SlickRenderImageLoaders.java

package de.lessvoid.nifty.slick2d.loaders;

import de.lessvoid.nifty.slick2d.render.image.SlickLoadImageException;
import de.lessvoid.nifty.slick2d.render.image.SlickRenderImage;
import de.lessvoid.nifty.slick2d.render.image.loader.ImageSlickRenderImageLoader;
import de.lessvoid.nifty.slick2d.render.image.loader.SlickRenderImageLoader;

import javax.annotation.Nonnull;
import java.util.Iterator;

/**
 * This class is used to trigger the actual image loading. It will query all known image loaders in order to load the
 * render image.
 *
 * @author Martin Karing <nitram@illarion.org>
 */
public final class SlickRenderImageLoaders extends AbstractSlickLoaders<SlickRenderImageLoader> {
  /**
   * The singleton instance of this class.
   */
  private static final SlickRenderImageLoaders INSTANCE = new SlickRenderImageLoaders();

  /**
   * Get the singleton instance of this class.
   *
   * @return the singleton instance
   */
  @Nonnull
  public static SlickRenderImageLoaders getInstance() {
    return INSTANCE;
  }

  /**
   * Private constructor so no instances but the singleton instance are created.
   */
  private SlickRenderImageLoaders() {
  }

  /**
   * Load the default implementation of the render image loader.
   */
  @Override
  public void loadDefaultLoaders(@Nonnull final SlickAddLoaderLocation order) {
    addLoader(new ImageSlickRenderImageLoader(), order);
  }

  /**
   * Load the image with the defined name.
   *
   * @param filename     name of the file that contains the image
   * @param filterLinear {@code true} in case a linear filter should be applied when resizing this image
   * @return the image loaded
   * @throws IllegalArgumentException in case all loaders fail to load the image
   */
  @Nonnull
  @SuppressWarnings("TypeMayBeWeakened")
  public SlickRenderImage loadImage(final String filename, final boolean filterLinear) {
    final Iterator<SlickRenderImageLoader> itr = getLoaderIterator();

    while (itr.hasNext()) {
      try {
        return itr.next().loadImage(filename, filterLinear);
      } catch (@Nonnull final SlickLoadImageException ignored) {
        // this loader failed... does not matter
      }
    }

    throw new IllegalArgumentException("Failed to load image \"" + filename + "\".");
  }
}