Question

I am trying to implement a custom implementation of switching buttons so that only one can be selected at a time. I have run into a weird error where I init an object using [[ajdSwitchButton alloc] init]. In the init I set a class property as follows self.currentSelection = 2.

The issue is that between the init and the first call to an IBAction method, the value is changed to 0. I cannot figure out why. Here is the relevant code:

ajdSwitchButton.h

#import <UIKit/UIKit.h>

@interface ajdSwitchButton : UIView

@property (nonatomic) NSInteger currentSelection;

// Button Outlets
@property (nonatomic, strong) IBOutlet UIButton *buttonOne;
@property (nonatomic, strong) IBOutlet UIButton *buttonTwo;

// Button Actions
- (IBAction)buttonPress:(id)sender;
- (IBAction)buttonPressTwo:(id)sender;

// Instance Methods
- (void)switchButtonState:(UIButton *)button;

@end

ajdSwitchButton.m

#import "ajdSwitchButton.h"

@implementation ajdSwitchButton

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        _currentSelection = 2;
    }
    return self;
}

// Handles button press actions for buttonOne
- (IBAction)buttonPress:(id)sender {
    NSLog(@"%@", self);
    // Y button pressed
    if (self.currentSelection == 2) {
        // No button is selected
        // Highlight and select buttonOne
        [self performSelector:@selector(switchButtonState:) withObject:self.buttonOne afterDelay:0.0];
    } else if (self.currentSelection == 1) {
        // No was previously selected
        // Unselect NO and select YES
        [self performSelector:@selector(switchButtonState:) withObject:self.buttonTwo afterDelay:0.0];
        [self performSelector:@selector(switchButtonState:) withObject:self.buttonOne afterDelay:0.0];
    } else {
    // Y button already pressed
    [self performSelector:@selector(switchButtonState:) withObject:self.buttonOne afterDelay:0.0];
    }
    self.currentSelection = 0;
}

- (IBAction)buttonPressTwo:(id)sender {
    // N button pressed
    NSLog(@"%i", self.currentSelection);
    if (self.currentSelection == 2) {
        // No button is selected
        // Highlight and select buttonOne
    [self performSelector:@selector(switchButtonState:) withObject:self.buttonTwo afterDelay:0.0];
} else if (self.currentSelection == 0) {
        // Yes was previously selected
        // Unselect YES and select NO
        [self performSelector:@selector(switchButtonState:) withObject:self.buttonTwo afterDelay:0.0];
        [self performSelector:@selector(switchButtonState:) withObject:self.buttonOne afterDelay:0.0];
    } else {
        // N button already pressed
        [self performSelector:@selector(switchButtonState:) withObject:self.buttonTwo afterDelay:0.0];
    }
    self.currentSelection = 1;
}

// Switches the look and state of the button
- (void)switchButtonState:(UIButton *)button {
    if (!button.selected) {
        button.highlighted = YES;
        button.selected = YES;
    } else {
        button.highlighted = NO;
        button.selected = NO;
    }
}
@end

I link an instance of ajdSwitchButton to an IBOutlet view within ViewController. Any help would be greatly appreciated.

EDIT: I pasted some NSLogs to check the memory value of the object directly after the init and as soon as the IBAction method is called. Here is the before and after:

<ajdSwitchButton: 0x746d2e0; frame = (0 0; 0 0); layer = <CALayer: 0x7472c40>>

<ajdSwitchButton: 0x7471b10; frame = (77 232; 180 83); autoresize = TM+BM; layer = <CALayer: 0x7471bf0>>

Answer 1

IBOutlets init through initWithCoder:(NSCoder)aDecoder, so you need to implement this method.

- (id)initWithCoder:(NSCoder *)aDecoder
{
    self = [super initWithCoder:aDecoder];
    if (self) {
        // Initialization code
        _currentSelection = 2;
    }
    return self;
}