Proyectos de Subversion Moodle

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * Course index keyboard navigation and aria-tree compatibility.

 *

 * Node tree and bootstrap collapsibles don't use the same HTML structure. However,

 * all keybindings and logic is compatible. This class translate the primitive opetations

 * to a bootstrap collapsible structure.

 *

 * @module     core_courseformat/local/courseeditor/contenttree

 * @class      core_courseformat/local/courseeditor/contenttree

 * @copyright  2021 Ferran Recio <ferran@moodle.com>

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

// The core/tree uses jQuery to expand all nodes.

import jQuery from 'jquery';

import Tree from 'core/tree';

import {getList} from 'core/normalise';

export default class extends Tree {

    /**

     * Setup the core/tree keyboard navigation.

     *

     * @param {Element|undefined} mainElement an alternative main element in case it is not from the parent component

     * @param {Object|undefined} selectors alternative selectors

     * @param {boolean} preventcache if the elements cache must be disabled.

     */

    constructor(mainElement, selectors, preventcache) {

        // Init this value with the parent DOM element.

        super(mainElement);

        // Get selectors from parent.

        this.selectors = {

            SECTION: selectors.SECTION,

            TOGGLER: selectors.TOGGLER,

            COLLAPSE: selectors.COLLAPSE,

            ENTER: selectors.ENTER ?? selectors.TOGGLER,

        };

        // The core/tree library saves the visible elements cache inside the main tree node.

        // However, in edit mode content can change suddenly so we need to refresh caches when needed.

        if (preventcache) {

            this._getVisibleItems = this.getVisibleItems;

            this.getVisibleItems = () => {

                this.refreshVisibleItemsCache();

                return this._getVisibleItems();

            };

        }

        // All jQuery events can be replaced when MDL-71979 is integrated.

        this.treeRoot.on('hidden.bs.collapse shown.bs.collapse', () => {

            this.refreshVisibleItemsCache();

        });

        // Register a custom callback for pressing enter key.

        this.registerEnterCallback(this.enterCallback.bind(this));

    }

    /**

     * Return the current active node.

     *

     * @return {Element|undefined} the active item if any

     */

    getActiveItem() {

        const activeItem = this.treeRoot.data('activeItem');

        if (activeItem) {

            return getList(activeItem)[0];

        }

        return undefined;

    }

    /**

     * Handle enter key on a collpasible node.

     *

     * @param {JQuery} jQueryItem the jQuery object

     */

    enterCallback(jQueryItem) {

        const item = getList(jQueryItem)[0];

        if (this.isGroupItem(jQueryItem)) {

            // Group elements is like clicking a topic but without loosing the focus.

            const enter = item.querySelector(this.selectors.ENTER);

            if (enter.getAttribute('href') !== '#') {

                window.location.href = enter.getAttribute('href');

            }

            enter.click();

        } else {

            // Activity links just follow the link href.

            const link = item.querySelector('a');

            if (link.getAttribute('href') !== '#') {

                window.location.href = link.getAttribute('href');

            } else {

                link.click();

            }

            return;

        }

    }

    /**

     * Handle an item click.

     *

     * @param {Event} event the click event

     * @param {jQuery} jQueryItem the item clicked

     */

    handleItemClick(event, jQueryItem) {

        const isChevron = event.target.closest(this.selectors.COLLAPSE);

        // Only chevron clicks toogle the sections always.

        if (isChevron) {

            super.handleItemClick(event, jQueryItem);

            return;

        }

        // This is a title or activity name click.

        jQueryItem.focus();

        if (this.isGroupItem(jQueryItem)) {

            this.expandGroup(jQueryItem);

        }

    }

    /**

     * Check if a gorup item is collapsed.

     *

     * @param {JQuery} jQueryItem  the jQuery object

     * @returns {boolean} if the element is collapsed

     */

    isGroupCollapsed(jQueryItem) {

        const item = getList(jQueryItem)[0];

        const toggler = item.querySelector(`[aria-expanded]`);

        return toggler.getAttribute('aria-expanded') === 'false';

    }

    /**

     * Toggle a group item.

     *

     * @param {JQuery} item  the jQuery object

     */

    toggleGroup(item) {

        // All jQuery in this segment of code can be replaced when MDL-71979 is integrated.

        const toggler = item.find(this.selectors.COLLAPSE);

        let collapsibleId = toggler.data('target') ?? toggler.attr('href');

        if (!collapsibleId) {

            return;

        }

        collapsibleId = collapsibleId.replace('#', '');

        // Bootstrap 4 uses jQuery to interact with collapsibles.

        const collapsible = jQuery(`#${collapsibleId}`);

        if (collapsible.length) {

            jQuery(`#${collapsibleId}`).collapse('toggle');

        }

    }

    /**

     * Expand a group item.

     *

     * @param {JQuery} item  the jQuery object

     */

    expandGroup(item) {

        if (this.isGroupCollapsed(item)) {

            this.toggleGroup(item);

        }

    }

    /**

     * Collpase a group item.

     *

     * @param {JQuery} item  the jQuery object

     */

    collapseGroup(item) {

        if (!this.isGroupCollapsed(item)) {

            this.toggleGroup(item);

        }

    }

    /**

     * Expand all groups.

     */

    expandAllGroups() {

        const togglers = getList(this.treeRoot)[0].querySelectorAll(this.selectors.SECTION);

        togglers.forEach(item => {

            this.expandGroup(jQuery(item));

        });

    }

}