cx| {
735                        cursor.paint(origin, cx);
736                    })
737                }
738            }
739        });
740    }
741
742    fn dispatch_event(
743        &mut self,
744        event: &gpui::Event,
745        bounds: gpui::geometry::rect::RectF,
746        visible_bounds: gpui::geometry::rect::RectF,
747        layout: &mut Self::LayoutState,
748        _paint: &mut Self::PaintState,
749        cx: &mut gpui::EventContext,
750    ) -> bool {
751        match event {
752            Event::ScrollWheel(e) => visible_bounds
753                .contains_point(e.position)
754                .then(|| {
755                    let origin = bounds.origin() + vec2f(layout.size.cell_width, 0.);
756
757                    if let Some(terminal) = self.terminal.upgrade(cx.app) {
758                        terminal.update(cx.app, |term, _| term.scroll_wheel(e, origin));
759                        cx.notify();
760                    }
761                })
762                .is_some(),
763            Event::KeyDown(KeyDownEvent { keystroke, .. }) => {
764                if !cx.is_parent_view_focused() {
765                    return false;
766                }
767
768                if let Some(view) = self.view.upgrade(cx.app) {
769                    view.update(cx.app, |view, cx| {
770                        view.clear_bel(cx);
771                        view.pause_cursor_blinking(cx);
772                    })
773                }
774
775                self.terminal
776                    .upgrade(cx.app)
777                    .map(|model_handle| {
778                        model_handle.update(cx.app, |term, _| term.try_keystroke(keystroke))
779                    })
780                    .unwrap_or(false)
781            }
782            _ => false,
783        }
784    }
785
786    fn metadata(&self) -> Option<&dyn std::any::Any> {
787        None
788    }
789
790    fn debug(
791        &self,
792        _bounds: gpui::geometry::rect::RectF,
793        _layout: &Self::LayoutState,
794        _paint: &Self::PaintState,
795        _cx: &gpui::DebugContext,
796    ) -> gpui::serde_json::Value {
797        json!({
798            "type": "TerminalElement",
799        })
800    }
801
802    fn rect_for_text_range(
803        &self,
804        _: Range<usize>,
805        bounds: RectF,
806        _: RectF,
807        layout: &Self::LayoutState,
808        _: &Self::PaintState,
809        _: &gpui::MeasurementContext,
810    ) -> Option<RectF> {
811        // Use the same origin that's passed to `Cursor::paint` in the paint
812        // method bove.
813        let mut origin = bounds.origin() + vec2f(layout.size.cell_width, 0.);
814
815        // TODO - Why is it necessary to move downward one line to get correct
816        // positioning? I would think that we'd want the same rect that is
817        // painted for the cursor.
818        origin += vec2f(0., layout.size.line_height);
819
820        Some(layout.cursor.as_ref()?.bounding_rect(origin))
821    }
822}
823
824fn to_highlighted_range_lines(
825    range: &RangeInclusive<Point>,
826    layout: &LayoutState,
827    origin: Vector2F,
828) -> Option<(f32, Vec<HighlightedRangeLine>)> {
829    // Step 1. Normalize the points to be viewport relative.
830    //When display_offset = 1, here's how the grid is arranged:
831    //--- Viewport top
832    //-2,0 -2,1...
833    //-1,0 -1,1...
834    //--------- Terminal Top
835    // 0,0  0,1...
836    // 1,0  1,1...
837    //--- Viewport Bottom
838    // 2,0  2,1...
839    //--------- Terminal Bottom
840
841    // Normalize to viewport relative, from terminal relative.
842    // lines are i32s, which are negative above the top left corner of the terminal
843    // If the user has scrolled, we use the display_offset to tell us which offset
844    // of the grid data we should be looking at. But for the rendering step, we don't
845    // want negatives. We want things relative to the 'viewport' (the area of the grid
846    // which is currently shown according to the display offset)
847    let unclamped_start = Point::new(
848        range.start().line + layout.display_offset,
849        range.start().column,
850    );
851    let unclamped_end = Point::new(range.end().line + layout.display_offset, range.end().column);
852
853    // Step 2. Clamp range to viewport, and return None if it doesn't overlap
854    if unclamped_end.line.0 < 0 || unclamped_start.line.0 > layout.size.num_lines() as i32 {
855        return None;
856    }
857
858    let clamped_start_line = unclamped_start.line.0.max(0) as usize;
859    let clamped_end_line = unclamped_end.line.0.min(layout.size.num_lines() as i32) as usize;
860    //Convert the start of the range to pixels
861    let start_y = origin.y() + clamped_start_line as f32 * layout.size.line_height;
862
863    // Step 3. Expand ranges that cross lines into a collection of single-line ranges.
864    //  (also convert to pixels)
865    let mut highlighted_range_lines = Vec::new();
866    for line in clamped_start_line..=clamped_end_line {
867        let mut line_start = 0;
868        let mut line_end = layout.size.columns();
869
870        if line == clamped_start_line {
871            line_start = unclamped_start.column.0 as usize;
872        }
873        if line == clamped_end_line {
874            line_end = unclamped_end.column.0 as usize + 1; //+1 for inclusive
875        }
876
877        highlighted_range_lines.push(HighlightedRangeLine {
878            start_x: origin.x() + line_start as f32 * layout.size.cell_width,
879            end_x: origin.x() + line_end as f32 * layout.size.cell_width,
880        });
881    }
882
883    Some((start_y, highlighted_range_lines))
884}