Fix handling of network transitions in RequirementsWatcher

Issue: #6733
PiperOrigin-RevId: 286621715

RELEASENOTES.md

@@ -8,6 +8,10 @@
   Also change `IcyInfo.rawMetadata` from `String` to `byte[]` to allow
   Also change `IcyInfo.rawMetadata` from `String` to `byte[]` to allow
   developers to handle data that's neither UTF-8 nor ISO-8859-1
   developers to handle data that's neither UTF-8 nor ISO-8859-1
   ([#6753](https://github.com/google/ExoPlayer/issues/6753)).
   ([#6753](https://github.com/google/ExoPlayer/issues/6753)).
+* Fix handling of network transitions in `RequirementsWatcher`
+  ([#6733](https://github.com/google/ExoPlayer/issues/6733)). Incorrect handling
+  could previously cause downloads to be paused when they should have been able
+  to proceed.
 
 
 ### 2.11.1 (2019-12-20) ###
 ### 2.11.1 (2019-12-20) ###
 
 

library/core/src/main/java/com/google/android/exoplayer2/scheduler/Requirements.java

@@ -163,9 +163,10 @@ public final class Requirements implements Parcelable {
   }
   }
 
 
   private static boolean isInternetConnectivityValidated(ConnectivityManager connectivityManager) {
   private static boolean isInternetConnectivityValidated(ConnectivityManager connectivityManager) {
-    if (Util.SDK_INT < 23) {
-      // TODO Check internet connectivity using http://clients3.google.com/generate_204 on API
-      // levels prior to 23.
+    // It's possible to query NetworkCapabilities from API level 23, but RequirementsWatcher only
+    // fires an event to update its Requirements when NetworkCapabilities change from API level 24.
+    // Since Requirements wont be updated, we assume connectivity is validated on API level 23.
+    if (Util.SDK_INT < 24) {
       return true;
       return true;
     }
     }
     Network activeNetwork = connectivityManager.getActiveNetwork();
     Network activeNetwork = connectivityManager.getActiveNetwork();
@@ -174,10 +175,8 @@ public final class Requirements implements Parcelable {
     }
     }
     NetworkCapabilities networkCapabilities =
     NetworkCapabilities networkCapabilities =
         connectivityManager.getNetworkCapabilities(activeNetwork);
         connectivityManager.getNetworkCapabilities(activeNetwork);
-    boolean validated =
-        networkCapabilities == null
-            || !networkCapabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED);
-    return !validated;
+    return networkCapabilities != null
+        && networkCapabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED);
   }
   }
 
 
   @Override
   @Override

library/core/src/main/java/com/google/android/exoplayer2/scheduler/RequirementsWatcher.java

@@ -23,7 +23,6 @@ import android.content.IntentFilter;
 import android.net.ConnectivityManager;
 import android.net.ConnectivityManager;
 import android.net.Network;
 import android.net.Network;
 import android.net.NetworkCapabilities;
 import android.net.NetworkCapabilities;
-import android.net.NetworkRequest;
 import android.os.Handler;
 import android.os.Handler;
 import android.os.Looper;
 import android.os.Looper;
 import android.os.PowerManager;
 import android.os.PowerManager;
@@ -62,7 +61,7 @@ public final class RequirementsWatcher {
   @Nullable private DeviceStatusChangeReceiver receiver;
   @Nullable private DeviceStatusChangeReceiver receiver;
 
 
   @Requirements.RequirementFlags private int notMetRequirements;
   @Requirements.RequirementFlags private int notMetRequirements;
-  @Nullable private CapabilityValidatedCallback networkCallback;
+  @Nullable private NetworkCallback networkCallback;
 
 
   /**
   /**
    * @param context Any context.
    * @param context Any context.
@@ -88,8 +87,8 @@ public final class RequirementsWatcher {
 
 
     IntentFilter filter = new IntentFilter();
     IntentFilter filter = new IntentFilter();
     if (requirements.isNetworkRequired()) {
     if (requirements.isNetworkRequired()) {
-      if (Util.SDK_INT >= 23) {
-        registerNetworkCallbackV23();
+      if (Util.SDK_INT >= 24) {
+        registerNetworkCallbackV24();
       } else {
       } else {
         filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
         filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
       }
       }
@@ -115,8 +114,8 @@ public final class RequirementsWatcher {
   public void stop() {
   public void stop() {
     context.unregisterReceiver(Assertions.checkNotNull(receiver));
     context.unregisterReceiver(Assertions.checkNotNull(receiver));
     receiver = null;
     receiver = null;
-    if (networkCallback != null) {
-      unregisterNetworkCallback();
+    if (Util.SDK_INT >= 24 && networkCallback != null) {
+      unregisterNetworkCallbackV24();
     }
     }
   }
   }
 
 
@@ -125,26 +124,21 @@ public final class RequirementsWatcher {
     return requirements;
     return requirements;
   }
   }
 
 
-  @TargetApi(23)
-  private void registerNetworkCallbackV23() {
+  @TargetApi(24)
+  private void registerNetworkCallbackV24() {
     ConnectivityManager connectivityManager =
     ConnectivityManager connectivityManager =
         Assertions.checkNotNull(
         Assertions.checkNotNull(
             (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE));
             (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE));
-    NetworkRequest request =
-        new NetworkRequest.Builder()
-            .addCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED)
-            .build();
-    networkCallback = new CapabilityValidatedCallback();
-    connectivityManager.registerNetworkCallback(request, networkCallback);
+    networkCallback = new NetworkCallback();
+    connectivityManager.registerDefaultNetworkCallback(networkCallback);
   }
   }
 
 
-  private void unregisterNetworkCallback() {
-    if (Util.SDK_INT >= 21) {
-      ConnectivityManager connectivityManager =
-          (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
-      connectivityManager.unregisterNetworkCallback(Assertions.checkNotNull(networkCallback));
-      networkCallback = null;
-    }
+  @TargetApi(24)
+  private void unregisterNetworkCallbackV24() {
+    ConnectivityManager connectivityManager =
+        (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
+    connectivityManager.unregisterNetworkCallback(Assertions.checkNotNull(networkCallback));
+    networkCallback = null;
   }
   }
 
 
   private void checkRequirements() {
   private void checkRequirements() {
@@ -165,8 +159,11 @@ public final class RequirementsWatcher {
     }
     }
   }
   }
 
 
-  @RequiresApi(api = 21)
-  private final class CapabilityValidatedCallback extends ConnectivityManager.NetworkCallback {
+  @RequiresApi(24)
+  private final class NetworkCallback extends ConnectivityManager.NetworkCallback {
+    boolean receivedCapabilitiesChange;
+    boolean networkValidated;
+
     @Override
     @Override
     public void onAvailable(Network network) {
     public void onAvailable(Network network) {
       onNetworkCallback();
       onNetworkCallback();
@@ -177,6 +174,17 @@ public final class RequirementsWatcher {
       onNetworkCallback();
       onNetworkCallback();
     }
     }
 
 
+    @Override
+    public void onCapabilitiesChanged(Network network, NetworkCapabilities networkCapabilities) {
+      boolean networkValidated =
+          networkCapabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED);
+      if (!receivedCapabilitiesChange || this.networkValidated != networkValidated) {
+        receivedCapabilitiesChange = true;
+        this.networkValidated = networkValidated;
+        onNetworkCallback();
+      }
+    }
+
     private void onNetworkCallback() {
     private void onNetworkCallback() {
       handler.post(
       handler.post(
           () -> {
           () -> {