Added settings to enable sync kept removed

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

@@ -941,9 +941,10 @@ class Core {
             SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
             boolean sync_unseen = prefs.getBoolean("sync_unseen", false);
             boolean sync_flagged = prefs.getBoolean("sync_flagged", true);
+            boolean sync_kept = prefs.getBoolean("sync_kept", false);
 
             Log.i(folder.name + " start sync after=" + sync_days + "/" + keep_days +
-                    " unseen=" + sync_unseen + " sync_flagged=" + sync_flagged);
+                    "sync unseen=" + sync_unseen + " flagged=" + sync_flagged + " kept=" + sync_kept);
 
             db.folder().setFolderSyncState(folder.id, "syncing");
 
@@ -987,7 +988,7 @@ class Core {
             }
 
             // Get list of local uids
-            final List<Long> uids = db.message().getUids(folder.id, null);
+            final List<Long> uids = db.message().getUids(folder.id, sync_kept ? null : sync_time);
             Log.i(folder.name + " local count=" + uids.size());
 
             // Reduce list of local uids

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

@@ -56,9 +56,10 @@ public class FragmentOptionsSynchronize extends FragmentBase implements SharedPr
     private TextView tvScheduleEnd;
     private SwitchCompat swUnseen;
     private SwitchCompat swFlagged;
+    private SwitchCompat swSyncKept;
 
     private final static String[] RESET_OPTIONS = new String[]{
-            "enabled", "poll_interval", "schedule", "schedule_start", "schedule_end", "sync_unseen", "sync_flagged"
+            "enabled", "poll_interval", "schedule", "schedule_start", "schedule_end", "sync_unseen", "sync_flagged", "sync_kept"
     };
 
     @Override
@@ -78,6 +79,7 @@ public class FragmentOptionsSynchronize extends FragmentBase implements SharedPr
         tvScheduleEnd = view.findViewById(R.id.tvScheduleEnd);
         swUnseen = view.findViewById(R.id.swUnseen);
         swFlagged = view.findViewById(R.id.swFlagged);
+        swSyncKept = view.findViewById(R.id.swSyncKept);
 
         setOptions();
 
@@ -174,6 +176,14 @@ public class FragmentOptionsSynchronize extends FragmentBase implements SharedPr
             }
         });
 
+        swSyncKept.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
+                prefs.edit().putBoolean("sync_kept", checked).apply();
+                ServiceSynchronize.reload(getContext(), false, "sync_kept=" + checked);
+            }
+        });
+
         PreferenceManager.getDefaultSharedPreferences(getContext()).registerOnSharedPreferenceChangeListener(this);
 
         return view;
@@ -236,6 +246,7 @@ public class FragmentOptionsSynchronize extends FragmentBase implements SharedPr
 
         swUnseen.setChecked(prefs.getBoolean("sync_unseen", false));
         swFlagged.setChecked(prefs.getBoolean("sync_flagged", true));
+        swSyncKept.setChecked(prefs.getBoolean("sync_kept", false));
     }
 
     private String formatHour(Context context, int minutes) {

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

@@ -174,6 +174,29 @@
                 app:layout_constraintStart_toStartOf="parent"
                 app:layout_constraintTop_toBottomOf="@id/swUnseen"
                 app:switchPadding="12dp" />
+
+            <androidx.appcompat.widget.SwitchCompat
+                android:id="@+id/swSyncKept"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="12dp"
+                android:checked="false"
+                android:text="@string/title_advanced_kept_removed"
+                app:layout_constraintStart_toStartOf="parent"
+                app:layout_constraintTop_toBottomOf="@id/swFlagged"
+                app:switchPadding="12dp" />
+
+            <TextView
+                android:id="@+id/tvSyncKept"
+                android:layout_width="0dp"
+                android:layout_height="wrap_content"
+                android:layout_marginEnd="48dp"
+                android:text="@string/title_advanced_sync_kept_hint"
+                android:textAppearance="@style/TextAppearance.AppCompat.Small"
+                android:textStyle="italic"
+                app:layout_constraintEnd_toEndOf="parent"
+                app:layout_constraintStart_toStartOf="parent"
+                app:layout_constraintTop_toBottomOf="@id/swSyncKept" />
         </androidx.constraintlayout.widget.ConstraintLayout>
     </ScrollView>
 </androidx.constraintlayout.widget.ConstraintLayout>

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

@@ -167,6 +167,7 @@
     <string name="title_advanced_schedule">Schedule</string>
     <string name="title_advanced_unseen">All unread messages</string>
     <string name="title_advanced_flagged">All starred messages</string>
+    <string name="title_advanced_kept_removed">Check if old messages were removed from the server</string>
 
     <string name="title_advanced_prefix_once">Prefix subject only once on replying or forwarding</string>
     <string name="title_advanced_autoresize">Automatically resize attached and embedded images</string>
@@ -235,6 +236,7 @@
     <string name="title_advanced_enabled_hint">Globally disable or enable receiving of messages</string>
     <string name="title_advanced_manual_hint">If synchronization is disabled, it is still possible to synchronize manually by pulling down the message list. This will synchronize messages and execute operations for a limited time.</string>
     <string name="title_advanced_poll_hint">Synchronizing periodically will compare local and remote messages each and every time, which is an expensive operation possibly resulting in extra battery usage, especially when there are a lot of messages to synchronize. Always synchronizing will avoid this by continuous listening for changes only.</string>
+    <string name="title_advanced_sync_kept_hint">This will use extra data and extra battery power, especially if there are a lot of messages kept on the device</string>
     <string name="title_advanced_schedule_hint">Tap on a time to set a time</string>
     <string name="title_advanced_metered_hint">Metered connections are generally mobile connections or paid Wi-Fi hotspots</string>
     <string name="title_advanced_metered_warning">Disabling this option will disable receiving and sending messages on mobile internet connections</string>