UIPageViewController that has UIPageControl with different dot colours

 Customise page control

  1. Create page control subclassing UIView
  2. Draw the coloured dots in - (void) drawRect:(CGRect) rect
  3. Control the touch events using - (void) touchesBegan:(NSSet *) touches withEvent:(UIEvent *) event
  4. Inform page view controller when user touch it using delegation.

Customise page view controller

  1. Override - (void) viewDidLayoutSubviews and search all the subviews and find the UIPageControl instance.
  2. Hide the UIPageControl instance and add the custom page control instance to its superview.
  3. Set the UIPageControl instance frame to custom page control.
  4. Bring the custom page control using [self.view bringSubviewToFront:pageControl];
  5. When custom page control informs you about the user touch then call the method - (void)setViewControllers:(nullable NSArray *)viewControllers direction:(UIPageViewControllerNavigationDirection)direction animated:(BOOL)animated completion:(void (^ __nullable)(BOOL finished))completion; to move to right or left page.

Page view controller delegate

  1. Update custom control page dots/index using
    - (void) pageViewController:(COPageViewController *)pageViewController didFinishAnimating:(BOOL)finished previousViewControllers:(NSArray *) previousViewControllers transitionCompleted:(BOOL) completed
  2. This method - (void) pageViewController:(COPageViewController *)pageViewController willTransitionToViewControllers:(NSArray *) pendingViewControllers will start when user swipes the page. What I did is maintained a variable that tells whether the page is still in transition, based on that I will allow the user interaction with custom page control.

 

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Present notification from foreground

iOS 10 adds the UNUserNotificationCenterDelegate protocol for handling notifications while your app is in the foreground.

- (void) userNotificationCenter:(UNUserNotificationCenter *) center
willPresentNotification:(UNNotification *) notification
withCompletionHandler:(void (^)(UNNotificationPresentationOptions options)) completionHandler
{
NSLog(@"Present notification from foreground");
completionHandler(UNNotificationPresentationOptionAlert + UNNotificationPresentationOptionSound);
}

iOS App Transport Security – Enforced from 2017 for Apple app submissions

The ATS requirement is here.

https://developer.apple.com/library/content/documentation/General/Reference/InfoPlistKeyReference/Articles/CocoaKeys.html#//apple_ref/doc/uid/TP40009251-SW59
(Section NSAppTransportSecurity)

In summary, below is what we need to do in the apps

1. Make every URLs to https
2. Ensure the TLS version is TLS1.2.
3. Have the certificate used in the server to client communication is trusted.

How do we detect if a URL is ATS compliant?

The nscurl tool on OS X El Capitan supports diagnosing ATS secure connections.

For example, /usr/bin/nscurl –ats-diagnostics https://www.example.com will display ATS connection information for http://www.example.com. Run /usr/bin/nscurl -h for more information.

This tools prints PASS / FAIL information. Ensure PASS results for test with diagnose dictionary with NO exceptions specified.

To view the certificate info of a particular Domain or test out the connection, TLS tool will be a good utility.
https://developer.apple.com/library/content/samplecode/sc1236/Introduction/Intro.html#//apple_ref/doc/uid/DTS40014927-Intro-DontLinkElementID_2

Does it affect Socket communication?

Below is the answer from Apple staff (https://forums.developer.apple.com/thread/48979)

Right now ATS is only enforced by our high-level APIs (NSURLSession, NSURLConnection, and anything layered on top of those), and there’s been no announcements about that changing.

Keep in mind, however, that ATS’s enhanced security requirements are not arbitrary; they are defined to give your users a good level of security on an increasingly hostile Internet. As such, your app should aim to comply with these requirements even if ATS is not actively enforcing them.

Using C++ to access file from Documents folder on iOS and Print the contents

void printFileInfo()
{

char *home = getenv(“HOME”);
char *subdir = “/Documents”;

std::stringstream ss;
ss << home << subdir << “/file.txt”;
std::string s = ss.str();

s.erase(0, strlen(“/private”)); // Erase “/Private” from the final string

char sss;

char letter ;
int i ;
std::string line ;

std::ifstream reader(s.c_str()) ;

if (!reader) {

std::cout << “Error opening input file” << std::endl ;
return -1 ;

}

for (i = 0; !reader.eof() ; i++) {

getline( reader , line ) ;
std::cout << s.c_str() << std::endl;
std::cout << line << std::endl ;

}
reader.close() ;

}

iPv6 Network not available issue

+ (instancetype)  reachabilityForInternetConnection
{

Reachability *reach = NULL;
NetworkStatus status = NotReachable;

struct sockaddr_in zeroAddress;
bzero(&zeroAddress, sizeof(zeroAddress));
zeroAddress.sin_len = sizeof(zeroAddress);
zeroAddress.sin_family = AF_INET;

reach = [self reachabilityWithAddress: (const struct sockaddr *) &zeroAddress];

if  (reach != NULL)
{

status = [reach currentReachabilityStatus];

if (status != NotReachable)
{

NSLog(@”Connected to Ipv4 Environment”);

return reach;

}

}

if  ([[UIDevice currentDevice].systemVersion floatValue] < 9.0)
{

// check whether you are in iPv6 environment

struct sockaddr_in6 zeroAddress1;
bzero(&zeroAddress1, sizeof(zeroAddress1));
zeroAddress1.sin6_len = sizeof(zeroAddress1);
zeroAddress1.sin6_family = AF_INET6;

reach = [self reachabilityWithAddress: (const struct sockaddr *) &zeroAddress1];

if  (reach != NULL)
{

status = [reach currentReachabilityStatus];

if (status != NotReachable)
{

NSLog(@”Connected to Ipv6 Environment”);

}

}

}

return reach;

}

CoreTelephony CTCallCenter

The [[CTCallCenter alloc] init] must be run in the main queue. Is it thread safe ??? Better call it on main thread only.

There is an iOS bug that causes instances of the CTCallCenter class to sometimes get notifications after they have been deallocated. Instead of instantiating, using, and releasing instances you must instead retain and never release them to work around the bug.

static CTCallCenter *netInfo; static dispatch_once_t dispatchToken; if (!netInfo) { dispatch_once(&dispatchToken, ^{ netInfo = [[CTCallCenter alloc] init]; }); }

 

How to programmatically know Bluetooth headset is connected to iOS device

Call this method to find out the bluetooth headset is connected or not.

 

- (BOOL) isBluetoothHeadsetConnected
{
    AVAudioSession *session = [AVAudioSession sharedInstance];
    AVAudioSessionRouteDescription *routeDescription = [session currentRoute];

    DEBUGLOG(@"Current Routes : %@", routeDescription);

    if (routeDescription)
    {
        NSArray *outputs = [routeDescription outputs];

        if (outputs && [outputs count] > 0)
        {
            AVAudioSessionPortDescription *portDescription = [outputs objectAtIndex:0];
            NSString *portType = [portDescription portType];

            DEBUGLOG(@"dataSourceName : %@", portType);

            if (portType && [portType isEqualToString:@"BluetoothA2DPOutput"])
            {
                return YES;
            }
        }
    }

    return NO;
}