Added generic avatar using the user's initials

[GitHub/WoltLab/WCF.git] / wcfsetup / install / files / lib / data / user / avatar / DefaultAvatar.class.php

<?php
namespace wcf\data\user\avatar;
use wcf\system\WCF;
use wcf\util\StringUtil;

/**
 * Represents a default avatar.
 * 
 * @author	Marcel Werk
 * @copyright	2001-2017 WoltLab GmbH
 * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
 * @package	WoltLabSuite\Core\Data\User\Avatar
 */
class DefaultAvatar implements IUserAvatar {
	/**
	 * image size
	 * @var	integer
	 */
	public $size = UserAvatar::AVATAR_SIZE;
	
	/**
	 * content of the `src` attribute
	 * @var string
	 */
	protected $src = '';
	
	/**
	 * DefaultAvatar constructor.
	 * 
	 * @param       string          $username       username for use with the 'initials' avatar type
	 */
	public function __construct($username = '') {
		if (defined('AVATAR_DEFAULT_TYPE') && AVATAR_DEFAULT_TYPE === 'initials' && !empty($username)) {
			$words = explode(' ', $username);
			$count = count($words);
			if ($count > 1) {
				// combine the first character of each the first and the last word
				$text = mb_strtoupper(mb_substr($words[0], 0, 1) . mb_substr($words[$count - 1], 0, 1));
			}
			else {
				// use the first two characters
				$text = mb_strtoupper(mb_substr($username, 0, 2));
			}
			
			$backgroundColor = substr(sha1($username), 0, 6);
			
			$perceptiveLuminance = $this->getPerceptiveLuminance(
				hexdec($backgroundColor[0] . $backgroundColor[1]),
				hexdec($backgroundColor[2] . $backgroundColor[3]),
				hexdec($backgroundColor[4] . $backgroundColor[5])
			);
			
			$textColor = ($perceptiveLuminance < 0.3) ? '000' : 'fff';
			
			// the <path> is basically a shorter version of a <rect>
			$svg = <<<SVG
<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16"><path fill="#{$backgroundColor}" d="M0 0h16v16H0z"/><text x="8" y="8" fill="#{$textColor}" text-anchor="middle" alignment-baseline="central" font-family="Arial" font-size="7">{$text}</text></svg>
SVG;
			
			$this->src = "data:image/svg+xml;base64," . base64_encode($svg);
		}
		else {
			$this->src = WCF::getPath().'images/avatars/avatar-default.svg';
		}
	}
	
	/**
	 * @inheritDoc
	 */
	public function getURL($size = null) {
		return $this->src;
	}
	
	/**
	 * @inheritDoc
	 */
	public function getImageTag($size = null) {
		if ($size === null) $size = $this->size;
		
		return '<img src="'.StringUtil::encodeHTML($this->getURL($size)).'" style="width: '.$size.'px; height: '.$size.'px" alt="" class="userAvatarImage">';
	}
	
	/**
	 * @inheritDoc
	 */
	public function getWidth() {
		return $this->size;
	}
	
	/**
	 * @inheritDoc
	 */
	public function getHeight() {
		return $this->size;
	}
	
	/**
	 * @inheritDoc
	 */
	public function canCrop() {
		return false;
	}
	
	/**
	 * @inheritDoc
	 */
	public function getCropImageTag($size = null) {
		return '';
	}
	
	/**
	 * Returns the perceived luminance of the given color.
	 * 
	 * @param       integer         $r
	 * @param       integer         $g
	 * @param       integer         $b
	 * @return      float           luminance expressed in a float in the range of 0 and 1
	 */
	protected function getPerceptiveLuminance($r, $g, $b) {
		return 1 - (0.299 * $r + 0.587 * $g + 0.114 * $b) / 255;
	}
}