Add the UI for the Interests Prototype.

chrome/android/java/src/org/chromium/chrome/browser/ntp/InterestsPage.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.accounts.Account;
+import android.accounts.AccountManager;
+import android.app.Activity;
+import android.app.Dialog;
+import android.content.Context;
+import android.view.LayoutInflater;
+import android.view.View;
+
+import org.chromium.base.Log;
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.NativePage;
+import org.chromium.chrome.browser.ntp.InterestsService.GetInterestsCallback;
+import org.chromium.chrome.browser.ntp.InterestsService.Interest;
+import org.chromium.chrome.browser.profiles.Profile;
+import org.chromium.chrome.browser.signin.OAuth2TokenService;
+import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.content_public.browser.LoadUrlParams;
+import org.chromium.sync.signin.AccountManagerHelper;
+import org.chromium.sync.signin.AccountManagerHelper.GetAuthTokenCallback;
+
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * List the interests of the user. When an interest is clicked the user is redirect to a google
+ * search with news about that subject.
+ */
+public class InterestsPage implements NativePage {
+    private final Profile mProfile;
+    private final InterestsPageView mPageView;
+    private final String mTitle;
+    private final int mBackgroundColor;
+
+    // Whether destroy() has been called.
+    private boolean mIsDestroyed;
+
+    private static final String TAG = "cr.browser.ntp";
+
+    /**
+     * Creates a InterestsPage to be shown in document mode.
+     *
+     * @param context The view context for showing the page.
+     * @param tab The tab from which interests page is loaded.
+     * @param profile The profile from which to load interests.
+     * @param listener The InterestsSelectedListener to notify when the user clicks an interest.
+     * @return The new InterestPage object.
+     */
+    public static InterestsPage buildPage(Context context, Tab tab,

[Marc Treib, 2015/09/18 13:26:03]

Any reason for not just calling the constructor directly?

[tache, 2015/09/21 15:35:55]

Done.

+            Profile profile, InterestsListener listener,
+            Activity activity) {
+        return new InterestsPage(
+                context, profile, tab, listener, activity);
+    }
+
+    private InterestsPage(Context context, final Profile profile, Tab tab,
+            InterestsListener listener, Activity activity) {
+        mProfile = profile;
+        mTitle = context.getResources().getString(R.string.ntp_interests);
+        mBackgroundColor = context.getResources().getColor(R.color.ntp_bg);
+
+        LayoutInflater inflater = LayoutInflater.from(context);
+
+        mPageView = (InterestsPageView) inflater.inflate(R.layout.interests_page, null);
+        mPageView.setListener(listener);
+
+        GetAuthTokenCallback callback = new AccountManagerHelper.GetAuthTokenCallback() {
+            @Override
+            public void tokenAvailable(String accessToken, boolean isTransientError) {
+                if (accessToken == null) {
+                    return;
+                }
+                new InterestsService(profile).getInterests(accessToken,
+                        new GetInterestsCallback() {
+                            @Override
+                            public void onInterestsAvailableCallback(Interest[] interests) {
+                                List<Interest> interestList = Arrays.asList(interests);

[Marc Treib, 2015/09/18 13:26:03]

Any particular reason for switching from array to List here?

[tache, 2015/09/21 15:35:55]

The native call returns the callback as an array. However most of the android
code I've seen seems to use Lists instead of an array

[Marc Treib, 2015/09/21 16:20:08]

Acknowledged, fair enough.

+
+                                mPageView.setInterests(interestList);
+                            }
+                        });
+            }
+        };
+
+        Account account = getCurrentAccount(context);
+
+        OAuth2TokenService.getOAuth2AccessToken(context,
+                activity,
+                account,

[Marc Treib, 2015/09/18 13:26:03]

Does this handle a null account?

[tache, 2015/09/21 15:35:55]

It should. I wrapped it in an if statement just to be sure

[Marc Treib, 2015/09/21 16:20:08]

Wouldn't it be great if OAuth2TokenService documented whether a null account is
okay... but since another parameter is marked @Nullable and the account isn't, I
guess checking for it here is the right call.

+                InterestsService.AUTH_SCOPE,
+                callback);
+    }
+
+    private Account getCurrentAccount(Context context) {
+        Account[] accounts = AccountManager.get(context).getAccounts();

[Marc Treib, 2015/09/18 13:26:03]

This seems wrong - AccountManager is an Android thing, not a Chrome thing, so it
might also return accounts that are not signed in to Chrome? Maybe even
non-Google accounts?
In native code, you'd use SigninManager[Base] to get the primary account. There
should be a Java version of that as well.

[tache, 2015/09/21 15:35:55]

I couldn't find anything that returns me the primary account. The closest thing
I found is the AccountManagerHelper which returns me the list of all google
accounts.

Switched to using AccountManagerHelper.

[Marc Treib, 2015/09/21 16:20:07]

ChromeSigninController.getSignedInUser()?

+
+        if (accounts.length > 1) {
+            Log.w(TAG, "Multiple accounts found. Using the first one.");
+            return accounts[0];
+        } else if (accounts.length == 0) {
+            Log.w(TAG, "No account found.");
+            return null;
+        }
+
+        return accounts[0];
+    }
+
+    /**
+     * Interface to be notified when the user clicks on a interest.
+     **/
+    public interface InterestsListener {
+        /**
+         * Called when a interest is selected.
+         *
+         * @param name The name of the selected interest.
+         */
+        void onInterestClicked(String name);
+    }
+
+    /**
+     * Default action to take when an interest is clicked. This redirects the current tab to a news
+     * search about the subject.
+     */
+    public static class DefaultInterestListener implements InterestsListener {
+        private static final String GOOGLE_SEARCH_URL = "https://www.google.com/search?tbm=nws&q=%s";

[Marc Treib, 2015/09/18 13:26:03]

nit: too-long line
also, .._URL_PATTERN?

[tache, 2015/09/21 15:35:55]

Done.

+        private Dialog mDialog;

[Marc Treib, 2015/09/18 13:26:03]

The dialog thing is weird. Why would a DefaultListener have to know about it?
Maybe just move the listener implementation to where it's actually used.

[tache, 2015/09/21 15:35:55]

Moved this to the NewTabPage class similarly.

+        private final Tab mTab;
+
+        public DefaultInterestListener(Tab tab) {
+            mTab = tab;
+        }
+
+        @Override
+        public void onInterestClicked(String name) {
+            if (mDialog == null) {
+                return;
+            }
+
+            String url = String.format(GOOGLE_SEARCH_URL, name);

[Marc Treib, 2015/09/18 13:26:03]

You need to URL encode the query string.

[tache, 2015/09/21 15:35:55]

Done.

+
+            mTab.loadUrl(new LoadUrlParams(url));
+            mDialog.dismiss();
+        }
+
+        public void setDialog(Dialog dialog) {
+            mDialog = dialog;
+        }
+    }
+
+    @Override
+    public String getTitle() {
+        return mTitle;
+    }
+
+    @Override
+    public int getBackgroundColor() {
+        return mBackgroundColor;
+    }
+
+    @Override
+    public View getView() {
+        return mPageView;
+    }
+
+    /**
+     * Releases internal resources. This must be called eventually, and the object should not used
+     * after calling this.
+     */
+    @Override
+    public void destroy() {
+        mIsDestroyed = true;

[Marc Treib, 2015/09/18 13:26:03]

Should this method do anything?
Also, mIsDestroyed isn't used.

[tache, 2015/09/21 15:35:55]

The InterestPage doesn't have any members that need to be destroyed explicitly.

Removed mIsDestroyed.

+    }
+
+    @Override
+    public String getHost() {
+        return "interests";
+    }
+
+    @Override
+    public String getUrl() {
+        return "chrome-native://interests";
+    }
+
+    @Override
+    public void updateForUrl(String url) {
+    }
+}