ScaleImageEffect.php

<?php

namespace Drupal\image\Plugin\ImageEffect;

use Drupal\Component\Utility\Image;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Image\ImageInterface;

/**
 * Scales an image resource.
 *
 * @ImageEffect(
 *   id = "image_scale",
 *   label = @Translation("Scale"),
 *   description = @Translation("Scaling will maintain the aspect-ratio of the original image. If only a single dimension is specified, the other dimension will be calculated.")
 * )
 */
class ScaleImageEffect extends ResizeImageEffect {
    
    /**
     * {@inheritdoc}
     */
    public function applyEffect(ImageInterface $image) {
        if (!$image->scale($this->configuration['width'], $this->configuration['height'], $this->configuration['upscale'])) {
            $this->logger
                ->error('Image scale failed using the %toolkit toolkit on %path (%mimetype, %dimensions)', [
                '%toolkit' => $image->getToolkitId(),
                '%path' => $image->getSource(),
                '%mimetype' => $image->getMimeType(),
                '%dimensions' => $image->getWidth() . 'x' . $image->getHeight(),
            ]);
            return FALSE;
        }
        return TRUE;
    }
    
    /**
     * {@inheritdoc}
     */
    public function transformDimensions(array &$dimensions, $uri) {
        if ($dimensions['width'] && $dimensions['height']) {
            Image::scaleDimensions($dimensions, $this->configuration['width'], $this->configuration['height'], $this->configuration['upscale']);
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function getSummary() {
        $summary = [
            '#theme' => 'image_scale_summary',
            '#data' => $this->configuration,
        ];
        $summary += parent::getSummary();
        return $summary;
    }
    
    /**
     * {@inheritdoc}
     */
    public function defaultConfiguration() {
        return parent::defaultConfiguration() + [
            'upscale' => FALSE,
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
        $form = parent::buildConfigurationForm($form, $form_state);
        $form['width']['#required'] = FALSE;
        $form['height']['#required'] = FALSE;
        $form['upscale'] = [
            '#type' => 'checkbox',
            '#default_value' => $this->configuration['upscale'],
            '#title' => $this->t('Allow Upscaling'),
            '#description' => $this->t('Let scale make images larger than their original size.'),
        ];
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function validateConfigurationForm(array &$form, FormStateInterface $form_state) {
        parent::validateConfigurationForm($form, $form_state);
        if ($form_state->isValueEmpty('width') && $form_state->isValueEmpty('height')) {
            $form_state->setErrorByName('data', $this->t('Width and height can not both be blank.'));
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
        parent::submitConfigurationForm($form, $form_state);
        $this->configuration['upscale'] = $form_state->getValue('upscale');
    }

}