material-components_material-components-ios/components/Tabs/examples/TabBarTextOnlyExample.m

// Copyright 2016-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>

#import "MDCTabBarDisplayDelegate.h"
#import "MaterialAppBar.h"
#import "MaterialButtons.h"
#import "MaterialCollections.h"
#import "MaterialContainerScheme.h"
#import "MaterialTabs+Theming.h"
#import "MaterialTabs.h"
#import "supplemental/TabBarTextOnlyExampleSupplemental.h"

@implementation TabBarTextOnlyExample

- (id)initWithCollectionViewLayout:(UICollectionViewLayout *)layout {
  self = [super initWithCollectionViewLayout:layout];
  if (self) {
    _containerScheme = [[MDCContainerScheme alloc] init];
    [self setupExampleViews:@[
      @"Change Alignment", @"Toggle Case", @"Clear Selection", @"Select First", @"Select Last"
    ]];
  }
  return self;
}

- (void)viewDidLoad {
  [super viewDidLoad];
  [self loadTabBar];
  self.appBarViewController.headerStackView.bottomBar = self.tabBar;
}

#pragma mark - Action

- (void)toggleCase:(id)sender {
  self.tabBar.displaysUppercaseTitles = !self.tabBar.displaysUppercaseTitles;
}

- (void)clearSelection:(id)sender {
  self.tabBar.selectedItem = nil;
}

#pragma mark - Private

- (void)loadTabBar {
  const CGRect bounds = self.view.bounds;

  // Long tab bar with lots of items of varying length. Also demonstrates configurable accent color.
  self.tabBar = [[MDCTabBar alloc] initWithFrame:CGRectMake(0, 0, CGRectGetWidth(bounds) - 20, 0)];
  self.tabBar.items = @[
    [[UITabBarItem alloc] initWithTitle:@"This Is" image:nil tag:0],
    [[UITabBarItem alloc] initWithTitle:@"A" image:nil tag:0],
    [[UITabBarItem alloc] initWithTitle:@"Tab Bar" image:nil tag:0],
    [[UITabBarItem alloc] initWithTitle:@"With" image:nil tag:0],
    [[UITabBarItem alloc] initWithTitle:@"A Variety of Titles of Varying Length That Might Be Long"
                                  image:nil
                                    tag:0],
  ];

  [self.tabBar applyPrimaryThemeWithScheme:self.containerScheme];

  self.tabBar.autoresizingMask =
      UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleBottomMargin;
  [self.tabBar sizeToFit];

  self.tabBar.displayDelegate = self;
}

- (void)changeAlignment:(id)sender {
  UIAlertController *sheet =
      [UIAlertController alertControllerWithTitle:nil
                                          message:nil
                                   preferredStyle:UIAlertControllerStyleActionSheet];
  sheet.popoverPresentationController.sourceView = (UICollectionViewCell *)sender;
  sheet.popoverPresentationController.sourceRect = ((UICollectionViewCell *)sender).bounds;
  [sheet addAction:[UIAlertAction actionWithTitle:@"Leading"
                                            style:UIAlertActionStyleDefault
                                          handler:^(UIAlertAction *_Nonnull action) {
                                            [self setAlignment:MDCTabBarAlignmentLeading];
                                          }]];
  [sheet addAction:[UIAlertAction actionWithTitle:@"Center"
                                            style:UIAlertActionStyleDefault
                                          handler:^(UIAlertAction *_Nonnull action) {
                                            [self setAlignment:MDCTabBarAlignmentCenter];
                                          }]];
  [sheet addAction:[UIAlertAction actionWithTitle:@"Justified"
                                            style:UIAlertActionStyleDefault
                                          handler:^(UIAlertAction *_Nonnull action) {
                                            [self setAlignment:MDCTabBarAlignmentJustified];
                                          }]];
  [sheet addAction:[UIAlertAction actionWithTitle:@"Selected Center"
                                            style:UIAlertActionStyleDefault
                                          handler:^(UIAlertAction *_Nonnull action) {
                                            [self setAlignment:MDCTabBarAlignmentCenterSelected];
                                          }]];
  [self presentViewController:sheet animated:YES completion:nil];
}

- (void)setAlignment:(MDCTabBarAlignment)alignment {
  [self.tabBar setAlignment:alignment animated:YES];
}

#pragma mark - Options in Collection View

- (void)collectionView:(UICollectionView *)collectionView
    didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
  [super collectionView:collectionView didSelectItemAtIndexPath:indexPath];
  switch (indexPath.row) {
    case 0:
      [self changeAlignment:[collectionView cellForItemAtIndexPath:indexPath]];
      break;

    case 1:
      [self toggleCase:collectionView];
      break;

    case 2:
      [self clearSelection:collectionView];
      break;

    case 3:
      [self.tabBar setSelectedItem:self.tabBar.items.firstObject animated:YES];
      break;

    case 4:
      [self.tabBar setSelectedItem:self.tabBar.items.lastObject animated:YES];
      break;

    default:
      // Unsupported
      break;
  }
}

#pragma mark - MDCTabBarDisplayDelegate

- (void)tabBar:(MDCTabBar *)tabBar willDisplayItem:(UITabBarItem *)item {
  NSLog(@"Will display item: %@", item.title);
}

- (void)tabBar:(MDCTabBar *)tabBar didEndDisplayingItem:(nonnull UITabBarItem *)item {
  NSLog(@"Did end displaying item: %@", item.title);
}

@end