Added option to collapse messages in conversations on back

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

@@ -1947,11 +1947,13 @@ public class FragmentMessages extends FragmentEx {
                 return true;
             }
 
-            if (expanded.size() > 1) {
+            SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getContext());
-                expanded.clear();
+            if (prefs.getBoolean("collapse", false))
-                adapter.notifyDataSetChanged();
+                if (expanded.size() > 0) {
-                return true;
+                    expanded.clear();
-            }
+                    adapter.notifyDataSetChanged();
+                    return true;
+                }
 
             return false;
         }

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

@@ -74,6 +74,7 @@ public class FragmentOptions extends FragmentEx implements SharedPreferences.OnS
     private SwitchCompat swSwipe;
     private SwitchCompat swActionbar;
     private SwitchCompat swAutoclose;
+    private SwitchCompat swCollapse;
     private SwitchCompat swConfirm;
     private SwitchCompat swSender;
 
@@ -111,6 +112,7 @@ public class FragmentOptions extends FragmentEx implements SharedPreferences.OnS
         swSwipe = view.findViewById(R.id.swSwipe);
         swActionbar = view.findViewById(R.id.swActionbar);
         swAutoclose = view.findViewById(R.id.swAutoclose);
+        swCollapse = view.findViewById(R.id.swCollapse);
         swConfirm = view.findViewById(R.id.swConfirm);
         swSender = view.findViewById(R.id.swSender);
 
@@ -303,6 +305,14 @@ public class FragmentOptions extends FragmentEx implements SharedPreferences.OnS
             }
         });
 
+        swCollapse.setChecked(prefs.getBoolean("collapse", false));
+        swCollapse.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
+                prefs.edit().putBoolean("collapse", checked).apply();
+            }
+        });
+
         swConfirm.setChecked(prefs.getBoolean("confirm", false));
         swConfirm.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
             @Override

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

@@ -346,6 +346,17 @@
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@id/swAutoclose" />
 
+        <androidx.appcompat.widget.SwitchCompat
+            android:id="@+id/swCollapse"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginStart="12dp"
+            android:layout_marginTop="12dp"
+            android:layout_marginEnd="12dp"
+            android:text="@string/title_advanced_collapse"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/tvAutocloseHint" />
+
         <androidx.appcompat.widget.SwitchCompat
             android:id="@+id/swConfirm"
             android:layout_width="match_parent"
@@ -355,7 +366,7 @@
             android:layout_marginEnd="12dp"
             android:text="@string/title_advanced_confirm"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/tvAutocloseHint" />
+            app:layout_constraintTop_toBottomOf="@id/swCollapse" />
 
         <androidx.appcompat.widget.SwitchCompat
             android:id="@+id/swSender"

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

@@ -124,6 +124,7 @@
     <string name="title_advanced_swipe">Swipe actions</string>
     <string name="title_advanced_actionbar">Conversation action bar</string>
     <string name="title_advanced_autoclose">Automatically close conversations</string>
+    <string name="title_advanced_collapse">Collapse messages in conversations on \'back\'</string>
     <string name="title_advanced_confirm">Confirm actions that might leak privacy sensitive information</string>
     <string name="title_advanced_sender">Allow editing sender address</string>
     <string name="title_advanced_download">Automatically download messages and attachments on a metered connection up to</string>