Function cursor_to_visual_pos

src/text_input.rs:1649–1673

Given visual lines and a global cursor position, return (visual_line_index, column_in_visual_line).

(visual_lines: &[VisualLine], cursor_pos: usize)

/// Given visual lines and a global cursor position, return (visual_line_index, column_in_visual_line).
pub fn cursor_to_visual_pos(visual_lines: &[VisualLine], cursor_pos: usize) -> (usize, usize) {
    for (i, vl) in visual_lines.iter().enumerate() {
        let line_end = vl.global_char_start + vl.char_count;
        if cursor_pos < line_end || i == visual_lines.len() - 1 {
            return (i, cursor_pos.saturating_sub(vl.global_char_start));
        }
        // If cursor_pos == line_end and this isn't the last line, it could be at the
        // start of the next line OR the end of this one. For wrapped lines (no \n),
        // prefer placing it at the start of the next line.
        if cursor_pos == line_end {
            // Check if next line continues from this one (wrapped) or is a new paragraph
            if i + 1 < visual_lines.len() {
                let next = &visual_lines[i + 1];
                if next.global_char_start == line_end {
                    // Wrapped continuation — cursor goes to start of next visual line
                    return (i + 1, 0);
                }
                // Hard break (\n between them) — cursor at end of this line
                return (i, cursor_pos - vl.global_char_start);
            }
            return (i, cursor_pos - vl.global_char_start);
        }
    }
    (0, 0)
}

/// Navigate cursor one visual line up. Returns the new global cursor position.
/// `col` is the desired column (preserved across up/down moves).