Allow subscribing to folders

FAQ.md

@@ -223,6 +223,7 @@ The low priority status bar notification shows the number of pending operations,
 * *body*: download message text
 * *attachment*: download attachment
 * *sync*: synchronize local and remote messages
+* *subscribe*: subscribe to remote folder
 
 Operations are processed only when there is a connection to the email server or when manually synchronizing.
 See also [this FAQ](#user-content-faq16).

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

@@ -132,7 +132,9 @@ class Core {
                     JSONArray jargs = new JSONArray(op.args);
 
                     try {
-                        if (message == null && !EntityOperation.SYNC.equals(op.name))
+                        if (message == null &&
+                                !EntityOperation.SYNC.equals(op.name) &&
+                                !EntityOperation.SUBSCRIBE.equals(op.name))
                             throw new MessageRemovedException();
 
                         db.operation().setOperationError(op.id, null);
@@ -144,7 +146,7 @@ class Core {
                                         EntityOperation.DELETE.equals(op.name) ||
                                         EntityOperation.SEND.equals(op.name) ||
                                         EntityOperation.SYNC.equals(op.name) ||
-                                        EntityOperation.WAIT.equals(op.name)))
+                                        EntityOperation.SUBSCRIBE.equals(op.name)))
                             throw new IllegalArgumentException(op.name + " without uid " + op.args);
 
                         // Operations should use database transaction when needed
@@ -217,7 +219,8 @@ class Core {
                                 onSynchronizeMessages(context, jargs, account, folder, (IMAPFolder) ifolder, state);
                                 break;
 
-                            case EntityOperation.WAIT:
+                            case EntityOperation.SUBSCRIBE:
+                                onSubscribeFolder(context, jargs, folder, (IMAPFolder) ifolder);
                                 break;
 
                             default:
@@ -792,6 +795,17 @@ class Core {
         }
     }
 
+    private static void onSubscribeFolder(Context context, JSONArray jargs, EntityFolder folder, IMAPFolder ifolder)
+            throws JSONException, MessagingException {
+        boolean subscribe = jargs.getBoolean(0);
+        ifolder.setSubscribed(subscribe);
+
+        DB db = DB.getInstance(context);
+        db.folder().setFolderSubscribed(folder.id, subscribe);
+
+        Log.i(folder.name + " subscribed=" + subscribe);
+    }
+
     private static void onSynchronizeMessages(
             Context context, JSONArray jargs,
             EntityAccount account, final EntityFolder folder,

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

@@ -553,7 +553,7 @@ public abstract class DB extends RoomDatabase {
                     @Override
                     public void migrate(SupportSQLiteDatabase db) {
                         Log.i("DB migration from version " + startVersion + " to " + endVersion);
-                        db.execSQL("DELETE FROM operation WHERE name = '" + EntityOperation.WAIT + "'");
+                        db.execSQL("DELETE FROM operation WHERE name = 'wait'");
                     }
                 })
                 .addMigrations(new Migration(51, 52) {

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

@@ -83,7 +83,7 @@ public class EntityOperation {
     static final String BODY = "body";
     static final String ATTACHMENT = "attachment";
     static final String SYNC = "sync";
-    static final String WAIT = "wait";
+    static final String SUBSCRIBE = "subscribe";
 
     static void queue(Context context, DB db, EntityMessage message, String name, Object... values) {
         JSONArray jargs = new JSONArray();
@@ -256,6 +256,26 @@ public class EntityOperation {
             ServiceSynchronize.process(context);
     }
 
+    static void subscribe(Context context, long fid, boolean subscribe) {
+        DB db = DB.getInstance(context);
+
+        EntityFolder folder = db.folder().getFolder(fid);
+
+        JSONArray jargs = new JSONArray();
+        jargs.put(subscribe);
+
+        EntityOperation operation = new EntityOperation();
+        operation.account = folder.account;
+        operation.folder = folder.id;
+        operation.message = null;
+        operation.name = SUBSCRIBE;
+        operation.args = jargs.toString();
+        operation.created = new Date().getTime();
+        operation.id = db.operation().insertOperation(operation);
+
+        Log.i("Queued subscribe=" + subscribe + " folder=" + folder);
+    }
+
     @Override
     public boolean equals(Object obj) {
         if (obj instanceof EntityOperation) {

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

@@ -61,6 +61,7 @@ public class FragmentFolder extends FragmentBase {
 
     private long id = -1;
     private long account = -1;
+    private Boolean subscribed = null;
     private boolean saving = false;
     private boolean deletable = false;
 
@@ -289,6 +290,8 @@ public class FragmentFolder extends FragmentBase {
 
     @Override
     public void onPrepareOptionsMenu(Menu menu) {
+        menu.findItem(R.id.menu_subscribe).setChecked(subscribed != null && subscribed);
+        menu.findItem(R.id.menu_subscribe).setVisible(id > 0 && subscribed != null);
         menu.findItem(R.id.menu_delete).setVisible(id > 0 && !saving && deletable);
         super.onPrepareOptionsMenu(menu);
     }
@@ -296,6 +299,11 @@ public class FragmentFolder extends FragmentBase {
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
+            case R.id.menu_subscribe:
+                subscribed = !item.isChecked();
+                item.setChecked(subscribed);
+                onMenuSubscribe();
+                return true;
             case R.id.menu_delete:
                 onMenuDelete();
                 return true;
@@ -304,6 +312,29 @@ public class FragmentFolder extends FragmentBase {
         }
     }
 
+    private void onMenuSubscribe() {
+        Bundle args = new Bundle();
+        args.putLong("id", id);
+        args.putBoolean("subscribed", subscribed);
+
+        new SimpleTask<Void>() {
+            @Override
+            protected Void onExecute(Context context, Bundle args) {
+                long id = args.getLong("id");
+                boolean subscribed = args.getBoolean("subscribed");
+
+                EntityOperation.subscribe(context, id, subscribed);
+
+                return null;
+            }
+
+            @Override
+            protected void onException(Bundle args, Throwable ex) {
+                Helper.unexpectedError(getContext(), getViewLifecycleOwner(), ex);
+            }
+        }.execute(getContext(), getViewLifecycleOwner(), args, "folder:subscribe");
+    }
+
     private void onMenuDelete() {
         new DialogBuilderLifecycle(getContext(), getViewLifecycleOwner())
                 .setMessage(R.string.title_folder_delete)
@@ -399,6 +430,7 @@ public class FragmentFolder extends FragmentBase {
                 cbDownload.setEnabled(cbSynchronize.isChecked());
                 btnSave.setEnabled(true);
 
+                subscribed = (folder == null ? null : folder.subscribed != null && folder.subscribed);
                 deletable = (folder != null && EntityFolder.USER.equals(folder.type));
                 getActivity().invalidateOptionsMenu();
             }

app/src/main/res/menu/menu_folder.xml

@@ -1,6 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
 <menu xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto">
+    <item
+        android:id="@+id/menu_subscribe"
+        android:checkable="true"
+        android:title="@string/title_subscribe"
+        app:showAsAction="never" />
+
     <item
         android:id="@+id/menu_delete"
         android:title="@string/title_delete"

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

@@ -365,6 +365,7 @@
 
     <string name="title_trash">Trash</string>
     <string name="title_copy">Copy &#8230;</string>
+    <string name="title_subscribe">Subscribe</string>
     <string name="title_delete">Delete</string>
     <string name="title_more">More</string>
     <string name="title_spam">Spam</string>