From d6a2978857e0866d7441f8e140338477545d59a5 Mon Sep 17 00:00:00 2001
From: Makoto Onuki <omakoto@google.com>
Date: Wed, 21 Jul 2010 14:29:49 -0700
Subject: [PATCH] First cut of two pane activity.

How to launch:
- Kick "Email 2 Pane" in the app drawer.

Major known issues:
- When you launches "Email 2 Pane", it starts directly; the logic in Welcom
  won't be executed.
- There's no UI to add accounts.  Use the old UI.
- There's no way to select non-default accounts.
- The on-screen buttons except for older/newer don't work.
- No contex menus work.

Change-Id: I38374acafafbae62e46f84294a7677e54686cfc2
---
 AndroidManifest.xml                           |  36 +-
 res/layout/message_list_xl.xml                | 118 +++++
 res/layout/message_view_header.xml            |   2 +-
 res/values/strings.xml                        |   4 +
 .../email/activity/DefaultAccountLoader.java  |  54 ++
 .../email/activity/MailboxListFragment.java   |  27 +-
 .../email/activity/MessageListFragment.java   |  25 +-
 .../android/email/activity/MessageListXL.java | 466 ++++++++++++++++++
 .../email/activity/MessageOrderManager.java   |   4 +
 .../email/activity/MessageViewFragment.java   |  19 +-
 10 files changed, 731 insertions(+), 24 deletions(-)
 create mode 100644 res/layout/message_list_xl.xml
 create mode 100644 src/com/android/email/activity/DefaultAccountLoader.java
 create mode 100644 src/com/android/email/activity/MessageListXL.java

diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index f3b74501b..a5b397314 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -4,9 +4,9 @@
      Licensed under the Apache License, Version 2.0 (the "License");
      you may not use this file except in compliance with the License.
      You may obtain a copy of the License at
-  
+
           http://www.apache.org/licenses/LICENSE-2.0
-  
+
      Unless required by applicable law or agreed to in writing, software
      distributed under the License is distributed on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -66,6 +66,20 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+        <!--
+            We show this on the home for the development purpose.
+            STOPSHIP: Remove label, and MAIN/LAUNCHER intent filter.
+        -->
+        <activity
+            android:name=".activity.MessageListXL"
+            android:label="@string/activity_label_2pane"
+            android:theme="@android:style/Theme.WithActionBar"
+            >
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
         <activity
             android:name=".activity.UpgradeAccounts"
             android:label="@string/upgrade_accounts_title"
@@ -146,8 +160,8 @@
             android:launchMode="singleTop"
             android:theme="@android:style/Theme.WithActionBar" >
         </activity>
-        
-        <activity 
+
+        <activity
             android:name=".activity.AccountShortcutPicker"
             android:label="@string/app_name"
             android:enabled="false"
@@ -157,12 +171,12 @@
                 <category android:name="android.intent.category.DEFAULT" />
             </intent-filter>
         </activity>
-        
+
         <activity
             android:name=".activity.MailboxList"
             android:theme="@android:style/Theme.WithActionBar" >
         </activity>
-        
+
         <activity
             android:name=".activity.MessageList"
             android:theme="@style/ThemeNoTitleBar">
@@ -188,7 +202,7 @@
                 <action android:name="android.intent.action.MAIN" />
             </intent-filter>
         </activity>
-                
+
         <activity
             android:name=".activity.MessageView"
             android:theme="@android:style/Theme.NoTitleBar" >
@@ -261,12 +275,12 @@
             android:enabled="false"
             >
         </service>
-        
+
         <!--EXCHANGE-REMOVE-SECTION-START-->
         <!--Required stanza to register the ContactsSyncAdapterService with SyncManager -->
-        <service 
-            android:name="com.android.exchange.ContactsSyncAdapterService" 
-        	android:exported="true">
+        <service
+            android:name="com.android.exchange.ContactsSyncAdapterService"
+            android:exported="true">
             <intent-filter>
                 <action android:name="android.content.SyncAdapter" />
             </intent-filter>
diff --git a/res/layout/message_list_xl.xml b/res/layout/message_list_xl.xml
new file mode 100644
index 000000000..e5323910b
--- /dev/null
+++ b/res/layout/message_list_xl.xml
@@ -0,0 +1,118 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2010 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:orientation="horizontal"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <!-- We put MailboxListFragment here at runtime. -->
+    <FrameLayout
+        android:id="@+id/left_pane"
+        android:layout_width="360dip"
+        android:layout_height="match_parent"
+        />
+
+    <!--
+        Right pane.
+        Because we need to show buttons for MessageView by ourselves, we need a linear layout here.
+        See also the comment below.
+    -->
+    <LinearLayout
+        xmlns:android="http://schemas.android.com/apk/res/android"
+        android:orientation="vertical"
+        android:layout_width="0dip"
+        android:layout_height="match_parent"
+        android:layout_weight="1"
+        >
+        <!-- We put MessageList/MessageViewFragment here at runtime. -->
+        <FrameLayout
+            android:id="@+id/right_pane"
+            android:layout_width="match_parent"
+            android:layout_height="0dip"
+            android:layout_weight="1" />
+        <!--
+            Bottom buttons
+            These buttons can't be in MessageViewFragment, because the button
+            layout changes on the phone layout.
+            (We can (probably) create a separate layout for XL devices, but not sure if that'd be
+            a good idea, at this point.)
+
+            However, putting these buttons means we have to show/hide them
+            according to the screen state, which means we can't just use the
+            fragment transaction to replace fragments.
+
+            Maybe we should create another fragment, MessageViewWithCommandsFragment,
+            on top of MessageViewFragment.
+         -->
+        <LinearLayout
+            android:id="@+id/message_view_buttons"
+            android:orientation="horizontal"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:paddingTop="5dip"
+            android:paddingLeft="4dip"
+            android:paddingRight="4dip"
+            android:paddingBottom="1dip"
+            android:background="@android:drawable/bottom_bar"
+            android:visibility="gone"
+            >
+            <Button
+                android:id="@+id/delete"
+                android:text="@string/delete_action"
+                android:layout_height="match_parent"
+                android:layout_width="0dip"
+                android:layout_weight="1" />
+            <Button
+                android:id="@+id/unread"
+                android:text="@string/unread_action"
+                android:layout_height="match_parent"
+                android:layout_width="0dip"
+                android:layout_weight="1" />
+            <Button
+                android:id="@+id/reply"
+                android:text="@string/reply_action"
+                android:layout_height="match_parent"
+                android:layout_width="0dip"
+                android:layout_weight="1" />
+            <Button
+                android:id="@+id/reply_all"
+                android:text="@string/reply_all_action"
+                android:layout_height="match_parent"
+                android:layout_width="0dip"
+                android:layout_weight="1" />
+            <Button
+                android:id="@+id/forward"
+                android:text="@string/forward_action"
+                android:layout_height="match_parent"
+                android:layout_width="0dip"
+                android:layout_weight="1" />
+            <Button
+                android:id="@+id/moveToNewer"
+                android:text="@string/message_view_move_to_newer"
+                android:layout_height="match_parent"
+                android:layout_width="0dip"
+                android:layout_weight="1" />
+            <Button
+                android:id="@+id/moveToOlder"
+                android:text="@string/message_view_move_to_older"
+                android:layout_height="match_parent"
+                android:layout_width="0dip"
+                android:layout_weight="1" />
+        </LinearLayout>
+    </LinearLayout>
+</LinearLayout>
diff --git a/res/layout/message_view_header.xml b/res/layout/message_view_header.xml
index 75f72eef2..1fcd4afde 100644
--- a/res/layout/message_view_header.xml
+++ b/res/layout/message_view_header.xml
@@ -23,7 +23,7 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/scrollview"
     android:layout_width="match_parent"
-    android:layout_height="0dip"
+    android:layout_height="match_parent"
     android:scrollbarStyle="outsideOverlay"
     android:fadingEdge="none"
     android:fillViewport="true"
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 6add7fa1b..cec6cd66e 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -737,4 +737,8 @@
          always a larger value because it represents the limit of displayed results.  -->
     <string name="gal_completed_limited_fmt">First <xliff:g id="results" example="20">%1$d</xliff:g>
         results from <xliff:g id="domain">%2$s</xliff:g></string>
+
+    <!-- Do Not Translate.  STOPSHIP: Dev version only.  Remove this. -->
+    <string name="activity_label_2pane">Email 2 Pane</string>
+
 </resources>
diff --git a/src/com/android/email/activity/DefaultAccountLoader.java b/src/com/android/email/activity/DefaultAccountLoader.java
new file mode 100644
index 000000000..fbf29dc32
--- /dev/null
+++ b/src/com/android/email/activity/DefaultAccountLoader.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.email.activity;
+
+import com.android.email.provider.EmailContent.Account;
+
+import android.content.AsyncTaskLoader;
+import android.content.Context;
+
+/**
+ * A Loader to load the default account id asynchronously.
+ *
+ * TODO Test it.
+ */
+public class DefaultAccountLoader extends AsyncTaskLoader<Long> {
+    public DefaultAccountLoader(Context context) {
+        super(context);
+    }
+
+    @Override
+    public Long loadInBackground() {
+        return Account.getDefaultAccountId(getContext());
+    }
+
+    @Override
+    public void destroy() {
+        stopLoading();
+    }
+
+    @Override
+    public void startLoading() {
+        cancelLoad();
+        forceLoad();
+    }
+
+    @Override
+    public void stopLoading() {
+        cancelLoad();
+    }
+}
diff --git a/src/com/android/email/activity/MailboxListFragment.java b/src/com/android/email/activity/MailboxListFragment.java
index 9410970ce..39c5d802b 100644
--- a/src/com/android/email/activity/MailboxListFragment.java
+++ b/src/com/android/email/activity/MailboxListFragment.java
@@ -53,7 +53,7 @@ public class MailboxListFragment extends ListFragment implements OnItemClickList
     private static final String MESSAGE_MAILBOX_ID_SELECTION = MessageColumns.MAILBOX_KEY + "=?";
 
     // Account & mailboxes access
-    private long mAccountId;
+    private long mAccountId = -1;
     private LoadMailboxesTask mLoadMailboxesTask;
     private MessageCountTask mMessageCountTask;
     private long mDraftMailboxKey = -1;
@@ -64,6 +64,8 @@ public class MailboxListFragment extends ListFragment implements OnItemClickList
     private MailboxesAdapter mListAdapter;
     private Callback mCallback;
 
+    private boolean mStarted;
+
     /**
      * Callback interface that owning activities must implement
      */
@@ -86,12 +88,10 @@ public class MailboxListFragment extends ListFragment implements OnItemClickList
         super.onActivityCreated(savedInstanceState);
 
         mActivity = getActivity();
-
         ListView listView = getListView();
         listView.setOnItemClickListener(this);
         listView.setItemsCanFocus(false);
         registerForContextMenu(listView);
-
         mListAdapter = new MailboxesAdapter(mActivity);
     }
 
@@ -103,6 +103,9 @@ public class MailboxListFragment extends ListFragment implements OnItemClickList
     public void bindActivityInfo(long accountId, Callback callback) {
         mAccountId = accountId;
         mCallback = callback;
+        if (mStarted) {
+            startLoading();
+        }
     }
 
     /**
@@ -111,8 +114,8 @@ public class MailboxListFragment extends ListFragment implements OnItemClickList
     @Override
     public void onStart() {
         super.onStart();
-        mLoadMailboxesTask = new LoadMailboxesTask(mAccountId);
-        mLoadMailboxesTask.execute();
+        mStarted = true;
+        startLoading();
     }
 
     /**
@@ -120,6 +123,7 @@ public class MailboxListFragment extends ListFragment implements OnItemClickList
      */
     @Override
     public void onResume() {
+        mStarted = false;
         super.onResume();
         updateMessageCount();
     }
@@ -139,12 +143,19 @@ public class MailboxListFragment extends ListFragment implements OnItemClickList
     /**
      * Called when the fragment is no longer in use.
      */
-   @Override
-   public void onDestroy() {
+    @Override
+    public void onDestroy() {
         super.onDestroy();
 
         mListAdapter.changeCursor(null);
-   }
+    }
+
+    private void startLoading() {
+        if (mAccountId != -1) {
+            mLoadMailboxesTask = new LoadMailboxesTask(mAccountId);
+            mLoadMailboxesTask.execute();
+        }
+    }
 
     /**
      * This is called via the activity
diff --git a/src/com/android/email/activity/MessageListFragment.java b/src/com/android/email/activity/MessageListFragment.java
index dda793efe..15d1aa24d 100644
--- a/src/com/android/email/activity/MessageListFragment.java
+++ b/src/com/android/email/activity/MessageListFragment.java
@@ -102,6 +102,8 @@ public class MessageListFragment extends ListFragment implements OnItemClickList
     private int mFirstSelectedItemHeight = -1;
     private boolean mCanAutoRefresh;
 
+    private boolean mStarted;
+
     /**
      * Callback interface that owning activities must implement
      */
@@ -166,6 +168,21 @@ public class MessageListFragment extends ListFragment implements OnItemClickList
         }
     }
 
+    @Override
+    public void onStart() {
+        super.onStart();
+        mStarted = true;
+        if (mAccountId != -1) {
+            startLoading();
+        }
+    }
+
+    @Override
+    public void onStop() {
+        mStarted = false;
+        super.onStop();
+    }
+
     @Override
     public void onResume() {
         super.onResume();
@@ -234,8 +251,14 @@ public class MessageListFragment extends ListFragment implements OnItemClickList
         mAccountId = accountId;
         mMailboxId = mailboxId;
 
+        if (mStarted) {
+            startLoading();
+        }
+    }
+
+    private void startLoading() {
         Utility.cancelTaskInterrupt(mLoadMessagesTask);
-        mLoadMessagesTask = new LoadMessagesTask(mailboxId, accountId);
+        mLoadMessagesTask = new LoadMessagesTask(mMailboxId, mAccountId);
         mLoadMessagesTask.execute();
     }
 
diff --git a/src/com/android/email/activity/MessageListXL.java b/src/com/android/email/activity/MessageListXL.java
new file mode 100644
index 000000000..cfe823e14
--- /dev/null
+++ b/src/com/android/email/activity/MessageListXL.java
@@ -0,0 +1,466 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.email.activity;
+
+import com.android.email.Email;
+import com.android.email.R;
+
+import android.app.Activity;
+import android.app.Fragment;
+import android.app.FragmentTransaction;
+import android.app.LoaderManager.LoaderCallbacks;
+import android.content.Context;
+import android.content.Loader;
+import android.os.Bundle;
+import android.util.Log;
+import android.view.View;
+
+import java.util.ArrayList;
+
+// TODO Where/when/how do we close loaders??  Do we have to?  Getting this error:
+// Finalizing a Cursor that has not been deactivated or closed.
+// database = /data/data/com.google.android.email/databases/EmailProvider.db,
+// table = Account, query = SELECT _id, displayName, emailAddress FROM Account
+
+/**
+ * Two pane activity for XL screen devices.
+ *
+ * TOOD Test it!
+ */
+public class MessageListXL extends Activity implements View.OnClickListener {
+    private static final String BUNDLE_KEY_ACCOUNT_ID = "MessageListXl.account_id";
+    private static final String BUNDLE_KEY_MAILBOX_ID = "MessageListXl.mailbox_id";
+    private static final String BUNDLE_KEY_MESSAGE_ID = "MessageListXl.message_id";
+
+    private static final int LOADER_ID_DEFAULT_ACCOUNT = 0;
+
+    private Context mContext;
+
+    private long mAccountId = -1;
+    private long mMailboxId = -1;
+    private long mMessageId = -1;
+
+    private MailboxListFragment mMailboxListFragment;
+    private MessageListFragment mMessageListFragment;
+    private MessageViewFragment mMessageViewFragment;
+
+    private View mMessageViewButtons;
+    private View mMoveToNewer;
+    private View mMoveToOlder;
+
+    private boolean mActivityInitialized;
+    private final ArrayList<Fragment> mRestoredFragments = new ArrayList<Fragment>();
+    private MessageOrderManager mOrderManager;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        setContentView(R.layout.message_list_xl);
+
+        final boolean isRestoring = (savedInstanceState != null);
+
+        mContext = getApplicationContext();
+
+        mMessageViewButtons = findViewById(R.id.message_view_buttons);
+        mMoveToNewer = findViewById(R.id.moveToNewer);
+        mMoveToOlder = findViewById(R.id.moveToOlder);
+        mMoveToNewer.setOnClickListener(this);
+        mMoveToOlder.setOnClickListener(this);
+
+        if (isRestoring) {
+            restoreSavedState(savedInstanceState);
+        }
+        if (mAccountId == -1) {
+            loadDefaultAccount();
+        }
+        // TODO Initialize accounts dropdown.
+
+        mActivityInitialized = true;
+        if (isRestoring) {
+            initRestoredFragments();
+        }
+    }
+
+    private void restoreSavedState(Bundle savedInstanceState) {
+        mAccountId = savedInstanceState.getLong(BUNDLE_KEY_ACCOUNT_ID, -1);
+        mMailboxId = savedInstanceState.getLong(BUNDLE_KEY_MAILBOX_ID, -1);
+        mMessageId = savedInstanceState.getLong(BUNDLE_KEY_MESSAGE_ID, -1);
+        if (Email.DEBUG) {
+            Log.d(Email.LOG_TAG, "MessageListXl: Restoring "
+                    + mAccountId + "," + mMailboxId + "," + mMessageId);
+        }
+    }
+
+    @Override
+    protected void onSaveInstanceState(Bundle outState) {
+        super.onSaveInstanceState(outState);
+        outState.putLong(BUNDLE_KEY_ACCOUNT_ID, mAccountId);
+        outState.putLong(BUNDLE_KEY_MAILBOX_ID, mMailboxId);
+        outState.putLong(BUNDLE_KEY_MESSAGE_ID, mMessageId);
+    }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
+        startMessageOrderManager();
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+
+        // TODO Add stuff that's done in MessageList.onResume().
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+    }
+
+    @Override
+    protected void onStop() {
+        super.onStop();
+        stopMessageOrderManager();
+    }
+
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+    }
+
+    @Override
+    public void onAttachFragment(Fragment fragment) {
+        if (!mActivityInitialized) {
+            // Fragments are being restored in super.onCreate().
+            // We can't initialize fragments until the activity is initialized, so remember them for
+            // now, and initialize them later in initRestoredFragments().
+            mRestoredFragments.add(fragment);
+            return;
+        }
+        if (Email.DEBUG) {
+            Log.d(Email.LOG_TAG, "MessageListXl.onAttachFragment fragment=" + fragment.getClass());
+        }
+        super.onAttachFragment(fragment);
+        initFragment(fragment);
+    }
+
+    private void initFragment(Fragment fragment) {
+        if (fragment instanceof MailboxListFragment) {
+            initMailboxListFragment((MailboxListFragment) fragment);
+        } else if (fragment instanceof MessageListFragment) {
+            initMessageListFragment((MessageListFragment) fragment);
+        } else if (fragment instanceof MessageViewFragment) {
+            initMessageViewFragment((MessageViewFragment) fragment);
+        }
+    }
+    /**
+     * Called from {@link #onCreate}.
+     * Initializes the fragmetns that are restored in super.onCreate().
+     */
+    private void initRestoredFragments() {
+        for (Fragment f : mRestoredFragments) {
+            initFragment(f);
+        }
+        mRestoredFragments.clear();
+    }
+
+    private void startMessageOrderManager() {
+        if (mMailboxId == -1) {
+            return;
+        }
+        if (mOrderManager != null && mOrderManager.getMailboxId() == mMailboxId) {
+            return;
+        }
+        stopMessageOrderManager();
+        mOrderManager = new MessageOrderManager(this, mMailboxId,
+                new MessageOrderManager.Callback() {
+            @Override
+            public void onMessagesChanged() {
+                updateNavigationArrows();
+            }
+
+            @Override
+            public void onMessageNotFound() {
+                // Current message removed.
+                selectMailbox(mMailboxId);
+            }
+        });
+    }
+
+    private void stopMessageOrderManager() {
+        if (mOrderManager != null) {
+            mOrderManager.close();
+            mOrderManager = null;
+        }
+    }
+
+    private void loadDefaultAccount() {
+        getLoaderManager().initLoader(LOADER_ID_DEFAULT_ACCOUNT, null, new LoaderCallbacks<Long>() {
+            @Override
+            public Loader<Long> onCreateLoader(int id, Bundle args) {
+                return new DefaultAccountLoader(mContext);
+            }
+
+            @Override
+            public void onLoadFinished(Loader<Long> loader, Long accountId) {
+                if (Email.DEBUG) {
+                    Log.d(Email.LOG_TAG, "Default account=" + accountId);
+                }
+                if (accountId == null || accountId == -1) {
+                    onNoAccountFound();
+                } else {
+                    selectAccount(accountId);
+                }
+            }
+        });
+    }
+
+    private void onNoAccountFound() {
+        // Open Welcome, which in turn shows the adding a new account screen.
+        Welcome.actionStart(this);
+        finish();
+        return;
+    }
+
+    // NOTE These selectXxx are *not* only methods where mXxxId's are changed.
+    // When the activity is re-created (e.g. for orientation change), the following things happen.
+    // - mXxxId's are restored from Bundle
+    // - Fragments are restored by the framework (in super.onCreate())
+    // - mXxxId's are set to fragments in initXxxFragment()
+    //
+    // So, if you want to do something when, for example, the current account changes,
+    // selectAccount() is probably not a good place to do it, because it'll be skipped when
+    // the activity is re-created.
+    // Instead, do that in initXxxFragment().  Alternatively, adding the same procedure to
+    // initRestoredFragments() too will probably work.
+
+    private void selectAccount(long accountId) {
+        // TODO Handle "combined mailboxes".  Who should take care of it?  This activity?
+        // MailboxListFragment??
+        if (Email.DEBUG) {
+            Log.d(Email.LOG_TAG, "selectAccount mAccountId=" + mAccountId);
+        }
+        if (accountId == -1) {
+            throw new RuntimeException();
+        }
+        if (mAccountId == accountId) {
+            return;
+        }
+        mAccountId = accountId;
+        mMailboxId = -1;
+        mMessageId = -1;
+
+        // TODO We don't have to replace the fragment, Just update it.
+        // That will be in accordance with our back model.
+
+        final MailboxListFragment fragment = new MailboxListFragment();
+        final FragmentTransaction ft = openFragmentTransaction();
+        ft.replace(R.id.left_pane, fragment);
+        if (mMessageListFragment != null) {
+            ft.remove(mMessageListFragment);
+        }
+        if (mMessageViewFragment != null) {
+            ft.remove(mMessageListFragment);
+        }
+        ft.commit();
+
+        // TODO Open inbox for the selected account.
+    }
+
+    private void selectMailbox(long mailboxId) {
+        if (Email.DEBUG) {
+            Log.d(Email.LOG_TAG, "selectMailbox mMailboxId=" + mMailboxId);
+        }
+        if (mMailboxId == mailboxId) {
+            return;
+        }
+
+        // TODO We don't have to replace the fragment, if it's already the message list.  Just
+        // update it.
+        // That will be in accordance with our back model.
+
+        mMailboxId = mailboxId;
+        mMessageId = -1;
+        MessageListFragment fragment = new MessageListFragment();
+        openFragmentTransaction().replace(R.id.right_pane, fragment).commit();
+    }
+
+    private void selectMessage(long messageId) {
+        // TODO: Deal with draft messages.  (open MessageCompose instead)
+        if (Email.DEBUG) {
+            Log.d(Email.LOG_TAG, "selectMessage messageId=" + mMessageId);
+        }
+        if (mMessageId == messageId) {
+            return;
+        }
+        mMessageId = messageId;
+        MessageViewFragment fragment = new MessageViewFragment();
+        openFragmentTransaction().replace(R.id.right_pane, fragment).commit();
+    }
+
+    private void initMailboxListFragment(MailboxListFragment fragment) {
+        if (Email.DEBUG) {
+            Log.d(Email.LOG_TAG, "initMailboxListFragment mAccountId=" + mAccountId);
+        }
+        if (mAccountId == -1) {
+            throw new RuntimeException();
+        }
+        mMessageListFragment = null;
+        mMessageViewFragment = null;
+        mMailboxListFragment = fragment;
+        fragment.bindActivityInfo(mAccountId, new MailboxListFragment.Callback() {
+            @Override
+            public void onRefresh(long accountId, long mailboxId) {
+                // Will be removed.
+            }
+
+            // TODO Rename to onSelectMailbox
+            @Override
+            public void onOpen(long accountId, long mailboxId) {
+                selectMailbox(mailboxId);
+            }
+        });
+    }
+
+    private void initMessageListFragment(MessageListFragment fragment) {
+        if (Email.DEBUG) {
+            Log.d(Email.LOG_TAG, "initMessageListFragment mMailboxId=" + mMailboxId);
+        }
+        if (mAccountId == -1 || mMailboxId == -1) {
+            throw new RuntimeException();
+        }
+        mMessageListFragment = fragment;
+        mMessageViewFragment = null;
+        mMessageViewButtons.setVisibility(View.GONE);
+        fragment.setCallback(new MessageListFragment.Callback() {
+            @Override
+            public void onSelectionChanged() {
+                // TODO Context mode
+            }
+
+            @Override
+            // TODO Rename to onSelectMessage
+            public void onMessageOpen(long messageId, long mailboxId) { // RENAME: OpenMessage ?
+                selectMessage(messageId);
+            }
+
+            @Override
+            public void onMailboxNotFound() { // RENAME: NotExists? (see MessageViewFragment)
+                // TODO: What to do??
+            }
+        });
+        fragment.openMailbox(mAccountId, mMailboxId);
+    }
+
+    private void initMessageViewFragment(MessageViewFragment fragment) {
+        if (Email.DEBUG) {
+            Log.d(Email.LOG_TAG, "initMessageViewFragment messageId=" + mMessageId);
+        }
+        if (mMessageId == -1) {
+            throw new RuntimeException();
+        }
+        mMessageViewFragment = fragment;
+        mMessageListFragment = null;
+        mMessageViewButtons.setVisibility(View.VISIBLE);
+        fragment.setCallback(new MessageViewFragment.Callback() {
+            @Override
+            public boolean onUrlInMessageClicked(String url) {
+                return false;
+            }
+
+            @Override
+            public void onRespondedToInvite(int response) {
+            }
+
+            @Override
+            public void onMessageSetUnread() {
+            }
+
+            @Override
+            public void onMessageNotExists() {
+            }
+
+            @Override
+            public void onLoadMessageStarted() {
+            }
+
+            @Override
+            public void onLoadMessageFinished() {
+            }
+
+            @Override
+            public void onLoadMessageError() {
+            }
+
+            @Override
+            public void onFetchAttachmentStarted(String attachmentName) {
+            }
+
+            @Override
+            public void onFetchAttachmentFinished() {
+            }
+
+            @Override
+            public void onFetchAttachmentError() {
+            }
+
+            @Override
+            public void onCalendarLinkClicked(long epochEventStartTime) {
+            }
+        });
+        fragment.openMessage(mMessageId);
+        startMessageOrderManager();
+        mOrderManager.moveTo(mMessageId);
+        updateNavigationArrows();
+    }
+
+    private void updateNavigationArrows() {
+        mMoveToNewer.setEnabled((mOrderManager != null) && mOrderManager.canMoveToNewer());
+        mMoveToOlder.setEnabled((mOrderManager != null) && mOrderManager.canMoveToOlder());
+    }
+
+    @Override
+    public void onClick(View view) {
+        switch (view.getId()) {
+            case R.id.moveToOlder:
+                moveToOlder();
+                break;
+            case R.id.moveToNewer:
+                moveToNewer();
+                break;
+        }
+    }
+
+    private boolean moveToOlder() {
+        if (mOrderManager != null && mOrderManager.moveToOlder()) {
+            mMessageId = mOrderManager.getCurrentMessageId();
+            mMessageViewFragment.openMessage(mMessageId);
+            return true;
+        }
+        return false;
+    }
+
+    private boolean moveToNewer() {
+        if (mOrderManager != null && mOrderManager.moveToNewer()) {
+            mMessageId = mOrderManager.getCurrentMessageId();
+            mMessageViewFragment.openMessage(mMessageId);
+            return true;
+        }
+        return false;
+    }
+}
diff --git a/src/com/android/email/activity/MessageOrderManager.java b/src/com/android/email/activity/MessageOrderManager.java
index cd3111ef4..15d359306 100644
--- a/src/com/android/email/activity/MessageOrderManager.java
+++ b/src/com/android/email/activity/MessageOrderManager.java
@@ -90,6 +90,10 @@ public class MessageOrderManager {
         startTask();
     }
 
+    public long getMailboxId() {
+        return mMailboxId;
+    }
+
     /**
      * @return a {@link Handler} for {@link ContentObserver}.
      *
diff --git a/src/com/android/email/activity/MessageViewFragment.java b/src/com/android/email/activity/MessageViewFragment.java
index 16bd0b035..2a244159e 100644
--- a/src/com/android/email/activity/MessageViewFragment.java
+++ b/src/com/android/email/activity/MessageViewFragment.java
@@ -151,6 +151,8 @@ public class MessageViewFragment extends Fragment implements View.OnClickListene
     // contains the HTML content as set in WebView.
     private String mHtmlTextWebView;
 
+    private boolean mStarted;
+
     /**
      * Encapsulates known information about a single attachment.
      */
@@ -332,6 +334,10 @@ public class MessageViewFragment extends Fragment implements View.OnClickListene
     @Override
     public void onStart() {
         super.onStart();
+        mStarted = true;
+        if (mMessageId != -1 || mFileEmailUri != null) {
+            openMessageInternal();
+        }
     }
 
     @Override
@@ -346,6 +352,7 @@ public class MessageViewFragment extends Fragment implements View.OnClickListene
 
     @Override
     public void onStop() {
+        mStarted = false;
         super.onStop();
     }
 
@@ -378,7 +385,9 @@ public class MessageViewFragment extends Fragment implements View.OnClickListene
         mLoadBodyTask = null;
         Utility.cancelTaskInterrupt(mLoadAttachmentsTask);
         mLoadAttachmentsTask = null;
-        mPresenceUpdater.cancelAll();
+        if (mPresenceUpdater != null) {
+            mPresenceUpdater.cancelAll();
+        }
     }
 
     /**
@@ -401,7 +410,9 @@ public class MessageViewFragment extends Fragment implements View.OnClickListene
         mFileEmailUri = null;
         mMessageId = messageId;
         mAccountId = -1;
-        openMessageInternal();
+        if (mStarted) {
+            openMessageInternal();
+        }
     }
 
     /** Called by activities to a URI to an EML file to open. */
@@ -409,7 +420,9 @@ public class MessageViewFragment extends Fragment implements View.OnClickListene
         mFileEmailUri = fileEmailUri;
         mMessageId = -1;
         mAccountId = -1;
-        openMessageInternal();
+        if (mStarted) {
+            openMessageInternal();
+        }
     }
 
     private void openMessageInternal() {