Added menu to delete non-selectable folders

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

@@ -414,6 +414,7 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
                 return false;
 
             SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+            boolean debug = prefs.getBoolean("debug", false);
 
             PopupMenuLifecycle popupMenu = new PopupMenuLifecycle(context, powner, view);
 
@@ -479,6 +480,10 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
                 popupMenu.getMenu().add(Menu.NONE, R.string.title_create_sub_folder, 16, R.string.title_create_sub_folder)
                         .setEnabled(folder.inferiors);
 
+            if (!folder.selectable && debug)
+                popupMenu.getMenu().add(Menu.NONE, R.string.title_delete, 17, R.string.title_delete)
+                        .setEnabled(folder.inferiors);
+
             popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
                 @Override
                 public boolean onMenuItemClick(MenuItem item) {
@@ -545,6 +550,10 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
                             onActionCreateFolder();
                             return true;
 
+                        case R.string.title_delete:
+                            onActionDeleteFolder();
+                            return true;
+
                         default:
                             return false;
                     }
@@ -713,6 +722,17 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
                                     .putExtra("account", folder.account)
                                     .putExtra("parent", folder.name));
                 }
+
+                private void onActionDeleteFolder() {
+                    Bundle aargs = new Bundle();
+                    aargs.putLong("id", folder.id);
+                    aargs.putString("question", context.getString(R.string.title_folder_delete));
+
+                    FragmentDialogAsk ask = new FragmentDialogAsk();
+                    ask.setArguments(aargs);
+                    ask.setTargetFragment(parentFragment, FragmentFolders.REQUEST_DELETE_FOLDER);
+                    ask.show(parentFragment.getParentFragmentManager(), "folder:delete");
+                }
             });
 
             popupMenu.show();

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

@@ -90,6 +90,7 @@ public class FragmentFolders extends FragmentBase {
     static final int REQUEST_SYNC = 1;
     static final int REQUEST_DELETE_LOCAL = 2;
     static final int REQUEST_EMPTY_FOLDER = 3;
+    static final int REQUEST_DELETE_FOLDER = 4;
 
     @Override
     public void onCreate(Bundle savedInstanceState) {
@@ -526,6 +527,10 @@ public class FragmentFolders extends FragmentBase {
                     if (resultCode == RESULT_OK && data != null)
                         onEmptyFolder(data.getBundleExtra("args"));
                     break;
+                case REQUEST_DELETE_FOLDER:
+                    if (resultCode == RESULT_OK && data != null)
+                        onDeleteFolder(data.getBundleExtra("args"));
+                    break;
             }
         } catch (Throwable ex) {
             Log.e(ex);
@@ -690,6 +695,41 @@ public class FragmentFolders extends FragmentBase {
         }.execute(this, args, "folder:delete");
     }
 
+    private void onDeleteFolder(Bundle args) {
+        new SimpleTask<Void>() {
+            @Override
+            protected Void onExecute(Context context, Bundle args) {
+                long id = args.getLong("id");
+
+                EntityFolder folder;
+
+                DB db = DB.getInstance(context);
+                try {
+                    db.beginTransaction();
+
+                    folder = db.folder().getFolder(id);
+                    if (folder == null)
+                        return null;
+
+                    db.folder().setFolderTbd(folder.id);
+
+                    db.setTransactionSuccessful();
+                } finally {
+                    db.endTransaction();
+                }
+
+                ServiceSynchronize.reload(context, folder.account, false, "delete folder");
+
+                return null;
+            }
+
+            @Override
+            protected void onException(Bundle args, Throwable ex) {
+                Log.unexpectedError(getParentFragmentManager(), ex);
+            }
+        }.execute(this, args, "folder:delete");
+    }
+
     public static class FragmentDialogApply extends FragmentDialogBase {
         @NonNull
         @Override