Blimp settings UI integration for Chrome, everything still lives in Blimp.

blimp/client/core/android/java/src/org/chromium/blimp/core/settings/AboutBlimpPreferences.java

Index: blimp/client/core/android/java/src/org/chromium/blimp/core/settings/AboutBlimpPreferences.java
diff --git a/blimp/client/core/android/java/src/org/chromium/blimp/core/settings/AboutBlimpPreferences.java b/blimp/client/core/android/java/src/org/chromium/blimp/core/settings/AboutBlimpPreferences.java
new file mode 100644
index 0000000000000000000000000000000000000000..d0d8c7d0e92fadf3168b4bb6c9ed59ee5b9e93c8
--- /dev/null
+++ b/blimp/client/core/android/java/src/org/chromium/blimp/core/settings/AboutBlimpPreferences.java
@@ -0,0 +1,136 @@
+// 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.
+
+package org.chromium.blimp.core.settings;
+
+import android.app.Activity;
+import android.content.Context;
+import android.content.DialogInterface;
+import android.os.Bundle;
+import android.preference.ListPreference;
+import android.preference.Preference;
+import android.preference.PreferenceFragment;
+import android.preference.PreferenceScreen;
+import android.support.v7.app.AlertDialog;
+
+import org.chromium.blimp.R;
+import org.chromium.blimp_public.BlimpSettingsCallbacks;
+
+// import org.chromium.chrome.browser.ApplicationLifetime;

[David Trainor- moved to gerrit, 2016/07/22 16:51:42]

?

[xingliu, 2016/07/23 23:50:36]

Done.

+
+/**
+ * Blimp preferences page in Chrome.
+ */
+public class AboutBlimpPreferences extends PreferenceFragment {
+
+    public static final String PREF_BLIMP_SWITCH = "blimp_switch";
+    private static final String PREF_ASSIGNER_URL = "blimp_assigner_url";

[David Trainor- moved to gerrit, 2016/07/22 16:51:42]

Public as well.  And javadocs for both :).  Or helper methods?

[xingliu, 2016/07/23 23:50:36]

Done.

+
+    private static BlimpSettingsCallbacks sSettingsCallback;
+
+    /**
+     * Attach the blimp setting preferences to a {@link PreferenceFragment}.
+     * @param fragment The fragment that blimp setting attach to.
+     */
+    public static void addBlimpPreferences(PreferenceFragment fragment) {
+        PreferenceScreen screen = fragment.getPreferenceScreen();
+
+        Preference blimpSetting = new Preference(fragment.getActivity());
+        blimpSetting.setTitle(R.string.blimp_about_blimp_preferences);
+        blimpSetting.setFragment(AboutBlimpPreferences.class.getName());
+        blimpSetting.setKey(AboutBlimpPreferences.PREF_BLIMP_SWITCH);
+
+        screen.addPreference(blimpSetting);
+        fragment.setPreferenceScreen(screen);
+    }
+
+    /**
+     * Register Chrome callback related to Blimp settings.
+     * @param callback
+     */
+    public static void registerCallback(BlimpSettingsCallbacks callback) {
+        sSettingsCallback = callback;
+    }
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        getActivity().setTitle(R.string.blimp_about_blimp_preferences);
+        addPreferencesFromResource(R.xml.blimp_preferences);
+
+        setupBlimpSwitch();
+        setupAssignerPreferences();
+    }
+
+    /**
+     * Setup the switch preference for blimp.
+     */
+    private void setupBlimpSwitch() {
+        // An alternative is to use {@link ChromeSwitchPreference}.

[David Trainor- moved to gerrit, 2016/07/22 16:51:42]

Can you add a TODO and a bug for when this is moved out of blimp/?

[xingliu, 2016/07/23 23:50:36]

Done.

+        final Preference pref = findPreference(PREF_BLIMP_SWITCH);
+
+        pref.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
+            @Override
+            public boolean onPreferenceChange(Preference preference, Object newValue) {
+                // For blimp client 0.6, if blimp switch changed, show restart
+                // dialog.
+                // TODO(xingliu): Figure out if we need to close all tabs before restart.
+                showRestartDialog(getActivity(), R.string.blimp_switch_changed_please_restart);
+                return true;
+            }
+        });
+    }
+
+    /**
+     * When the user taps on the current assigner, a list of available assigners pops up.
+     * User is allowed to change the assigner which is saved to shared preferences.
+     * A dialog is displayed which prompts the user to restart the application.
+     */
+    private void setupAssignerPreferences() {
+        final Activity activity = getActivity();
+
+        final ListPreference lp = (ListPreference) findPreference(PREF_ASSIGNER_URL);
+        lp.setSummary(lp.getValue());
+
+        lp.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
+            @Override
+            public boolean onPreferenceChange(Preference preference, Object newValue) {
+                String newAssignmentUrl = (String) newValue;
+                lp.setSummary(newAssignmentUrl);
+                showRestartDialog(activity, R.string.blimp_assigner_changed_please_restart);
+                return true;
+            }
+        });
+    }
+
+    /**
+     * Show restart browser dialog.
+     * @param context The context where we display the restart browser dialog.
+     * @param message The message shown to the user.
+     */
+    private static void showRestartDialog(final Context context, int message) {
+        new AlertDialog.Builder(context)
+                .setTitle(R.string.blimp_restart_blimp)
+                .setMessage(message)
+                .setPositiveButton(R.string.blimp_restart_now,
+                        new DialogInterface.OnClickListener() {
+                            @Override
+                            public void onClick(DialogInterface dialog, int which) {
+                                restartBrowser(context);
+                            }
+                        })
+                .create()
+                .show();
+    }
+
+    /**
+     * Restart the browser.
+     * @param context The context of restart application dialog.
+     */
+    private static void restartBrowser(Context context) {

[David Trainor- moved to gerrit, 2016/07/22 16:51:42]

Do we need the context?

[xingliu, 2016/07/23 23:50:36]

Done.

+        if (sSettingsCallback != null) {
+            sSettingsCallback.onRestartBrowserRequested();

[David Trainor- moved to gerrit, 2016/07/22 16:51:42]

Just to confirm, there's no way to avoid restarting right?  If so, we should
undo the preference changes that were made or something.

[xingliu, 2016/07/23 23:50:36]

Not sure why we need undo the preferences, is it set the switch to default after
changing the assigner url? 

[David Trainor- moved to gerrit, 2016/07/27 17:31:34]

I just meant the restart dialog (and subsequent restart) is unavoidable once
they reach this point right?

[xingliu, 2016/07/27 23:52:04]

Oh, restart will be triggered only if user clicks a button in the dialog. User
can tap elsewhere to dismiss the dialog and not to restart.

If we need to force the user to quit, I can do it in next OAuth token CL(token
is almost done). AlertDialog can control that behavior(if user can tap outside
to dismiss or press backbutton to dismiss). 

+        }
+    }
+}