Reset fragment state when opening a new account/mailbox

Without this, there's a small window where a fragment is in a valid
state after openXxx() before the list is loaded.

Bug 3420361

Change-Id: I7f84a94dec1419762aa6b24188c023abe974d2bf

src/com/android/email/activity/MailboxListFragment.java

@@ -28,6 +28,7 @@ import com.android.emailcommon.utility.Utility;
 
 import android.app.Activity;
 import android.app.ListFragment;
+import android.app.LoaderManager;
 import android.app.LoaderManager.LoaderCallbacks;
 import android.content.ClipData;
 import android.content.ClipDescription;
@@ -74,14 +75,6 @@ public class MailboxListFragment extends ListFragment implements OnItemClickList
     // The amount of time to scroll by one pixel, in ms
     private static final int SCROLL_SPEED = 4;
 
-    // Colors used for drop targets
-    private static Integer sDropTrashColor;
-    private static Drawable sDropActiveDrawable;
-
-    private long mLastLoadedAccountId = -1;
-    private long mAccountId = -1;
-    private long mSelectedMailboxId = -1;
-
     private RefreshManager mRefreshManager;
 
     // UI Support
@@ -91,9 +84,18 @@ public class MailboxListFragment extends ListFragment implements OnItemClickList
 
     private ListView mListView;
 
-    private boolean mOpenRequested;
     private boolean mResumed;
 
+    // Colors used for drop targets
+    private static Integer sDropTrashColor;
+    private static Drawable sDropActiveDrawable;
+
+    private long mLastLoadedAccountId = -1;
+    private long mAccountId = -1;
+    private long mSelectedMailboxId = -1;
+
+    private boolean mOpenRequested;
+
     // True if a drag is currently in progress
     private boolean mDragInProgress = false;
     // The mailbox id of the dragged item's mailbox.  We use it to prevent that box from being a
@@ -194,6 +196,21 @@ public class MailboxListFragment extends ListFragment implements OnItemClickList
         mCallback = (callback == null) ? EmptyCallback.INSTANCE : callback;
     }
 
+    private void clearContent() {
+        mLastLoadedAccountId = -1;
+        mAccountId = -1;
+        mSelectedMailboxId = -1;
+
+        mOpenRequested = false;
+        mDragInProgress = false;
+
+        stopLoader();
+        if (mListAdapter != null) {
+            mListAdapter.swapCursor(null);
+        }
+        setListShownNoAnimation(false);
+    }
+
     /**
      * @param accountId the account we're looking at
      */
@@ -207,6 +224,7 @@ public class MailboxListFragment extends ListFragment implements OnItemClickList
         if (mAccountId == accountId) {
             return;
         }
+        clearContent();
         mOpenRequested = true;
         mAccountId = accountId;
         if (mResumed) {
@@ -322,6 +340,11 @@ public class MailboxListFragment extends ListFragment implements OnItemClickList
                 new MailboxListLoaderCallbacks(accountChanging));
     }
 
+    private void stopLoader() {
+        final LoaderManager lm = getLoaderManager();
+        lm.destroyLoader(LOADER_ID_MAILBOX_LIST);
+    }
+
     private class MailboxListLoaderCallbacks implements LoaderCallbacks<Cursor> {
         private boolean mAccountChanging;
 

src/com/android/email/activity/MessageListFragment.java

@@ -103,6 +103,11 @@ public class MessageListFragment extends ListFragment
     private static final int LOADER_ID_MAILBOX_LOADER = 1;
     private static final int LOADER_ID_MESSAGES_LOADER = 2;
 
+    // Controller access
+    private Controller mController;
+    private RefreshManager mRefreshManager;
+    private RefreshListener mRefreshListener = new RefreshListener();
+
     // UI Support
     private Activity mActivity;
     private Callback mCallback = EmptyCallback.INSTANCE;
@@ -130,16 +135,14 @@ public class MessageListFragment extends ListFragment
     private boolean mIsRefreshable;
     private int mCountTotalAccounts;
 
-    // Controller access
-    private Controller mController;
-    private RefreshManager mRefreshManager;
-    private RefreshListener mRefreshListener = new RefreshListener();
-
     // Misc members
     private boolean mDoAutoRefresh;
 
     private boolean mOpenRequested;
 
+    /** Whether "Send all messages" should be shown. */
+    private boolean mShowSendCommand;
+
     /**
      * Visibility.  On XL, message list is normally visible, except when message view is shown
      * in full-screen on portrait.
@@ -157,9 +160,6 @@ public class MessageListFragment extends ListFragment
     private ActionMode mSelectionMode;
     private SelectionModeCallback mLastSelectionModeCallback;
 
-    /** Whether "Send all messages" should be shown. */
-    private boolean mShowSendCommand;
-
     private Utility.ListStateSaver mSavedListState;
 
     private MessageOpenTask mMessageOpenTask;
@@ -370,6 +370,17 @@ public class MessageListFragment extends ListFragment
      */
     public void clearContent() {
         mMailboxId = -1;
+        mLastLoadedMailboxId = -1;
+        mSelectedMessageId = -1;
+        mAccount = null;
+        mMailbox = null;
+        mIsEasAccount = false;
+        mIsRefreshable = false;
+        mCountTotalAccounts = 0;
+        mDoAutoRefresh = false;
+        mOpenRequested = false;
+        mShowSendCommand = false;
+
         stopLoaders();
         onDeselectAll();
         if (mListAdapter != null) {
@@ -395,10 +406,11 @@ public class MessageListFragment extends ListFragment
             return;
         }
 
+        clearContent();
+
         mOpenRequested = true;
         mMailboxId = mailboxId;
 
-        onDeselectAll();
         if (mResumed) {
             startLoading();
         }