leave and delete (#4262)

* deleting groups/channels is available after leaving only

* update CHANGELOG

* Update src/main/java/org/thoughtcrime/securesms/ConversationActivity.java

Co-authored-by: adb <adb@merlinux.eu>

* mailing lists are not encrypted

---------

Co-authored-by: adb <adb@merlinux.eu>

src/main/java/com/b44t/messenger/DcChat.java

@@ -1,5 +1,7 @@
 package com.b44t.messenger;
 
+import org.thoughtcrime.securesms.util.Util;
+
 public class DcChat {
 
     public static final int DC_CHAT_TYPE_UNDEFINED   = 0;
@@ -56,6 +58,16 @@ public class DcChat {
       return type != DC_CHAT_TYPE_SINGLE;
     }
 
+    public boolean shallLeaveBeforeDelete(DcContext dcContext) {
+      if (isInBroadcast()) {
+        final int[] members = dcContext.getChatContacts(getId());
+        return Util.contains(members, DcContact.DC_CONTACT_ID_SELF);
+      } else if (isMultiUser() && isEncrypted() && canSend() && !isOutBroadcast()) {
+        return true;
+      }
+      return false;
+    }
+
     public boolean isMailingList() {
         return getType() == DC_CHAT_TYPE_MAILINGLIST;
     }

src/main/java/org/thoughtcrime/securesms/BaseConversationListFragment.java

@@ -29,6 +29,7 @@ import androidx.core.graphics.drawable.IconCompat;
 import androidx.fragment.app.Fragment;
 
 import com.b44t.messenger.DcChat;
+import com.b44t.messenger.DcContact;
 import com.b44t.messenger.DcContext;
 import com.google.android.material.snackbar.Snackbar;
 
@@ -267,11 +268,19 @@ public abstract class BaseConversationListFragment extends Fragment implements A
       alertText = activity.getResources().getQuantityString(R.plurals.ask_delete_chat, chatsCount, chatsCount);
     }
 
+    String alertButton = getString(R.string.delete_for_me);
+    for (long chatId : selectedChats) {
+      if (dcContext.getChat((int) chatId).shallLeaveBeforeDelete(dcContext)) {
+        alertButton = getString(R.string.menu_leave_and_delete);
+        break;
+      }
+    }
+
     AlertDialog.Builder alert = new AlertDialog.Builder(activity);
     alert.setMessage(alertText);
     alert.setCancelable(true);
 
-    alert.setPositiveButton(R.string.delete, (dialog, which) -> {
+    alert.setPositiveButton(alertButton, (dialog, which) -> {
 
       if (!selectedChats.isEmpty()) {
         new AsyncTask<Void, Void, Void>() {
@@ -290,6 +299,9 @@ public abstract class BaseConversationListFragment extends Fragment implements A
             int accountId = dcContext.getAccountId();
             for (long chatId : selectedChats) {
               DcHelper.getNotificationCenter(requireContext()).removeNotifications(accountId, (int) chatId);
+              if (dcContext.getChat((int) chatId).shallLeaveBeforeDelete(dcContext)) {
+                dcContext.removeContactFromChat((int) chatId, DcContact.DC_CONTACT_ID_SELF);
+              }
               dcContext.deleteChat((int) chatId);
               DirectShareUtil.clearShortcut(requireContext(), (int) chatId);
             }

src/main/java/org/thoughtcrime/securesms/ConversationActivity.java

@@ -528,15 +528,12 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
       menu.findItem(R.id.menu_ephemeral_messages).setVisible(false);
     }
 
-    if (isMultiUser()) {
-      if (dcChat.isInBroadcast() && !dcChat.isContactRequest()) {
-        menu.findItem(R.id.menu_leave).setTitle(R.string.menu_leave_channel).setVisible(true);
-      } else if (dcChat.isEncrypted()
-          && dcChat.canSend()
-          && !dcChat.isOutBroadcast()
-          && !dcChat.isMailingList()) {
-        menu.findItem(R.id.menu_leave).setVisible(true);
+    if (dcChat.shallLeaveBeforeDelete(DcHelper.getContext(context))) {
+      if (dcChat.isInBroadcast()) {
+        menu.findItem(R.id.menu_leave).setTitle(R.string.menu_leave_channel);
       }
+      menu.findItem(R.id.menu_leave).setVisible(true);
+      menu.findItem(R.id.menu_delete_chat).setVisible(false);
     }
 
     if (isArchived()) {
@@ -729,9 +726,15 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
         DcHelper.getContext(context).removeContactFromChat(chatId, DcContact.DC_CONTACT_ID_SELF);
         Toast.makeText(this, getString(R.string.done), Toast.LENGTH_SHORT).show();
       })
-      .setNegativeButton(R.string.cancel, null)
+      .setNegativeButton(R.string.menu_leave_and_delete, (d, which) -> {
+        DcHelper.getContext(context).removeContactFromChat(chatId, DcContact.DC_CONTACT_ID_SELF);
+        DcHelper.getContext(context).deleteChat(chatId);
+        Toast.makeText(this, getString(R.string.done), Toast.LENGTH_SHORT).show();
+      })
+      .setNeutralButton(R.string.cancel, null)
       .show();
     Util.redPositiveButton(dialog);
+    Util.redButton(dialog, AlertDialog.BUTTON_NEGATIVE);
   }
 
   private void handleArchiveChat() {