changesize.php

<?php
// 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/>.


/**
 * Changes the text size via PHP or AJAX                               (1)
 *
 * This file finds the current font size, increases/decreases/resets it
 * as specified, and stores it in the $USER->fontsize session variable.
 * If requested via AJAX, it also returns the font size as a JSON
 * string or suiable error code. If not, it redirects the user back to
 * where they came from.                                               (2)
 *
 * @package   block_accessibility                                      (3)
 * @author      Mark Johnson <mark.johnson@tauntons.ac.uk>
 * @copyright   2010 Tauntons College, UK
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later (5)
 */

header('Cache-Control: no-cache');

// INITIALIZATION
// =========================================================
require_once('../../config.php');
require_once($CFG->dirroot.'/blocks/accessibility/lib.php');
require_login();


// if the user hasn't already changed the size, we need to find a default/referent so we know where we're increasing/decreasing from
if (!isset($USER->defaultfontsize)) {
    $USER->defaultfontsize = DEFAULT_FONTSIZE;

    // if javascript enabled, get current font-size value directly from the page
    // UPDATE 24.09.2014. It turns out not to be correct, needs to be adjusted...at least for clean theme...
    /*
    $cur = optional_param('cur', 0, PARAM_INT);
    if ($cur) $USER->defaultfontsize = $cur;
    */
}

// GET THE CURRENT FONT-SIZE VALUE IN PX
// =========================================================
// NOTE: User settings priority: 1. $USER session, 2. database, 3. default
$current = $USER->defaultfontsize;
if (isset($USER->fontsize)) {
    $current = $USER->fontsize; // user session
}
else if ($userstyle = $DB->get_record('block_accessibility', array('userid' => $USER->id))) {
    $current = $userstyle->fontsize; // user stored settings
}

// if value is in %, convert it to px to get array index of px so we are able to increment it...
if ($current > MAX_PX_FONTSIZE) { // must be in % then
    // If we're already dealing with a percentage,
    $current = accessibility_getsize($current); // Get the size in pixels
}

// ok, we have font size in px now, get new percentage value from it
// ...

// CALCULATE THE NEW FONT SIZE
// =========================================================
$op = required_param('op', PARAM_TEXT);
switch($op) {
    case 'inc':
        if ($current == MAX_PX_FONTSIZE) {
            // If we're at the upper limit, don't increase any further.
            $new = accessibility_getsize($current);
        } else {
            // Otherwise, increase
            $new = accessibility_getsize($current+1);
        }
        break;
    case 'dec':
        if ($current == MIN_PX_FONTSIZE) {
            // If we're at the lower limit, don't decrease any further.
            $new = accessibility_getsize($current);
        } else {
            $new = accessibility_getsize($current-1);
        }
        break;
    case 'reset':
        // Clear the fontsize stored in the session
        unset($USER->fontsize); 
        unset($USER->defaultfontsize);

        // Clear user records in database
        $urlparams = array(
            'op' => 'reset',
            'size' => true,
            'userid' => $USER->id
        );
        if(!accessibility_is_ajax()){
            $redirect = required_param('redirect', PARAM_TEXT);
            $urlparams['redirect'] = $redirect; 
        }

        $redirecturl = new moodle_url('/blocks/accessibility/database.php', $urlparams);
        redirect($redirecturl);


        // ... REDIRECTED! EXIT
        
        break;
    default: // ERROR   
        if (accessibility_is_ajax()) header('HTTP/1.0 400 Bad Request');
        else print_error('invalidop', 'block_accessibility');
        exit();
}

// SET THE NEW FONT SIZE IN % !!
// =========================================================
$USER->fontsize = $new; // If we've just increased or decreased, save the new size to the session

if (accessibility_is_ajax()) {
    // no redirect
    // it would be good idea to include userstyles.php here as HTTP response
    // this would save one extra HTTP request from module.js
} else {
    // Otherwise, redirect the user
    // if action is not achieved through ajax, redirect back to page is required
    $redirect = required_param('redirect', PARAM_TEXT);
    $redirecturl = new moodle_url($redirect);
    redirect($redirecturl);
}