device-navigation/dist/nav-controller/enter-into.js

Navigate HTML elements in two dimensions with non-pointer devices.

import { focusElement } from '../util/focus.js';
import { NavAction } from './navigate.js';
/**
 * Enter into the currently focused node's children. Focuses the first child. Fails if there are no
 * children to focus.
 *
 * @category Internal
 */
export function enterInto(navTree, currentlyFocused) {
    if (!currentlyFocused) {
        return {
            success: false,
            reason: 'no focused node to enter into',
            direction: undefined,
            navAction: NavAction.Enter,
        };
    }
    if (!currentlyFocused.position.node.children.length) {
        return {
            success: false,
            reason: 'no children to enter into',
            direction: undefined,
            navAction: NavAction.Enter,
        };
    }
    const newNode = currentlyFocused.position.node.children[0]?.[0];
    if (!newNode) {
        return {
            success: false,
            reason: 'failed to find first child to enter into',
            direction: undefined,
            navAction: NavAction.Enter,
        };
    }
    focusElement(newNode.element);
    return {
        success: true,
        defaulted: false,
        wrapped: false,
        newElement: newNode.element,
        direction: undefined,
        navAction: NavAction.Enter,
        coords: {
            x: 0,
            y: 0,
        },
    };
}