UIStepper. Find out whether incremented or decremented

Question

Figuring out whether the plus or minus button was pressed in UIStepper I use this method:

- (void)stepperOneChanged:(UIStepper*)stepperOne

And I compare stepperOne.value with a global value saved in my TableView Class.
I dont think this is the right way.

So to clarify i will show the "bad" code i am using:

- (void)stepperOneChanged:(UIStepper*)stepperOne
{
      BOOL PlusButtonPressed=NO;  
      if(stepperOne.value>globalValue)  
      {   
          PlusButtonPressed =YES;  
      }  
      globalValue=stepperOne.value;

    ////do what you need to do with the PlusButtonPressed boolean
}

So what is the right way to do this? (without having to save global variables)

Answer 1

---

This is simple and shorter way to identify whether "+" clicked Or "-" clicked of UIStepper

---

//First You have to declare oldValue as an int (or long/float/NSInteger etc. etc.) in Header File 
//So that you can access globally to that particular implementation file

- (void)viewDidLoad
{
     [super viewDidLoad];
     oldValue=stepperObj.value;
}

- (IBAction)stepperStep:(id)sender 
{
        if (stepperObj.value>oldValue) {
             oldValue=oldValue+1;
             //Your Code You Wanted To Perform On Increment
        }
       else {
             oldValue=oldValue-1;
             //Your Code You Wanted To Perform On Decrement
        }
}

Answer 2

So I thought about a subclass for this. It turns out to be not so bad (except for wrapped values).

Using the subclass

- (IBAction)stepperOneChanged:(UIStepper*)stepperOne
{
    if (stepperOne.plusMinusState == JLTStepperPlus) {
       // Plus button pressed
    }
    else if (stepperOne.plusMinusState == JLTStepperMinus) {
       // Minus button pressed
    } else {
       // Shouldn't happen unless value is set programmatically.
    }
}

JLTStepper.h

#import <UIKit/UIKit.h>

typedef enum JLTStepperPlusMinusState_ {
    JLTStepperMinus = -1,
    JLTStepperPlus  = 1,
    JLTStepperUnset = 0
} JLTStepperPlusMinusState;

@interface JLTStepper : UIStepper
@property (nonatomic) JLTStepperPlusMinusState plusMinusState;
@end

JLTStepper.m

#import "JLTStepper.h"

@implementation JLTStepper
- (void)setValue:(double)value
{
    BOOL isPlus  = self.value < value;
    BOOL isMinus = self.value > value;

    if (self.wraps) { // Handing wrapped values is tricky
        if (self.value > self.maximumValue - self.stepValue) {
            isPlus  = value < self.minimumValue + self.stepValue;
            isMinus = isMinus && !isPlus;
        } else if (self.value < self.minimumValue + self.stepValue) {
            isMinus = value > self.maximumValue - self.stepValue;
            isPlus  = isPlus && !isMinus;
        }
    }

    if (isPlus)
        self.plusMinusState = JLTStepperPlus;
    else if (isMinus)
        self.plusMinusState = JLTStepperMinus;

    [super setValue:value];
}
@end