components/Tabs/src/MDCTabBarDelegate.h

// Copyright 2020-present the Material Components for iOS authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#import <UIKit/UIKit.h>

@class MDCTabBar;

/**
 Delegate protocol for MDCTabBar. Clients may implement this protocol to receive notifications of
 selection changes in the tab bar or to determine the bar's position.
 */
__deprecated_msg(
    "Use MDCTabBarViewDelegate instead. See go/material-ios-tabbar-migration for more details.")
    @protocol MDCTabBarDelegate<UIBarPositioningDelegate>

@optional

/**
 Called before the selected item changes by user action. This method is not called for programmatic
 changes to the tab bar's selected item. Return YES to allow the selection.
 If you don't implement all items changes are allowed.
 */
- (BOOL)tabBar:(nonnull MDCTabBar *)tabBar shouldSelectItem:(nonnull UITabBarItem *)item;

/**
 Called before the selected item changes by user action. This method is not called for programmatic
 changes to the tab bar's selected item.  NOTE: Will be deprecated. Use tabBar:shouldSelectItem:.
 */
- (void)tabBar:(nonnull MDCTabBar *)tabBar willSelectItem:(nonnull UITabBarItem *)item;

/**
 Called when the selected item changes by user action. This method is not called for programmatic
 changes to the tab bar's selected item.
 */
- (void)tabBar:(nonnull MDCTabBar *)tabBar didSelectItem:(nonnull UITabBarItem *)item;

@end