[ios] Active web state observer in tab collection.

ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.mm

Index: ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.mm
diff --git a/ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.mm b/ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.mm
index 5f64f9d9b6d245fb73e3ca8ef41d491c70632b49..c7b88cb376cbda6b303f70bdc1ba43eb9deecfcf 100644
--- a/ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.mm
+++ b/ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.mm
@@ -49,8 +49,6 @@
     [self.tabs.leadingAnchor constraintEqualToAnchor:self.view.leadingAnchor],
     [self.tabs.trailingAnchor constraintEqualToAnchor:self.view.trailingAnchor],
   ]];
-
-  [self selectItemAtIndex:self.selectedIndex];
 }
 
 - (UIStatusBarStyle)preferredStatusBarStyle {
@@ -104,6 +102,7 @@
   [cell setAppearanceForTabTitle:self.items[index].title
                          favicon:nil
                         cellSize:CGSizeZero];
+  [cell setSelected:(index == self.selectedIndex)];
   return cell;
 }
 
@@ -138,40 +137,60 @@
 
 #pragma mark - TabCollectionConsumer methods
 
-- (void)insertItem:(TabCollectionItem*)item atIndex:(int)index {
+- (void)insertItem:(TabCollectionItem*)item
+           atIndex:(int)index
+     selectedIndex:(int)selectedIndex {
+  DCHECK_GE(index, 0);
   DCHECK_LE(static_cast<NSUInteger>(index), self.items.count);
   [self.items insertObject:item atIndex:index];
   [self.tabs insertItemsAtIndexPaths:@[ [self indexPathForIndex:index] ]];
+  [self selectItemAtIndex:selectedIndex];

[marq (ping after 24h), 2017/05/30 11:09:43]

I think I don't like the view controller calling consumer methods on itself. I'd
rather have (say) a custom setter for selectedIndex that does the work currently
in -selectItemAtIndex.

[edchin, 2017/06/01 23:52:28]

Good idea. Done.

 }
 
-- (void)deleteItemAtIndex:(int)index {
+- (void)deleteItemAtIndex:(int)index selectedIndex:(int)selectedIndex {
+  DCHECK_GE(index, 0);
   DCHECK_LT(static_cast<NSUInteger>(index), self.items.count);
   [self.items removeObjectAtIndex:index];
   [self.tabs deleteItemsAtIndexPaths:@[ [self indexPathForIndex:index] ]];
+  [self selectItemAtIndex:selectedIndex];
 }
 
-- (void)moveItemFromIndex:(int)fromIndex toIndex:(int)toIndex {
+- (void)moveItemFromIndex:(int)fromIndex
+                  toIndex:(int)toIndex
+            selectedIndex:(int)selectedIndex {
   TabCollectionItem* item = self.items[fromIndex];
   [self.items removeObjectAtIndex:fromIndex];
   [self.items insertObject:item atIndex:toIndex];
   [self.tabs moveItemAtIndexPath:[self indexPathForIndex:fromIndex]
                      toIndexPath:[self indexPathForIndex:toIndex]];
+  [self selectItemAtIndex:selectedIndex];
 }
 
 - (void)replaceItemAtIndex:(int)index withItem:(TabCollectionItem*)item {
-  [self.items removeObjectAtIndex:index];
-  [self.items insertObject:item atIndex:index];
+  DCHECK_GE(index, 0);
+  DCHECK_LT(static_cast<NSUInteger>(index), self.items.count);
+  self.items[index] = item;
+  [self.tabs reloadItemsAtIndexPaths:@[ [self indexPathForIndex:index] ]];
 }
 
 - (void)selectItemAtIndex:(int)index {
+  NSMutableArray* indexPaths = [[NSMutableArray alloc] init];
+  if (self.selectedIndex >= 0 &&
+      static_cast<NSUInteger>(self.selectedIndex) < self.items.count) {
+    [indexPaths addObject:[self indexPathForIndex:self.selectedIndex]];
+  }
+  if (index >= 0 && self.selectedIndex != index) {
+    DCHECK_LT(static_cast<NSUInteger>(index), self.items.count);
+    [indexPaths addObject:[self indexPathForIndex:index]];
+  }
   self.selectedIndex = index;
-  [self.tabs selectItemAtIndexPath:[self indexPathForIndex:index]
-                          animated:YES
-                    scrollPosition:UITableViewScrollPositionNone];
+  [self.tabs reloadItemsAtIndexPaths:indexPaths];

[marq (ping after 24h), 2017/05/30 11:09:44]

Should this use -selectItemsAtIndexPath:animated:scrollPosition: and
deselectItemAtIndexPath:animated: instead of reloading the items?

[edchin, 2017/06/01 23:52:29]

Yes, selection should be done on the collection view rather than on cells.
This is now updated to work properly.

 }
 
-- (void)populateItems:(NSArray<TabCollectionItem*>*)items {
+- (void)populateItems:(NSArray<TabCollectionItem*>*)items
+        selectedIndex:(int)selectedIndex {
   self.items = [items mutableCopy];
+  self.selectedIndex = selectedIndex;
   [self.tabs reloadData];
 }