Haketilo

/**

 * This file is part of Haketilo.

 *

 * Function: Operations on DOM elements.

 *

 * Copyright (C) 2021 Wojtek Kosior

 *

 * This program 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.

 *

 * This program 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.

 *

 * As additional permission under GNU GPL version 3 section 7, you

 * may distribute forms of that code without the copy of the GNU

 * GPL normally required by section 4, provided you include this

 * license notice and, in case of non-source distribution, a URL

 * through which recipients can access the Corresponding Source.

 * If you modify file(s) with this exception, you may extend this

 * exception to your version of the file(s), but you are not

 * obligated to do so. If you do not wish to do so, delete this

 * exception statement from your version.

 *

 * As a special exception to the GPL, any HTML file which merely

 * makes function calls to this code, and for that purpose

 * includes it by reference shall be deemed a separate work for

 * copyright law purposes. If you modify this code, you may extend

 * this exception to your version of the code, but you are not

 * obligated to do so. If you do not wish to do so, delete this

 * exception statement from your version.

 *

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

 * along with this program.  If not, see <https://www.gnu.org/licenses/>.

 *

 * I, Wojtek Kosior, thereby promise not to sue for violation of this file's

 * license. Although I request that you do not make use of this code in a

 * proprietary program, I am not going to enforce this in court.

 */

#EXPORT  id => document.getElementById(id)  AS by_id

const known_templates = new Map();

function get_template(template_id)

{

    let template = known_templates.get(template_id) || null;

    if (template)

	return template;

    for (const template_node of document.getElementsByTagName("TEMPLATE")) {

	template = template_node.content.getElementById(template_id);

	if (template)

	    break;

    }

    known_templates.set(template_id, template);

    return template;

}

#EXPORT get_template

function clone_template(template_id)

{

    const clone = get_template(template_id).cloneNode(true);

    const result_object = {};

    const to_process = [clone];

    while (to_process.length > 0) {

	const element = to_process.pop();

	let template_key = element.getAttribute("data-template") || element.id;

	if (template_key)

	    result_object[template_key] = element;

	element.removeAttribute("id");

	element.removeAttribute("data-template");

	for (const child of element.children)

	    to_process.push(child);

    }

    return result_object;

}

#EXPORT clone_template

function Showable(on_show_cb, on_hide_cb) {

    this.shown = false;

    /*

     * Wrap the requested callback into one that only executes it if showable is

     * not shown.

     */

    this.when_hidden = cb => {

	const wrapped_cb = (...args) => {

	    if (!this.shown)

		return cb(...args);

	}

	return wrapped_cb;

    }

    this.show = () => {

	if (this.shown)

	    return false;

	this.shown = true;

	try {

	    on_show_cb();

	} catch(e) {

	    console.error("Haketilo:", e);

	}

	return true;

    }

    this.hide = () => {

	if (!this.shown)

	    return false;

	this.shown = false;

	try {

	    on_hide_cb();

	} catch(e) {

	    console.error("Haketilo:", e);

	}

	return true;

    }

}

#EXPORT Showable