[ios] Close the tab button.

This CL adds the functionality to each of the close buttons in the tab
strip.

Bug: 1128249
Change-Id: I8f1357e2d13bb46319f4b59b5d6720964ddd1e9d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2564642
Commit-Queue: Nazerke Kalidolda <nazerke@google.com>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#832382}

ios/chrome/browser/ui/tab_switcher/tab_strip/tab_strip_cell.h

@@ -7,6 +7,14 @@
 
 #import <UIKit/UIKit.h>
 
+@class TabStripCell;
+
+// Informs the receiver of actions on the cell.
+@protocol TabStripCellDelegate
+// Informs the receiver that the close button on the cell was tapped.
+- (void)closeButtonTappedForCell:(TabStripCell*)cell;
+@end
+
 // UICollectionViewCell that contains a Tab title with a leading imageView
 // and a close tab button.
 @interface TabStripCell : UICollectionViewCell
@@ -17,6 +25,8 @@
 // Unique identifier for the cell's contents. This is used to ensure that
 // updates in an asynchronous callback are only made if the item is the same.
 @property(nonatomic, copy) NSString* itemIdentifier;
+// Delegate to inform the TabStrip on the cell.
+@property(nonatomic, weak) id<TabStripCellDelegate> delegate;
 
 @end
 

ios/chrome/browser/ui/tab_switcher/tab_strip/tab_strip_cell.mm

@@ -57,6 +57,9 @@ const CGFloat kTitleInset = 10.0;
       [closeButton.centerYAnchor
           constraintEqualToAnchor:self.contentView.centerYAnchor],
     ]];
+    [closeButton addTarget:self
+                    action:@selector(closeButtonTapped:)
+          forControlEvents:UIControlEventTouchUpInside];
 
     UILabel* titleLabel = [[UILabel alloc] init];
     [self.contentView addSubview:titleLabel];
@@ -82,4 +85,9 @@ const CGFloat kTitleInset = 10.0;
   self.itemIdentifier = nil;
 }
 
+// Selector registered to the close button.
+- (void)closeButtonTapped:(id)sender {
+  [self.delegate closeButtonTappedForCell:self];
+}
+
 @end

ios/chrome/browser/ui/tab_switcher/tab_strip/tab_strip_consumer_delegate.h

@@ -16,6 +16,10 @@
 // Tells the receiver to show to the selected tab.
 - (void)selectTab:(int)index;
 
+// Tells the receiver to close the item with identifier |itemID|. If there is
+// no item with that identifier, no item is closed.
+- (void)closeItemWithID:(NSString*)itemID;
+
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_TAB_SWITCHER_TAB_STRIP_TAB_STRIP_CONSUMER_DELEGATE_H_

ios/chrome/browser/ui/tab_switcher/tab_strip/tab_strip_mediator.mm

@@ -74,6 +74,18 @@ web::WebState* GetWebStateWithId(WebStateList* web_state_list,
   return nullptr;
 }
 
+// Returns the index of the tab with |identifier| in |web_state_list|. Returns
+// -1 if not found.
+int GetIndexOfTabWithId(WebStateList* web_state_list, NSString* identifier) {
+  for (int i = 0; i < web_state_list->count(); i++) {
+    web::WebState* web_state = web_state_list->GetWebStateAt(i);
+    TabIdTabHelper* tab_helper = TabIdTabHelper::FromWebState(web_state);
+    if ([identifier isEqualToString:tab_helper->tab_id()])
+      return i;
+  }
+  return -1;
+}
+
 }  // namespace
 
 @interface TabStripMediator () <CRWWebStateObserver, WebStateListObserving> {
@@ -204,6 +216,12 @@ web::WebState* GetWebStateWithId(WebStateList* web_state_list,
   _webStateList->ActivateWebStateAt(index);
 }
 
+- (void)closeItemWithID:(NSString*)itemID {
+  int index = GetIndexOfTabWithId(self.webStateList, itemID);
+  if (index >= 0)
+    self.webStateList->CloseWebStateAt(index, WebStateList::CLOSE_USER_ACTION);
+}
+
 #pragma mark - Private
 
 // Calls |-populateItems:selectedItemID:| on the consumer.

ios/chrome/browser/ui/tab_switcher/tab_strip/tab_strip_view_controller.mm

@@ -30,7 +30,7 @@ const CGFloat kNewTabButtonBottomImageInset = -2.0;
 
 }  // namespace
 
-@interface TabStripViewController ()
+@interface TabStripViewController () <TabStripCellDelegate>
 
 @property(nonatomic, strong) UIButton* buttonNewTab;
 // The local model backing the collection view.
@@ -150,6 +150,7 @@ const CGFloat kNewTabButtonBottomImageInset = -2.0;
 // theme.
 - (void)configureCell:(TabStripCell*)cell withItem:(TabSwitcherItem*)item {
   if (item) {
+    cell.delegate = self;
     cell.itemIdentifier = item.identifier;
     cell.titleLabel.text = item.title;
     NSString* itemIdentifier = item.identifier;
@@ -186,4 +187,10 @@ const CGFloat kNewTabButtonBottomImageInset = -2.0;
   [self.delegate selectTab:index];
 }
 
+#pragma mark - TabStripCellDelegate
+
+- (void)closeButtonTappedForCell:(TabStripCell*)cell {
+  [self.delegate closeItemWithID:cell.itemIdentifier];
+}
+
 @end