ImageHeaderParser.java

package com.bumptech.glide.load;

import com.bumptech.glide.load.engine.bitmap_recycle.ArrayPool;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;

/**
 * Interface for the ImageHeaderParser.
 */
public interface ImageHeaderParser {
  /**
   * A constant indicating we were unable to parse the orientation from the image either because
   * no exif segment containing orientation data existed, or because of an I/O error attempting to
   * read the exif segment.
   */
  int UNKNOWN_ORIENTATION = -1;

  /**
   * The format of the image data including whether or not the image may include transparent
   * pixels.
   */
  enum ImageType {
    GIF(true),
    JPEG(false),
    RAW(false),
    /** PNG type with alpha. */
    PNG_A(true),
    /** PNG type without alpha. */
    PNG(false),
    /** WebP type with alpha. */
    WEBP_A(true),
    /** WebP type without alpha. */
    WEBP(false),
    /**
     * Unrecognized type.
     */
    UNKNOWN(false);
    private final boolean hasAlpha;

    ImageType(boolean hasAlpha) {
      this.hasAlpha = hasAlpha;
    }

    public boolean hasAlpha() {
      return hasAlpha;
    }
  }

  ImageType getType(InputStream is) throws IOException;
  ImageType getType(ByteBuffer byteBuffer) throws IOException;

  /**
   * Parse the orientation from the image header. If it doesn't handle this image type (or this is
   * not an image) it will return a default value rather than throwing an exception.
   *
   * @return The exif orientation if present or -1 if the header couldn't be parsed or doesn't
   * contain an orientation
   * @throws IOException
   */
  int getOrientation(InputStream is, ArrayPool byteArrayPool) throws IOException;
  int getOrientation(ByteBuffer byteBuffer, ArrayPool byteArrayPool) throws IOException;
}