Add ability to multiselect groups

app/src/main/java/com/beemdevelopment/aegis/Preferences.java

@@ -86,6 +86,10 @@ public class Preferences {
         return _prefs.getBoolean("pref_tap_to_reveal", false);
     }
 
+    public boolean isGroupMultiselectEnabled() {
+        return _prefs.getBoolean("pref_groups_multiselect", false);
+    }
+
     public boolean isEntryHighlightEnabled() {
         return _prefs.getBoolean("pref_highlight_entry", false);
     }

app/src/main/java/com/beemdevelopment/aegis/ui/MainActivity.java

@@ -274,6 +274,7 @@ public class MainActivity extends AegisActivity implements EntryListView.Listene
 
     private void initializeGroups() {
         _groupChip.removeAllViews();
+        _groupChip.setSingleSelection(!_prefs.isGroupMultiselectEnabled());
 
         for (VaultGroup group : _groups) {
             addChipTo(_groupChip, new VaultGroupModel(group));
@@ -313,29 +314,24 @@ public class MainActivity extends AegisActivity implements EntryListView.Listene
         }
 
         chip.setOnCheckedChangeListener((group1, isChecked) -> {
-            Set<UUID> groupFilter = new HashSet<>();
             if (_actionMode != null) {
                 _actionMode.finish();
             }
 
             setSaveChipVisibility(true);
 
-            if (!isChecked) {
-                group1.setChecked(false);
+            // Reset group filter if last checked group gets unchecked
+            if (!isChecked && _groupFilter.size() == 1) {
+                Set<UUID> groupFilter = new HashSet<>();
+
+                chipGroup.clearCheck();
                 _groupFilter = groupFilter;
                 _entryListView.setGroupFilter(groupFilter);
                 return;
             }
 
-            Object chipTag = group1.getTag();
-            if (chipTag == GroupPlaceholderType.NO_GROUP) {
-                groupFilter.add(null);
-            } else {
-                groupFilter = getGroupFilter(chipGroup);
-            }
-
-            _groupFilter = groupFilter;
-            _entryListView.setGroupFilter(groupFilter);
+            _groupFilter = getGroupFilter(chipGroup);
+            _entryListView.setGroupFilter(_groupFilter);
         });
 
         chipGroup.addView(chip);
@@ -368,8 +364,10 @@ public class MainActivity extends AegisActivity implements EntryListView.Listene
 
     private static Set<UUID> getGroupFilter(ChipGroup chipGroup) {
         return chipGroup.getCheckedChipIds().stream()
+                .filter(Objects::nonNull)
                 .map(i -> {
                     Chip chip = chipGroup.findViewById(i);
+
                     if (chip.getTag() instanceof VaultGroupModel) {
                         VaultGroupModel group = (VaultGroupModel) chip.getTag();
                         return group.getUUID();
@@ -377,7 +375,6 @@ public class MainActivity extends AegisActivity implements EntryListView.Listene
 
                     return null;
                 })
-                .filter(Objects::nonNull)
                 .collect(Collectors.toSet());
     }
 

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

@@ -39,8 +39,7 @@
                     android:id="@+id/groupChipGroup"
                     android:layout_width="match_parent"
                     android:layout_height="wrap_content"
-                    app:selectionRequired="true"
-                    app:singleSelection="true"/>
+                    app:selectionRequired="true"/>
             </LinearLayout>
         </HorizontalScrollView>
     </com.google.android.material.appbar.AppBarLayout>

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

@@ -373,6 +373,8 @@
 
     <string name="pref_highlight_entry_title">Highlight tokens when tapped</string>
     <string name="pref_highlight_entry_summary">Make tokens easier to distinguish from each other by temporarily highlighting them when tapped</string>
+    <string name="pref_groups_multiselect_title">Multiselect groups</string>
+    <string name="pref_groups_multiselect_summary">Allow the selection of multiple groups at the same time</string>
     <string name="pref_minimize_on_copy_title">Minimize on copy</string>
     <string name="pref_minimize_on_copy_summary">Minimize the app after copying a token</string>
     <string name="pref_copy_behavior_title">Copy tokens to the clipboard</string>

app/src/main/res/xml/preferences_behavior.xml

@@ -26,6 +26,13 @@
         android:title="@string/pref_copy_behavior_title"
         app:iconSpaceReserved="false"/>
 
+    <androidx.preference.SwitchPreferenceCompat
+        android:defaultValue="false"
+        android:key="pref_groups_multiselect"
+        android:title="@string/pref_groups_multiselect_title"
+        android:summary="@string/pref_groups_multiselect_summary"
+        app:iconSpaceReserved="false"/>
+
     <androidx.preference.SwitchPreferenceCompat
         android:defaultValue="false"
         android:key="pref_highlight_entry"