webfeed: Add JNI for unread content observer

Bug: 1152592
Change-Id: I1b1454b6fa492d51953226ca165f2eb24d3a7702
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2848182
Reviewed-by: Carlos Knippschild <carlosk@chromium.org>
Commit-Queue: Dan H <harringtond@chromium.org>
Cr-Commit-Position: refs/heads/master@{#875903}

chrome/browser/android/feed/v2/feed_service_bridge.cc

@@ -9,6 +9,7 @@
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
+#include "base/android/scoped_java_ref.h"
 #include "base/check_op.h"
 #include "base/time/time.h"
 #include "chrome/browser/android/feed/v2/feed_service_factory.h"
@@ -32,6 +33,13 @@ FeedService* GetFeedService() {
   return FeedServiceFactory::GetForBrowserContext(profile);
 }
 
+FeedApi* GetFeedApi() {
+  FeedService* service = GetFeedService();
+  if (!service)
+    return nullptr;
+  return service->GetStream();
+}
+
 }  // namespace
 
 static jboolean JNI_FeedServiceBridge_IsEnabled(JNIEnv* env) {
@@ -55,19 +63,18 @@ static int JNI_FeedServiceBridge_GetLoadMoreTriggerScrollDistanceDp(
 
 static void JNI_FeedServiceBridge_ReportOpenVisitComplete(JNIEnv* env,
                                                           jlong visitTimeMs) {
-  FeedService* service = GetFeedService();
-  if (!service)
+  FeedApi* api = GetFeedApi();
+  if (!api)
     return;
-  service->GetStream()->ReportOpenVisitComplete(
-      base::TimeDelta::FromMilliseconds(visitTimeMs));
+  api->ReportOpenVisitComplete(base::TimeDelta::FromMilliseconds(visitTimeMs));
 }
 
 static base::android::ScopedJavaLocalRef<jstring>
 JNI_FeedServiceBridge_GetClientInstanceId(JNIEnv* env) {
-  FeedService* service = GetFeedService();
   std::string instance_id;
-  if (service) {
-    instance_id = service->GetStream()->GetClientInstanceId();
+  FeedApi* api = GetFeedApi();
+  if (api) {
+    instance_id = api->GetClientInstanceId();
   }
   return base::android::ConvertUTF8ToJavaString(env, instance_id);
 }
@@ -87,6 +94,20 @@ static jlong JNI_FeedServiceBridge_GetReliabilityLoggingId(JNIEnv* env) {
   return FeedServiceBridge::GetReliabilityLoggingId();
 }
 
+static jlong JNI_FeedServiceBridge_AddUnreadContentObserver(
+    JNIEnv* env,
+    const base::android::JavaParamRef<jobject>& j_observer,
+    jboolean is_web_feed) {
+  FeedApi* api = GetFeedApi();
+  if (!api)
+    return 0;
+  JavaUnreadContentObserver* observer = new JavaUnreadContentObserver(
+      base::android::ScopedJavaGlobalRef<jobject>(j_observer));
+  api->AddUnreadContentObserver(is_web_feed ? kWebFeedStream : kForYouStream,
+                                observer);
+  return reinterpret_cast<jlong>(observer);
+}
+
 std::string FeedServiceBridge::GetLanguageTag() {
   JNIEnv* env = base::android::AttachCurrentThread();
   return ConvertJavaStringToUTF8(env,
@@ -134,4 +155,21 @@ uint64_t FeedServiceBridge::GetReliabilityLoggingId() {
       g_browser_process->metrics_service()->GetClientId(), profile_prefs);
 }
 
+JavaUnreadContentObserver::JavaUnreadContentObserver(
+    base::android::ScopedJavaGlobalRef<jobject> j_observer)
+    : obj_(j_observer) {}
+
+feed::JavaUnreadContentObserver::~JavaUnreadContentObserver() = default;
+
+void JavaUnreadContentObserver::HasUnreadContentChanged(
+    bool has_unread_content) {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  Java_UnreadContentObserver_hasUnreadContentChanged(env, obj_,
+                                                     has_unread_content);
+}
+
+void JavaUnreadContentObserver::Destroy(JNIEnv*) {
+  delete this;
+}
+
 }  // namespace feed

chrome/browser/android/feed/v2/feed_service_bridge.h

@@ -7,6 +7,8 @@
 
 #include <string>
 
+#include "base/android/jni_android.h"
+#include "components/feed/core/v2/public/feed_api.h"
 #include "components/feed/core/v2/public/types.h"
 
 namespace feed {
@@ -22,6 +24,19 @@ class FeedServiceBridge {
   static uint64_t GetReliabilityLoggingId();
 };
 
+class JavaUnreadContentObserver : public FeedApi::UnreadContentObserver {
+ public:
+  JavaUnreadContentObserver(
+      base::android::ScopedJavaGlobalRef<jobject> j_observer);
+  ~JavaUnreadContentObserver() override;
+
+  void HasUnreadContentChanged(bool has_unread_content) override;
+  void Destroy(JNIEnv*);
+
+ private:
+  base::android::ScopedJavaGlobalRef<jobject> obj_;
+};
+
 }  // namespace feed
 
 #endif  // CHROME_BROWSER_ANDROID_FEED_V2_FEED_SERVICE_BRIDGE_H_

chrome/browser/feed/android/java/src/org/chromium/chrome/browser/feed/FeedServiceBridge.java

@@ -12,6 +12,7 @@
 import org.chromium.base.ContextUtils;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
+import org.chromium.base.annotations.NativeClassQualifiedName;
 import org.chromium.base.annotations.NativeMethods;
 import org.chromium.chrome.browser.xsurface.ImagePrefetcher;
 import org.chromium.chrome.browser.xsurface.ProcessScope;
@@ -126,6 +127,33 @@ public static long getReliabilityLoggingId() {
         return FeedServiceBridgeJni.get().getReliabilityLoggingId();
     }
 
+    /** Observes whether or not the Feed stream contains unread content */
+    public static class UnreadContentObserver {
+        private long mNativePtr;
+
+        /**
+         * Begins observing.
+         *
+         * @param isWebFeed  Whether to observe the Web Feed, or the For-you Feed.
+         */
+        UnreadContentObserver(boolean isWebFeed) {
+            mNativePtr = FeedServiceBridgeJni.get().addUnreadContentObserver(this, isWebFeed);
+        }
+
+        /** Stops observing. Must be called when this observer is no longer needed */
+        public void destroy() {
+            FeedServiceBridgeJni.get().destroy(mNativePtr);
+            mNativePtr = 0;
+        }
+
+        /**
+         * Called to signal whether unread content is available. Called once after the observer is
+         * initialized, and after that, called each time unread content status changes.
+         */
+        @CalledByNative("UnreadContentObserver")
+        public void hasUnreadContentChanged(boolean hasUnreadContent) {}
+    }
+
     @NativeMethods
     public interface Natives {
         boolean isEnabled();
@@ -137,5 +165,8 @@ public interface Natives {
         int getVideoPreviewsTypePreference();
         void setVideoPreviewsTypePreference(int videoPreviewsType);
         long getReliabilityLoggingId();
+        long addUnreadContentObserver(Object object, boolean isWebFeed);
+        @NativeClassQualifiedName("feed::JavaUnreadContentObserver")
+        void destroy(long nativePtr);
     }
 }