Add new NTP layout with snippet cards and hide it behind a flag

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

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabRecyclerView.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabScrollView.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabRecyclerView.java
similarity index 67%
copy from chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabScrollView.java
copy to chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabRecyclerView.java
index b354d6b00cccdc02a1f9ef036d3ba66bb0bab505..2e3953023517d509c12a24d2c8f6af5db2d75ffc 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabScrollView.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabRecyclerView.java
@@ -1,4 +1,4 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
+// Copyright 2016 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.
 
@@ -7,25 +7,23 @@ package org.chromium.chrome.browser.ntp;
 import android.content.Context;
 import android.graphics.Canvas;
 import android.os.Build;
+import android.support.v7.widget.LinearLayoutManager;
+import android.support.v7.widget.RecyclerView;
 import android.util.AttributeSet;
-import android.util.Log;
 import android.view.GestureDetector;
-import android.view.KeyEvent;
 import android.view.MotionEvent;
-import android.view.View;
 import android.view.inputmethod.EditorInfo;
 import android.view.inputmethod.InputConnection;
-import android.widget.ScrollView;
 
+import org.chromium.base.Log;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.widget.FadingShadow;
 
 /**
- * Simple wrapper on top of a ScrollView that will acquire focus when tapped.  Ensures the
+ * Simple wrapper on top of a RecyclerView that will acquire focus when tapped.  Ensures the
  * New Tab page receives focus when clicked.
  */
-public class NewTabScrollView extends ScrollView {
-
+public class NewTabRecyclerView extends RecyclerView {
     private static final String TAG = "NewTabScrollView";
 
     /**
@@ -42,18 +40,16 @@ public class NewTabScrollView extends ScrollView {
     private GestureDetector mGestureDetector;
     private OnScrollListener mOnScrollListener;
 
-    private NewTabPageLayout mNewTabPageLayout;
-
     private FadingShadow mFadingShadow;
 
     /**
      * Constructor needed to inflate from XML.
      */
-    public NewTabScrollView(Context context, AttributeSet attrs) {
+    public NewTabRecyclerView(Context context, AttributeSet attrs) {
         super(context, attrs);
 
-        mGestureDetector = new GestureDetector(
-                getContext(), new GestureDetector.SimpleOnGestureListener() {
+        mGestureDetector =
+                new GestureDetector(getContext(), new GestureDetector.SimpleOnGestureListener() {
                     @Override
                     public boolean onSingleTapUp(MotionEvent e) {
                         boolean retVal = super.onSingleTapUp(e);
@@ -61,6 +57,7 @@ public class NewTabScrollView extends ScrollView {
                         return retVal;
                     }
                 });
+        setLayoutManager(new LinearLayoutManager(getContext()));
     }
 
     /**
@@ -76,23 +73,6 @@ public class NewTabScrollView extends ScrollView {
     }
 
     @Override
-    protected void onFinishInflate() {
-        super.onFinishInflate();
-
-        View child = getChildAt(0);
-        if (child instanceof NewTabPageLayout) mNewTabPageLayout = (NewTabPageLayout) child;
-    }
-
-    @Override
-    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
-        if (mNewTabPageLayout != null) {
-            mNewTabPageLayout.setParentScrollViewportHeight(
-                    MeasureSpec.getSize(heightMeasureSpec));
-        }
-        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
-    }
-
-    @Override
     public boolean onInterceptTouchEvent(MotionEvent ev) {
         mGestureDetector.onTouchEvent(ev);
         return super.onInterceptTouchEvent(ev);
@@ -136,29 +116,6 @@ public class NewTabScrollView extends ScrollView {
     }
 
     @Override
-    public void focusableViewAvailable(View v) {

[newt (away), 2016/03/23 05:29:38]

Are you sure it's OK to remove (i.e. not add) this? IIRC, this prevents "odd
jumps" when focusing the fakebox in landscape mode on a phone.

[May, 2016/03/23 19:22:57]

Looks fine to me. See video:
https://drive.google.com/open?id=0B1flmW1uZoFBMUVRS3NkVkl1U2c

Is there something I should be looking out for?

(Ignore non-centered-ness of the logo and searchbox, I've filed a bug to fix
that later)

[newt (away), 2016/03/24 19:47:38]

This code is still needed.

See https://gerrit-int.chromium.org/44249 for why this was added in the first
place.

In general, don't remove a bug fix unless you understand why it was added and
are reasonably confident that it's no longer needed.

-        // To avoid odd jumps during NTP animation transitions, we do not attempt to give focus
-        // to child views if this scroll view already has focus.
-        if (hasFocus()) return;
-        super.focusableViewAvailable(v);
-    }
-
-    @Override
-    public boolean executeKeyEvent(KeyEvent event) {
-        // Ignore all key events except arrow keys and spacebar. Otherwise, the ScrollView consumes
-        // unwanted events (including the hardware menu button and app-level keyboard shortcuts).
-        // http://crbug.com/308322
-        switch (event.getKeyCode()) {
-            case KeyEvent.KEYCODE_DPAD_UP:
-            case KeyEvent.KEYCODE_DPAD_DOWN:
-            case KeyEvent.KEYCODE_SPACE:
-                return super.executeKeyEvent(event);
-            default:
-                return false;
-        }
-    }
-
-    @Override
     public InputConnection onCreateInputConnection(EditorInfo outAttrs) {
         // Fixes lanscape transitions when unfocusing the URL bar: crbug.com/288546
         outAttrs.imeOptions = EditorInfo.IME_FLAG_NO_FULLSCREEN;
@@ -173,8 +130,8 @@ public class NewTabScrollView extends ScrollView {
             float shadowStrength = getBottomFadingEdgeStrength();
             float shadowHeight = getVerticalFadingEdgeLength();
             setVerticalFadingEdgeEnabled(false);
-            mFadingShadow.drawShadow(this, canvas, FadingShadow.POSITION_BOTTOM,
-                    shadowHeight, shadowStrength);
+            mFadingShadow.drawShadow(
+                    this, canvas, FadingShadow.POSITION_BOTTOM, shadowHeight, shadowStrength);
         }
     }
 }