com.bumptech.glide.load.resource.bitmap.DrawableTransformation Maven / Gradle / Ivy

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A fast and efficient image loading library for Android focused on smooth scrolling.
There is a newer version: 5.0.0-rc01
package com.bumptech.glide.load.resource.bitmap;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import androidx.annotation.NonNull;
import com.bumptech.glide.Glide;
import com.bumptech.glide.load.Transformation;
import com.bumptech.glide.load.engine.Resource;
import com.bumptech.glide.load.engine.bitmap_recycle.BitmapPool;
import java.security.MessageDigest;

/**
 * Applies a {@link Bitmap} {@link Transformation} to {@link Drawable}s by first attempting to
 * convert the {@link Drawable} to a {@link Bitmap} and then running the {@link Transformation} on
 * the converted {@link Bitmap}.
 *
 * This class is relatively efficient for {@link BitmapDrawable} where the {@link Bitmap} is
 * readily accessible. For non-{@link Bitmap} based {@link Drawable}s, this class must first try to
 * draw the {@link Drawable} to a {@link Bitmap} using {@link android.graphics.Canvas}, which is
 * less efficient. {@link Drawable}s that implement {@link android.graphics.drawable.Animatable}
 * will fail with an exception. {@link Drawable}s that return <= 0 for {@link
 * Drawable#getIntrinsicHeight()} and/or {@link Drawable#getIntrinsicWidth()} will fail with an
 * exception if the requested size is {@link
 * com.bumptech.glide.request.target.Target#SIZE_ORIGINAL}. {@link Drawable}s without intrinsic
 * dimensions are drawn using the dimensions provided in {@link Transformation#transform(Context,
 * Resource, int, int)}. As a result, they may be transformed incorrectly or in unexpected ways.
 */
public class DrawableTransformation implements Transformation {

  private final Transformation wrapped;
  private final boolean isRequired;

  public DrawableTransformation(Transformation wrapped, boolean isRequired) {
    this.wrapped = wrapped;
    this.isRequired = isRequired;
  }

  @SuppressWarnings("unchecked")
  public Transformation asBitmapDrawable() {
    return (Transformation) (Transformation) this;
  }

  @NonNull
  @Override
  public Resource transform(
      @NonNull Context context, @NonNull Resource resource, int outWidth, int outHeight) {
    BitmapPool bitmapPool = Glide.get(context).getBitmapPool();
    Drawable drawable = resource.get();
    Resource bitmapResourceToTransform =
        DrawableToBitmapConverter.convert(bitmapPool, drawable, outWidth, outHeight);
    if (bitmapResourceToTransform == null) {
      if (isRequired) {
        throw new IllegalArgumentException("Unable to convert " + drawable + " to a Bitmap");
      } else {
        return resource;
      }
    }
    Resource transformedBitmapResource =
        wrapped.transform(context, bitmapResourceToTransform, outWidth, outHeight);

    if (transformedBitmapResource.equals(bitmapResourceToTransform)) {
      transformedBitmapResource.recycle();
      return resource;
    } else {
      return newDrawableResource(context, transformedBitmapResource);
    }
  }

  // It's clearer to cast the result in a separate line from obtaining it.
  @SuppressWarnings({"unchecked", "PMD.UnnecessaryLocalBeforeReturn"})
  private Resource newDrawableResource(Context context, Resource transformed) {
    Resource result =
        LazyBitmapDrawableResource.obtain(context.getResources(), transformed);
    return (Resource) result;
  }

  @Override
  public boolean equals(Object o) {
    if (o instanceof DrawableTransformation) {
      DrawableTransformation other = (DrawableTransformation) o;
      return wrapped.equals(other.wrapped);
    }
    return false;
  }

  @Override
  public int hashCode() {
    return wrapped.hashCode();
  }

  @Override
  public void updateDiskCacheKey(@NonNull MessageDigest messageDigest) {
    wrapped.updateDiskCacheKey(messageDigest);
  }
}