chrome/browser/android/ntp/ntp_snippets_bridge.h

// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CHROME_BROWSER_ANDROID_NTP_NTP_SNIPPETS_BRIDGE_H_
#define CHROME_BROWSER_ANDROID_NTP_NTP_SNIPPETS_BRIDGE_H_

#include <jni.h>

#include "base/android/scoped_java_ref.h"
#include "base/memory/weak_ptr.h"
#include "base/scoped_observer.h"
#include "base/task/cancelable_task_tracker.h"
#include "components/history/core/browser/history_service.h"
#include "components/ntp_snippets/category.h"
#include "components/ntp_snippets/category_status.h"
#include "components/ntp_snippets/content_suggestions_service.h"

namespace gfx {
class Image;
}

// The C++ counterpart to SnippetsBridge.java. Enables Java code to access
// the list of snippets to show on the NTP
class NTPSnippetsBridge
    : public ntp_snippets::ContentSuggestionsService::Observer {
 public:
  NTPSnippetsBridge(JNIEnv* env,
                    const base::android::JavaParamRef<jobject>& j_profile);
  void Destroy(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);

  void SetObserver(JNIEnv* env,
                   const base::android::JavaParamRef<jobject>& obj,
                   const base::android::JavaParamRef<jobject>& j_observer);

  void FetchImage(JNIEnv* env,
                  const base::android::JavaParamRef<jobject>& obj,
                  const base::android::JavaParamRef<jstring>& snippet_id,
                  const base::android::JavaParamRef<jobject>& j_callback);

  // Discards the snippet with the given ID.
  void DiscardSnippet(JNIEnv* env,
                      const base::android::JavaParamRef<jobject>& obj,
                      const base::android::JavaParamRef<jstring>& snippet_id);

  // Checks if the URL has been visited.
  void SnippetVisited(JNIEnv* env,
                      const base::android::JavaParamRef<jobject>& obj,
                      const base::android::JavaParamRef<jobject>& callback,
                      const base::android::JavaParamRef<jstring>& jurl);

  // Returns the status of |category|.
  // See CategoryStatus for more info.
  int GetCategoryStatus(JNIEnv* env,
                        const base::android::JavaParamRef<jobject>& obj,
                        jint category);

  static bool Register(JNIEnv* env);

 private:
  ~NTPSnippetsBridge() override;

  // ContentSuggestionsService::Observer overrides
  void OnNewSuggestions() override;
  void OnCategoryStatusChanged(
      ntp_snippets::Category category,
      ntp_snippets::CategoryStatus new_status) override;
  void ContentSuggestionsServiceShutdown() override;

  void OnImageFetched(base::android::ScopedJavaGlobalRef<jobject> callback,
                      const std::string& snippet_id,
                      const gfx::Image& image);

  ntp_snippets::ContentSuggestionsService* content_suggestions_service_;
  history::HistoryService* history_service_;
  base::CancelableTaskTracker tracker_;

  ScopedObserver<ntp_snippets::ContentSuggestionsService,
                 ntp_snippets::ContentSuggestionsService::Observer>
      content_suggestions_service_observer_;

  // Used to notify the Java side when new snippets have been fetched.
  base::android::ScopedJavaGlobalRef<jobject> observer_;

  base::WeakPtrFactory<NTPSnippetsBridge> weak_ptr_factory_;

  DISALLOW_COPY_AND_ASSIGN(NTPSnippetsBridge);
};

#endif  // CHROME_BROWSER_ANDROID_NTP_NTP_SNIPPETS_BRIDGE_H_