[NTP Snippets] Show a status card when there are no available snippets

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

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageAdapter.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageAdapter.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageAdapter.java
index d668f989b396ae0b0e0e444007df63b2a6794f6c..1a739f973a7bc489c7ba3c07facf70fef78e5ce0 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageAdapter.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageAdapter.java
@@ -5,14 +5,11 @@
 package org.chromium.chrome.browser.ntp.cards;
 
 import android.graphics.Canvas;
-import android.support.v4.view.animation.FastOutLinearInInterpolator;
 import android.support.v7.widget.RecyclerView;
 import android.support.v7.widget.RecyclerView.Adapter;
 import android.support.v7.widget.RecyclerView.ViewHolder;
 import android.support.v7.widget.helper.ItemTouchHelper;
-import android.view.View;
 import android.view.ViewGroup;
-import android.view.animation.Interpolator;
 
 import org.chromium.base.Log;
 import org.chromium.chrome.browser.ntp.NewTabPageLayout;
@@ -21,6 +18,7 @@
 import org.chromium.chrome.browser.ntp.snippets.SnippetArticle;
 import org.chromium.chrome.browser.ntp.snippets.SnippetArticleViewHolder;
 import org.chromium.chrome.browser.ntp.snippets.SnippetHeaderListItem;
+import org.chromium.chrome.browser.ntp.snippets.SnippetHeaderViewHolder;
 import org.chromium.chrome.browser.ntp.snippets.SnippetsBridge.SnippetsObserver;
 
 import java.util.ArrayList;
@@ -34,11 +32,11 @@
  */
 public class NewTabPageAdapter extends Adapter<NewTabPageViewHolder> implements SnippetsObserver {
     private static final String TAG = "Ntp";
-    private static final Interpolator FADE_INTERPOLATOR = new FastOutLinearInInterpolator();
 
     private final NewTabPageManager mNewTabPageManager;
     private final NewTabPageLayout mNewTabPageLayout;
     private final AboveTheFoldListItem mAboveTheFoldListItem;
+    private final SnippetHeaderListItem mHeaderListItem;
     private final List<NewTabPageListItem> mNewTabPageListItems;
     private final ItemTouchCallbacks mItemTouchCallbacks;
     private NewTabPageRecyclerView mRecyclerView;
@@ -49,11 +47,8 @@
         public void onSwiped(ViewHolder viewHolder, int direction) {
             mRecyclerView.onItemDismissStarted(viewHolder.itemView);
 
-            // This is going to have a effect at the next layout pass, which is going to happen
-            // after the item has been removed from the adapter and the layout.
-            mRecyclerView.refreshBottomSpacing();
-
             NewTabPageAdapter.this.dismissItem(viewHolder);
+            addStatusCardIfNecessary();
         }
 
         @Override
@@ -79,8 +74,7 @@ public int getMovementFlags(RecyclerView recyclerView, ViewHolder viewHolder) {
             assert viewHolder instanceof NewTabPageViewHolder;
 
             int swipeFlags = 0;
-            NewTabPageViewHolder ntpViewHolder = (NewTabPageViewHolder) viewHolder;
-            if (ntpViewHolder.isDismissable()) {
+            if (((NewTabPageViewHolder) viewHolder).isDismissable()) {
                 swipeFlags = ItemTouchHelper.START | ItemTouchHelper.END;
             }
 
@@ -90,10 +84,9 @@ public int getMovementFlags(RecyclerView recyclerView, ViewHolder viewHolder) {
         @Override
         public void onChildDraw(Canvas c, RecyclerView recyclerView, ViewHolder viewHolder,
                 float dX, float dY, int actionState, boolean isCurrentlyActive) {
-            View itemView = viewHolder.itemView;
-            float input = Math.abs(dX) / itemView.getMeasuredWidth();
-            float alpha = 1 - FADE_INTERPOLATOR.getInterpolation(input);
-            itemView.setAlpha(alpha);
+            assert viewHolder instanceof NewTabPageViewHolder;
+
+            ((NewTabPageViewHolder) viewHolder).updateViewStateForDismiss(dX);
             super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
         }
     }
@@ -110,10 +103,12 @@ public NewTabPageAdapter(NewTabPageManager manager, NewTabPageLayout newTabPageL
         mNewTabPageManager = manager;
         mNewTabPageLayout = newTabPageLayout;
         mAboveTheFoldListItem = new AboveTheFoldListItem();
+        mHeaderListItem = new SnippetHeaderListItem();
         mItemTouchCallbacks = new ItemTouchCallbacks();
         mNewTabPageListItems = new ArrayList<NewTabPageListItem>();
-        mNewTabPageListItems.add(mAboveTheFoldListItem);
         mWantsSnippets = true;
+
+        loadSnippets(new ArrayList<SnippetArticle>());
         mNewTabPageManager.setSnippetsObserver(this);
     }
 
@@ -154,23 +149,28 @@ public int getItemViewType(int position) {
 
     @Override
     public NewTabPageViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+        assert parent == mRecyclerView;
+
         if (viewType == NewTabPageListItem.VIEW_TYPE_ABOVE_THE_FOLD) {
             return new NewTabPageViewHolder(mNewTabPageLayout);
         }
 
         if (viewType == NewTabPageListItem.VIEW_TYPE_HEADER) {
-            return new NewTabPageViewHolder(SnippetHeaderListItem.createView(parent));
+            return new SnippetHeaderViewHolder(SnippetHeaderListItem.createView(parent));
         }
 
         if (viewType == NewTabPageListItem.VIEW_TYPE_SNIPPET) {
-            return new SnippetArticleViewHolder(
-                    SnippetArticleViewHolder.createView(parent), mNewTabPageManager);
+            return new SnippetArticleViewHolder(mRecyclerView, mNewTabPageManager);
         }
 
         if (viewType == NewTabPageListItem.VIEW_TYPE_SPACING) {
             return new NewTabPageViewHolder(SpacingListItem.createView(parent));
         }
 
+        if (viewType == NewTabPageListItem.VIEW_TYPE_STATUS) {
+            return new StatusListItem.ViewHolder(mRecyclerView, this);
+        }
+
         return null;
     }
 
@@ -184,6 +184,12 @@ public int getItemCount() {
         return mNewTabPageListItems.size();
     }
 
+    /** Start a request for new snippets. */
+    public void reloadSnippets() {
+        mWantsSnippets = true;
+        mNewTabPageManager.fetchSnippets();
+    }
+
     private void loadSnippets(List<SnippetArticle> listSnippets) {
         // Copy thumbnails over
         for (SnippetArticle newSnippet : listSnippets) {
@@ -195,10 +201,19 @@ private void loadSnippets(List<SnippetArticle> listSnippets) {
                             .getThumbnailBitmap());
         }
 
+        boolean hasContentToShow = !listSnippets.isEmpty();
+        mHeaderListItem.setVisible(hasContentToShow);
+
         mNewTabPageListItems.clear();
         mNewTabPageListItems.add(mAboveTheFoldListItem);
-        mNewTabPageListItems.add(new SnippetHeaderListItem());
-        mNewTabPageListItems.addAll(listSnippets);
+        mNewTabPageListItems.add(mHeaderListItem);
+
+        if (hasContentToShow) {
+            mNewTabPageListItems.addAll(listSnippets);
+        } else {
+            mNewTabPageListItems.add(new StatusListItem());
+        }
+
         mNewTabPageListItems.add(new SpacingListItem());
 
         notifyDataSetChanged();
@@ -228,6 +243,18 @@ private void dismissItem(ViewHolder itemViewHolder) {
         notifyItemRemoved(position);
     }
 
+    private void addStatusCardIfNecessary() {
+        if (mNewTabPageListItems.size() == 3 /* above-the-fold + header + spacing */) {
+            // TODO(dgn) hack until we refactor the entire class with sections, etc.
+            // (see https://crbug.com/616090)
+            mNewTabPageListItems.add(2, new StatusListItem());
+
+            // We also want to refresh the header and the bottom padding.
+            mHeaderListItem.setVisible(false);
+            notifyDataSetChanged();
+        }
+    }
+
     List<NewTabPageListItem> getItemsForTesting() {
         return mNewTabPageListItems;
     }