+<?php
+
+namespace Drupal\system\Plugin\ImageToolkit\Operation\gd;
+
+/**
+ * Defines GD2 Scale operation.
+ *
+ * @ImageToolkitOperation(
+ * id = "gd_scale",
+ * toolkit = "gd",
+ * operation = "scale",
+ * label = @Translation("Scale"),
+ * description = @Translation("Scales an image while maintaining aspect ratio. The resulting image can be smaller for one or both target dimensions.")
+ * )
+ */
+class Scale extends Resize {
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function arguments() {
+ return [
+ 'width' => [
+ 'description' => 'The target width, in pixels. This value is omitted then the scaling will based only on the height value',
+ 'required' => FALSE,
+ 'default' => NULL,
+ ],
+ 'height' => [
+ 'description' => 'The target height, in pixels. This value is omitted then the scaling will based only on the width value',
+ 'required' => FALSE,
+ 'default' => NULL,
+ ],
+ 'upscale' => [
+ 'description' => 'Boolean indicating that files smaller than the dimensions will be scaled up. This generally results in a low quality image',
+ 'required' => FALSE,
+ 'default' => FALSE,
+ ],
+ ];
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function validateArguments(array $arguments) {
+ // Assure at least one dimension.
+ if (empty($arguments['width']) && empty($arguments['height'])) {
+ throw new \InvalidArgumentException("At least one dimension ('width' or 'height') must be provided to the image 'scale' operation");
+ }
+
+ // Calculate one of the dimensions from the other target dimension,
+ // ensuring the same aspect ratio as the source dimensions. If one of the
+ // target dimensions is missing, that is the one that is calculated. If both
+ // are specified then the dimension calculated is the one that would not be
+ // calculated to be bigger than its target.
+ $aspect = $this->getToolkit()->getHeight() / $this->getToolkit()->getWidth();
+ if (($arguments['width'] && !$arguments['height']) || ($arguments['width'] && $arguments['height'] && $aspect < $arguments['height'] / $arguments['width'])) {
+ $arguments['height'] = (int) round($arguments['width'] * $aspect);
+ }
+ else {
+ $arguments['width'] = (int) round($arguments['height'] / $aspect);
+ }
+
+ // Assure integers for all arguments.
+ $arguments['width'] = (int) round($arguments['width']);
+ $arguments['height'] = (int) round($arguments['height']);
+
+ // Fail when width or height are 0 or negative.
+ if ($arguments['width'] <= 0) {
+ throw new \InvalidArgumentException("Invalid width ('{$arguments['width']}') specified for the image 'scale' operation");
+ }
+ if ($arguments['height'] <= 0) {
+ throw new \InvalidArgumentException("Invalid height ('{$arguments['height']}') specified for the image 'scale' operation");
+ }
+
+ return $arguments;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function execute(array $arguments = []) {
+ // Don't scale if we don't change the dimensions at all.
+ if ($arguments['width'] !== $this->getToolkit()->getWidth() || $arguments['height'] !== $this->getToolkit()->getHeight()) {
+ // Don't upscale if the option isn't enabled.
+ if ($arguments['upscale'] || ($arguments['width'] <= $this->getToolkit()->getWidth() && $arguments['height'] <= $this->getToolkit()->getHeight())) {
+ return parent::execute($arguments);
+ }
+ }
+ return TRUE;
+ }
+
+}