The BUILD file is updated to include the new native ad and native template source paths.

source/plugin/Assets/Plugins/Android/GoogleMobileAdsPlugin.androidlib/src/main/java/com/google/unity/ads/nextgen/AdWrapper.java

@@ -1,6 +1,8 @@
 package com.google.unity.ads.nextgen;
 
 import com.google.android.libraries.ads.mobile.sdk.appopen.AppOpenAd;
+import com.google.android.libraries.ads.mobile.sdk.banner.BannerAd;
+import com.google.android.libraries.ads.mobile.sdk.banner.BannerAdRequest;
 import com.google.android.libraries.ads.mobile.sdk.common.AdLoadCallback;
 import com.google.android.libraries.ads.mobile.sdk.common.AdRequest;
 import com.google.android.libraries.ads.mobile.sdk.interstitial.InterstitialAd;
@@ -35,6 +37,22 @@ public static AdWrapper<AppOpenAd> forAppOpen() {
     return new AdWrapper<>(AppOpenAd::load);
   }
 
+  /** Creates a new AdWrapper for loading BannerAds. */
+  public static AdWrapper<BannerAd> forBanner() {
+    return new AdWrapper<BannerAd>(
+        new AdLoader<BannerAd>() {
+          @Override
+          public void load(AdRequest adRequest, AdLoadCallback<BannerAd> callback) {
+            if (adRequest instanceof BannerAdRequest) {
+              BannerAd.load((BannerAdRequest) adRequest, callback);
+            } else {
+              throw new IllegalArgumentException(
+                  "AdRequest must be of type BannerAdRequest for Banner Ads");
+            }
+          }
+        });
+  }
+
   /** Creates a new AdWrapper for loading InterstitialAds. */
   public static AdWrapper<InterstitialAd> forInterstitial() {
     return new AdWrapper<>(InterstitialAd::load);

source/plugin/Assets/Plugins/Android/GoogleMobileAdsPlugin.androidlib/src/main/java/com/google/unity/ads/nextgen/UnityBannerAd.java

@@ -26,6 +26,7 @@
 import android.widget.FrameLayout;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
 import com.google.android.libraries.ads.mobile.sdk.banner.BannerAd;
 import com.google.android.libraries.ads.mobile.sdk.banner.BannerAdEventCallback;
 import com.google.android.libraries.ads.mobile.sdk.banner.BannerAdRequest;
@@ -54,9 +55,13 @@ protected static class Insets {
   /** The {@link BannerAd} to display to the user. */
   private BannerAd bannerAd;
 
+  /** The {@link AdWrapper} used to load ads. */
+  private final AdWrapper<BannerAd> adWrapper;
+
   /** The {@link View} that contains the banner ad. */
   private View adView;
 
+
   /** A code indicating where to place the ad. */
   private int positionCode;
 
@@ -91,8 +96,14 @@ protected static class Insets {
   private View.OnLayoutChangeListener layoutChangeListener;
 
   public UnityBannerAd(Activity activity, UnityBannerAdCallback callback) {
+    this(activity, callback, AdWrapper.forBanner());
+  }
+
+  @VisibleForTesting
+  UnityBannerAd(Activity activity, UnityBannerAdCallback callback, AdWrapper<BannerAd> adWrapper) {
     unityPlayerActivity = activity;
     this.callback = callback;
+    this.adWrapper = adWrapper;
   }
 
   /**
@@ -121,7 +132,7 @@ public void create(final int positionX, final int positionY) {
   }
 
   protected void load(final BannerAdRequest adRequest) {
-    BannerAd.load(
+    adWrapper.load(
         adRequest,
         new AdLoadCallback<BannerAd>() {
           @Override
@@ -368,13 +379,19 @@ public void destroy() {
         .getDecorView()
         .getRootView()
         .removeOnLayoutChangeListener(layoutChangeListener);
+
+    layoutChangeListener = null;
   }
 
   /**
    * Sets the layout change listener for the {@link AdView} to detect orientation changes and
    * reposition banner ads as required.
    */
   protected void setLayoutChangeListener() {
+    if (layoutChangeListener != null) {
+      return;
+    }
+
     layoutChangeListener =
         new View.OnLayoutChangeListener() {
           @Override

source/plugin/Assets/Plugins/Android/GoogleMobileAdsPlugin.androidlib/src/main/java/com/google/unity/ads/nextgen/UnityBannerAdPreloader.java

@@ -0,0 +1,163 @@
+package com.google.unity.ads.nextgen;
+
+import android.app.Activity;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
+import com.google.android.libraries.ads.mobile.sdk.banner.BannerAd;
+import com.google.android.libraries.ads.mobile.sdk.banner.BannerAdPreloader;
+import com.google.android.libraries.ads.mobile.sdk.common.AdLoadCallback;
+import com.google.android.libraries.ads.mobile.sdk.common.AdRequest;
+import com.google.android.libraries.ads.mobile.sdk.common.LoadAdError;
+import com.google.android.libraries.ads.mobile.sdk.common.PreloadCallback;
+import com.google.android.libraries.ads.mobile.sdk.common.PreloadConfiguration;
+import com.google.android.libraries.ads.mobile.sdk.common.ResponseInfo;
+import java.util.Map;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+/** Unity implementation of the {@link BannerAdPreloader}. */
+public class UnityBannerAdPreloader {
+
+  /** The {@code Activity} on which the banner ad will display. */
+  private final Activity activity;
+
+  /** An executor used to run the callbacks. */
+  private final ExecutorService service;
+
+  /**
+   * A {@code UnityPreloadCallback} implemented in Unity via {@code AndroidJavaProxy} to receive ad
+   * events.
+   */
+  private final UnityPreloadCallback preloadCallback;
+
+  private final BannerAdPreloaderWrapper preloaderWrapper;
+
+  public UnityBannerAdPreloader(Activity activity, UnityPreloadCallback preloadCallback) {
+    this(
+        activity,
+        preloadCallback,
+        new BannerAdPreloaderWrapper(),
+        Executors.newSingleThreadExecutor());
+  }
+
+  @VisibleForTesting
+  public UnityBannerAdPreloader(
+      Activity activity,
+      UnityPreloadCallback preloadCallback,
+      BannerAdPreloaderWrapper preloaderWrapper,
+      ExecutorService service) {
+    this.activity = activity;
+    this.preloadCallback = preloadCallback;
+    this.service = service;
+    this.preloaderWrapper = preloaderWrapper;
+  }
+
+  public boolean start(String preloadId, PreloadConfiguration preloadConfiguration) {
+    return preloaderWrapper.start(
+        preloadId,
+        preloadConfiguration,
+        new PreloadCallback() {
+          @Override
+          public void onAdPreloaded(@NonNull String preloadId, ResponseInfo responseInfo) {
+            service.execute(
+                () -> {
+                  if (preloadCallback != null) {
+                    preloadCallback.onAdPreloaded(preloadId, responseInfo);
+                  }
+                });
+          }
+
+          @Override
+          public void onAdsExhausted(@NonNull String preloadId) {
+            service.execute(
+                () -> {
+                  if (preloadCallback != null) {
+                    preloadCallback.onAdsExhausted(preloadId);
+                  }
+                });
+          }
+
+          @Override
+          public void onAdFailedToPreload(@NonNull String preloadId, @NonNull LoadAdError adError) {
+            service.execute(
+                () -> {
+                  if (preloadCallback != null) {
+                    preloadCallback.onAdFailedToPreload(preloadId, adError);
+                  }
+                });
+          }
+        });
+  }
+
+  public boolean isAdAvailable(String preloadId) {
+    return preloaderWrapper.isAdAvailable(preloadId);
+  }
+
+  public int getNumAdsAvailable(String preloadId) {
+    return preloaderWrapper.getNumAdsAvailable(preloadId);
+  }
+
+  @SuppressWarnings("VisibleForTests")
+  @Nullable
+  public UnityBannerAd pollAd(String preloadId, UnityBannerAdCallback callback) {
+    final BannerAd pooledAd = preloaderWrapper.pollAd(preloadId);
+    if (pooledAd == null) {
+      return null;
+    }
+    AdWrapper<BannerAd> preloadedWrapper =
+        new AdWrapper<BannerAd>(
+            new AdWrapper.AdLoader<BannerAd>() {
+              @Override
+              public void load(AdRequest adRequest, AdLoadCallback<BannerAd> loadCallback) {
+                loadCallback.onAdLoaded(pooledAd);
+              }
+            });
+    return new UnityBannerAd(activity, callback, preloadedWrapper);
+  }
+
+  @Nullable
+  public PreloadConfiguration getConfiguration(String preloadId) {
+    return preloaderWrapper.getConfiguration(preloadId);
+  }
+
+  public Map<String, PreloadConfiguration> getConfigurations() {
+    return preloaderWrapper.getConfigurations();
+  }
+
+  public void destroy(String preloadId) {
+    boolean unused = preloaderWrapper.destroy(preloadId);
+  }
+
+  /** Wrapper for BannerAdPreloader static methods to facilitate testing. */
+  @VisibleForTesting
+  public static class BannerAdPreloaderWrapper {
+    public boolean start(String preloadId, PreloadConfiguration config, PreloadCallback callback) {
+      return BannerAdPreloader.start(preloadId, config, callback);
+    }
+
+    public boolean isAdAvailable(String preloadId) {
+      return BannerAdPreloader.isAdAvailable(preloadId);
+    }
+
+    public int getNumAdsAvailable(String preloadId) {
+      return BannerAdPreloader.getNumAdsAvailable(preloadId);
+    }
+
+    public BannerAd pollAd(String preloadId) {
+      return BannerAdPreloader.pollAd(preloadId);
+    }
+
+    public PreloadConfiguration getConfiguration(String preloadId) {
+      return BannerAdPreloader.getConfiguration(preloadId);
+    }
+
+    public Map<String, PreloadConfiguration> getConfigurations() {
+      return BannerAdPreloader.getConfigurations();
+    }
+
+    public boolean destroy(String preloadId) {
+      return BannerAdPreloader.destroy(preloadId);
+    }
+  }
+}