MESSENGER-5799 add settings alert save changes

Riot/Modules/Settings/SettingsViewController.m

@@ -890,6 +890,10 @@ SSOAuthenticationPresenterDelegate>
     self.tableView.sectionFooterHeight = UITableViewAutomaticDimension;
     self.tableView.estimatedSectionFooterHeight = 50;
     
+    
+    // bwi: #5799 show alert if user has changed the avatar without saving it
+    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:[BWIL10n settingsCustomBackButton] style:UIBarButtonItemStylePlain target:self action:@selector(customBackButtonAction)];
+    
     MXWeakify(self);
     
     // Add observer to handle removed accounts
@@ -5560,6 +5564,43 @@ SSOAuthenticationPresenterDelegate>
 }
 
 
+- (void) customBackButtonAction {
+    // bwi: #5799 show alert if user has changed the avatar without saving it
+    if ((nil != newAvatarImage || shouldRemoveAvatarImage) && !isSavingInProgress)
+    {
+        MXWeakify(self);
+        [currentAlert dismissViewControllerAnimated:NO completion:nil];
+        UIAlertController *saveChangesAlert = [UIAlertController alertControllerWithTitle:[BWIL10n settingsSaveChangesAlertTitle]
+                                                                              message:nil
+                                                                       preferredStyle:UIAlertControllerStyleAlert];
+        
+
+        [saveChangesAlert addAction:[UIAlertAction actionWithTitle:[BWIL10n settingsSaveChangesAlertDoNotSaveButton] style:UIAlertActionStyleDefault handler:^(UIAlertAction * action) {
+            MXStrongifyAndReturnIfNil(self);
+            dispatch_async(dispatch_get_main_queue(), ^{
+                [self.navigationController popViewControllerAnimated:true];
+            });
+            self->currentAlert = nil;
+        }]];
+        
+        [saveChangesAlert addAction:[UIAlertAction actionWithTitle:[BWIL10n settingsSaveChangesAlertSaveButton] style:UIAlertActionStyleDefault handler:^(UIAlertAction * action) {
+            MXStrongifyAndReturnIfNil(self);
+            dispatch_async(dispatch_get_main_queue(), ^{
+                [self onSave:nil];
+            });
+            self->currentAlert = nil;
+        }]];
+        
+        [self presentViewController:saveChangesAlert animated:YES completion:nil];
+        currentAlert = saveChangesAlert;
+    }
+    else
+    {
+        [self.navigationController popViewControllerAnimated:true];
+    }
+}
+
+
 #pragma mark - ThreadsBetaCoordinatorBridgePresenterDelegate
 
 - (void)threadsBetaCoordinatorBridgePresenterDelegateDidTapEnable:(ThreadsBetaCoordinatorBridgePresenter *)coordinatorBridgePresenter