interface ResponsiveImageStyleInterface

interface ResponsiveImageStyleInterface extends ConfigEntityInterface {
    
    /**
     * The machine name for the empty image breakpoint image style option.
     */
    const EMPTY_IMAGE = '_empty image_';
    
    /**
     * The machine name for the original image breakpoint image style option.
     */
    const ORIGINAL_IMAGE = '_original image_';
    
    /**
     * Checks if there is at least one mapping defined.
     *
     * @return bool
     *   Whether the entity has any image style mappings.
     */
    public function hasImageStyleMappings();
    
    /**
     * Returns the mappings of breakpoint ID and multiplier to image style.
     *
     * @return array[]
     *   The image style mappings. Keyed by breakpoint ID then multiplier.
     *   The value is the image style mapping array with following keys:
     *     - image_mapping_type: Either 'image_style' or 'sizes'.
     *     - image_mapping:
     *       - If image_mapping_type is 'image_style', the image style ID.
     *       - If image_mapping_type is 'sizes', an array with following keys:
     *         - sizes: The value for the 'sizes' attribute.
     *         - sizes_image_styles: The image styles to use for the 'srcset'
     *           attribute.
     *     - breakpoint_id: The breakpoint ID for this mapping.
     *     - multiplier: The multiplier for this mapping.
     */
    public function getKeyedImageStyleMappings();
    
    /**
     * Returns the image style mappings for the responsive image style.
     *
     * @return array[]
     *   An array of image style mappings. Each image style mapping array
     *   contains the following keys:
     *   - breakpoint_id
     *   - multiplier
     *   - image_mapping_type
     *   - image_mapping
     */
    public function getImageStyleMappings();
    
    /**
     * Sets the breakpoint group for the responsive image style.
     *
     * @param string $breakpoint_group
     *   The responsive image style breakpoint group.
     *
     * @return $this
     */
    public function setBreakpointGroup($breakpoint_group);
    
    /**
     * Returns the breakpoint group for the responsive image style.
     *
     * @return string
     *   The breakpoint group.
     */
    public function getBreakpointGroup();
    
    /**
     * Sets the fallback image style for the responsive image style.
     *
     * @param string $fallback_image_style
     *   The fallback image style ID.
     *
     * @return $this
     */
    public function setFallbackImageStyle($fallback_image_style);
    
    /**
     * Returns the fallback image style ID for the responsive image style.
     *
     * @return string
     *   The fallback image style ID.
     */
    public function getFallbackImageStyle();
    
    /**
     * Gets the image style mapping for a breakpoint ID and multiplier.
     *
     * @param string $breakpoint_id
     *   The breakpoint ID.
     * @param string $multiplier
     *   The multiplier.
     *
     * @return array|null
     *   The image style mapping. NULL if the mapping does not exist.
     *   The image style mapping has following keys:
     *     - image_mapping_type: Either 'image_style' or 'sizes'.
     *     - image_mapping:
     *       - If image_mapping_type is 'image_style', the image style ID.
     *       - If image_mapping_type is 'sizes', an array with following keys:
     *         - sizes: The value for the 'sizes' attribute.
     *         - sizes_image_styles: The image styles to use for the 'srcset'
     *           attribute.
     *     - breakpoint_id: The breakpoint ID for this image style mapping.
     *     - multiplier: The multiplier for this image style mapping.
     */
    public function getImageStyleMapping($breakpoint_id, $multiplier);
    
    /**
     * Checks if there is at least one image style mapping defined.
     *
     * @param array $image_style_mapping
     *   The image style mapping.
     *
     * @return bool
     *   Whether the image style mapping is empty.
     */
    public static function isEmptyImageStyleMapping(array $image_style_mapping);
    
    /**
     * Adds an image style mapping to the responsive image configuration entity.
     *
     * @param string $breakpoint_id
     *   The breakpoint ID.
     * @param string $multiplier
     *   The multiplier.
     * @param array $image_style_mapping
     *   The mapping image style mapping.
     *
     * @return $this
     */
    public function addImageStyleMapping($breakpoint_id, $multiplier, array $image_style_mapping);
    
    /**
     * Removes all image style mappings from the responsive image style.
     *
     * @return $this
     */
    public function removeImageStyleMappings();
    
    /**
     * Gets all the image styles IDs involved in the responsive image mapping.
     *
     * @return string[]
     */
    public function getImageStyleIds();

}