Method change_focus

src/engine.rs:5796–5825

Internal: changes focus, firing on_unfocus on old and on_focus on new.

(&mut self, new_id: u32)

    /// Internal: changes focus, firing on_unfocus on old and on_focus on new.
    pub(crate) fn change_focus(&mut self, new_id: u32) {
        let old_id = self.focused_element_id;
        if old_id == new_id {
            return;
        }
        self.focused_element_id = new_id;
        if new_id == 0 {
            self.focus_from_keyboard = false;
        }

        // Fire on_unfocus on old element
        if old_id != 0 {
            if let Some(item) = self.layout_element_map.get_mut(&old_id) {
                let id_copy = item.element_id.clone();
                if let Some(ref mut callback) = item.on_unfocus_fn {
                    callback(id_copy);
                }
            }
        }

        // Fire on_focus on new element
        if new_id != 0 {
            if let Some(item) = self.layout_element_map.get_mut(&new_id) {
                let id_copy = item.element_id.clone();
                if let Some(ref mut callback) = item.on_focus_fn {
                    callback(id_copy);
                }
            }
        }
    }

    /// Fire the on_press callback for the element with the given u32 ID.
    /// Used by screen reader action handling.