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iOS

Posted by Will Macleod
Will Macleod
Courses Plus Student 18,780 Points

Clear out the predictionLabel text when a user double-taps on the screen. You can achieve this by checking the tapCount

Struggling on the second half of the Animating and Intercepting Events Extra credit section. How do I tell my label to disappear when the user a double taps the screen.

Will Macleod
Will Macleod
Courses Plus Student 18,780 Points

// // THViewController.m // CrystalBall // // Created by Amit Bijlani on 8/27/13. // Copyright (c) 2013 Treehouse. All rights reserved. //

import "THViewController.h"

import "THCrystalBall.h"

import <AudioToolbox/AudioToolbox.h>

@interface THViewController ()

@end

@implementation THViewController { SystemSoundID soundEffect;

}

  • (void)viewDidLoad { [super viewDidLoad];

    NSString *soundPath = [[NSBundle mainBundle]pathForResource:@"MusicStingSciFiOr SDT045201" ofType:@"wav"]; NSURL *soundURL = [NSURL fileURLWithPath:soundPath]; AudioServicesCreateSystemSoundID(CFBridgingRetain(soundURL), &soundEffect);

    self.crystalBallPredictions = [[THCrystalBall alloc]init];

    self.crystalBallColours = [[THCrystalBall alloc]init];

    self.crystalBallFonts = [[THCrystalBall alloc]init];

    //NSLog (@"Font families: %@", [UIFont familyNames]);

    self.backgroundImageView.animationImages = [[NSArray alloc]initWithObjects:[UIImage imageNamed:@"CB00001"], [UIImage imageNamed:@"CB00002"], [UIImage imageNamed:@"CB00003"], [UIImage imageNamed:@"CB00004"], [UIImage imageNamed:@"CB00005"], [UIImage imageNamed:@"CB00006"], [UIImage imageNamed:@"CB00007"], [UIImage imageNamed:@"CB00008"], [UIImage imageNamed:@"CB00009"], [UIImage imageNamed:@"CB00010"], [UIImage imageNamed:@"CB00011"], [UIImage imageNamed:@"CB00012"], [UIImage imageNamed:@"CB00013"], [UIImage imageNamed:@"CB00014"], [UIImage imageNamed:@"CB00015"], [UIImage imageNamed:@"CB00016"], [UIImage imageNamed:@"CB00017"], [UIImage imageNamed:@"CB00018"], [UIImage imageNamed:@"CB00019"], [UIImage imageNamed:@"CB00020"], [UIImage imageNamed:@"CB00021"], [UIImage imageNamed:@"CB00022"], [UIImage imageNamed:@"CB00023"], [UIImage imageNamed:@"CB00024"], [UIImage imageNamed:@"CB00025"], [UIImage imageNamed:@"CB00026"], [UIImage imageNamed:@"CB00027"], [UIImage imageNamed:@"CB00028"], [UIImage imageNamed:@"CB00029"], [UIImage imageNamed:@"CB00030"], [UIImage imageNamed:@"CB00031"], [UIImage imageNamed:@"CB00032"], [UIImage imageNamed:@"CB00033"], [UIImage imageNamed:@"CB00034"], [UIImage imageNamed:@"CB00035"], [UIImage imageNamed:@"CB00036"], [UIImage imageNamed:@"CB00037"], [UIImage imageNamed:@"CB00038"], [UIImage imageNamed:@"CB00039"], [UIImage imageNamed:@"CB00040"], [UIImage imageNamed:@"CB00041"], [UIImage imageNamed:@"CB00042"], [UIImage imageNamed:@"CB00043"], [UIImage imageNamed:@"CB00044"], [UIImage imageNamed:@"CB00045"], [UIImage imageNamed:@"CB00046"], [UIImage imageNamed:@"CB00047"], [UIImage imageNamed:@"CB00048"], [UIImage imageNamed:@"CB00049"], [UIImage imageNamed:@"CB00050"], [UIImage imageNamed:@"CB00051"], [UIImage imageNamed:@"CB00052"], [UIImage imageNamed:@"CB00053"], [UIImage imageNamed:@"CB00054"], [UIImage imageNamed:@"CB00055"], [UIImage imageNamed:@"CB00056"], [UIImage imageNamed:@"CB00057"], [UIImage imageNamed:@"CB00058"], [UIImage imageNamed:@"CB00059"], [UIImage imageNamed:@"CB00060"],nil];

    self.backgroundImageView.animationDuration = 3.5f; self.backgroundImageView.animationRepeatCount = 1;

}

  • (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. }

pragma mark - Prediction

  • (void) makePrediction { self.predictionLabel.text = [self.crystalBallPredictions randomPrediction]; self.predictionLabel.textColor = [self.crystalBallColours randomColour]; self.predictionLabel.font = [self.crystalBallFonts randomFont]; [self.backgroundImageView startAnimating];

    [UIView animateWithDuration:2.0f animations:^{ self.predictionLabel.frame = CGRectMake(50 , 190, self.predictionLabel.frame.size.width, self.predictionLabel.frame.size.height); }];

    AudioServicesPlayAlertSound(soundEffect);

    [UIView animateWithDuration:7.0f animations:^{ self.predictionLabel.alpha = 1.0f; }]; }

  • (void) predictionNil { self.predictionLabel.text = nil; self.predictionLabel.textColor = nil; self.predictionLabel.font = nil; self.predictionLabel.alpha = 0.0f;

    [UIView animateWithDuration:3.0f animations:^{ self.predictionLabel.frame = CGRectMake(50 , 2000, self.predictionLabel.frame.size.width, self.predictionLabel.frame.size.height); }]; [UIView animateWithDuration:3.0f animations:^{ self.predictionLabel.frame = CGRectMake(50 , 1000, self.predictionLabel.frame.size.width, self.predictionLabel.frame.size.height); }]; }

pragma mark - Motion Events

  • (void) motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event { [self predictionNil]; }

  • (void) motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event { if (motion == UIEventSubtypeMotionShake) { [self makePrediction]; } }

  • (void) motionCancelled:(UIEventSubtype)motion withEvent:(UIEvent *)event { NSLog(@"motion canclled"); }

pragma mark - Touch Events

  • (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

    [self predictionNil]; }

  • (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { [self makePrediction]; }

pragma mark - Button Events

  • (IBAction)buttonPressed { [self predictionNil]; [self makePrediction]; }

@end

1 Answer

Rasmus Rønholt
PLUS
Rasmus Rønholt
Courses Plus Student 17,358 Points
Rasmus Rønholt
Rasmus Rønholt
Courses Plus Student 17,358 Points

From Event Handling Guide for iOS:

If your custom responder is a subclass of UIView or UIViewController, you should implement all of the event handling methods.

Hence, you need to implement ALL of the following events:

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event;

Also check out UIGestureRecognizer which enables you to listen for taps like so e.g. in your viewDidLoad:

UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(someMethod)];
tapGesture.numberOfTapsRequired = 2;
[self.view addGestureRecognizer:tapGesture];

Best /Rasmus