[Android NTP] Reduce API surface of NewTabPageAdapter.

Remove:
* getSignInPromoPosition()
* getSuggestionPosition()

Change to default visibility:
* getBottomSpacerPosition()
* getLastContentItemPosition()

Change to private:
* hasAllBeenDismissed()
* getSuggestionsSection()
* getChildPositionOffset()

Two methods are added for tests:
* getSectionForTesting()
* getRootForTesting()

BUG=616090

Review-Url: https://codereview.chromium.org/2532953002
Cr-Commit-Position: refs/heads/master@{#436327}

chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageAdapter.java

@@ -32,7 +32,6 @@ import org.chromium.chrome.browser.ntp.snippets.SuggestionsSource;
 import org.chromium.chrome.browser.offlinepages.OfflinePageBridge;
 
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -118,10 +117,10 @@ public class NewTabPageAdapter
 
             // We use our own implementation of the dismissal animation, so we don't call the
             // parent implementation. (by default it changes the translation-X and elevation)
-            mRecyclerView.updateViewStateForDismiss(dX, viewHolder);
+            mRecyclerView.updateViewStateForDismiss(dX, (NewTabPageViewHolder) viewHolder);
 
             // If there is another item that should be animated at the same time, do the same to it.
-            ViewHolder siblingViewHolder = getDismissSibling(viewHolder);
+            NewTabPageViewHolder siblingViewHolder = getDismissSibling(viewHolder);
             if (siblingViewHolder != null) {
                 mRecyclerView.updateViewStateForDismiss(dX, siblingViewHolder);
             }
@@ -388,26 +387,14 @@ public class NewTabPageAdapter
         return RecyclerView.NO_POSITION;
     }
 
-    public int getSignInPromoPosition() {
-        return getChildPositionOffset(mSigninPromo);
-    }
-
-    public int getBottomSpacerPosition() {
+    int getBottomSpacerPosition() {
         return getChildPositionOffset(mBottomSpacer);
     }
 
-    public int getLastContentItemPosition() {
+    int getLastContentItemPosition() {
         return getChildPositionOffset(hasAllBeenDismissed() ? mAllDismissed : mFooter);
     }
 
-    public int getSuggestionPosition(SnippetArticle article) {
-        for (int i = 0; i < mRoot.getItemCount(); i++) {
-            SnippetArticle articleToCheck = mRoot.getSuggestionAt(i);
-            if (articleToCheck != null && articleToCheck.equals(article)) return i;
-        }
-        return RecyclerView.NO_POSITION;
-    }
-
     private void setSuggestions(@CategoryInt int category, List<SnippetArticle> suggestions,
             @CategoryStatusEnum int status) {
         // Count the number of suggestions before this category.
@@ -560,24 +547,16 @@ public class NewTabPageAdapter
     /**
      * Returns another view holder that should be dismissed at the same time as the provided one.
      */
-    public ViewHolder getDismissSibling(ViewHolder viewHolder) {
+    public NewTabPageViewHolder getDismissSibling(ViewHolder viewHolder) {
         int swipePos = viewHolder.getAdapterPosition();
         int siblingPosDelta = mRoot.getDismissSiblingPosDelta(swipePos);
         if (siblingPosDelta == 0) return null;
 
-        return mRecyclerView.findViewHolderForAdapterPosition(siblingPosDelta + swipePos);
+        return (NewTabPageViewHolder) mRecyclerView.findViewHolderForAdapterPosition(
+                siblingPosDelta + swipePos);
     }
 
-    /**
-     * @return The info associated to the provided category.
-     * @throws NullPointerException if {@code category} isn't currently registered with the adapter.
-     * */
-    public SuggestionsCategoryInfo getCategoryInfo(@CategoryInt int category) {
-        return mSections.get(category).getCategoryInfo();
-    }
-
-    @VisibleForTesting
-    public boolean hasAllBeenDismissed() {
+    private boolean hasAllBeenDismissed() {
         return mSections.isEmpty() && !mSigninPromo.isVisible();
     }
 
@@ -601,20 +580,13 @@ public class NewTabPageAdapter
      * @return Returns the {@link SuggestionsSection} that contains the item at
      *     {@code itemPosition}, or null if the item is not part of one.
      */
-    @VisibleForTesting
-    SuggestionsSection getSuggestionsSection(int itemPosition) {
+    private SuggestionsSection getSuggestionsSection(int itemPosition) {
         TreeNode child = mRoot.getChildForPosition(itemPosition);
         if (!(child instanceof SuggestionsSection)) return null;
         return (SuggestionsSection) child;
     }
 
-    @VisibleForTesting
-    List<TreeNode> getChildren() {
-        return Collections.unmodifiableList(mChildren);
-    }
-
-    @VisibleForTesting
-    int getChildPositionOffset(TreeNode child) {
+    private int getChildPositionOffset(TreeNode child) {
         return mRoot.getStartingOffsetForChild(child);
     }
 
@@ -632,12 +604,20 @@ public class NewTabPageAdapter
         return RecyclerView.NO_POSITION;
     }
 
-    private void announceItemRemoved(String suggestionTitle) {
+    SuggestionsSection getSectionForTesting(@CategoryInt int category) {
+        return mSections.get(category);
+    }
+
+    InnerNode getRootForTesting() {
+        return mRoot;
+    }
+
+    private void announceItemRemoved(String itemTitle) {
         // In tests the RecyclerView can be null.
         if (mRecyclerView == null) return;
 
         mRecyclerView.announceForAccessibility(mRecyclerView.getResources().getString(
-                R.string.ntp_accessibility_item_removed, suggestionTitle));
+                R.string.ntp_accessibility_item_removed, itemTitle));
     }
 
     private void announceItemRemoved(@StringRes int stringToAnnounce) {

chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageRecyclerView.java

@@ -185,7 +185,7 @@ public class NewTabPageRecyclerView extends RecyclerView implements TouchDisable
      * Updates the space added at the end of the list to make sure the above/below the fold
      * distinction can be preserved.
      */
-    public void refreshBottomSpacing() {
+    private void refreshBottomSpacing() {
         ViewHolder bottomSpacingViewHolder = findBottomSpacer();
 
         // It might not be in the layout yet if it's not visible or ready to be displayed.
@@ -536,8 +536,8 @@ public class NewTabPageRecyclerView extends RecyclerView implements TouchDisable
      * @param dX The amount of horizontal displacement caused by user's action.
      * @param viewHolder The view holder containing the view to be updated.
      */
-    public void updateViewStateForDismiss(float dX, ViewHolder viewHolder) {
-        if (!((NewTabPageViewHolder) viewHolder).isDismissable()) return;
+    public void updateViewStateForDismiss(float dX, NewTabPageViewHolder viewHolder) {
+        if (!viewHolder.isDismissable()) return;
 
         viewHolder.itemView.setTranslationX(dX);
 

chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/SuggestionsSection.java

@@ -50,7 +50,7 @@ public class SuggestionsSection extends InnerNode {
         mOfflinePageBridge = offlinePageBridge;
 
         mHeader = new SectionHeader(info.getTitle());
-        mSuggestionsList = new SuggestionsList(this);
+        mSuggestionsList = new SuggestionsList(this, info);
         mStatus = StatusItem.createNoSuggestionsItem(this);
         mMoreButton = new ActionItem(this);
         mProgressIndicator = new ProgressItem(this);
@@ -61,9 +61,11 @@ public class SuggestionsSection extends InnerNode {
 
     private static class SuggestionsList extends ChildNode implements Iterable<SnippetArticle> {
         private final List<SnippetArticle> mSuggestions = new ArrayList<>();
+        private final SuggestionsCategoryInfo mCategoryInfo;
 
-        public SuggestionsList(NodeParent parent) {
+        public SuggestionsList(NodeParent parent, SuggestionsCategoryInfo categoryInfo) {
             super(parent);
+            mCategoryInfo = categoryInfo;
         }
 
         @Override
@@ -80,7 +82,8 @@ public class SuggestionsSection extends InnerNode {
         @Override
         public void onBindViewHolder(NewTabPageViewHolder holder, int position) {
             assert holder instanceof SnippetArticleViewHolder;
-            ((SnippetArticleViewHolder) holder).onBindViewHolder(getSuggestionAt(position));
+            ((SnippetArticleViewHolder) holder)
+                    .onBindViewHolder(getSuggestionAt(position), mCategoryInfo);
         }
 
         @Override

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

@@ -66,6 +66,7 @@ public class SnippetArticleViewHolder
 
     private FetchImageCallback mImageCallback;
     private SnippetArticle mArticle;
+    private SuggestionsCategoryInfo mCategoryInfo;
     private int mPublisherFaviconSizePx;
 
     private final boolean mUseFaviconService;
@@ -149,10 +150,9 @@ public class SnippetArticleViewHolder
      * Updates the layout taking into account screen dimensions and the type of snippet displayed.
      */
     private void updateLayout() {
-        SuggestionsCategoryInfo info =
-                mRecyclerView.getNewTabPageAdapter().getCategoryInfo(mArticle.mCategory);
         boolean narrow = mUiConfig.getCurrentDisplayStyle() == UiConfig.DISPLAY_STYLE_NARROW;
-        boolean minimal = info.getCardLayout() == ContentSuggestionsCardLayout.MINIMAL_CARD;
+        boolean minimal =
+                mCategoryInfo.getCardLayout() == ContentSuggestionsCardLayout.MINIMAL_CARD;
 
         // If the screen is narrow or we are using the minimal layout, hide the article snippet.
         boolean hideSnippet = narrow || minimal;
@@ -185,13 +185,14 @@ public class SnippetArticleViewHolder
         mPublisherBar.setLayoutParams(params);
     }
 
-    public void onBindViewHolder(SnippetArticle article) {
+    public void onBindViewHolder(SnippetArticle article, SuggestionsCategoryInfo categoryInfo) {
         super.onBindViewHolder();
 
         // No longer listen for offline status changes to the old article.
         if (mArticle != null) mArticle.setOfflineStatusChangeRunnable(null);
 
         mArticle = article;
+        mCategoryInfo = categoryInfo;
         updateLayout();
 
         mHeadlineTextView.setText(mArticle.mTitle);

chrome/android/javatests/src/org/chromium/chrome/browser/ntp/cards/NewTabPageRecyclerViewTest.java

@@ -117,7 +117,7 @@ public class NewTabPageRecyclerViewTest extends ChromeTabbedActivityTestBase {
 
         // Scroll the last suggestion into view and click it.
         SnippetArticle suggestion = suggestions.get(suggestions.size() - 1);
-        int suggestionPosition = getAdapter().getSuggestionPosition(suggestion);
+        int suggestionPosition = getSuggestionPosition(suggestion);
         scrollToPosition(suggestionPosition);
         final View suggestionView = waitForView(suggestionPosition);
         ChromeTabUtils.waitForTabPageLoaded(mTab, new Runnable() {
@@ -135,12 +135,13 @@ public class NewTabPageRecyclerViewTest extends ChromeTabbedActivityTestBase {
     public void testAllDismissed() throws InterruptedException, TimeoutException {
         setSuggestionsAndWaitForUpdate(3);
         assertEquals(3, mSource.getSuggestionsForCategory(KnownCategories.ARTICLES).size());
-        assertFalse(getAdapter().hasAllBeenDismissed());
+        assertEquals(RecyclerView.NO_POSITION,
+                getAdapter().getFirstPositionForType(ItemViewType.ALL_DISMISSED));
         assertEquals(1, mSource.getCategories().length);
         assertEquals(KnownCategories.ARTICLES, mSource.getCategories()[0]);
 
         // Dismiss the sign in promo.
-        int signinPromoPosition = getAdapter().getSignInPromoPosition();
+        int signinPromoPosition = getAdapter().getFirstPositionForType(ItemViewType.PROMO);
         scrollToPosition(signinPromoPosition);
         View signinPromoView = waitForView(signinPromoPosition);
         getAdapter().dismissItem(signinPromoPosition);
@@ -155,11 +156,11 @@ public class NewTabPageRecyclerViewTest extends ChromeTabbedActivityTestBase {
             waitForViewToDetach(cardView);
             cardPosition = getAdapter().getFirstCardPosition();
         }
-        assertTrue(getAdapter().hasAllBeenDismissed());
         assertEquals(0, mSource.getCategories().length);
 
         // Click the refresh button on the all dismissed item.
-        int allDismissedPosition = getAdapter().getLastContentItemPosition();
+        int allDismissedPosition = getAdapter().getFirstPositionForType(ItemViewType.ALL_DISMISSED);
+        assertTrue(allDismissedPosition != RecyclerView.NO_POSITION);
         scrollToPosition(allDismissedPosition);
         View allDismissedView = waitForView(allDismissedPosition);
         singleClickView(allDismissedView.findViewById(R.id.action_button));
@@ -178,8 +179,7 @@ public class NewTabPageRecyclerViewTest extends ChromeTabbedActivityTestBase {
         assertEquals(10, suggestions.size());
 
         // Scroll a suggestion into view.
-        int suggestionPosition =
-                getAdapter().getSuggestionPosition(suggestions.get(suggestions.size() - 1));
+        int suggestionPosition = getSuggestionPosition(suggestions.get(suggestions.size() - 1));
         scrollToPosition(suggestionPosition);
         View suggestionView = waitForView(suggestionPosition);
 
@@ -246,6 +246,15 @@ public class NewTabPageRecyclerViewTest extends ChromeTabbedActivityTestBase {
         return getRecyclerView().getNewTabPageAdapter();
     }
 
+    private int getSuggestionPosition(SnippetArticle article) {
+        NewTabPageAdapter adapter = getAdapter();
+        for (int i = 0; i < adapter.getItemCount(); i++) {
+            SnippetArticle articleToCheck = adapter.getSuggestionAt(i);
+            if (articleToCheck != null && articleToCheck.equals(article)) return i;
+        }
+        return RecyclerView.NO_POSITION;
+    }
+
     private void scrollToPosition(final int position) {
         final NewTabPageRecyclerView recyclerView = getRecyclerView();