Adding addTarget: method to custom UIView

Question

I created a custom UIView something like UIStepper, because I don't like the appearance of the UIStepper. I want UIStepper have a personal count label so I added it to my custom view and created a method to increase-decrease it. Now I need a [customView addTarget:(id) action:(del) forControlEvents:(UIControlEvents)] method to catch UIControlEventValueChanged; but I couldn't find anything about implementing it. I dig around the UIButton.h, UIStepper.h files but no luck too.. Can anyone help me to do that?

Here is how I created the custom view...

CounterView.h

#import <UIKit/UIKit.h>

@interface CounterView : UIView
@property NSString* name;
@property NSInteger count;
@property UILabel *label;
@property NSInteger customTag;

- (id)initWithX:(CGFloat)xPoint WithY:(CGFloat)yPoint WithName:(NSString*)newName withCount:(NSInteger)newCount withCustomTag:(NSInteger)newTag;
@end

CounterView.m

@implementation CounterView

- (id)initWithX:(CGFloat)xPoint WithY:(CGFloat)yPoint WithName:(NSString*)newName withCount:(NSInteger)newCount withCustomTag:(NSInteger)newTag
{
self = [super initWithFrame:CGRectMake(xPoint, yPoint, 24, 52)];
if (self) {
    self.customTag = newTag;
    self.count = newCount;
    self.name = newName;

    UIButton *btnUp = [[UIButton alloc] initWithFrame:CGRectMake(3, 2, 18, 12)];
    [btnUp setImage:[UIImage imageNamed:@"top.png"] forState:UIControlStateNormal];
    [btnUp addTarget:self action:@selector(increaseValue) forControlEvents:UIControlEventTouchUpInside];
    UIButton *btnDown = [[UIButton alloc] initWithFrame:CGRectMake(3, 38, 18, 12)];
    [btnDown setImage:[UIImage imageNamed:@"bottom.png"] forState:UIControlStateNormal];
    [btnDown addTarget:self action:@selector(decreaseValue) forControlEvents:UIControlEventTouchUpInside];
    self.label = [[UILabel alloc] initWithFrame:CGRectMake(0, 14, 24, 24)];
    [self.label setText:[NSString stringWithFormat:@"%ld", (long)self.count]];
    self.label.textAlignment = NSTextAlignmentCenter;

    [self addSubview:btnUp];
    [self addSubview:btnDown];
    [self addSubview:self.label];
}
return self;
}

-(void) increaseValue{
self.count++;
[self.label setText:[NSString stringWithFormat:@"%ld", (long)self.count]];
}
-(void) decreaseValue{
self.count--;
[self.label setText:[NSString stringWithFormat:@"%ld", (long)self.count]];
}
@end

Answer 1

Just allow the actions to be set from outside of your control. Here is how to do it:

@interface CounterView : UIView
...
@property(nonatomic, strong) UIButton *btnUp;
@property(nonatomic, strong) UIButton *btnDown;

- (void)addUpTarget:(id)target action:(SEL)action;
- (void)addDownTarget:(id)target action:(SEL)action;

@end

@implementation CounterView

...

- (void)addUpTarget:(id)target action:(SEL)action
{
    [_btnUp addTarget:target action:action forControlEvents:UIControlEventTouchUpInside];
}

- (void)addDownTarget:(id)target action:(SEL)action
{
    [_btnDonw addTarget:target action:action forControlEvents:UIControlEventTouchUpInside];
}

...

@end

Then use methods:

- (void)addUpTarget:(id)target action:(SEL)action;
- (void)addDonwTarget:(id)target action:(SEL)action;

to set a target and actions for increasing and decreasing the values.

Answer 2

in the ViewController where you instantiate your CounterView you add this

UITapGestureRecognizer *singleFingerTap = 
  [[UITapGestureRecognizer alloc] initWithTarget:self 
                                          action:@selector(handleSingleTap:)];
[yourViewInstantiation addGestureRecognizer:singleFingerTap];
[singleFingerTap release];

and the you implement the call back method:

- (void)handleSingleTap:(UITapGestureRecognizer *)recognizer {
  CGPoint location = [recognizer locationInView:[recognizer.view superview]];

  //Do stuff here...
}

i hope that help you !