GoogleMapsApiHelper.java

package helpers;

import com.google.maps.PendingResult;

import java.util.concurrent.CompletableFuture;

/**
 * Helper methods for Google Maps API.
 */
public final class GoogleMapsApiHelper {
  /**
   * Private constructor for utility class to prevent instantiation.
   */
  private GoogleMapsApiHelper() {
  }

  /**
   * Wrap the {@link PendingResult} to {@link CompletableFuture}.
   */
  public static <T> CompletableFuture<T> toCompletable(PendingResult<T> pendingResult) {
    final CompletableFuture<T> future = new CompletableFuture<>();
    pendingResult.setCallback(new CompletableCallback<>(future));
    return future;
  }

  private static class CompletableCallback<T> implements PendingResult.Callback<T> {
    private final CompletableFuture<T> future;

    public CompletableCallback(final CompletableFuture<T> future) {
      this.future = future;
    }

    @Override
    public void onResult(final T result) {
      this.future.complete(result);
    }

    @Override
    public void onFailure(final Throwable e) {
      this.future.completeExceptionally(e);
    }
  }
}