expo-image-manipulator/src/ImageManipulatorContext.ts

Provides functions that let you manipulation images on the local file system, eg: resize, crop.

import { SharedObject } from 'expo';

import type { ActionCrop, ActionExtent } from './ImageManipulator.types';
import type { ImageRef } from './ImageRef';
import ExpoImageManipulator from './NativeImageManipulatorModule';

/**
 * A context for an image manipulation. It provides synchronous, chainable functions that schedule transformations on the original image to the background thread.
 * Use an asynchronous [`renderAsync`](#renderasync) to await for all transformations to finish and access the final image.
 */
export declare class ImageManipulatorContext extends SharedObject {
  /**
   * Resizes the image to the given size.
   * @param size Values correspond to the result image dimensions. If you specify only one value, the other will
   * be calculated automatically to preserve image ratio.
   */
  resize(size: { width?: number | null; height?: number | null }): ImageManipulatorContext;

  /**
   * Rotates the image by the given number of degrees.
   * @param degrees Degrees to rotate the image. Rotation is clockwise when the value is positive and
   * counter-clockwise when negative.
   */
  rotate(degrees: number): ImageManipulatorContext;

  /**
   * Flips the image vertically or horizontally.
   * @param flipType An axis on which image will be flipped. Only one flip per transformation is available. If you
   * want to flip according to both axes then provide two separate transformations.
   */
  flip(flipType: 'vertical' | 'horizontal'): ImageManipulatorContext;

  /**
   * Crops the image to the given rectangle's origin and size.
   * @param rect Fields specify top-left corner and dimensions of a crop rectangle.
   */
  crop(rect: ActionCrop['crop']): ImageManipulatorContext;

  /**
   * Set the image size and offset. If the image is enlarged, unfilled areas are set to the `backgroundColor`.
   * To position the image, use `originX` and `originY`.
   *
   * @platform web
   */
  extent(options: ActionExtent['extent']): ImageManipulatorContext;

  /**
   * Resets the manipulator context to the originally loaded image.
   */
  reset(): ImageManipulatorContext;

  /**
   * Awaits for all manipulation tasks to finish and resolves with a reference to the resulted native image.
   */
  renderAsync(): Promise<ImageRef>;
}

export default ExpoImageManipulator.Context as typeof ImageManipulatorContext;