UI Gesture in iPhone

Introduction

In this article I will create a Single view application. Here I use a single label from outlet. When we perform a gesture it shows the relevant message on the Simulator screen.

To understand it we use the following.

Step 1

Open XCode by double-clicking on it.

Step 2

Create a New XCode Project by clicking on it.

Step 3

Now Select Single View Application and click on Next.

Step 4

Now provide your Product Name and Company Identifier.

Step 5

Select the location where you want to save your project and click on Create.

Step 6 

Now here we write code:

RecognizerViewController.h

//
// RecognizerViewController.h
// UIGesture
//
// Created by Sachin Bhardwaj on 11/12/12.
// Copyright (c) 2012 Sachin Bhardwaj. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface RecognizerViewController : UIViewController

@property (strong, nonatomic) IBOutlet UILabel *statusLabel;

@end

RecognizerViewController.m

//
//  RecognizerViewController.m
//  UIGesture
//
//  Created by Sachin Bhardwaj on 11/12/12.
//  Copyright (c) 2012 Sachin Bhardwaj. All rights reserved.
//

#import "RecognizerViewController.h"

@interface RecognizerViewController ()

@end

@implementation RecognizerViewController
@synthesize statusLabel;
- (void)viewDidLoad
{
    [super viewDidLoad];
      UITapGestureRecognizer *doubleTap =
    [[UITapGestureRecognizer alloc]
     initWithTarget:self
     action:@selector(tapDetected:)];
    doubleTap.numberOfTapsRequired = 2;
    [self.view addGestureRecognizer:doubleTap];
    
    UITapGestureRecognizer *SingleTap =
    [[UITapGestureRecognizer alloc]
     initWithTarget:self
     action:@selector(tapDetectedS:)];
    SingleTap.numberOfTapsRequired = 1;
    [self.view addGestureRecognizer:SingleTap];

    
    UIPinchGestureRecognizer *pinchRecognizer =
    [[UIPinchGestureRecognizer alloc]
     initWithTarget:self
     action:@selector(pinchDetected:)];
    [self.view addGestureRecognizer:pinchRecognizer];
    
    UIRotationGestureRecognizer *rotationRecognizer =
    [[UIRotationGestureRecognizer alloc]
     initWithTarget:self
     action:@selector(rotationDetected:)];
    [self.view addGestureRecognizer:rotationRecognizer];
    
    UISwipeGestureRecognizer *swipeRecognizerR =
    [[UISwipeGestureRecognizer alloc]
     initWithTarget:self
     action:@selector(swipeDetected:)];
    swipeRecognizerR.direction = UISwipeGestureRecognizerDirectionRight;
    [self.view addGestureRecognizer:swipeRecognizerR];
    
    UISwipeGestureRecognizer *swipeRecognizerUp =
    [[UISwipeGestureRecognizer alloc]
     initWithTarget:self
     action:@selector(swipeDetectedUp:)];
    swipeRecognizerUp.direction = UISwipeGestureRecognizerDirectionUp;
    [self.view addGestureRecognizer:swipeRecognizerUp];
    
    UISwipeGestureRecognizer *swipeRecognizerDown =
    [[UISwipeGestureRecognizer alloc]
     initWithTarget:self
     action:@selector(swipeDetectedDown:)];
    swipeRecognizerDown.direction = UISwipeGestureRecognizerDirectionDown;
    [self.view addGestureRecognizer:swipeRecognizerDown];
    
    UISwipeGestureRecognizer *swipeRecognizerL =
    [[UISwipeGestureRecognizer alloc]
     initWithTarget:self
     action:@selector(swipeDetectedL:)];
    swipeRecognizerL.direction = UISwipeGestureRecognizerDirectionLeft;
    [self.view addGestureRecognizer:swipeRecognizerL];

    
    UILongPressGestureRecognizer *longPressRecognizer =
    [[UILongPressGestureRecognizer alloc]
     initWithTarget:self
     action:@selector(longPressDetected:)];
    longPressRecognizer.minimumPressDuration = 2;
    longPressRecognizer.numberOfTouchesRequired = 1;
    [self.view addGestureRecognizer:longPressRecognizer];
}

- (IBAction)longPressDetected:(UIGestureRecognizer *)sender {
    statusLabel.text = @"Long Press";
}

- (IBAction)swipeDetectedUp:(UIGestureRecognizer *)sender {
    statusLabel.text = @"Up Swipe";
}

- (IBAction)swipeDetectedDown:(UIGestureRecognizer *)sender {
    statusLabel.text = @"Down Swipe";
}

- (IBAction)swipeDetected:(UIGestureRecognizer *)sender {
    statusLabel.text = @"Right Swipe";
}

- (IBAction)swipeDetectedL:(UIGestureRecognizer *)sender {
    statusLabel.text = @"Left Swipe";
}

- (IBAction)tapDetectedS:(UIGestureRecognizer *)sender {
    statusLabel.text = @"Single Tap";
}
- (IBAction)tapDetected:(UIGestureRecognizer *)sender {
    statusLabel.text = @"Double Tap";
}

- (IBAction)pinchDetected:(UIGestureRecognizer *)sender {
    
    CGFloat scale =
    [(UIPinchGestureRecognizer *)sender scale];
    CGFloat velocity =
    [(UIPinchGestureRecognizer *)sender velocity];
    
    NSString *resultString = [[NSString alloc] initWithFormat:
                              @"Pinch - scale = %f, velocity = %f",
                              scale, velocity];
    statusLabel.text = resultString;
}

- (IBAction)rotationDetected:(UIGestureRecognizer *)sender {
    CGFloat radians =
    [(UIRotationGestureRecognizer *)sender rotation];
    CGFloat velocity =
    [(UIRotationGestureRecognizer *)sender velocity];
    
    NSString *resultString = [[NSString alloc] initWithFormat:
                              @"Rotation - Radians = %f, velocity = %f",
                              radians, velocity];
    statusLabel.text = resultString;
}
- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

Step 7

Click on the Run button to show the output.

Output 1 in iPhone

Output 2 in iPhone

When we perform a single-click on the iPhone screen it recognize it and shows this output. 

Output 3 in iPhone

When we perform a double-click on the iPhone screen it recognizes it and shows this output. 

Output 4 in iPhone

When we perform a single click for a long time (just 2 seconds) on the iPhone screen it recognizes it and shows this output. 

Output 5 in iPhone

When we swipe our finger up on the iPhone screen it recognizes it and shows this output. 

Output 6 in iPhone

When we swipe our finger down on the iPhone screen it recognizes it and shows this output. 

Output 7 in iPhone