Method update_text_input_scroll

src/engine.rs:6279–6364

Update scroll offsets for text inputs to ensure cursor visibility.

(&mut self)

    /// Update scroll offsets for text inputs to ensure cursor visibility.
    pub fn update_text_input_scroll(&mut self) {
        let focused = self.focused_element_id;
        if focused == 0 {
            return;
        }
        // Get bounding box for the focused text input
        let (visible_width, visible_height) = self.layout_element_map
            .get(&focused)
            .map(|item| (item.bounding_box.width, item.bounding_box.height))
            .unwrap_or((0.0, 0.0));
        if visible_width <= 0.0 {
            return;
        }

        // Get cursor x-position
        if let Some(state) = self.text_edit_states.get(&focused) {
            let config_idx = self.text_input_element_ids.iter()
                .position(|&id| id == focused);
            if let Some(idx) = config_idx {
                if let Some(cfg) = self.text_input_configs.get(idx) {
                    if let Some(ref measure_fn) = self.measure_text_fn {
                        let disp_text = crate::text_input::display_text(
                            &state.text,
                            &cfg.placeholder,
                            cfg.is_password && !cfg.is_multiline,
                        );
                        if !state.text.is_empty() {
                            if cfg.is_multiline {
                                // Multiline: use visual lines with word wrapping
                                let visual_lines = crate::text_input::wrap_lines(
                                    &disp_text,
                                    visible_width,
                                    cfg.font_asset,
                                    cfg.font_size,
                                    measure_fn.as_ref(),
                                );
                                #[cfg(feature = "text-styling")]
                                let raw_cursor = state.cursor_pos_raw();
                                #[cfg(not(feature = "text-styling"))]
                                let raw_cursor = state.cursor_pos;
                                let (cursor_line, cursor_col) = crate::text_input::cursor_to_visual_pos(&visual_lines, raw_cursor);
                                let vl_text = visual_lines.get(cursor_line).map(|vl| vl.text.as_str()).unwrap_or("");
                                let line_positions = crate::text_input::compute_char_x_positions(
                                    vl_text,
                                    cfg.font_asset,
                                    cfg.font_size,
                                    measure_fn.as_ref(),
                                );
                                let cursor_x = line_positions.get(cursor_col).copied().unwrap_or(0.0);
                                let cfg_font_asset = cfg.font_asset;
                                let cfg_font_size = cfg.font_size;
                                let cfg_line_height_val = cfg.line_height;
                                let natural_height = self.font_height(cfg_font_asset, cfg_font_size);
                                let line_height = if cfg_line_height_val > 0 { cfg_line_height_val as f32 } else { natural_height };
                                if let Some(state_mut) = self.text_edit_states.get_mut(&focused) {
                                    state_mut.ensure_cursor_visible(cursor_x, visible_width);
                                    state_mut.ensure_cursor_visible_vertical(cursor_line, line_height, visible_height);
                                }