Objective-C

Building the interface

To be able to place the call, you need to add two elements to the screen:

A UILabel to show the connection status
A UIButton to start and end calls

Open ViewController.m and add these two programmatically by replacing the entire file content with the following:

#import "ViewController.h"
#import <NexmoClient/NexmoClient.h>

@interface ViewController ()
@property UIButton *callButton;
@property UILabel *connectionStatusLabel;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.connectionStatusLabel = [[UILabel alloc] init];
    self.connectionStatusLabel.text = @"Unknown";
    self.connectionStatusLabel.textAlignment = NSTextAlignmentCenter;
    self.connectionStatusLabel.translatesAutoresizingMaskIntoConstraints = NO;
    [self.view addSubview:self.connectionStatusLabel];
    
    self.callButton = [UIButton buttonWithType:UIButtonTypeSystem];
    self.callButton.translatesAutoresizingMaskIntoConstraints = NO;
    [self.callButton setAlpha:0];
    [self.callButton addTarget:self action:@selector(callButtonPressed) forControlEvents:UIControlEventTouchUpInside];
    [self.callButton setTitle:@"Call" forState:UIControlStateNormal];
    [self.view addSubview:self.callButton];
    
    [NSLayoutConstraint activateConstraints:@[
        [self.connectionStatusLabel.topAnchor constraintEqualToAnchor:self.view.safeAreaLayoutGuide.topAnchor constant:20],
        [self.connectionStatusLabel.leadingAnchor constraintEqualToAnchor:self.view.leadingAnchor constant:20],
        [self.connectionStatusLabel.trailingAnchor constraintEqualToAnchor:self.view.trailingAnchor constant:-20],
        
        [self.callButton.topAnchor constraintEqualToAnchor:self.connectionStatusLabel.bottomAnchor constant:40],
        [self.callButton.leadingAnchor constraintEqualToAnchor:self.view.leadingAnchor constant:20],
        [self.callButton.trailingAnchor constraintEqualToAnchor:self.view.trailingAnchor constant:-20]
    ]];
}

- (void)callButtonPressed {
    
}

@end