Swift: conditional unwrapping, checking error is nil or not

var error: NSError?

// now use error in functions like

audioSession.overrideOutputAudioPort(AVAudioSessionPortOverride.None, error: &error)

//and now conditional unwrapped

 if let routeChangeError = error {

            NSLog("error %@",routeChangeError)

  }

Swift: changing AVAudioSession route (voice from speaker to headphone and vice versa)

 NSNotificationCenter.defaultCenter().addObserver(self, selector: "handleAVAudioSessionRouteChange:", name: AVAudioSessionRouteChangeNotification, object: nil)

@objc private func handleAVAudioSessionRouteChange(notification : NSNotification) {

        

        println("change route \(notification.userInfo)")

        let audioSession = AVAudioSession.sharedInstance()

        var error : NSError?

        let audioRouteChangeReason = notification.userInfo![AVAudioSessionRouteChangeReasonKey] as UInt

        

        switch audioRouteChangeReason {

        case AVAudioSessionRouteChangeReason.NewDeviceAvailable.rawValue:

            println("headphone plugged in")

        audioSession.overrideOutputAudioPort(AVAudioSessionPortOverride.None, error: &error)

        case AVAudioSessionRouteChangeReason.OldDeviceUnavailable.rawValue:

            println("headphone pulled out")

            audioSession.overrideOutputAudioPort(AVAudioSessionPortOverride.Speaker, error: &error)

        default:

            break

        }

    }

Swift NSUserDefault

setting  

NSUserDefaults.standardUserDefaults().setObject(myvalue, forKey: "mykey")

        NSUserDefaults.standardUserDefaults().synchronize()

reading

Swift

1 2 3 4 5

let defaults = NSUserDefaults.standardUserDefaults() if let name = defaults.stringForKey("myKey") {     println(name) }

stringForKey

IntegerForKey

ObjectForKey 

use based on requirements 

swift - Function with parameter and return value

• func sayHello(personName: String) -> String {
• let greeting = "Hello, " + personName + "!"
• return greeting
• }

objective-c gesture recognizer calling multiple time till state end

In viewdidLoad

UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPress:)];

    longPress.minimumPressDuration=1.0f;

    [self.deleteDigitButton addGestureRecognizer:longPress];

Long press button

timer is being used to call itself through longPress timer function

- (void)longPress:(UILongPressGestureRecognizer*)gesture {

    

    if( gesture.state == UIGestureRecognizerStateBegan ) {

        NSLog(@"DialerViewController.Long Press");

        

        NSString *digits = [PhoneNumberFormatter unformat: self.TextField.text];

        if(digits.length > 0 && (gesture.state != UIGestureRecognizerStateEnded || gesture.state != UIGestureRecognizerStateCancelled || gesture.state != UIGestureRecognizerStateFailed)) {

            digits = [digits substringToIndex:digits.length - 1];

            self.TextField.text = [PhoneNumberFormatter format:digits];

            [self.TextField setNeedsDisplay];

            

            NSTimeInterval timeInterval = 0.1; //seconds

            [NSTimer scheduledTimerWithTimeInterval:timeInterval

                                             target:self

                                           selector:@selector(longPressTimer:)

                                           userInfo:gesture

                                           repeats:NO];

            

        }

    }

}

longPressTimer function

-(void)longPressTimer:(NSTimer *)timer{

    UILongPressGestureRecognizer *gesture = [timer userInfo];

    [self longPress:gesture];

}

Swift: Animation

import UIKit

class ViewController: UIViewController {

//    let container = UIView()

//    let redSquare = UIView()

//    let blueSquare = UIView()

let coloredSquare = UIView()

    override func viewDidLoad() {

        super.viewDidLoad()

        

        // set container frame and add to the screen

//        self.container.frame = CGRect(x: 60, y: 60, width: 200, height: 200)

//        self.view.addSubview(container)

//        

//        // set red square frame up

//        // we want the blue square to have the same position as redSquare

//        // so lets just reuse blueSquare.frame

//        self.redSquare.frame = CGRect(x: 0, y: 0, width: 200, height: 200)

//        self.blueSquare.frame = redSquare.frame

//        

//        // set background colors

//        self.redSquare.backgroundColor = UIColor.redColor()

//        self.blueSquare.backgroundColor = UIColor.blueColor()

//        

//        // for now just add the redSquare

//        // we'll add blueSquare as part of the transition animation

//        self.container.addSubview(self.redSquare)

        

        

        let button   = UIButton.buttonWithType(UIButtonType.System) as UIButton

        button.frame = CGRectMake(300, 100, 100, 50)

        button.backgroundColor = UIColor.greenColor()

        button.setTitle("Test Button", forState: UIControlState.Normal)

        button.addTarget(self, action: "buttonAction:", forControlEvents: UIControlEvents.TouchUpInside)

        

        self.view.addSubview(button)

    }

    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

        // Dispose of any resources that can be recreated.

    }

    func buttonAction(sender:UIButton!)

    {

        println("Button tapped")

//        let views = (frontView: self.redSquare, backView: self.blueSquare)

//        

//        // set a transition style

//        let transitionOptions = UIViewAnimationOptions.TransitionFlipFromBottom

//        

//        UIView.transitionWithView(self.container, duration: 1.0, options: transitionOptions, animations: {

//            // remove the front object...

//            views.frontView.removeFromSuperview()

//            

//            // ... and add the other object

//            self.container.addSubview(views.backView)

//            

//            }, completion: { finished in

//                // any code entered here will be applied

//                // .once the animation has completed

//        })

        

        self.coloredSquare.backgroundColor = UIColor.blueColor()

        

        // set frame (position and size) of the square

        // iOS coordinate system starts at the top left of the screen

        // so this square will be at top left of screen, 50x50pt

        // CG in CGRect stands for Core Graphics

        self.coloredSquare.frame = CGRect(x: 150, y: 420, width: 150, height: 1)

        

        // finally, add the square to the screen

        self.view.addSubview(coloredSquare)

        

        

        let duration=1.0

        let delay = 0.0 // delay will be 0.0 seconds (e.g. nothing)

        let options = UIViewAnimationOptions.CurveEaseInOut

        UIView.animateWithDuration(duration, delay: delay, options: options, animations: {

            //self.coloredSquare.backgroundColor = UIColor.redColor()

            

            // for the x-position I entered 320-50 (width of screen - width of the square)

            // if you want, you could just enter 270

            // but I prefer to enter the math as a reminder of what's happenings

            self.coloredSquare.frame = CGRect(x: 150, y: 120, width: 150, height: 300)

            }, completion : { animationFinished in

            

                self.coloredSquare.removeFromSuperview()

            

            })

        

        

    }

}

objective-c sound on pressing button custom dialer buttons

This is code for adding sound on dialer buttons 

SystemSoundID soundID;

    NSString *effectTitle=[NSString stringWithFormat:@"%@%ld",@"DTMF_0",(long)digitButton.tag];

    NSString *soundPath = [[NSBundle mainBundle] pathForResource:effectTitle ofType:@"wav"];

    NSURL *soundUrl = [NSURL fileURLWithPath:soundPath];

    

    AudioServicesCreateSystemSoundID ((__bridge CFURLRef)soundUrl, &soundID);

    AudioServicesPlaySystemSound(soundID);

Objective-c String NSString concatenation

[NSString stringWithFormat:@"%@/%@/%@", one, two, three];

or

result = [result stringByAppendingString:first];

Swift MFMailComposeViewController autorotation

Make class

import Foundation

import UIKit

import MessageUI

class MailComposeViewController: MFMailComposeViewController {

    override func shouldAutorotate() -> Bool {

        return false

    }

    

    override func supportedInterfaceOrientations() -> Int {

        return UIInterfaceOrientation.Portrait.rawValue

    }

    

}

and then -------------

used in some controller

  let mailComposer = MailComposeViewController()

        

        if MFMailComposeViewController.canSendMail() {

            mailComposer.mailComposeDelegate = self

            

            let subject = NSLocalizedString("EmailSubject", comment: "Email subject: Feedback for  Version [version number]") + " " + self.getVersionNumber()

            mailComposer.setSubject(subject)

            mailComposer.setToRecipients(["feedback@abc.com"])

            mailComposer.shouldAutorotate()

            self.presentViewController(mailComposer, animated: true, completion: nil)

            

        }

Objective-c : permission for camera

#import <AVFoundation/AVFoundation.h>

AVAuthorizationStatus status = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];

    if(status == AVAuthorizationStatusAuthorized) { // authorized

    }
    else if(status == AVAuthorizationStatusDenied){ // denied

    }
    else if(status == AVAuthorizationStatusRestricted){ // restricted


    }
    else if(status == AVAuthorizationStatusNotDetermined){ // not determined

        [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
            if(granted){ // Access has been granted ..do something

            } else { // Access denied ..do something

            }
        }];
    }

Swift: making textview not editable

textView.userInteractionEnabled=false;

textView.editable=false;