Added setting to enable/disable conversation threading

FAQ.md

@@ -52,7 +52,6 @@ Anything on this list is in random order and *might* be added in the near future
 * Better design: please let me know what you have in mind [in this forum](https://forum.xda-developers.com/android/apps-games/source-email-t3824168).
 * Hide archived messages: hiding archived messages which exists in other folders too would have a performance impact.
 * Save all attachments: there is no [Storage Access Framework](https://developer.android.com/guide/topics/providers/document-provider) API to selected multiple files to save.
-* Show single messages: listing single messages just clutters the list without much benefit, so this will not be added.
 * S/MIME encryption: only PGP encryption will be supported, see [this FAQ](#user-content-faq12) for more information.
 
 Since FairEmail is meant to be privacy friendly, the following will not be added:

app/src/main/java/eu/faircode/email/ActivityBase.java

@@ -92,7 +92,8 @@ abstract class ActivityBase extends AppCompatActivity implements SharedPreferenc
             if (this.getClass().equals(ActivitySetup.class))
                 startActivity(getIntent());
         } else if (!this.getClass().equals(ActivitySetup.class) &&
-                ("compact".equals(key) ||
+                ("threading".equals(key) ||
+                        "compact".equals(key) ||
                         "avatars".equals(key) ||
                         "identicons".equals(key) ||
                         "preview".equals(key) ||

app/src/main/java/eu/faircode/email/ActivityView.java

@@ -1077,6 +1077,7 @@ public class ActivityView extends ActivityBilling implements FragmentManager.OnB
         Bundle args = new Bundle();
         args.putLong("account", intent.getLongExtra("account", -1));
         args.putString("thread", intent.getStringExtra("thread"));
+        args.putLong("id", intent.getLongExtra("id", -1));
         args.putBoolean("found", intent.getBooleanExtra("found", false));
 
         FragmentMessages fragment = new FragmentMessages();

app/src/main/java/eu/faircode/email/AdapterMessage.java

@@ -113,6 +113,7 @@ public class AdapterMessage extends PagedListAdapter<TupleMessageEx, AdapterMess
     private boolean outgoing;
     private IProperties properties;
 
+    private boolean threading;
     private boolean compact;
     private boolean contacts;
     private boolean avatars;
@@ -353,7 +354,7 @@ public class AdapterMessage extends PagedListAdapter<TupleMessageEx, AdapterMess
             vwColor.setBackgroundColor(message.accountColor == null ? Color.TRANSPARENT : message.accountColor);
 
             ivExpander.setImageResource(show_expanded ? R.drawable.baseline_expand_less_24 : R.drawable.baseline_expand_more_24);
-            if (viewType == ViewType.THREAD)
+            if (viewType == ViewType.THREAD && threading)
                 ivExpander.setVisibility(EntityFolder.DRAFTS.equals(message.folderType) ? View.INVISIBLE : View.VISIBLE);
             else
                 ivExpander.setVisibility(View.GONE);
@@ -386,7 +387,7 @@ public class AdapterMessage extends PagedListAdapter<TupleMessageEx, AdapterMess
             tvPreview.setText(message.preview);
             tvPreview.setVisibility(preview && !TextUtils.isEmpty(message.preview) ? View.VISIBLE : View.GONE);
 
-            if (viewType == ViewType.THREAD) {
+            if (viewType == ViewType.THREAD || !threading) {
                 tvCount.setVisibility(View.GONE);
                 ivThread.setVisibility(View.GONE);
             } else {
@@ -565,6 +566,7 @@ public class AdapterMessage extends PagedListAdapter<TupleMessageEx, AdapterMess
                             new Intent(ActivityView.ACTION_VIEW_THREAD)
                                     .putExtra("account", message.account)
                                     .putExtra("thread", message.thread)
+                                    .putExtra("id", message.id)
                                     .putExtra("found", message.ui_found));
                 }
             }
@@ -1519,6 +1521,7 @@ public class AdapterMessage extends PagedListAdapter<TupleMessageEx, AdapterMess
 
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
 
+        this.threading = prefs.getBoolean("threading", true);
         this.compact = prefs.getBoolean("compact", false);
         this.contacts = (ContextCompat.checkSelfPermission(context, Manifest.permission.READ_CONTACTS)
                 == PackageManager.PERMISSION_GRANTED);

app/src/main/java/eu/faircode/email/DaoMessage.java

@@ -58,7 +58,7 @@ public interface DaoMessage {
             " WHERE account.`synchronize`" +
             " AND (NOT message.ui_hide OR :debug)" +
             " AND NOT ui_found" +
-            " GROUP BY account.id, CASE WHEN message.thread IS NULL THEN message.id ELSE message.thread END" +
+            " GROUP BY account.id, CASE WHEN message.thread IS NULL OR NOT :threading THEN message.id ELSE message.thread END" +
             " HAVING SUM(unified) > 0" +
             " ORDER BY CASE" +
             "  WHEN 'unread' = :sort THEN NOT message.ui_seen" +
@@ -66,7 +66,7 @@ public interface DaoMessage {
             "  ELSE 0" +
             " END DESC, message.received DESC")
     @SuppressWarnings(RoomWarnings.CURSOR_MISMATCH)
-    DataSource.Factory<Integer, TupleMessageEx> pagedUnifiedInbox(String sort, boolean debug);
+    DataSource.Factory<Integer, TupleMessageEx> pagedUnifiedInbox(boolean threading, String sort, boolean debug);
 
     @Query("SELECT message.*" +
             ", account.name AS accountName, identity.color AS accountColor, account.notify AS accountNotify" +
@@ -91,7 +91,7 @@ public interface DaoMessage {
             " WHERE (message.account = f.account OR folder.type = '" + EntityFolder.OUTBOX + "')" +
             " AND (NOT message.ui_hide OR :debug)" +
             " AND ui_found = :found" +
-            " GROUP BY CASE WHEN message.thread IS NULL THEN message.id ELSE message.thread END" +
+            " GROUP BY CASE WHEN message.thread IS NULL OR NOT :threading THEN message.id ELSE message.thread END" +
             " HAVING SUM(CASE WHEN folder.id = :folder THEN 1 ELSE 0 END) > 0" +
             " ORDER BY CASE" +
             "  WHEN 'unread' = :sort THEN NOT message.ui_seen" +
@@ -99,7 +99,7 @@ public interface DaoMessage {
             "  ELSE 0" +
             " END DESC, message.received DESC")
     @SuppressWarnings(RoomWarnings.CURSOR_MISMATCH)
-    DataSource.Factory<Integer, TupleMessageEx> pagedFolder(long folder, String sort, boolean found, boolean debug);
+    DataSource.Factory<Integer, TupleMessageEx> pagedFolder(long folder, boolean threading, String sort, boolean found, boolean debug);
 
     @Query("SELECT message.*" +
             ", account.name AS accountName, identity.color AS accountColor, account.notify AS accountNotify" +
@@ -125,6 +125,7 @@ public interface DaoMessage {
             " JOIN folder ON folder.id = message.folder" +
             " WHERE message.account = :account" +
             " AND message.thread = :thread" +
+            " AND (:id IS NULL OR message.id = :id)" +
             " AND ui_found = :found" +
             " AND (NOT message.ui_hide OR :debug)" +
             " ORDER BY CASE" +
@@ -132,7 +133,7 @@ public interface DaoMessage {
             "  WHEN 'starred' = :sort THEN message.ui_flagged" +
             "  ELSE 0" +
             " END DESC, message.received DESC")
-    DataSource.Factory<Integer, TupleMessageEx> pagedThread(long account, String thread, boolean found, String sort, boolean debug);
+    DataSource.Factory<Integer, TupleMessageEx> pagedThread(long account, String thread, Long id, boolean found, String sort, boolean debug);
 
     @Query("SELECT COUNT(id)" +
             " FROM message" +

app/src/main/java/eu/faircode/email/FragmentMessages.java

@@ -93,9 +93,11 @@ public class FragmentMessages extends FragmentEx {
     private long folder = -1;
     private boolean outgoing = false;
     private String thread = null;
+    private long id = -1;
     private boolean found = false;
     private String search = null;
 
+    private boolean threading = true;
     private boolean actionbar = false;
     private boolean autoclose = false;
 
@@ -136,10 +138,12 @@ public class FragmentMessages extends FragmentEx {
         folder = args.getLong("folder", -1);
         outgoing = args.getBoolean("outgoing", false);
         thread = args.getString("thread");
+        id = args.getLong("id", -1);
         found = args.getBoolean("found", false);
         search = args.getString("search");
 
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getContext());
+        threading = prefs.getBoolean("threading", true);
         actionbar = prefs.getBoolean("actionbar", true);
         autoclose = prefs.getBoolean("autoclose", false);
 
@@ -1222,7 +1226,7 @@ public class FragmentMessages extends FragmentEx {
 
             switch (viewType) {
                 case UNIFIED:
-                    messages = new LivePagedListBuilder<>(db.message().pagedUnifiedInbox(sort, debug), LOCAL_PAGE_SIZE).build();
+                    messages = new LivePagedListBuilder<>(db.message().pagedUnifiedInbox(threading, sort, debug), LOCAL_PAGE_SIZE).build();
                     break;
                 case FOLDER:
                     if (searchCallback == null)
@@ -1255,14 +1259,15 @@ public class FragmentMessages extends FragmentEx {
                             .setPrefetchDistance(REMOTE_PAGE_SIZE)
                             .build();
                     LivePagedListBuilder<Integer, TupleMessageEx> builder = new LivePagedListBuilder<>(
-                            db.message().pagedFolder(folder, sort, false, debug), config);
+                            db.message().pagedFolder(folder, threading, sort, false, debug), config);
                     if (browse)
                         builder.setBoundaryCallback(searchCallback);
                     messages = builder.build();
 
                     break;
                 case THREAD:
-                    messages = new LivePagedListBuilder<>(db.message().pagedThread(account, thread, found, sort, debug), LOCAL_PAGE_SIZE).build();
+                    messages = new LivePagedListBuilder<>(
+                            db.message().pagedThread(account, thread, threading ? null : id, found, sort, debug), LOCAL_PAGE_SIZE).build();
                     break;
             }
         } else {
@@ -1299,7 +1304,7 @@ public class FragmentMessages extends FragmentEx {
                     .setPrefetchDistance(REMOTE_PAGE_SIZE)
                     .build();
             LivePagedListBuilder<Integer, TupleMessageEx> builder = new LivePagedListBuilder<>(
-                    db.message().pagedFolder(folder, "time", true, false), config);
+                    db.message().pagedFolder(folder, threading, "time", true, false), config);
             builder.setBoundaryCallback(searchCallback);
             messages = builder.build();
         }
@@ -1497,6 +1502,7 @@ public class FragmentMessages extends FragmentEx {
                 new Intent(ActivityView.ACTION_VIEW_THREAD)
                         .putExtra("account", target.account)
                         .putExtra("thread", target.thread)
+                        .putExtra("id", target.id)
                         .putExtra("found", target.found));
     }
 

app/src/main/java/eu/faircode/email/FragmentOptions.java

@@ -43,9 +43,10 @@ import androidx.appcompat.widget.SwitchCompat;
 public class FragmentOptions extends FragmentEx implements SharedPreferences.OnSharedPreferenceChangeListener {
     private SwitchCompat swEnabled;
     private SwitchCompat swMetered;
+    private SwitchCompat swThreading;
+    private SwitchCompat swCompact;
     private SwitchCompat swAvatars;
     private SwitchCompat swIdenticons;
-    private SwitchCompat swCompact;
     private SwitchCompat swPreview;
     private SwitchCompat swLight;
     private SwitchCompat swBrowse;
@@ -69,6 +70,7 @@ public class FragmentOptions extends FragmentEx implements SharedPreferences.OnS
         // Get controls
         swEnabled = view.findViewById(R.id.swEnabled);
         swMetered = view.findViewById(R.id.swMetered);
+        swThreading = view.findViewById(R.id.swThreading);
         swCompact = view.findViewById(R.id.swCompact);
         swAvatars = view.findViewById(R.id.swAvatars);
         swIdenticons = view.findViewById(R.id.swIdenticons);
@@ -107,6 +109,14 @@ public class FragmentOptions extends FragmentEx implements SharedPreferences.OnS
             }
         });
 
+        swThreading.setChecked(prefs.getBoolean("threading", true));
+        swThreading.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
+                prefs.edit().putBoolean("threading", checked).apply();
+            }
+        });
+
         swCompact.setChecked(prefs.getBoolean("compact", false));
         swCompact.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
             @Override

app/src/main/java/eu/faircode/email/ViewModelMessages.java

@@ -56,18 +56,20 @@ public class ViewModelMessages extends ViewModel {
                 next = item;
         }
         return new Target[]{
-                prev == null ? null : new Target(prev.account, prev.thread, prev.ui_found),
+                prev == null ? null : new Target(prev.account, prev.thread, prev.id, prev.ui_found),
-                next == null ? null : new Target(next.account, next.thread, next.ui_found)};
+                next == null ? null : new Target(next.account, next.thread, next.id, next.ui_found)};
     }
 
     class Target {
         long account;
         String thread;
+        long id;
         boolean found;
 
-        Target(long account, String thread, boolean found) {
+        Target(long account, String thread, long id, boolean found) {
             this.account = account;
             this.thread = thread;
+            this.id = id;
             this.found = found;
         }
     }

app/src/main/res/layout/fragment_options.xml

@@ -29,6 +29,15 @@
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@id/swEnabled" />
 
+        <androidx.appcompat.widget.SwitchCompat
+            android:id="@+id/swThreading"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="12dp"
+            android:text="@string/title_advanced_threading"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/swMetered" />
+
         <androidx.appcompat.widget.SwitchCompat
             android:id="@+id/swCompact"
             android:layout_width="match_parent"
@@ -36,7 +45,7 @@
             android:layout_marginTop="12dp"
             android:text="@string/title_advanced_compact"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/swMetered" />
+            app:layout_constraintTop_toBottomOf="@id/swThreading" />
 
         <androidx.appcompat.widget.SwitchCompat
             android:id="@+id/swAvatars"

app/src/main/res/values/strings.xml

@@ -98,6 +98,7 @@
     <string name="title_advanced">Advanced options</string>
     <string name="title_advanced_enabled">Synchronize</string>
     <string name="title_advanced_metered">Use metered connections</string>
+    <string name="title_advanced_threading">Conversation threading</string>
     <string name="title_advanced_compact">Compact message view</string>
     <string name="title_advanced_avatars">Show contact photos</string>
     <string name="title_advanced_identicons">Show identicons</string>