SegmentedViewController

gistfile1.txt

//
//  SegmentedViewController.m
//  ViewControllerTest
//
//  Created by Koen van der Drift on 2/25/17.
//  Copyright © 2017 Koen van der Drift. All rights reserved.
//

#import "SegmentedViewController.h"

#import "RedViewController.h"
#import "TableViewController.h"

@interface SegmentedViewController ()
@property (nonatomic, strong) UISegmentedControl *segmentedControl;
@property (nonatomic, strong) UIToolbar *toolbar;
@property (nonatomic, strong) UIViewController *currentVC;
@end

@implementation SegmentedViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    self.view.backgroundColor = [UIColor whiteColor];
    self.navigationController.navigationBar.translucent = YES;
    
    self.title = @"Segmented Control Test";
    
    [self setUpViewControllers];
    
    if (self.viewControllers.count)
    {
        self.segmentedControl = [[UISegmentedControl alloc] initWithItems: self.segmentTitles];
        [self.segmentedControl addTarget: self
                                  action: @selector(segmentClicked:)
                        forControlEvents: UIControlEventValueChanged];
        self.segmentedControl.apportionsSegmentWidthsByContent = YES;
        
        self.toolbar = [[UIToolbar alloc] init];
        
        self.toolbar.translucent = YES;
        self.toolbar.delegate = self;
        self.toolbar.clipsToBounds = YES;
        
        UIBarButtonItem *segmentedControlButtonItem = [[UIBarButtonItem alloc] initWithCustomView: self.segmentedControl];
        UIBarButtonItem *flexibleItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem: UIBarButtonSystemItemFlexibleSpace
                                                                                      target: nil
                                                                                      action: nil];
        
        [self.toolbar setItems: @[flexibleItem, segmentedControlButtonItem, flexibleItem] animated: YES];
        
        [self.navigationController.view addSubview: self.toolbar];
        
        self.segmentedControl.selectedSegmentIndex = 0;
    }
    
    if (!self.currentVC)
    {
        // set the first child vc
        
        UIViewController *vc = self.viewControllers.firstObject;
        
        [self addChildViewController: vc];
        
        vc.view.frame = [self frameForChildView];
        [self.view addSubview: vc.view];
        [vc didMoveToParentViewController: self];
        
        self.currentVC = vc;
    }
}

- (void) viewDidLayoutSubviews
{
    [super viewDidLayoutSubviews];
    
    self.toolbar.frame = CGRectMake(0, self.topLayoutGuide.length, CGRectGetWidth(self.view.bounds), 44.0f);
    self.currentVC.view.frame = [self frameForChildView];
}


- (void) setUpViewControllers
{
    RedViewController *rvc = [[RedViewController alloc] init];
    TableViewController *tvc = [[TableViewController alloc] init];
    
    self.viewControllers = @[tvc, rvc];
    self.segmentTitles = @[@"Table", @"Red"];
}

- (void)segmentClicked:(id)sender
{
    if (sender == self.segmentedControl)
    {
        NSUInteger index = self.segmentedControl.selectedSegmentIndex;
        [self selectViewControllerAtIndex: index];
    }
}

- (void) selectViewControllerAtIndex: (NSUInteger) index
{
    [self loadViewController: self.viewControllers[index]];
    
    if (self.segmentedControl.selectedSegmentIndex != index)
        self.segmentedControl.selectedSegmentIndex = index;
}


- (void)loadViewController:(UIViewController *)vc
{
    if (self.currentVC == vc)
        return;
    
    [self addChildViewController: vc];
    [self.currentVC willMoveToParentViewController: nil];
    
    [self transitionFromViewController: self.currentVC
                      toViewController: vc
                              duration: 0
                               options: UIViewAnimationOptionLayoutSubviews
                            animations: ^{
                                vc.view.frame = [self frameForChildView];
                                [self.view addSubview: vc.view];
                            } completion:^(BOOL finished) {
                                [vc didMoveToParentViewController: self];
                                [self.currentVC removeFromParentViewController];
                                self.currentVC = vc;
                            }
     ];
}


- (CGRect) frameForChildView
{
    CGRect frame = CGRectMake(0, 0, CGRectGetWidth(self.view.bounds), CGRectGetHeight(self.view.bounds));
    
    frame.origin.y += 44.0f;
    frame.size.height -= self.bottomLayoutGuide.length;
    
    return frame;
}


@end