fix(ios): optimize ListView continuousUpdate (#13549)

* fix(ios): optimize ListView continuousUpdate * simply if statement
tidev · Sep 10, 2022 · ca73559 · ca73559
1 parent 2453af6
commit ca73559
Showing 1 changed file with 9 additions and 2 deletions.
diff --git a/iphone/Classes/TiUIListView.m b/iphone/Classes/TiUIListView.m
@@ -79,6 +79,8 @@ @implementation TiUIListView {
   BOOL isSearched;
   UIView *dimmingView;
   BOOL isSearchBarInNavigation;
+  int lastVisibleItem;
+  int lastVisibleSection;
 }
 
 #ifdef TI_USE_AUTOLAYOUT
@@ -1969,6 +1971,13 @@ - (void)scrollViewDidScroll:(UIScrollView *)scrollView
           [eventArgs setValue:NUMINTEGER([indexPath section]) forKey:@"firstVisibleSectionIndex"];
           [eventArgs setValue:section forKey:@"firstVisibleSection"];
           [eventArgs setValue:[section itemAtIndex:[indexPath row]] forKey:@"firstVisibleItem"];
+
+          if (lastVisibleItem != [indexPath row] || lastVisibleSection != [indexPath section]) {
+            // only log if the item changes
+            [self.proxy fireEvent:@"scrolling" withObject:eventArgs propagate:NO];
+            lastVisibleItem = [indexPath row];
+            lastVisibleSection = [indexPath section];
+          }
         } else {
           section = [[self listViewProxy] sectionForIndex:0];
 
@@ -1978,8 +1987,6 @@ - (void)scrollViewDidScroll:(UIScrollView *)scrollView
           [eventArgs setValue:section forKey:@"firstVisibleSection"];
           [eventArgs setValue:NUMINTEGER(-1) forKey:@"firstVisibleItem"];
         }
-
-        [self.proxy fireEvent:@"scrolling" withObject:eventArgs propagate:NO];
       });
     }
   }