Changed terminology from Thread to Sort. Added sorting on sender,

flag, unread and attachments.

Really, really, needs better icons.

res/menu/folder_message_list_option.xml

@@ -1,17 +1,48 @@
 <?xml version="1.0" encoding="utf-8"?>
 <menu xmlns:android="http://schemas.android.com/apk/res/android">
-	<item
+   <item
-		android:id="@+id/refresh"
-        android:alphabeticShortcut="r"
-		android:title="@string/refresh_action"
-		android:icon="@drawable/ic_menu_refresh"
-	/>
-    <item
 		android:id="@+id/compose"
         android:alphabeticShortcut="c"
 		android:title="@string/compose_action"
 		android:icon="@drawable/ic_menu_compose"
 	/>
+	<item
+		android:id="@+id/set_sort"
+		android:title="@string/sort_by"
+		android:icon="@drawable/ic_menu_set_sort">
+		
+		<menu>
+			<item
+				android:id="@+id/set_sort_date"
+				android:title="@string/sort_by_date"
+			/>
+			<item
+				android:id="@+id/set_sort_subject"
+				android:title="@string/sort_by_subject"
+			/>
+			<item
+				android:id="@+id/set_sort_sender"
+				android:title="@string/sort_by_sender"
+			/>
+			<item
+				android:id="@+id/set_sort_flag"
+				android:title="@string/sort_by_flag"
+			/>
+			<item
+				android:id="@+id/set_sort_unread"
+				android:title="@string/sort_by_unread"
+			/>
+			<item
+				android:id="@+id/set_sort_attach"
+				android:title="@string/sort_by_attach"
+			/>
+		</menu>
+	</item>
+		<item
+		android:id="@+id/reverse_sort"
+		android:title="@string/reverse_sort_action"
+		android:icon="@drawable/ic_menu_reverse_sort"
+	/>
 	<item
 		android:id="@+id/empty_trash"
         android:alphabeticShortcut="e"
@@ -28,10 +59,12 @@
 		android:title="@string/account_settings_action"
 		android:icon="@android:drawable/ic_menu_preferences"
 	/>
-	<item
+		<item
-		android:id="@+id/thread"
+		android:id="@+id/refresh"
-		android:title="@string/thread_action"
+        android:alphabeticShortcut="r"
-		android:icon="@drawable/ic_menu_thread"
+		android:title="@string/refresh_action"
+		android:icon="@drawable/ic_menu_refresh"
 	/>
 
+
 </menu>

res/values/strings.xml

@@ -60,8 +60,8 @@
     <string name="add_attachment_action">Add attachment</string>
     <string name="dump_settings_action">Dump settings</string>
     <string name="empty_trash_action">Empty Trash</string>
-    <string name="thread_action">Thread</string>
+    <string name="set_sort_action">Choose sort</string>
-    <string name="unthread_action">Unthread</string>
+    <string name="reverse_sort_action">Reverse sort</string>
     <string name="about_action">About</string>
 
     <string name="accounts_context_menu_title">Account options</string>
@@ -115,7 +115,7 @@ Welcome to K-9 Mail setup.  K-9 is an open source email client for Android based
  * Better IMAP support 
  * Saving attachments to SD
  * Empty Trash
- * Threading
+ * Message sorting
  * ...and more
 \nPlease note that K-9 does not support most free hotmail accounts and, like many email clients, has some quirks when talking to Microsoft Exchange.
 \nSubmit bug reports, contribute new features and ask questions at http://code.google.com/p/k9mail
@@ -356,6 +356,27 @@ Welcome to K-9 Mail setup.  K-9 is an open source email client for Android based
 
     <string name="account_settings_deleted_items_label">Deleted Items Folder</string>
     <string name="account_settings_deleted_items_summary">Set the deleted items folder</string>
+    
+    <string name="sort_earliest_first">Earliest messages first</string>
+    <string name="sort_latest_first">Latest messages first</string>
+    <string name="sort_sender_alpha">Sender alphabetical</string>
+    <string name="sort_sender_re_alpha">Sender reverse alphabetical</string>
+    <string name="sort_subject_alpha">Subject alphabetical</string>
+    <string name="sort_subject_re_alpha">Subject reverse alphabetical</string>
+    <string name="sort_flagged_first">Flagged messages first</string>
+    <string name="sort_flagged_last">Unflagged messages first</string>
+    <string name="sort_unread_first">Unread messages first</string>
+    <string name="sort_unread_last">Read messages first</string>
+    <string name="sort_attach_first">Messages with attachments first</string>
+    <string name="sort_unattached_first">Messages without attachments first</string>
+    
+    <string name="sort_by">Sort by...</string>
+    <string name="sort_by_date">Date</string>
+    <string name="sort_by_sender">Sender</string>
+    <string name="sort_by_subject">Subject</string>
+    <string name="sort_by_flag">Flag</string>
+    <string name="sort_by_unread">Read/unread</string>
+    <string name="sort_by_attach">Attachments</string>
 
     <string name="account_delete_dlg_title">Remove</string>
     <string name="account_delete_dlg_instructions_fmt">The account \"<xliff:g id="account">%s</xliff:g>\" will be removed from Email.</string>
@@ -376,6 +397,6 @@ Welcome to K-9 Mail setup.  K-9 is an open source email client for Android based
     Message\u000AK, N - Next Message\u000AZ - Zoom Out\u000AShift-Z -
     Zoom In\u000aG - Flag</string>
     <string name="message_list_help_key">Del (or D) - Delete\u000AR -
-    Reply\u000AA - Reply All\u000AC - Compose\u000AF - Forward\u000aG - Flag\u000AT - Thread\u000AQ
+    Reply\u000AA - Reply All\u000AC - Compose\u000AF - Forward\u000aG - Flag\u000AO - Sort type\u000AI - Sort order\u000AQ
     - Return to Accounts</string>
 </resources>

src/com/android/email/MessagingController.java

@@ -108,7 +108,44 @@ public class MessagingController implements Runnable {
     //private Set<MessagingListener> mListeners = Collections.synchronizedSet(new HashSet<MessagingListener>());
     private Set<MessagingListener> mListeners = new CopyOnWriteArraySet<MessagingListener>();
     
-    private boolean threading = false;
+    private HashMap<SORT_TYPE, Boolean> sortAscending = new HashMap<SORT_TYPE, Boolean>();
+  
+    public enum SORT_TYPE { 
+      SORT_DATE(R.string.sort_earliest_first, R.string.sort_latest_first, false),
+      SORT_SUBJECT(R.string.sort_subject_alpha, R.string.sort_subject_re_alpha, true), 
+      SORT_SENDER(R.string.sort_sender_alpha, R.string.sort_sender_re_alpha, true), 
+      SORT_UNREAD(R.string.sort_unread_first, R.string.sort_unread_last, true),
+      SORT_FLAGGED(R.string.sort_flagged_first, R.string.sort_flagged_last, true), 
+      SORT_ATTACHMENT(R.string.sort_attach_first, R.string.sort_unattached_first, true);
+      
+      private int ascendingToast;
+      private int descendingToast;
+      private boolean defaultAscending;
+      
+      SORT_TYPE(int ascending, int descending, boolean ndefaultAscending)
+      {
+        ascendingToast = ascending;
+        descendingToast = descending;
+        defaultAscending = ndefaultAscending;
+      }
+      
+      public int getToast(boolean ascending)
+      {
+        if (ascending)
+        {
+          return ascendingToast;
+        }
+        else
+        {
+          return descendingToast;
+        }
+      }
+      public boolean isDefaultAscending()
+      {
+        return defaultAscending;
+      }
+    };
+    private SORT_TYPE sortType = SORT_TYPE.SORT_DATE;
     
     private MessagingListener checkMailListener = null;
     
@@ -2503,13 +2540,28 @@ s             * critical data as fast as possible, and then we'll fill in the de
       }
     }
 
-    public boolean isThreading()
+    public SORT_TYPE getSortType()
     {
-      return threading;
+      return sortType;
     }
 
-    public void setThreading(boolean threading)
+    public void setSortType(SORT_TYPE sortType)
     {
-      this.threading = threading;
+      this.sortType = sortType;
+    }
+
+    public boolean isSortAscending(SORT_TYPE sortType)
+    {
+      Boolean sortAsc = sortAscending.get(sortType);
+      if (sortAsc == null)
+      {
+        return sortType.isDefaultAscending();
+      }
+      else return sortAsc;
+    }
+
+    public void setSortAscending(SORT_TYPE sortType, boolean nsortAscending)
+    {
+      sortAscending.put(sortType, nsortAscending);
     }
 }

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

@@ -1,10 +1,12 @@
 package com.android.email.activity;
 
+import java.lang.reflect.Array;
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Date;
+import java.util.EnumMap;
 import java.util.List;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.regex.Matcher;
@@ -41,6 +43,7 @@ import android.widget.ExpandableListView.ExpandableListContextMenuInfo;
 import com.android.email.Account;
 import com.android.email.Email;
 import com.android.email.MessagingController;
+import static com.android.email.MessagingController.SORT_TYPE;
 import com.android.email.MessagingListener;
 import com.android.email.R;
 import com.android.email.Utility;
@@ -130,8 +133,6 @@ public class FolderMessageList extends ExpandableListActivity
     private LayoutInflater mInflater;
 
     private Account mAccount;
-    
-    private Menu optionsMenu = null;
 
 
     /**
@@ -152,7 +153,9 @@ public class FolderMessageList extends ExpandableListActivity
 
 	private DateFormat timeFormat = null;
 	
-	private boolean thread = false;
+	private SORT_TYPE sortType = SORT_TYPE.SORT_DATE;
+	private boolean sortAscending = true;
+	private boolean sortDateAscending = false;
 
 	private DateFormat getDateFormat()
 	{
@@ -577,6 +580,9 @@ public class FolderMessageList extends ExpandableListActivity
 	{
     super.onResume();
 		clearFormats();
+	  sortType = MessagingController.getInstance(getApplication()).getSortType();
+	  sortAscending = MessagingController.getInstance(getApplication()).isSortAscending(sortType);
+    sortDateAscending = MessagingController.getInstance(getApplication()).isSortAscending(SORT_TYPE.SORT_DATE);
 
 		MessagingController.getInstance(getApplication()).addListener(
 				mAdapter.mListener);
@@ -585,9 +591,7 @@ public class FolderMessageList extends ExpandableListActivity
 		
 		NotificationManager notifMgr = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
 		notifMgr.cancel(mAccount.getAccountNumber());
-    thread = MessagingController.getInstance(getApplication()).isThreading();
+ 
-
-
   }
 
     @Override
@@ -644,7 +648,8 @@ public class FolderMessageList extends ExpandableListActivity
 	        case KeyEvent.KEYCODE_C: { onCompose(); return true;}
 	        case KeyEvent.KEYCODE_Q: { onAccounts(); return true; }
 	        case KeyEvent.KEYCODE_S: { onEditAccount(); return true; }
-	        case KeyEvent.KEYCODE_T: { onToggleThread(); return true; }
+	        case KeyEvent.KEYCODE_O: { onCycleSort(); return true; }
+	        case KeyEvent.KEYCODE_I: { onToggleSortAscending(); return true; }
 	        case KeyEvent.KEYCODE_H: {
 	            Toast toast = Toast.makeText(this, R.string.message_list_help_key, Toast.LENGTH_LONG);
 	            toast.show();
@@ -785,19 +790,57 @@ public class FolderMessageList extends ExpandableListActivity
         MessageCompose.actionCompose(this, mAccount);
     }
 	
-	private void onToggleThread()
+	private void changeSort(SORT_TYPE newSortType)
 	{
-	  thread = !thread;
+	  sortType = newSortType;
-	  
+	  MessagingController.getInstance(getApplication()).setSortType(sortType);
-	  for (FolderInfoHolder folder : mAdapter.mFolders)
+	  sortAscending = MessagingController.getInstance(getApplication()).isSortAscending(sortType);
-	  { 
+	  sortDateAscending = MessagingController.getInstance(getApplication()).isSortAscending(SORT_TYPE.SORT_DATE);
-  	  Collections.sort(folder.messages);
+	  reSort();
-	  }
-	  mAdapter.notifyDataSetChanged();
-	  setMenuThread();
-	  MessagingController.getInstance(getApplication()).setThreading(thread);
-	  
 	}
+	
+	private void reSort()
+	{ 
+	  int toastString = sortType.getToast(sortAscending);
+
+    Toast toast = Toast.makeText(this, toastString, Toast.LENGTH_SHORT);
+    toast.show();
+    
+    for (FolderInfoHolder folder : mAdapter.mFolders)
+    { 
+      Collections.sort(folder.messages);
+    }
+    mAdapter.notifyDataSetChanged();
+    
+	}
+	
+	private void onCycleSort()
+	{  
+	  SORT_TYPE[] sorts = SORT_TYPE.values();
+	  int curIndex = 0;
+	  for (int i = 0; i < sorts.length; i++)
+	  {
+	    if (sorts[i] == sortType)
+	    {
+	      curIndex = i;
+	      break;
+	    }
+	  }
+	  curIndex++;
+	  if (curIndex == sorts.length)
+	  {
+	    curIndex = 0;
+	  }
+	  
+	  changeSort(sorts[curIndex]);
+	}
+	
+	private void onToggleSortAscending()
+  {
+	  sortAscending = !sortAscending;
+    MessagingController.getInstance(getApplication()).setSortAscending(sortType, sortAscending);
+	  reSort();
+  }
 
 	private void onDelete(MessageInfoHolder holder)
 	{
@@ -908,41 +951,43 @@ public class FolderMessageList extends ExpandableListActivity
             case R.id.account_settings:
                 onEditAccount();
                 return true;
-            case R.id.thread:
+            case R.id.set_sort_date:
-              onToggleThread();
+              changeSort(SORT_TYPE.SORT_DATE);
               return true;
-			case R.id.empty_trash:
+            case R.id.set_sort_subject:
-				onEmptyTrash(mAccount);
+              changeSort(SORT_TYPE.SORT_SUBJECT);
-				return true;
+              return true;
+            case R.id.set_sort_sender:
+              changeSort(SORT_TYPE.SORT_SENDER);
+              return true;
+            case R.id.set_sort_flag:
+              changeSort(SORT_TYPE.SORT_FLAGGED);
+              return true;
+            case R.id.set_sort_unread:
+              changeSort(SORT_TYPE.SORT_UNREAD);
+              return true;
+            case R.id.set_sort_attach:
+              changeSort(SORT_TYPE.SORT_ATTACHMENT);
+              return true;
+            case R.id.reverse_sort:
+              onToggleSortAscending();
+              return true;
+      			case R.id.empty_trash:
+      				onEmptyTrash(mAccount);
+      				return true;
 
             default:
                 return super.onOptionsItemSelected(item);
-        }
+		}  
-    }
+  }
 
     @Override
 	public boolean onCreateOptionsMenu(Menu menu)
 	{
         super.onCreateOptionsMenu(menu);
         getMenuInflater().inflate(R.menu.folder_message_list_option, menu);
-        optionsMenu = menu;
-        setMenuThread();
         return true;
     }
-    
-    private void setMenuThread()
-    {
-      Menu menu = optionsMenu;
-      if (menu != null)
-      {
-        MenuItem threadItem = menu.findItem(R.id.thread);
-        if (threadItem != null)
-        {
-          threadItem.setTitle(thread ? R.string.unthread_action : R.string.thread_action);
-          threadItem.setIcon(thread ? R.drawable.ic_menu_unthread : R.drawable.ic_menu_thread);
-        }
-      }
-    }
 
     @Override
 	public boolean onContextItemSelected(MenuItem item)
@@ -1082,6 +1127,7 @@ public class FolderMessageList extends ExpandableListActivity
     }
 	}
 
+
 	private String truncateStatus(String mess)
 	{
 		if (mess != null && mess.length() > 27)
@@ -1977,9 +2023,13 @@ public class FolderMessageList extends ExpandableListActivity
                 }
             }
 
+			@Override
 			public int compareTo(MessageInfoHolder o)
 			{
-			  if (thread)
+			  int ascender = (sortAscending ? 1 : -1);
+			  int comparison = 0;
+			  
+			  if (sortType == SORT_TYPE.SORT_SUBJECT)
 			  {
   			  if (compareSubject == null)
   			  {
@@ -1989,15 +2039,35 @@ public class FolderMessageList extends ExpandableListActivity
   			  {
   			    o.compareSubject = stripPrefixes(o.subject).toLowerCase();
   			  }
-  			  int subjCompare = this.compareSubject.compareTo(o.compareSubject);
+  			  comparison = this.compareSubject.compareTo(o.compareSubject);
-  			  if (subjCompare != 0)
-  			  {
-  			    return subjCompare;
-  			  }
 			  }
-			  
+			  else if (sortType == SORT_TYPE.SORT_SENDER)
-        return this.compareDate.compareTo(o.compareDate) * -1;
+			  {
-            }
+			    comparison = this.sender.toLowerCase().compareTo(o.sender.toLowerCase());
+			  }
+			  else if (sortType == SORT_TYPE.SORT_FLAGGED)
+			  {
+			    comparison = (this.flagged ? 0 : 1) - (o.flagged ? 0 : 1); 
+
+			  }
+        else if (sortType == SORT_TYPE.SORT_UNREAD)
+        {
+          comparison = (this.read ? 1 : 0) - (o.read ? 1 : 0); 
+        }
+        else if (sortType == SORT_TYPE.SORT_ATTACHMENT)
+        {
+          comparison = (this.hasAttachments ? 0 : 1) - (o.hasAttachments ? 0 : 1); 
+ 
+        }
+        if (comparison != 0)
+        {
+          return comparison * ascender;
+        }
+
+	       int dateAscender = (sortDateAscending ? 1 : -1);
+
+        return this.compareDate.compareTo(o.compareDate) * dateAscender;
+      }
 			Pattern pattern = null;
 			String patternString = "^ *(re|fw|fwd): *";
 			private String stripPrefixes(String in)