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::<Self>(view_id, view_id, 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            .on_scroll(TerminalElement::generic_button_handler(
432                connection,
433                origin,
434                move |terminal, origin, e, _cx| {
435                    terminal.scroll_wheel(e, origin);
436                },
437            ));
438
439        // Mouse mode handlers:
440        // All mouse modes need the extra click handlers
441        if mode.intersects(TermMode::MOUSE_MODE) {
442            region = region
443                .on_down(
444                    MouseButton::Right,
445                    TerminalElement::generic_button_handler(
446                        connection,
447                        origin,
448                        move |terminal, origin, e, _cx| {
449                            terminal.mouse_down(&e, origin);
450                        },
451                    ),
452                )
453                .on_down(
454                    MouseButton::Middle,
455                    TerminalElement::generic_button_handler(
456                        connection,
457                        origin,
458                        move |terminal, origin, e, _cx| {
459                            terminal.mouse_down(&e, origin);
460                        },
461                    ),
462                )
463                .on_up(
464                    MouseButton::Right,
465                    TerminalElement::generic_button_handler(
466                        connection,
467                        origin,
468                        move |terminal, origin, e, _cx| {
469                            terminal.mouse_up(&e, origin);
470                        },
471                    ),
472                )
473                .on_up(
474                    MouseButton::Middle,
475                    TerminalElement::generic_button_handler(
476                        connection,
477                        origin,
478                        move |terminal, origin, e, _cx| {
479                            terminal.mouse_up(&e, origin);
480                        },
481                    ),
482                )
483        }
484        //Mouse move manages both dragging and motion events
485        if mode.intersects(TermMode::MOUSE_DRAG | TermMode::MOUSE_MOTION) {
486            region = region
487                //TODO: This does not fire on right-mouse-down-move events.
488                .on_move(move |event, cx| {
489                    if cx.is_parent_view_focused() {
490                        if let Some(conn_handle) = connection.upgrade(cx.app) {
491                            conn_handle.update(cx.app, |terminal, cx| {
492                                terminal.mouse_move(&event, origin);
493                                cx.notify();
494                            })
495                        }
496                    }
497                })
498        }
499
500        cx.scene.push_mouse_region(region);
501    }
502
503    ///Configures a text style from the current settings.
504    pub fn make_text_style(font_cache: &FontCache, settings: &Settings) -> TextStyle {
505        // Pull the font family from settings properly overriding
506        let family_id = settings
507            .terminal_overrides
508            .font_family
509            .as_ref()
510            .or(settings.terminal_defaults.font_family.as_ref())
511            .and_then(|family_name| font_cache.load_family(&[family_name]).log_err())
512            .unwrap_or(settings.buffer_font_family);
513
514        let font_size = settings
515            .terminal_overrides
516            .font_size
517            .or(settings.terminal_defaults.font_size)
518            .unwrap_or(settings.buffer_font_size);
519
520        let font_id = font_cache
521            .select_font(family_id, &Default::default())
522            .unwrap();
523
524        TextStyle {
525            color: settings.theme.editor.text_color,
526            font_family_id: family_id,
527            font_family_name: font_cache.family_name(family_id).unwrap(),
528            font_id,
529            font_size,
530            font_properties: Default::default(),
531            underline: Default::default(),
532        }
533    }
534}
535
536impl Element for TerminalElement {
537    type LayoutState = LayoutState;
538    type PaintState = ();
539
540    fn layout(
541        &mut self,
542        constraint: gpui::SizeConstraint,
543        cx: &mut gpui::LayoutContext,
544    ) -> (gpui::geometry::vector::Vector2F, Self::LayoutState) {
545        let settings = cx.global::<Settings>();
546        let font_cache = cx.font_cache();
547
548        //Setup layout information
549        let terminal_theme = settings.theme.terminal.clone(); //TODO: Try to minimize this clone.
550        let text_style = TerminalElement::make_text_style(font_cache, settings);
551        let selection_color = settings.theme.editor.selection.selection;
552        let match_color = settings.theme.search.match_background;
553        let dimensions = {
554            let line_height = font_cache.line_height(text_style.font_size);
555            let cell_width = font_cache.em_advance(text_style.font_id, text_style.font_size);
556            TerminalSize::new(line_height, cell_width, constraint.max)
557        };
558
559        let search_matches = if let Some(terminal_model) = self.terminal.upgrade(cx) {
560            terminal_model.read(cx).matches.clone()
561        } else {
562            Default::default()
563        };
564
565        let background_color = if self.modal {
566            terminal_theme.colors.modal_background
567        } else {
568            terminal_theme.colors.background
569        };
570        let terminal_handle = self.terminal.upgrade(cx).unwrap();
571
572        terminal_handle.update(cx.app, |terminal, cx| {
573            terminal.set_size(dimensions);
574            terminal.try_sync(cx)
575        });
576
577        let TerminalContent {
578            cells,
579            mode,
580            display_offset,
581            cursor_char,
582            selection,
583            cursor,
584            ..
585        } = &terminal_handle.read(cx).last_content;
586
587        // searches, highlights to a single range representations
588        let mut relative_highlighted_ranges = Vec::new();
589        for search_match in search_matches {
590            relative_highlighted_ranges.push((search_match, match_color))
591        }
592        if let Some(selection) = selection {
593            relative_highlighted_ranges.push((selection.start..=selection.end, selection_color));
594        }
595
596        // then have that representation be converted to the appropriate highlight data structure
597
598        let (cells, rects) = TerminalElement::layout_grid(
599            cells,
600            &text_style,
601            &terminal_theme,
602            cx.text_layout_cache,
603            cx.font_cache(),
604            self.modal,
605        );
606
607        //Layout cursor. Rectangle is used for IME, so we should lay it out even
608        //if we don't end up showing it.
609        let cursor = if let AlacCursorShape::Hidden = cursor.shape {
610            None
611        } else {
612            let cursor_point = DisplayCursor::from(cursor.point, *display_offset);
613            let cursor_text = {
614                let str_trxt = cursor_char.to_string();
615
616                let color = if self.focused {
617                    terminal_theme.colors.background
618                } else {
619                    terminal_theme.colors.foreground
620                };
621
622                cx.text_layout_cache.layout_str(
623                    &str_trxt,
624                    text_style.font_size,
625                    &[(
626                        str_trxt.len(),
627                        RunStyle {
628                            font_id: text_style.font_id,
629                            color,
630                            underline: Default::default(),
631                        },
632                    )],
633                )
634            };
635
636            TerminalElement::shape_cursor(cursor_point, dimensions, &cursor_text).map(
637                move |(cursor_position, block_width)| {
638                    let shape = match cursor.shape {
639                        AlacCursorShape::Block if !self.focused => CursorShape::Hollow,
640                        AlacCursorShape::Block => CursorShape::Block,
641                        AlacCursorShape::Underline => CursorShape::Underscore,
642                        AlacCursorShape::Beam => CursorShape::Bar,
643                        AlacCursorShape::HollowBlock => CursorShape::Hollow,
644                        //This case is handled in the if wrapping the whole cursor layout
645                        AlacCursorShape::Hidden => unreachable!(),
646                    };
647
648                    Cursor::new(
649                        cursor_position,
650                        block_width,
651                        dimensions.line_height,
652                        terminal_theme.colors.cursor,
653                        shape,
654                        Some(cursor_text),
655                    )
656                },
657            )
658        };
659
660        //Done!
661        (
662            constraint.max,
663            LayoutState {
664                cells,
665                cursor,
666                background_color,
667                size: dimensions,
668                rects,
669                relative_highlighted_ranges,
670                mode: *mode,
671                display_offset: *display_offset,
672            },
673        )
674    }
675
676    fn paint(
677        &mut self,
678        bounds: gpui::geometry::rect::RectF,
679        visible_bounds: gpui::geometry::rect::RectF,
680        layout: &mut Self::LayoutState,
681        cx: &mut gpui::PaintContext,
682    ) -> Self::PaintState {
683        //Setup element stuff
684        let clip_bounds = Some(visible_bounds);
685
686        cx.paint_layer(clip_bounds, |cx| {
687            let origin = bounds.origin() + vec2f(layout.size.cell_width, 0.);
688
689            //Elements are ephemeral, only at paint time do we know what could be clicked by a mouse
690            self.attach_mouse_handlers(origin, self.view.id(), visible_bounds, layout.mode, cx);
691
692            cx.scene.push_cursor_region(gpui::CursorRegion {
693                bounds,
694                style: gpui::CursorStyle::IBeam,
695            });
696
697            cx.paint_layer(clip_bounds, |cx| {
698                //Start with a background color
699                cx.scene.push_quad(Quad {
700                    bounds: RectF::new(bounds.origin(), bounds.size()),
701                    background: Some(layout.background_color),
702                    border: Default::default(),
703                    corner_radius: 0.,
704                });
705
706                for rect in &layout.rects {
707                    rect.paint(origin, layout, cx)
708                }
709            });
710
711            //Draw Highlighted Backgrounds
712            cx.paint_layer(clip_bounds, |cx| {
713                for (relative_highlighted_range, color) in layout.relative_highlighted_ranges.iter()
714                {
715                    if let Some((start_y, highlighted_range_lines)) =
716                        to_highlighted_range_lines(relative_highlighted_range, layout, origin)
717                    {
718                        let hr = HighlightedRange {
719                            start_y, //Need to change this
720                            line_height: layout.size.line_height,
721                            lines: highlighted_range_lines,
722                            color: color.clone(),
723                            //Copied from editor. TODO: move to theme or something
724                            corner_radius: 0.15 * layout.size.line_height,
725                        };
726                        hr.paint(bounds, cx.scene);
727                    }
728                }
729            });
730
731            //Draw the text cells
732            cx.paint_layer(clip_bounds, |cx| {
733                for cell in &layout.cells {
734                    cell.paint(origin, layout, visible_bounds, cx);
735                }
736            });
737
738            //Draw cursor
739            if self.cursor_visible {
740                if let Some(cursor) = &layout.cursor {
741                    cx.paint_layer(clip_bounds, |cx| {
742                        cursor.paint(origin, cx);
743                    })
744                }
745            }
746        });
747    }
748
749    fn dispatch_event(
750        &mut self,
751        event: &gpui::Event,
752        _bounds: gpui::geometry::rect::RectF,
753        _visible_bounds: gpui::geometry::rect::RectF,
754        _layout: &mut Self::LayoutState,
755        _paint: &mut Self::PaintState,
756        cx: &mut gpui::EventContext,
757    ) -> bool {
758        if let Event::KeyDown(KeyDownEvent { keystroke, .. }) = event {
759            if !cx.is_parent_view_focused() {
760                return false;
761            }
762
763            if let Some(view) = self.view.upgrade(cx.app) {
764                view.update(cx.app, |view, cx| {
765                    view.clear_bel(cx);
766                    view.pause_cursor_blinking(cx);
767                })
768            }
769
770            self.terminal
771                .upgrade(cx.app)
772                .map(|model_handle| {
773                    model_handle.update(cx.app, |term, cx| {
774                        term.try_keystroke(
775                            keystroke,
776                            cx.global::<Settings>()
777                                .terminal_overrides
778                                .option_as_meta
779                                .unwrap_or(false),
780                        )
781                    })
782                })
783                .unwrap_or(false)
784        } else {
785            false
786        }
787    }
788
789    fn metadata(&self) -> Option<&dyn std::any::Any> {
790        None
791    }
792
793    fn debug(
794        &self,
795        _bounds: gpui::geometry::rect::RectF,
796        _layout: &Self::LayoutState,
797        _paint: &Self::PaintState,
798        _cx: &gpui::DebugContext,
799    ) -> gpui::serde_json::Value {
800        json!({
801            "type": "TerminalElement",
802        })
803    }
804
805    fn rect_for_text_range(
806        &self,
807        _: Range<usize>,
808        bounds: RectF,
809        _: RectF,
810        layout: &Self::LayoutState,
811        _: &Self::PaintState,
812        _: &gpui::MeasurementContext,
813    ) -> Option<RectF> {
814        // Use the same origin that's passed to `Cursor::paint` in the paint
815        // method bove.
816        let mut origin = bounds.origin() + vec2f(layout.size.cell_width, 0.);
817
818        // TODO - Why is it necessary to move downward one line to get correct
819        // positioning? I would think that we'd want the same rect that is
820        // painted for the cursor.
821        origin += vec2f(0., layout.size.line_height);
822
823        Some(layout.cursor.as_ref()?.bounding_rect(origin))
824    }
825}
826
827fn to_highlighted_range_lines(
828    range: &RangeInclusive<Point>,
829    layout: &LayoutState,
830    origin: Vector2F,
831) -> Option<(f32, Vec<HighlightedRangeLine>)> {
832    // Step 1. Normalize the points to be viewport relative.
833    // When display_offset = 1, here's how the grid is arranged:
834    //-2,0 -2,1...
835    //--- Viewport top
836    //-1,0 -1,1...
837    //--------- Terminal Top
838    // 0,0  0,1...
839    // 1,0  1,1...
840    //--- Viewport Bottom
841    // 2,0  2,1...
842    //--------- Terminal Bottom
843
844    // Normalize to viewport relative, from terminal relative.
845    // lines are i32s, which are negative above the top left corner of the terminal
846    // If the user has scrolled, we use the display_offset to tell us which offset
847    // of the grid data we should be looking at. But for the rendering step, we don't
848    // want negatives. We want things relative to the 'viewport' (the area of the grid
849    // which is currently shown according to the display offset)
850    let unclamped_start = Point::new(
851        range.start().line + layout.display_offset,
852        range.start().column,
853    );
854    let unclamped_end = Point::new(range.end().line + layout.display_offset, range.end().column);
855
856    // Step 2. Clamp range to viewport, and return None if it doesn't overlap
857    if unclamped_end.line.0 < 0 || unclamped_start.line.0 > layout.size.num_lines() as i32 {
858        return None;
859    }
860
861    let clamped_start_line = unclamped_start.line.0.max(0) as usize;
862    let clamped_end_line = unclamped_end.line.0.min(layout.size.num_lines() as i32) as usize;
863    //Convert the start of the range to pixels
864    let start_y = origin.y() + clamped_start_line as f32 * layout.size.line_height;
865
866    // Step 3. Expand ranges that cross lines into a collection of single-line ranges.
867    //  (also convert to pixels)
868    let mut highlighted_range_lines = Vec::new();
869    for line in clamped_start_line..=clamped_end_line {
870        let mut line_start = 0;
871        let mut line_end = layout.size.columns();
872
873        if line == clamped_start_line {
874            line_start = unclamped_start.column.0 as usize;
875        }
876        if line == clamped_end_line {
877            line_end = unclamped_end.column.0 as usize + 1; //+1 for inclusive
878        }
879
880        highlighted_range_lines.push(HighlightedRangeLine {
881            start_x: origin.x() + line_start as f32 * layout.size.cell_width,
882            end_x: origin.x() + line_end as f32 * layout.size.cell_width,
883        });
884    }
885
886    Some((start_y, highlighted_range_lines))
887}