Pin the snippets to the bottom of the page and introduce a peeking card to indicate to the user the…

chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageLayout.java

 // Copyright 2015 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.ntp;
 
 import android.content.Context;
 import android.content.res.Resources;
+import android.support.v7.widget.RecyclerView;
 import android.util.AttributeSet;
 import android.view.View;
 import android.widget.LinearLayout;
 
 import org.chromium.chrome.R;
 
 /**
  * Layout for the new tab page. This positions the page elements in the correct vertical positions.
  * There are no separate phone and tablet UIs; this layout adapts based on the available space.
  */
 public class NewTabPageLayout extends LinearLayout {
 
     // Space permitting, the spacers will grow from 0dp to the heights given below. If there is
     // additional space, it will be distributed evenly between the top and bottom spacers.
     private static final float TOP_SPACER_HEIGHT_DP = 44f;
     private static final float MIDDLE_SPACER_HEIGHT_DP = 24f;
     private static final float BOTTOM_SPACER_HEIGHT_DP = 44f;
     private static final float TOTAL_SPACER_HEIGHT_DP = TOP_SPACER_HEIGHT_DP
             + MIDDLE_SPACER_HEIGHT_DP + BOTTOM_SPACER_HEIGHT_DP;
 
     private final int mTopSpacerHeight;
     private final int mMiddleSpacerHeight;
     private final int mBottomSpacerHeight;
     private final int mTotalSpacerHeight;
     private final int mMostVisitedLayoutBleed;
 
     private int mParentScrollViewportHeight;
 
+    private boolean mUseCardsUiEnabled;

[Bernhard Bauer, 2016/05/05 18:04:40]

Nit: I would call this either |mUseCardsUi| or |mCardsUiEnabled|.

[mcwilliams, 2016/05/05 18:21:11]

Done.

     private View mTopSpacer;
     private View mMiddleSpacer;
     private View mBottomSpacer;
     private View mScrollCompensationSpacer;
 
     private LogoView mSearchProviderLogoView;
     private View mSearchBoxView;
     private MostVisitedLayout mMostVisitedLayout;
 
     /**
@@ skipping 28 matching lines @@
      * <p>
      * As this is required in onMeasure, we can not rely on the parent having the proper
      * size set yet and thus must be told explicitly of this size.
      *
      * @param height The height of the scroll viewport containing this view.
      */
     public void setParentScrollViewportHeight(int height) {
         mParentScrollViewportHeight = height;
     }
 
+    /**
+     *

[Bernhard Bauer, 2016/05/05 18:04:40]

Javadoc please.

[mcwilliams, 2016/05/05 18:21:11]

:)

+     */
+    public void setUseCardsUiEnabled(boolean useCardsUi) {
+        mUseCardsUiEnabled = useCardsUi;
+    }
+
     @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         mScrollCompensationSpacer.getLayoutParams().height = 0;
         super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+
+        // Check if we are showing snippets. If Most Likely is fully rendered on the initial page
+        // load and has enough space for the peeking card, push snippets to the bottom of the page
+        // to show the peeking card.
+        if (mUseCardsUiEnabled) {
+            int peekingCardHeight = getContext().getResources().getDimensionPixelSize(
+                    R.dimen.snippets_padding_and_peeking_card_height);
+            if (mParentScrollViewportHeight >= getMeasuredHeight() + peekingCardHeight) {
+                RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) getLayoutParams();
+                params.height = mParentScrollViewportHeight - peekingCardHeight;
+            }
+        }
+        // TODO(https://crbug.com/609487): Push snippets below the fold when most likely
+        // is not fully rendered.
+
         distributeExtraSpace(mTopSpacer.getMeasuredHeight());
 
         int minScrollAmountRequired = 0;
         for (int i = 0; i < getChildCount(); i++) {
             View child = getChildAt(i);
 
             MarginLayoutParams layoutParams = (MarginLayoutParams) child.getLayoutParams();
             if (child.getVisibility() != View.GONE) {
                 minScrollAmountRequired += layoutParams.topMargin;
             }
@@ skipping 63 matching lines @@
 
         int widthSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.EXACTLY);
         mTopSpacer.measure(widthSpec,
                 MeasureSpec.makeMeasureSpec(topSpacerHeight, MeasureSpec.EXACTLY));
         mMiddleSpacer.measure(widthSpec,
                 MeasureSpec.makeMeasureSpec(middleSpacerHeight, MeasureSpec.EXACTLY));
         mBottomSpacer.measure(widthSpec,
                 MeasureSpec.makeMeasureSpec(bottomSpacerHeight, MeasureSpec.EXACTLY));
     }
 }