Use application context to load ads - Android only

packages/google_mobile_ads/android/build.gradle

@@ -26,7 +26,6 @@ android {
 
     defaultConfig {
         minSdkVersion 19
-        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
     lintOptions {
         disable 'InvalidPackage'
@@ -36,7 +35,13 @@ android {
       testImplementation 'junit:junit:4.12'
       testImplementation 'org.hamcrest:hamcrest:2.2'
       testImplementation 'org.mockito:mockito-inline:3.9.0'
+      testImplementation 'org.robolectric:robolectric:4.4'
     }
+  testOptions {
+    unitTests {
+      includeAndroidResources = true
+    }
+  }
 }
 
 afterEvaluate {

packages/google_mobile_ads/android/src/main/java/io/flutter/plugins/googlemobileads/AdInstanceManager.java

@@ -15,13 +15,13 @@
 package io.flutter.plugins.googlemobileads;
 
 import android.app.Activity;
+import android.os.Handler;
+import android.os.Looper;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.google.android.gms.ads.AdError;
 import com.google.android.gms.ads.ResponseInfo;
-import io.flutter.plugin.common.BinaryMessenger;
 import io.flutter.plugin.common.MethodChannel;
-import io.flutter.plugin.common.StandardMethodCodec;
 import io.flutter.plugins.googlemobileads.FlutterAd.FlutterAdError;
 import io.flutter.plugins.googlemobileads.FlutterAd.FlutterResponseInfo;
 import java.util.HashMap;
@@ -35,23 +35,29 @@
  * provide access until the ad is disposed.
  */
 class AdInstanceManager {
-  @NonNull Activity activity;
+  @Nullable private Activity activity;
 
   @NonNull private final Map<Integer, FlutterAd> ads;
   @NonNull private final MethodChannel channel;
 
-  AdInstanceManager(@NonNull Activity activity, @NonNull BinaryMessenger binaryMessenger) {
-    this.activity = activity;
+  /**
+   * Initializes the ad instance manager. We only need a method channel to start loading ads, but an
+   * activity must be present in order to attach any to the view hierarchy.
+   */
+  AdInstanceManager(@NonNull MethodChannel channel) {
+    this.channel = channel;
     this.ads = new HashMap<>();
-    final StandardMethodCodec methodCodec = new StandardMethodCodec(new AdMessageCodec(activity));
-    this.channel =
-        new MethodChannel(binaryMessenger, "plugins.flutter.io/google_mobile_ads", methodCodec);
   }
 
-  void setActivity(@NonNull Activity activity) {
+  void setActivity(@Nullable Activity activity) {
     this.activity = activity;
   }
 
+  @Nullable
+  Activity getActivity() {
+    return activity;
+  }
+
   @Nullable
   FlutterAd adForId(int id) {
     return ads.get(id);
@@ -210,12 +216,13 @@ boolean showAdWithId(int id) {
 
   /** Invoke the method channel using the UI thread. Otherwise the message gets silently dropped. */
   private void invokeOnAdEvent(final Map<Object, Object> arguments) {
-    activity.runOnUiThread(
-        new Runnable() {
-          @Override
-          public void run() {
-            channel.invokeMethod("onAdEvent", arguments);
-          }
-        });
+    new Handler(Looper.getMainLooper())
+        .post(
+            new Runnable() {
+              @Override
+              public void run() {
+                channel.invokeMethod("onAdEvent", arguments);
+              }
+            });
   }
 }

packages/google_mobile_ads/android/src/main/java/io/flutter/plugins/googlemobileads/AdMessageCodec.java

@@ -50,7 +50,7 @@ class AdMessageCodec extends StandardMessageCodec {
   static final byte VALUE_NATIVE_AD_OPTIONS = (byte) 144;
   static final byte VALUE_VIDEO_OPTIONS = (byte) 145;
 
-  @NonNull final Context context;
+  @NonNull Context context;
   @NonNull final FlutterAdSize.AdSizeFactory adSizeFactory;
 
   AdMessageCodec(@NonNull Context context) {
@@ -64,6 +64,10 @@ class AdMessageCodec extends StandardMessageCodec {
     this.adSizeFactory = adSizeFactory;
   }
 
+  void setContext(@NonNull Context context) {
+    this.context = context;
+  }
+
   @Override
   protected void writeValue(ByteArrayOutputStream stream, Object value) {
     if (value instanceof FlutterAdSize) {

packages/google_mobile_ads/android/src/main/java/io/flutter/plugins/googlemobileads/FlutterAdLoader.java

@@ -36,11 +36,14 @@
  */
 public class FlutterAdLoader {
 
-  public FlutterAdLoader() {}
+  @NonNull private final Context context;
+
+  public FlutterAdLoader(@NonNull Context context) {
+    this.context = context;
+  }
 
   /** Load an app open ad. */
   public void loadAppOpen(
-      @NonNull Context context,
       @NonNull String adUnitId,
       @NonNull AdRequest adRequest,
       int orientation,
@@ -50,7 +53,6 @@ public void loadAppOpen(
 
   /** Load an ad manager app open ad. */
   public void loadAdManagerAppOpen(
-      @NonNull Context context,
       @NonNull String adUnitId,
       @NonNull AdManagerAdRequest adRequest,
       int orientation,
@@ -60,7 +62,6 @@ public void loadAdManagerAppOpen(
 
   /** Load an interstitial ad. */
   public void loadInterstitial(
-      @NonNull Context context,
       @NonNull String adUnitId,
       @NonNull AdRequest adRequest,
       @NonNull InterstitialAdLoadCallback loadCallback) {
@@ -69,7 +70,6 @@ public void loadInterstitial(
 
   /** Load an ad manager interstitial ad. */
   public void loadAdManagerInterstitial(
-      @NonNull Context context,
       @NonNull String adUnitId,
       @NonNull AdManagerAdRequest adRequest,
       @NonNull AdManagerInterstitialAdLoadCallback loadCallback) {
@@ -78,7 +78,6 @@ public void loadAdManagerInterstitial(
 
   /** Load a rewarded ad. */
   public void loadRewarded(
-      @NonNull Context context,
       @NonNull String adUnitId,
       @NonNull AdRequest adRequest,
       @NonNull RewardedAdLoadCallback loadCallback) {
@@ -87,7 +86,6 @@ public void loadRewarded(
 
   /** Load an ad manager rewarded ad. */
   public void loadAdManagerRewarded(
-      @NonNull Context context,
       @NonNull String adUnitId,
       @NonNull AdManagerAdRequest adRequest,
       @NonNull RewardedAdLoadCallback loadCallback) {
@@ -96,7 +94,6 @@ public void loadAdManagerRewarded(
 
   /** Load a native ad. */
   public void loadNativeAd(
-      @NonNull Context context,
       @NonNull String adUnitId,
       @NonNull OnNativeAdLoadedListener onNativeAdLoadedListener,
       @NonNull NativeAdOptions nativeAdOptions,
@@ -112,7 +109,6 @@ public void loadNativeAd(
 
   /** Load an ad manager native ad. */
   public void loadAdManagerNativeAd(
-      @NonNull Context context,
       @NonNull String adUnitId,
       @NonNull OnNativeAdLoadedListener onNativeAdLoadedListener,
       @NonNull NativeAdOptions nativeAdOptions,

packages/google_mobile_ads/android/src/main/java/io/flutter/plugins/googlemobileads/FlutterAdManagerInterstitialAd.java

@@ -58,7 +58,6 @@ public FlutterAdManagerInterstitialAd(
   @Override
   void load() {
     flutterAdLoader.loadAdManagerInterstitial(
-        manager.activity,
         adUnitId,
         request.asAdManagerAdRequest(),
         new DelegatingAdManagerInterstitialAdCallbacks(this));
@@ -85,8 +84,12 @@ public void show() {
       Log.e(TAG, "The interstitial wasn't loaded yet.");
       return;
     }
+    if (manager.getActivity() == null) {
+      Log.e(TAG, "Tried to show interstitial before activity was bound to the plugin.");
+      return;
+    }
     ad.setFullScreenContentCallback(new FlutterFullScreenContentCallback(manager, adId));
-    ad.show(manager.activity);
+    ad.show(manager.getActivity());
   }
 
   @Override

packages/google_mobile_ads/android/src/main/java/io/flutter/plugins/googlemobileads/FlutterAppOpenAd.java

@@ -60,14 +60,12 @@ class FlutterAppOpenAd extends FlutterAd.FlutterOverlayAd {
   void load() {
     if (request != null) {
       flutterAdLoader.loadAppOpen(
-          manager.activity,
           adUnitId,
           request.asAdRequest(),
           getOrientation(),
           new DelegatingAppOpenAdLoadCallback(this));
     } else if (adManagerAdRequest != null) {
       flutterAdLoader.loadAdManagerAppOpen(
-          manager.activity,
           adUnitId,
           adManagerAdRequest.asAdManagerAdRequest(),
           getOrientation(),
@@ -101,9 +99,12 @@ void show() {
       Log.w(TAG, "Tried to show app open ad before it was loaded");
       return;
     }
-
+    if (manager.getActivity() == null) {
+      Log.e(TAG, "Tried to show app open ad before activity was bound to the plugin.");
+      return;
+    }
     ad.setFullScreenContentCallback(new FlutterFullScreenContentCallback(manager, adId));
-    ad.show(manager.activity);
+    ad.show(manager.getActivity());
   }
 
   @Override

packages/google_mobile_ads/android/src/main/java/io/flutter/plugins/googlemobileads/FlutterInterstitialAd.java

@@ -48,10 +48,7 @@ public FlutterInterstitialAd(
   void load() {
     if (manager != null && adUnitId != null && request != null) {
       flutterAdLoader.loadInterstitial(
-          manager.activity,
-          adUnitId,
-          request.asAdRequest(),
-          new DelegatingInterstitialAdLoadCallback(this));
+          adUnitId, request.asAdRequest(), new DelegatingInterstitialAdLoadCallback(this));
     }
   }
 
@@ -76,8 +73,12 @@ public void show() {
       Log.e(TAG, "Error showing interstitial - the interstitial ad wasn't loaded yet.");
       return;
     }
+    if (manager.getActivity() == null) {
+      Log.e(TAG, "Tried to show interstitial before activity was bound to the plugin.");
+      return;
+    }
     ad.setFullScreenContentCallback(new FlutterFullScreenContentCallback(manager, adId));
-    ad.show(manager.activity);
+    ad.show(manager.getActivity());
   }
 
   @Override

packages/google_mobile_ads/android/src/main/java/io/flutter/plugins/googlemobileads/FlutterNativeAd.java

@@ -49,6 +49,7 @@ static class Builder {
     @Nullable private Map<String, Object> customOptions;
     @Nullable private Integer id;
     @Nullable private FlutterNativeAdOptions nativeAdOptions;
+    @Nullable private FlutterAdLoader flutterAdLoader;
 
     public Builder setAdFactory(@NonNull NativeAdFactory adFactory) {
       this.adFactory = adFactory;
@@ -90,6 +91,11 @@ public Builder setNativeAdOptions(@Nullable FlutterNativeAdOptions nativeAdOptio
       return this;
     }
 
+    public Builder setFlutterAdLoader(@NonNull FlutterAdLoader flutterAdLoader) {
+      this.flutterAdLoader = flutterAdLoader;
+      return this;
+    }
+
     FlutterNativeAd build() {
       if (manager == null) {
         throw new IllegalStateException("AdInstanceManager cannot not be null.");
@@ -110,7 +116,7 @@ FlutterNativeAd build() {
                 adUnitId,
                 adFactory,
                 adManagerRequest,
-                new FlutterAdLoader(),
+                flutterAdLoader,
                 customOptions,
                 nativeAdOptions);
       } else {
@@ -121,7 +127,7 @@ FlutterNativeAd build() {
                 adUnitId,
                 adFactory,
                 request,
-                new FlutterAdLoader(),
+                flutterAdLoader,
                 customOptions,
                 nativeAdOptions);
       }
@@ -179,15 +185,10 @@ void load() {
             : nativeAdOptions.asNativeAdOptions();
     if (request != null) {
       flutterAdLoader.loadNativeAd(
-          manager.activity, adUnitId, loadedListener, options, adListener, request.asAdRequest());
+          adUnitId, loadedListener, options, adListener, request.asAdRequest());
     } else if (adManagerRequest != null) {
       flutterAdLoader.loadAdManagerNativeAd(
-          manager.activity,
-          adUnitId,
-          loadedListener,
-          options,
-          adListener,
-          adManagerRequest.asAdManagerAdRequest());
+          adUnitId, loadedListener, options, adListener, adManagerRequest.asAdManagerAdRequest());
     } else {
       Log.e(TAG, "A null or invalid ad request was provided.");
     }

packages/google_mobile_ads/android/src/main/java/io/flutter/plugins/googlemobileads/FlutterRewardedAd.java

@@ -108,11 +108,10 @@ public FlutterRewardedAd(
   void load() {
     final RewardedAdLoadCallback adLoadCallback = new DelegatingRewardedCallback(this);
     if (request != null) {
-      flutterAdLoader.loadRewarded(
-          manager.activity, adUnitId, request.asAdRequest(), adLoadCallback);
+      flutterAdLoader.loadRewarded(adUnitId, request.asAdRequest(), adLoadCallback);
     } else if (adManagerRequest != null) {
       flutterAdLoader.loadAdManagerRewarded(
-          manager.activity, adUnitId, adManagerRequest.asAdManagerAdRequest(), adLoadCallback);
+          adUnitId, adManagerRequest.asAdManagerAdRequest(), adLoadCallback);
     } else {
       Log.e(TAG, "A null or invalid ad request was provided.");
     }
@@ -138,10 +137,13 @@ public void show() {
       Log.e(TAG, "Error showing rewarded - the rewarded ad wasn't loaded yet.");
       return;
     }
-
+    if (manager.getActivity() == null) {
+      Log.e(TAG, "Tried to show rewarded ad before activity was bound to the plugin.");
+      return;
+    }
     rewardedAd.setFullScreenContentCallback(new FlutterFullScreenContentCallback(manager, adId));
     rewardedAd.setOnAdMetadataChangedListener(new DelegatingRewardedCallback(this));
-    rewardedAd.show(manager.activity, new DelegatingRewardedCallback(this));
+    rewardedAd.show(manager.getActivity(), new DelegatingRewardedCallback(this));
   }
 
   @Override