ios/chrome/browser/ui/tab_grid/grid/grid_consumer.h

// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef IOS_CHROME_BROWSER_UI_TAB_GRID_GRID_GRID_CONSUMER_H_
#define IOS_CHROME_BROWSER_UI_TAB_GRID_GRID_GRID_CONSUMER_H_

@class GridItem;

// Supports idempotent insert/delete/updates to a grid.
@protocol GridConsumer

// Many of the following methods pass a |selectedItemID| as a parameter,
// indicating the identifier of the item that should be in the selected state
// after the method is called. In every such case, a nil |selectedItemID|
// indicates that no item should be selected (typically because there are no
// items). It is up to the consumer to determine how to handle a
// |selectedItemID| that is not the identifier of any current items.

// Tells the consumer to replace its current set of items with |items| and
// update the selected item ID to be |selectedItemID|. It's an error to pass
// an |items| array containing items without unique IDs.
- (void)populateItems:(NSArray<GridItem*>*)items
       selectedItemID:(NSString*)selectedItemID;

// Tells the consumer to insert |item| at |index| and update the selected item
// ID to be |selectedItemID|. It's an error if |item|'s ID duplicates an
// ID already passed to the consumer (and not yet removed).
- (void)insertItem:(GridItem*)item
           atIndex:(NSUInteger)index
    selectedItemID:(NSString*)selectedItemID;

// Tells the consumer to remove the item with ID |removedItemID| and update the
// selected item ID to be |selectedItemID|.
- (void)removeItemWithID:(NSString*)removedItemID
          selectedItemID:(NSString*)selectedItemID;

// Tells the consumer to update the selected item ID to be |selectedItemID|.
- (void)selectItemWithID:(NSString*)selectedItemID;

// Tells the consumer to replace the item with ID |itemID| with |item|.
// It's an error if |item|'s ID duplicates any other item's ID besides |itemID|.
// The consumer should ignore this call if |itemID| has not yet been inserted.
- (void)replaceItemID:(NSString*)itemID withItem:(GridItem*)item;

// Tells the consumer to move the item with id |itemID| to |toIndex|. Note that
// the ID of the selected item isn't changed by this method, although the index
// of that item might be.
- (void)moveItemWithID:(NSString*)itemID toIndex:(NSUInteger)toIndex;

@end

#endif  // IOS_CHROME_BROWSER_UI_TAB_GRID_GRID_GRID_CONSUMER_H_