Zine: support multiple sections in the ui

chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetsBridge.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetsBridge.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetsBridge.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetsBridge.java
index 2aec52832f4da90f22231b9e7f8aae6c378de4ec..3440fa3536e2929d8b6dffeac8e909f25198ef38 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetsBridge.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetsBridge.java
@@ -26,19 +26,22 @@
      * An observer for events in the snippets service.
      */
     public interface SnippetsObserver {
-        void onSnippetsReceived(List<SnippetArticleListItem> snippets);
+        /** Called when suggestions for a category were received. */
+        void onSuggestionsReceived(
+                @SuggestionsCategory int category, List<SnippetArticleListItem> suggestions);
 
-        /** Called when the ARTICLES category changed its status. */
-        void onCategoryStatusChanged(int newStatus);
+        /** Called when the status for a category has changed. */
+        void onCategoryStatusChanged(
+                @SuggestionsCategory int category, @SuggestionsCategoryStatus int newStatus);
     }
 
-    public static boolean isCategoryStatusAvailable(int status) {
+    public static boolean isCategoryStatusAvailable(@SuggestionsCategoryStatus int status) {
         // Note: This code is duplicated in content_suggestions_category_status.cc.
         return status == ContentSuggestionsCategoryStatus.AVAILABLE_LOADING
                 || status == ContentSuggestionsCategoryStatus.AVAILABLE;
     }
 
-    public static boolean isCategoryStatusInitOrAvailable(int status) {
+    public static boolean isCategoryStatusInitOrAvailable(@SuggestionsCategoryStatus int status) {
         // Note: This code is duplicated in content_suggestions_category_status.cc.
         return status == ContentSuggestionsCategoryStatus.INITIALIZING
                 || isCategoryStatusAvailable(status);
@@ -121,29 +124,31 @@ public void setObserver(SnippetsObserver observer) {
         nativeSetObserver(mNativeSnippetsBridge, observer == null ? null : this);
     }
 
-    public int getCategoryStatus() {
+    @SuggestionsCategoryStatus
+    public int getCategoryStatus(@SuggestionsCategory int category) {
         assert mNativeSnippetsBridge != 0;
-        return nativeGetCategoryStatus(mNativeSnippetsBridge);
+        return nativeGetCategoryStatus(mNativeSnippetsBridge, category);
     }
 
     @CalledByNative
-    private void onSnippetsAvailable(String[] ids, String[] titles, String[] urls, String[] ampUrls,
-            String[] previewText, long[] timestamps, String[] publishers, float[] scores) {
+    private void onSuggestionsAvailable(int category, String[] ids, String[] titles, String[] urls,

[PEConn, 2016/07/29 10:01:43]

Will all the different categories be providing the same data here? Maybe offline
documents care about both URLs and AMP URLs but for future types of suggestion
this doesn't seem very general.

I think the reason we're passing the parameters like this (as a lists of fields
as opposed to just a list of objects) is that it's a pain to build Java objects
in native code. Ideally what we'd have is something like:

@CalledByNative
ArticleSnippet createSnippet(String id, String title, String url, ...) {...}

@CalledByNative
OfflinePage createOfflinePage(String id, String title, ...) {...}

Which are called to create the list of objects in native code, then
|onSuggestionsAvailable| just takes a category and a list of NewTabPageListItem.

[Bernhard Bauer, 2016/08/01 15:01:33]

I think the general idea is indeed that all categories are going to provide
(most of) the same data. We also don't want to use different classes for content
suggestions from different categories, as they would have the same UI anyway. I
do like constructing the Java suggestions via a create() method though -- the
arrays we pass in here have to be converted in a loop each as well, so it's not
like that actually saves overhead.

+            String[] ampUrls, String[] previewText, long[] timestamps, String[] publishers,
+            float[] scores) {
         assert mNativeSnippetsBridge != 0;
         assert mObserver != null;
 
-        List<SnippetArticleListItem> newSnippets = new ArrayList<>(ids.length);
+        List<SnippetArticleListItem> suggestions = new ArrayList<>(ids.length);
         for (int i = 0; i < ids.length; i++) {
-            newSnippets.add(new SnippetArticleListItem(ids[i], titles[i], publishers[i],
+            suggestions.add(new SnippetArticleListItem(ids[i], titles[i], publishers[i],
                     previewText[i], urls[i], ampUrls[i], timestamps[i], scores[i], i));
         }
 
-        mObserver.onSnippetsReceived(newSnippets);
+        mObserver.onSuggestionsReceived(category, suggestions);
     }
 
     @CalledByNative
-    private void onCategoryStatusChanged(int newStatus) {
-        if (mObserver != null) mObserver.onCategoryStatusChanged(newStatus);
+    private void onCategoryStatusChanged(int category, int newStatus) {
+        if (mObserver != null) mObserver.onCategoryStatusChanged(category, newStatus);
     }
 
     private native long nativeInit(Profile profile);
@@ -156,5 +161,5 @@ private static native void nativeSnippetVisited(long nativeNTPSnippetsBridge,
             Callback<Boolean> callback, String url);
     private native void nativeFetchImage(
             long nativeNTPSnippetsBridge, String snippetId, Callback<Bitmap> callback);
-    private native int nativeGetCategoryStatus(long nativeNTPSnippetsBridge);
+    private native int nativeGetCategoryStatus(long nativeNTPSnippetsBridge, int category);
 }