95 lines
2.7 KiB
PHP
95 lines
2.7 KiB
PHP
<?php
|
|
|
|
declare(strict_types=1);
|
|
|
|
/*
|
|
* This file is part of the TYPO3 CMS project.
|
|
*
|
|
* It is free software; you can redistribute it and/or modify it under
|
|
* the terms of the GNU General Public License, either version 2
|
|
* of the License, or any later version.
|
|
*
|
|
* For the full copyright and license information, please read the
|
|
* LICENSE.txt file that was distributed with this source code.
|
|
*
|
|
* The TYPO3 project - inspiring people to share!
|
|
*/
|
|
|
|
namespace TYPO3\CMS\Core\Html\Srcset;
|
|
|
|
/**
|
|
* Represents a source candidate for the HTML srcset attribute
|
|
*/
|
|
abstract class SrcsetCandidate
|
|
{
|
|
public const WIDTH_UNIT = 'w';
|
|
public const DENSITY_UNIT = 'x';
|
|
|
|
protected ?string $uri = null;
|
|
|
|
/**
|
|
* @param string $descriptor srcset width (like "300w") or density (like "2x") descriptor.
|
|
* @param int|null $referenceWidth Needs to be provided if $descriptor is a density descriptor
|
|
* (like "2x") to be able to resolve the relative image dimensions.
|
|
* The absolute $referenceWidth will be used as "1x" width.
|
|
*/
|
|
public static function createFromDescriptor(string $descriptor, ?int $referenceWidth = null): SrcsetCandidate
|
|
{
|
|
$mode = substr($descriptor, -1);
|
|
$value = substr($descriptor, 0, -1);
|
|
if (is_numeric($value)) {
|
|
if ($mode === static::DENSITY_UNIT) {
|
|
// '1.5x'
|
|
return new DensitySrcsetCandidate((float)$value, $referenceWidth);
|
|
}
|
|
if ($mode === static::WIDTH_UNIT) {
|
|
// '200w'
|
|
return new WidthSrcsetCandidate((int)$value);
|
|
}
|
|
}
|
|
throw new \InvalidArgumentException(
|
|
'Invalid srcset descriptor provided, must be a numeric value that ends with "w" or "x": ' . $descriptor,
|
|
1774527269,
|
|
);
|
|
}
|
|
|
|
abstract public function getDescriptor(): string;
|
|
abstract public function getCalculatedWidth(): int;
|
|
|
|
public function setUri(string $uri): static
|
|
{
|
|
$this->uri = $uri;
|
|
return $this;
|
|
}
|
|
|
|
public function getUri(): ?string
|
|
{
|
|
return $this->uri;
|
|
}
|
|
|
|
/**
|
|
* Ensures that the provided URI can be used safely in a srcset attribute
|
|
*/
|
|
public function getSanitizedUri(): ?string
|
|
{
|
|
if ($this->uri === null) {
|
|
return null;
|
|
}
|
|
|
|
return strtr($this->uri, [
|
|
' ' => '%20',
|
|
',' => '%2C',
|
|
]);
|
|
}
|
|
|
|
public function generateSrcset(): string
|
|
{
|
|
return $this->getSanitizedUri() . ' ' . $this->getDescriptor();
|
|
}
|
|
|
|
public function __toString()
|
|
{
|
|
return $this->generateSrcset();
|
|
}
|
|
}
|