Fixed startActivityForResult() failing for MessageList

Fixes issue 3638

AndroidManifest.xml

@@ -27,9 +27,6 @@
     <uses-permission android:name="android.permission.WAKE_LOCK"/>
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 
-    <!-- In order to properly manage the BACK key, we do some check on the running tasks -->
-    <uses-permission android:name="android.permission.GET_TASKS" />
-
     <uses-permission android:name="org.thialfihar.android.apg.permission.READ_KEY_DETAILS" />
 
     <permission android:name="com.fsck.k9.permission.READ_ATTACHMENT"
@@ -207,7 +204,7 @@
         </activity>
         <activity
             android:name="com.fsck.k9.activity.MessageList"
-            android:launchMode="singleInstance"
+            android:launchMode="singleTask"
             android:configChanges="locale"
             >
         </activity>

src/com/fsck/k9/activity/MessageList.java

@@ -25,7 +25,6 @@ import android.util.TypedValue;
 import android.view.ContextMenu;
 import android.view.ContextMenu.ContextMenuInfo;
 import android.view.GestureDetector;
-import android.view.GestureDetector.SimpleOnGestureListener;
 import android.view.KeyEvent;
 import android.view.LayoutInflater;
 import android.view.Menu;
@@ -554,6 +553,9 @@ public class MessageList
 
     public static Intent actionHandleFolderIntent(Context context, Account account, String folder) {
         Intent intent = new Intent(context, MessageList.class);
+        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
+        intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
         intent.putExtra(EXTRA_ACCOUNT, account.getUuid());
 
         if (folder != null) {
@@ -573,6 +575,9 @@ public class MessageList
         }
         intent.putExtra(EXTRA_INTEGRATE, integrate);
         intent.putExtra(EXTRA_TITLE, title);
+        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
+        intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
         context.startActivity(intent);
     }
 
@@ -589,6 +594,9 @@ public class MessageList
         intent.putExtra(EXTRA_ACCOUNT_UUIDS, searchSpecification.getAccountUuids());
         intent.putExtra(EXTRA_FOLDER_NAMES, searchSpecification.getFolderNames());
         intent.putExtra(EXTRA_TITLE, title);
+        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
+        intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
         context.startActivity(intent);
     }
 
@@ -618,6 +626,12 @@ public class MessageList
 
         mInflater = getLayoutInflater();
         initializeLayout();
+
+        // Only set "touchable" when we're first starting up the activity.
+        // Otherwise we get force closes when the user toggles it midstream.
+        mTouchView = K9.messageListTouchable();
+        mPreviewLines = K9.messageListPreviewLines();
+
         onNewIntent(getIntent());
     }
 
@@ -625,22 +639,30 @@ public class MessageList
     public void onNewIntent(Intent intent) {
         setIntent(intent); // onNewIntent doesn't autoset our "internal" intent
 
-        // Only set "touchable" when we're first starting up the activity.
-        // Otherwise we get force closes when the user toggles it midstream.
-        mTouchView = K9.messageListTouchable();
-        mPreviewLines = K9.messageListPreviewLines();
-
         String accountUuid = intent.getStringExtra(EXTRA_ACCOUNT);
-        mAccount = Preferences.getPreferences(this).getAccount(accountUuid);
+        Account account = Preferences.getPreferences(this).getAccount(accountUuid);
-        mFolderName = intent.getStringExtra(EXTRA_FOLDER);
+        String folderName = intent.getStringExtra(EXTRA_FOLDER);
-        mQueryString = intent.getStringExtra(EXTRA_QUERY);
+        String queryString = intent.getStringExtra(EXTRA_QUERY);
 
-        if (mAccount != null && !mAccount.isAvailable(this)) {
+        if (account != null && !account.isAvailable(this)) {
             Log.i(K9.LOG_TAG, "not opening MessageList of unavailable account");
             onAccountUnavailable();
             return;
         }
 
+        if (account != null && account.equals(mAccount) &&
+                folderName != null && folderName.equals(mFolderName) &&
+                ((queryString != null && queryString.equals(mQueryString)) ||
+                        (queryString == null && mQueryString == null))) {
+            // We're likely just returning from the MessageView activity with "Manage back button"
+            // enabled. So just leave the activity in the state it was left in.
+            return;
+        }
+
+        mAccount = account;
+        mFolderName = folderName;
+        mQueryString = queryString;
+
         String queryFlags = intent.getStringExtra(EXTRA_QUERY_FLAGS);
         if (queryFlags != null) {
             String[] flagStrings = queryFlags.split(",");
@@ -1070,7 +1092,7 @@ public class MessageList
             MessageReference ref = message.message.makeMessageReference();
             Log.i(K9.LOG_TAG, "MessageList sending message " + ref);
 
-            MessageView.actionView(this, ref, messageRefs, getIntent());
+            MessageView.actionView(this, ref, messageRefs);
         }
 
         /*

src/com/fsck/k9/activity/MessageView.java

@@ -1,7 +1,5 @@
 package com.fsck.k9.activity;
 
-import android.app.ActivityManager;
-import android.app.ActivityManager.RunningTaskInfo;
 import android.app.Dialog;
 import android.app.ProgressDialog;
 import android.content.Context;
@@ -36,7 +34,6 @@ import java.util.*;
 public class MessageView extends K9Activity implements OnClickListener {
     private static final String EXTRA_MESSAGE_REFERENCE = "com.fsck.k9.MessageView_messageReference";
     private static final String EXTRA_MESSAGE_REFERENCES = "com.fsck.k9.MessageView_messageReferences";
-    private static final String EXTRA_ORIGINATING_INTENT = "com.fsck.k9.MessageView_originatingIntent";
     private static final String EXTRA_NEXT = "com.fsck.k9.MessageView_next";
     private static final String SHOW_PICTURES = "showPictures";
     private static final String STATE_PGP_DATA = "pgpData";
@@ -65,12 +62,6 @@ public class MessageView extends K9Activity implements OnClickListener {
         HAS_SUPER_ON_BACK_METHOD = hasOnBackMethod;
     }
 
-    /**
-     * If user opt-in for the "Manage BACK button", we have to remember how to get back to the
-     * originating activity (just recreating a new Intent could lose the calling activity state)
-     */
-    private Intent mCreatorIntent;
-
     private SingleMessageView mMessageView;
 
     private PgpData mPgpData;
@@ -275,20 +266,8 @@ public class MessageView extends K9Activity implements OnClickListener {
         // or later, or by the code above on earlier versions of the
         // platform.
         if (K9.manageBack()) {
-            final ActivityManager activityManager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
+            String folder = (mMessage != null) ? mMessage.getFolder().getName() : null;
-            // retrieve the current+previous tasks
+            MessageList.actionHandleFolder(this, mAccount, folder);
-            final List<RunningTaskInfo> runningTasks = activityManager.getRunningTasks(2);
-            final RunningTaskInfo previousTask = runningTasks.get(1);
-            final String originatingActivity = mCreatorIntent.getComponent().getClassName();
-            if (originatingActivity.equals(previousTask.topActivity.getClassName())) {
-                // we can safely just finish ourself since the most recent task matches our creator
-                // this enable us not to worry about restoring the state of our creator
-            } else {
-                // the previous task top activity doesn't match our creator (previous task is from
-                // another app and user used long-pressed-HOME to display MessageView)
-                // launching our creator
-                startActivity(mCreatorIntent);
-            }
             finish();
         } else if (HAS_SUPER_ON_BACK_METHOD) {
             super.onBackPressed();
@@ -348,29 +327,15 @@ public class MessageView extends K9Activity implements OnClickListener {
 
     }
 
-    /**
-     * @param context
-     * @param messRef
-     * @param messReferences
-     * @param originatingIntent
-     *         The intent that allow us to get back to the calling screen, for when the 'Manage
-     *         "Back" button' option is enabled. Never {@code null}.
-     */
     public static void actionView(Context context, MessageReference messRef,
-            ArrayList<MessageReference> messReferences, final Intent originatingIntent) {
+            ArrayList<MessageReference> messReferences) {
         Intent i = new Intent(context, MessageView.class);
         i.putExtra(EXTRA_MESSAGE_REFERENCE, messRef);
         i.putParcelableArrayListExtra(EXTRA_MESSAGE_REFERENCES, messReferences);
-        i.putExtra(EXTRA_ORIGINATING_INTENT, originatingIntent);
         i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
         context.startActivity(i);
     }
 
-    @Override
-    protected void onNewIntent(final Intent intent) {
-        mCreatorIntent = intent.getParcelableExtra(EXTRA_ORIGINATING_INTENT);
-    }
-
     @Override
     public void onCreate(Bundle icicle) {
         super.onCreate(icicle, false);
@@ -412,8 +377,6 @@ public class MessageView extends K9Activity implements OnClickListener {
         setTitle("");
         final Intent intent = getIntent();
 
-        mCreatorIntent = getIntent().getParcelableExtra(EXTRA_ORIGINATING_INTENT);
-
         Uri uri = intent.getData();
         if (icicle != null) {
             mMessageReference = icicle.getParcelable(EXTRA_MESSAGE_REFERENCE);