Zine: support multiple sections in the ui

chrome/browser/android/ntp/ntp_snippets_bridge.cc

 // 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.
 
 #include "chrome/browser/android/ntp/ntp_snippets_bridge.h"
 
 #include <jni.h>
 
 #include "base/android/callback_android.h"
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
 #include "base/callback.h"
 #include "chrome/browser/history/history_service_factory.h"
 #include "chrome/browser/ntp_snippets/content_suggestions_service_factory.h"
 #include "chrome/browser/ntp_snippets/ntp_snippets_service_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_android.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "components/history/core/browser/history_service.h"
 #include "components/ntp_snippets/content_suggestion.h"
 #include "components/ntp_snippets/ntp_snippets_service.h"
 #include "jni/SnippetsBridge_jni.h"
 #include "ui/gfx/android/java_bitmap.h"
 #include "ui/gfx/image/image.h"
 
 using base::android::AttachCurrentThread;
 using base::android::ConvertJavaStringToUTF8;
+using base::android::ConvertUTF8ToJavaString;
 using base::android::JavaParamRef;
-using base::android::ToJavaArrayOfStrings;
-using base::android::ToJavaLongArray;
-using base::android::ToJavaFloatArray;
 using base::android::ScopedJavaGlobalRef;
 using base::android::ScopedJavaLocalRef;
 using ntp_snippets::ContentSuggestionsCategory;
 using ntp_snippets::ContentSuggestionsCategoryStatus;
 
 namespace {
 
 void SnippetVisitedHistoryRequestCallback(
       base::android::ScopedJavaGlobalRef<jobject> callback,
       bool success,
@@ skipping 76 matching lines @@
   base::android::ScopedJavaGlobalRef<jobject> callback(jcallback);
 
   history_service_->QueryURL(
       GURL(ConvertJavaStringToUTF8(env, jurl)),
       false,
       base::Bind(&SnippetVisitedHistoryRequestCallback, callback),
       &tracker_);
 }
 
 int NTPSnippetsBridge::GetCategoryStatus(JNIEnv* env,
-                                         const JavaParamRef<jobject>& obj) {
+                                         const JavaParamRef<jobject>& obj,
+                                         jint category) {
   return static_cast<int>(content_suggestions_service_->GetCategoryStatus(
-      ContentSuggestionsCategory::ARTICLES));
+      static_cast<ContentSuggestionsCategory>(category)));
 }
 
 NTPSnippetsBridge::~NTPSnippetsBridge() {}
 
 void NTPSnippetsBridge::OnNewSuggestions() {
   if (observer_.is_null())
     return;
 
-  std::vector<std::string> ids;
-  std::vector<std::string> titles;
-  // URL for the article. This will also be used to find the favicon for the
-  // article.
-  std::vector<std::string> urls;
-  // URL for the AMP version of the article if it exists. This will be used as
-  // the URL to direct the user to on tap.
-  std::vector<std::string> amp_urls;
-  std::vector<std::string> snippets;
-  std::vector<int64_t> timestamps;
-  std::vector<std::string> publishers;
-  std::vector<float> scores;
-
   // Show all suggestions from all categories, even though we currently display
   // them in a single section on the UI.
   // TODO(pke): This is only for debugging new sections and will be replaced
   // with proper multi-section UI support.
+  JNIEnv* env = base::android::AttachCurrentThread();
+  ScopedJavaLocalRef<jobject> suggestions =
+      Java_SnippetsBridge_createSuggestionList(env);
   for (ContentSuggestionsCategory category :
        content_suggestions_service_->GetCategories()) {
     if (content_suggestions_service_->GetCategoryStatus(category) !=
         ContentSuggestionsCategoryStatus::AVAILABLE) {
       continue;
     }
     for (const ntp_snippets::ContentSuggestion& suggestion :
          content_suggestions_service_->GetSuggestionsForCategory(category)) {
-      ids.push_back(suggestion.id());
-      titles.push_back(suggestion.title());
-      // The url from source_info is a url for a site that is one of the
-      // HOST_RESTRICT parameters, so this is preferred.
-      urls.push_back(suggestion.url().spec());
-      amp_urls.push_back(suggestion.amp_url().spec());
-      snippets.push_back(suggestion.snippet_text());
-      timestamps.push_back(suggestion.publish_date().ToJavaTime());
-      publishers.push_back(suggestion.publisher_name());
-      scores.push_back(suggestion.score());
+      Java_SnippetsBridge_addSuggestion(

[PEConn, 2016/08/01 16:26:51]

I do like this approach but is there any overhead to flitting back and forth
between Java and native code? I don't think there should be, but there could be
some annoying conversion logic eating the CPU.

[Bernhard Bauer, 2016/08/02 13:03:27]

My gut feeling would be a lot of the time would be spent in UTF conversions,
which we are going to have to do either way. The other thing is that things like
ToJavaArrayOfStrings also have to call into Java for each item, so I think the
total overhead is comparable both ways.

+          env, suggestions.obj(),
+          ConvertUTF8ToJavaString(env, suggestion.id()).obj(),
+          ConvertUTF8ToJavaString(env, suggestion.title()).obj(),
+          ConvertUTF8ToJavaString(env, suggestion.publisher_name()).obj(),
+          ConvertUTF8ToJavaString(env, suggestion.snippet_text()).obj(),
+          ConvertUTF8ToJavaString(env, suggestion.url().spec()).obj(),
+          ConvertUTF8ToJavaString(env, suggestion.amp_url().spec()).obj(),
+          suggestion.publish_date().ToJavaTime(), suggestion.score());
     }
   }
 
-  JNIEnv* env = base::android::AttachCurrentThread();
-  Java_SnippetsBridge_onSnippetsAvailable(
-      env, observer_.obj(), ToJavaArrayOfStrings(env, ids).obj(),
-      ToJavaArrayOfStrings(env, titles).obj(),
-      ToJavaArrayOfStrings(env, urls).obj(),
-      ToJavaArrayOfStrings(env, amp_urls).obj(),
-      ToJavaArrayOfStrings(env, snippets).obj(),
-      ToJavaLongArray(env, timestamps).obj(),
-      ToJavaArrayOfStrings(env, publishers).obj(),
-      ToJavaFloatArray(env, scores).obj());
+  // TODO(mvanouwerkerk): Do not hard code ARTICLES.
+  Java_SnippetsBridge_onSuggestionsAvailable(
+      env, observer_.obj(),
+      static_cast<int>(ContentSuggestionsCategory::ARTICLES),
+      suggestions.obj());
 }
 
 void NTPSnippetsBridge::OnCategoryStatusChanged(
     ContentSuggestionsCategory category,
     ContentSuggestionsCategoryStatus new_status) {
+  // TODO(mvanouwerkerk): Do not hard code ARTICLES.
   if (category != ContentSuggestionsCategory::ARTICLES)
     return;
 
   JNIEnv* env = base::android::AttachCurrentThread();
   Java_SnippetsBridge_onCategoryStatusChanged(env, observer_.obj(),
+                                              static_cast<int>(category),
                                               static_cast<int>(new_status));
 }
 
 void NTPSnippetsBridge::ContentSuggestionsServiceShutdown() {
   observer_.Reset();
   content_suggestions_service_observer_.Remove(content_suggestions_service_);
 }
 
 void NTPSnippetsBridge::OnImageFetched(ScopedJavaGlobalRef<jobject> callback,
                                        const std::string& snippet_id,
                                        const gfx::Image& image) {
   ScopedJavaLocalRef<jobject> j_bitmap;
   if (!image.IsEmpty())
     j_bitmap = gfx::ConvertToJavaBitmap(image.ToSkBitmap());
 
   base::android::RunCallbackAndroid(callback, j_bitmap);
 }
 
 // static
 bool NTPSnippetsBridge::Register(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }