Added a UI for the Interests Prototype.

chrome/android/java/src/org/chromium/chrome/browser/ntp/InterestsView.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.graphics.drawable.Drawable;
+import android.util.AttributeSet;
+import android.util.LruCache;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ArrayAdapter;
+import android.widget.FrameLayout;
+import android.widget.GridView;
+
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.ntp.InterestsItemView.DrawingData;
+import org.chromium.chrome.browser.ntp.InterestsPage.InterestsListener;
+import org.chromium.chrome.browser.ntp.InterestsService.Interest;
+
+import java.util.List;
+
+/**
+ * The user's interests, displayed with a two column grid view.
+ */
+public class InterestsView extends FrameLayout {
+    private InterestsListener mListener;
+    private GridView mInterestsGrid;
+    private final InterestsListAdapter mAdapter;
+    private final LruCache<String, Drawable> mImageCache;
+    private DrawingData mDrawingData;
+
+    public InterestsView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        mAdapter = new InterestsListAdapter(context);
+        mImageCache = new LruCache<>(30);
+    }
+
+    public void setListener(InterestsListener listener) {

[Marc Treib, 2015/11/19 12:42:19]

Comment that this must be called before setInterests? (That *is* the case,
right?)

[PEConn, 2015/11/20 11:23:41]

Done.

+        mListener = listener;
+    }
+
+    public void setInterests(List<Interest> interests) {
+        mAdapter.addAll(interests);
+    }
+
+    @Override
+    protected void onFinishInflate() {
+        super.onFinishInflate();
+
+        mInterestsGrid = (GridView) findViewById(R.id.interests_list_view);
+        mInterestsGrid.setAdapter(mAdapter);
+    }
+
+    private class InterestsListAdapter extends ArrayAdapter<Interest> {
+        private Context mContext = null;

[Marc Treib, 2015/11/19 12:42:19]

Do you need this? |getContext()| should give you the same thing, no?

[PEConn, 2015/11/20 11:23:40]

Done.

+
+        public InterestsListAdapter(Context context) {
+            super(context, 0);
+            mContext = context;
+        }
+
+        @Override
+        public View getView(int position, View convertView, ViewGroup parent) {
+            assert mListener != null;
+
+            if (mDrawingData == null) {
+                mDrawingData = new InterestsItemView.DrawingData(getContext());

[Marc Treib, 2015/11/19 12:42:19]

Can you just initialize this in the InterestsView ctor?

[PEConn, 2015/11/20 11:23:40]

Done.

+            }
+
+            Interest interest = getItem(position);
+
+            InterestsItemView view;
+            if (convertView instanceof InterestsItemView) {
+                view = (InterestsItemView) convertView;
+                view.reset(interest);
+            } else {
+                view = new InterestsItemView(mContext, interest,
+                        mListener, mImageCache, mDrawingData);
+            }
+            return view;
+        }
+    }
+}