Struct cosmic_text::Cursor

source ·

pub struct Cursor {
    pub line: usize,
    pub index: usize,
}

Expand description

Current cursor location

Fields§

§line: usize

Text line the cursor is on

§index: usize

Index of glyph at cursor (will insert behind this glyph)

Implementations§

source §

impl Cursor

source

pub const fn new(line: usize, index: usize) -> Self

Create a new cursor

Examples found in repository ?

src/buffer.rs (line 451)

    pub fn hit(&self, x: i32, y: i32) -> Option<Cursor> {
        #[cfg(feature = "std")]
        let instant = std::time::Instant::now();

        let font_size = self.metrics.font_size;
        let line_height = self.metrics.line_height;

        let mut new_cursor_opt = None;

        let mut runs = self.layout_runs().peekable();
        let mut first_run = true;
        while let Some(run) = runs.next() {
            let line_y = run.line_y;

            if first_run && y < line_y - font_size {
                first_run = false;
                let new_cursor = Cursor::new(run.line_i, 0);
                new_cursor_opt = Some(new_cursor);
            } else if y >= line_y - font_size
                    && y < line_y - font_size + line_height
            {
                let mut new_cursor_glyph = run.glyphs.len();
                let mut new_cursor_char = 0;

                let mut first_glyph = true;

                'hit: for (glyph_i, glyph) in run.glyphs.iter().enumerate() {
                    if first_glyph {
                        first_glyph = false;
                        if (run.rtl && x > glyph.x as i32) || (!run.rtl && x < 0) {
                            new_cursor_glyph = 0;
                            new_cursor_char = 0;
                        }
                    }
                    if x >= glyph.x as i32
                    && x <= (glyph.x + glyph.w) as i32
                    {
                        new_cursor_glyph = glyph_i;

                        let cluster = &run.text[glyph.start..glyph.end];
                        let total = cluster.grapheme_indices(true).count();
                        let mut egc_x = glyph.x;
                        let egc_w = glyph.w / (total as f32);
                        for (egc_i, egc) in cluster.grapheme_indices(true) {
                            if x >= egc_x as i32
                            && x <= (egc_x + egc_w) as i32
                            {
                                new_cursor_char = egc_i;

                                let right_half = x >= (egc_x + egc_w / 2.0) as i32;
                                if right_half != glyph.level.is_rtl() {
                                    // If clicking on last half of glyph, move cursor past glyph
                                    new_cursor_char += egc.len();
                                }
                                break 'hit;
                            }
                            egc_x += egc_w;
                        }

                        let right_half = x >= (glyph.x + glyph.w / 2.0) as i32;
                        if right_half != glyph.level.is_rtl() {
                            // If clicking on last half of glyph, move cursor past glyph
                            new_cursor_char = cluster.len();
                        }
                        break 'hit;
                    }
                }

                let mut new_cursor = Cursor::new(run.line_i, 0);

                match run.glyphs.get(new_cursor_glyph) {
                    Some(glyph) => {
                        // Position at glyph
                        new_cursor.index = glyph.start + new_cursor_char;
                    },
                    None => if let Some(glyph) = run.glyphs.last() {
                        // Position at end of line
                        new_cursor.index = glyph.end;
                    },
                }

                new_cursor_opt = Some(new_cursor);

                break;
            } else if runs.peek().is_none() && y > run.line_y {
                let mut new_cursor = Cursor::new(run.line_i, 0);
                if let Some(glyph) = run.glyphs.last() {
                    new_cursor.index = glyph.end;
                }
                new_cursor_opt = Some(new_cursor);
            }
        }

        #[cfg(feature = "std")]
        log::trace!("click({}, {}): {:?}", x, y, instant.elapsed());

        new_cursor_opt
    }