[Explore sites]: Clean up code and remove unneeded header to ESP.

Also fixes a number of issues:
1. Re-reinforce the max 2 rows of sites on categories
2. Update tests to account for the 4-sites-per-row rule

Change-Id: I27b232466314ce0398c6f5ba31ebdb340e6dbdfc
Reviewed-on: https://chromium-review.googlesource.com/c/1377141Reviewed-by: Justin DeWitt <dewittj@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Cathy Li <chili@chromium.org>
Cr-Commit-Position: refs/heads/master@{#619598}

chrome/android/java/res/layout/explore_sites_title_card.xml

-<?xml version="1.0" encoding="utf-8"?>
-<!-- Copyright 2018 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. -->
-
-    <TextView
-        xmlns:android="http://schemas.android.com/apk/res/android"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:gravity="center"
-        android:textAppearance="@style/BlackHeadline"
-        android:text="@string/explore_sites_title"
-        android:paddingBottom="@dimen/explore_sites_category_padding"
-        android:paddingTop="@dimen/explore_sites_page_padding"/>
-

chrome/android/java/src/org/chromium/chrome/browser/explore_sites/CategoryCardAdapter.java

@@ -12,9 +12,8 @@ import android.text.SpannableString;
 import android.text.SpannableStringBuilder;
 
 import org.chromium.chrome.R;
-import org.chromium.chrome.browser.modelutil.ListObservable;
+import org.chromium.chrome.browser.modelutil.ForwardingListObservable;
 import org.chromium.chrome.browser.modelutil.ListObservable.ListObserver;
-import org.chromium.chrome.browser.modelutil.ListObservableImpl;
 import org.chromium.chrome.browser.modelutil.PropertyKey;
 import org.chromium.chrome.browser.modelutil.PropertyModel;
 import org.chromium.chrome.browser.modelutil.PropertyObservable;
@@ -33,17 +32,16 @@ import java.lang.annotation.RetentionPolicy;
 /**
  * Recycler view adapter delegate for a model containing a list of category cards and an error code.
  */
-class CategoryCardAdapter extends ListObservableImpl<Void>
+class CategoryCardAdapter extends ForwardingListObservable<Void>
         implements RecyclerViewAdapter
                            .Delegate<CategoryCardViewHolderFactory.CategoryCardViewHolder, Void>,
                    PropertyObservable.PropertyObserver<PropertyKey>, ListObserver<Void> {
-    @IntDef({ViewType.HEADER, ViewType.CATEGORY, ViewType.LOADING, ViewType.ERROR})
+    @IntDef({ViewType.CATEGORY, ViewType.LOADING, ViewType.ERROR})
     @Retention(RetentionPolicy.SOURCE)
     public @interface ViewType {
-        int HEADER = 0;
-        int CATEGORY = 1;
-        int LOADING = 2;
-        int ERROR = 3;
+        int CATEGORY = 0;
+        int LOADING = 1;
+        int ERROR = 2;
     }
 
     private final RoundedIconGenerator mIconGenerator;
@@ -75,8 +73,7 @@ class CategoryCardAdapter extends ListObservableImpl<Void>
                 != ExploreSitesPage.CatalogLoadingState.SUCCESS) {
             return 1;
         }
-        // Add 1 for title.
-        return mCategoryModel.get(ExploreSitesPage.CATEGORY_LIST_KEY).size() + 1;
+        return mCategoryModel.get(ExploreSitesPage.CATEGORY_LIST_KEY).size();
     }
 
     @Override
@@ -89,7 +86,6 @@ class CategoryCardAdapter extends ListObservableImpl<Void>
             case ExploreSitesPage.CatalogLoadingState.LOADING_NET:
                 return ViewType.LOADING;
             case ExploreSitesPage.CatalogLoadingState.SUCCESS:
-                if (position == 0) return ViewType.HEADER;
                 return ViewType.CATEGORY;
             default:
                 assert(false);
@@ -102,10 +98,8 @@ class CategoryCardAdapter extends ListObservableImpl<Void>
             int position, @Nullable Void payload) {
         if (holder.getItemViewType() == ViewType.CATEGORY) {
             ExploreSitesCategoryCardView view = (ExploreSitesCategoryCardView) holder.itemView;
-            // Position - 1 because there is always title.
-            view.setCategory(
-                    mCategoryModel.get(ExploreSitesPage.CATEGORY_LIST_KEY).get(position - 1),
-                    position - 1, mIconGenerator, mContextMenuManager, mNavDelegate, mProfile);
+            view.setCategory(mCategoryModel.get(ExploreSitesPage.CATEGORY_LIST_KEY).get(position),
+                    position, mIconGenerator, mContextMenuManager, mNavDelegate, mProfile);
         } else if (holder.getItemViewType() == ViewType.LOADING) {
             // Start spinner.
             LoadingView spinner = holder.itemView.findViewById(R.id.loading);
@@ -139,28 +133,8 @@ class CategoryCardAdapter extends ListObservableImpl<Void>
             }
         }
         if (key == ExploreSitesPage.SCROLL_TO_CATEGORY_KEY) {
-            int pos = mCategoryModel.get(ExploreSitesPage.SCROLL_TO_CATEGORY_KEY);
-            // Add 1 for title.
-            mLayoutManager.scrollToPosition(pos + 1);
+            mLayoutManager.scrollToPosition(
+                    mCategoryModel.get(ExploreSitesPage.SCROLL_TO_CATEGORY_KEY));
         }
     }
-
-    @Override
-    public void onItemRangeInserted(ListObservable source, int index, int count) {
-        // Add 1 because of title.
-        notifyItemRangeInserted(index + 1, count);
-    }
-
-    @Override
-    public void onItemRangeRemoved(ListObservable source, int index, int count) {
-        // Add 1 because of title.
-        notifyItemRangeRemoved(index + 1, count);
-    }
-
-    @Override
-    public void onItemRangeChanged(
-            ListObservable<Void> source, int index, int count, @Nullable Void payload) {
-        // Add 1 because of title.
-        notifyItemRangeChanged(index + 1, count, payload);
-    }
 }

chrome/android/java/src/org/chromium/chrome/browser/explore_sites/CategoryCardViewHolderFactory.java

@@ -27,11 +27,6 @@ class CategoryCardViewHolderFactory implements RecyclerViewAdapter.ViewHolderFac
             ViewGroup parent, @CategoryCardAdapter.ViewType int viewType) {
         View view;
         switch (viewType) {
-            case CategoryCardAdapter.ViewType.HEADER:
-                view = LayoutInflater.from(parent.getContext())
-                               .inflate(R.layout.explore_sites_title_card, parent,
-                                       /* attachToRoot = */ false);
-                break;
             case CategoryCardAdapter.ViewType.CATEGORY:
                 view = LayoutInflater.from(parent.getContext())
                                .inflate(R.layout.explore_sites_category_card_view, parent,

chrome/android/java/src/org/chromium/chrome/browser/explore_sites/ExploreSitesCategory.java

@@ -23,21 +23,24 @@ import java.util.List;
  */
 public class ExploreSitesCategory {
     private static final String TAG = "ExploreSitesCategory";
-    // The ID to use when creating the More button, that should not scroll the ESP when clicked.
-    public static final int MORE_BUTTON_ID = -1;
+    // The ID to use when creating placeholder icons on the NTP when there is no data or the More
+    // button.
+    private static final int PLACEHOLDER_ID = -1;
 
     static final int MAX_COLUMNS = 4;
 
     // This enum must match the numbering for ExploreSites.CategoryClick in histograms.xml.  Do not
     // reorder or remove items, only add new items before COUNT.
     @Retention(RetentionPolicy.SOURCE)
-    @IntDef({CategoryType.DEFAULT, CategoryType.SOCIAL, CategoryType.ENTERTAINMENT,
-            CategoryType.SPORT, CategoryType.NEWS, CategoryType.SHOPPING, CategoryType.REFERENCE,
-            CategoryType.BANKING, CategoryType.GOVERNMENT, CategoryType.TRAVEL,
-            CategoryType.EDUCATION, CategoryType.JOBS, CategoryType.APPS_GAMES,
-            CategoryType.FAVORITE, CategoryType.GOOGLE, CategoryType.FOOD, CategoryType.HEALTH,
-            CategoryType.BOOKS, CategoryType.TECHNOLOGY, CategoryType.SCIENCE, CategoryType.COUNT})
+    @IntDef({CategoryType.MORE_BUTTON, CategoryType.DEFAULT, CategoryType.SOCIAL,
+            CategoryType.ENTERTAINMENT, CategoryType.SPORT, CategoryType.NEWS,
+            CategoryType.SHOPPING, CategoryType.REFERENCE, CategoryType.BANKING,
+            CategoryType.GOVERNMENT, CategoryType.TRAVEL, CategoryType.EDUCATION, CategoryType.JOBS,
+            CategoryType.APPS_GAMES, CategoryType.FAVORITE, CategoryType.GOOGLE, CategoryType.FOOD,
+            CategoryType.HEALTH, CategoryType.BOOKS, CategoryType.TECHNOLOGY, CategoryType.SCIENCE,
+            CategoryType.COUNT})
     public @interface CategoryType {
+        int MORE_BUTTON = -1; // This is not included in histograms.xml.
         int DEFAULT = 0;
         int SOCIAL = 1;
         int ENTERTAINMENT = 2;
@@ -62,6 +65,11 @@ public class ExploreSitesCategory {
         int COUNT = 20;
     }
 
+    public static ExploreSitesCategory createPlaceholder(
+            @CategoryType int categoryType, String title) {
+        return new ExploreSitesCategory(PLACEHOLDER_ID, categoryType, title);
+    }
+
     private int mCategoryId;
 
     private @CategoryType int mCategoryType;
@@ -95,7 +103,11 @@ public class ExploreSitesCategory {
     }
 
     public boolean isPlaceholder() {
-        return mCategoryId == -1;
+        return mCategoryId == PLACEHOLDER_ID;
+    }
+
+    public boolean isMoreButton() {
+        return mCategoryType == CategoryType.MORE_BUTTON;
     }
 
     public String getTitle() {

chrome/android/java/src/org/chromium/chrome/browser/explore_sites/ExploreSitesCategoryCardView.java

@@ -89,10 +89,9 @@ public class ExploreSitesCategoryCardView extends LinearLayout {
             // Remove from model (category).
             mCategory.removeSite(mTileIndex);
 
-            // Update the view This may add any sites that we didn't have room for before.  It
-            // should reset the tile indexeds for views we keep.
-            updateTileViews(
-                    mCategory.getSites(), mCategory.getNumDisplayed(), mCategory.getMaxRows());
+            // Update the view. This may add sites that we didn't have room for before.  It
+            // should reset the tile indexes for views we keep.
+            updateTileViews(mCategory);
         }
         @Override
         public String getUrl() {
@@ -160,14 +159,14 @@ public class ExploreSitesCategoryCardView extends LinearLayout {
         mCategory = category;
 
         updateTitle(category.getTitle());
-        updateTileViews(category.getSites(), category.getNumDisplayed(), category.getMaxRows());
+        updateTileViews(category);
     }
 
     public void updateTitle(String categoryTitle) {
         mTitleView.setText(categoryTitle);
     }
 
-    public void updateTileViews(List<ExploreSitesSite> sites, int numSitesToShow, int maxRows) {
+    public void updateTileViews(ExploreSitesCategory category) {
         // Clear observers.
         for (PropertyModelChangeProcessor<PropertyModel, ExploreSitesTileView, PropertyKey>
                         observer : mModelChangeProcessors) {
@@ -177,11 +176,12 @@ public class ExploreSitesCategoryCardView extends LinearLayout {
 
         // Only show rows that would be fully populated by original list of sites. This is
         // calculated within the category.
-        mTileView.setMaxRows(maxRows);
+        mTileView.setMaxRows(Math.min(category.getMaxRows(), MAX_ROWS));
 
         // Maximum number of sites that can be shown, defined as min of
         // numSitesToShow and maxRows * maxCols.
-        int tileMax = Math.min(maxRows * ExploreSitesCategory.MAX_COLUMNS, numSitesToShow);
+        int tileMax = Math.min(category.getMaxRows() * ExploreSitesCategory.MAX_COLUMNS,
+                category.getNumDisplayed());
 
         // Remove extra tiles if too many.
         if (mTileView.getChildCount() > tileMax) {
@@ -199,7 +199,7 @@ public class ExploreSitesCategoryCardView extends LinearLayout {
 
         // Initialize all the non-empty tiles again to update.
         int tileIndex = 0;
-        for (ExploreSitesSite site : sites) {
+        for (ExploreSitesSite site : category.getSites()) {
             if (tileIndex >= tileMax) break;
             final PropertyModel siteModel = site.getModel();
             // Skip blacklisted sites.

chrome/android/java/src/org/chromium/chrome/browser/explore_sites/ExploreSitesPage.java

@@ -33,7 +33,6 @@ import org.chromium.chrome.browser.profiles.Profile;
 import org.chromium.chrome.browser.tab.EmptyTabObserver;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tab.TabObserver;
-import org.chromium.chrome.browser.tabmodel.TabModelSelector;
 import org.chromium.chrome.browser.widget.RoundedIconGenerator;
 import org.chromium.content_public.browser.NavigationController;
 import org.chromium.content_public.browser.NavigationEntry;
@@ -70,7 +69,6 @@ public class ExploreSitesPage extends BasicNativePage {
         int LOADING_NET = 4; // Retrieving catalog resources from internet.
     }
 
-    private TabModelSelector mTabModelSelector;
     private NativePageHost mHost;
     private Tab mTab;
     private TabObserver mTabObserver;
@@ -97,7 +95,6 @@ public class ExploreSitesPage extends BasicNativePage {
         mHost = host;
         mTab = mHost.getActiveTab();
 
-        mTabModelSelector = activity.getTabModelSelector();
         mTitle = activity.getString(R.string.explore_sites_title);
         mView = (ViewGroup) activity.getLayoutInflater().inflate(
                 R.layout.explore_sites_page_layout, null);
@@ -118,8 +115,9 @@ public class ExploreSitesPage extends BasicNativePage {
                         context.getResources(), R.color.default_favicon_background_color),
                 context.getResources().getDimensionPixelSize(R.dimen.tile_view_icon_text_size));
 
-        NativePageNavigationDelegateImpl navDelegate =
-                new NativePageNavigationDelegateImpl(activity, mProfile, host, mTabModelSelector);
+        NativePageNavigationDelegateImpl navDelegate = new NativePageNavigationDelegateImpl(
+                activity, mProfile, host, activity.getTabModelSelector());
+
         // Don't direct reference activity because it might change if tab is reparented.
         Runnable closeContextMenuCallback =
                 () -> host.getActiveTab().getActivity().closeContextMenu();
@@ -139,8 +137,6 @@ public class ExploreSitesPage extends BasicNativePage {
 
         ExploreSitesBridge.getEspCatalog(mProfile, this::translateToModel);
         RecordUserAction.record("Android.ExploreSitesPage.Open");
-
-        // TODO(chili): Set layout to be an observer of list model
     }
 
     void translateToModel(@Nullable List<ExploreSitesCategory> categoryList) {

chrome/android/java/src/org/chromium/chrome/browser/explore_sites/ExploreSitesPageLayout.java

-// Copyright 2018 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.
-
-package org.chromium.chrome.browser.explore_sites;
-
-import android.view.View;
-
-import org.chromium.chrome.browser.profiles.Profile;
-
-/**
- * Class to manage layout of explore sites page.
- */
-public class ExploreSitesPageLayout {
-    private View mParent;
-    private Profile mProfile;
-
-    public ExploreSitesPageLayout(View parent, Profile profile) {
-        mParent = parent;
-        mProfile = profile;
-    }
-}

chrome/android/java/src/org/chromium/chrome/browser/explore_sites/ExploreSitesSection.java

@@ -76,20 +76,19 @@ public class ExploreSitesSection {
         List<ExploreSitesCategory> categoryList = new ArrayList<>();
 
         // News category.
-        ExploreSitesCategory category =
-                new ExploreSitesCategory(-1 /* category_id */, CategoryType.NEWS,
-                        getContext().getString(R.string.explore_sites_default_category_news));
+        ExploreSitesCategory category = ExploreSitesCategory.createPlaceholder(CategoryType.NEWS,
+                getContext().getString(R.string.explore_sites_default_category_news));
         category.setDrawable(getVectorDrawable(R.drawable.ic_article_blue_24dp));
         categoryList.add(category);
 
         // Shopping category.
-        category = new ExploreSitesCategory(-1 /* category_id */, CategoryType.SHOPPING,
+        category = ExploreSitesCategory.createPlaceholder(CategoryType.SHOPPING,
                 getContext().getString(R.string.explore_sites_default_category_shopping));
         category.setDrawable(getVectorDrawable(R.drawable.ic_shopping_basket_blue_24dp));
         categoryList.add(category);
 
         // Sport category.
-        category = new ExploreSitesCategory(-1 /* category_id */, CategoryType.SPORT,
+        category = ExploreSitesCategory.createPlaceholder(CategoryType.SPORT,
                 getContext().getString(R.string.explore_sites_default_category_sports));
         category.setDrawable(getVectorDrawable(R.drawable.ic_directions_run_blue_24dp));
         categoryList.add(category);
@@ -98,8 +97,8 @@ public class ExploreSitesSection {
     }
 
     private ExploreSitesCategory createMoreTileCategory() {
-        ExploreSitesCategory category = new ExploreSitesCategory(-1 /* category_id */,
-                ExploreSitesCategory.MORE_BUTTON_ID, getContext().getString(R.string.more));
+        ExploreSitesCategory category = ExploreSitesCategory.createPlaceholder(
+                CategoryType.MORE_BUTTON, getContext().getString(R.string.more));
         category.setDrawable(getVectorDrawable(R.drawable.ic_arrow_forward_blue_24dp));
         return category;
     }
@@ -147,8 +146,7 @@ public class ExploreSitesSection {
             ExploreSitesCategoryTileView v =
                     (ExploreSitesCategoryTileView) mExploreSection.getChildAt(i);
             ExploreSitesCategory category = v.getCategory();
-            if (category == null || category.getType() == ExploreSitesCategory.MORE_BUTTON_ID)
-                continue;
+            if (category == null || category.isMoreButton()) continue;
             viewTypes.put(category.getType(), v);
         }
 

chrome/android/java_sources.gni

@@ -648,7 +648,6 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/explore_sites/ExploreSitesCategoryTileView.java",
   "java/src/org/chromium/chrome/browser/explore_sites/ExploreSitesEnums.java",
   "java/src/org/chromium/chrome/browser/explore_sites/ExploreSitesPage.java",
-  "java/src/org/chromium/chrome/browser/explore_sites/ExploreSitesPageLayout.java",
   "java/src/org/chromium/chrome/browser/explore_sites/ExploreSitesSection.java",
   "java/src/org/chromium/chrome/browser/explore_sites/ExploreSitesSite.java",
   "java/src/org/chromium/chrome/browser/explore_sites/ExploreSitesTileView.java",

chrome/android/javatests/src/org/chromium/chrome/browser/explore_sites/ExploreSitesPageTest.java

@@ -52,10 +52,12 @@ public class ExploreSitesPageTest {
 
     ArrayList<ExploreSitesCategory> getTestingCatalog() {
         final ArrayList<ExploreSitesCategory> categoryList = new ArrayList<>();
-        for (int i = 0; i < 4; i++) {
+        for (int i = 0; i < 5; i++) {
             ExploreSitesCategory category =
                     new ExploreSitesCategory(i, i, "Category #" + Integer.toString(i));
-            for (int j = 0; j < 8; j++) {
+            // 0th category would be filtered out. Tests that row maximums are obeyed.
+            int numSites = 4 * i + 1;
+            for (int j = 0; j < numSites; j++) {
                 ExploreSitesSite site = new ExploreSitesSite(
                         i * 8 + j, "Site #" + Integer.toString(j), "https://example.com/", false);
                 category.addSite(site);