How do you swap UIButton positions by swiping and/or dragging?

Question

I'm currently writing a program where I have UIButtons arranged in a square. in a NIB. I swap the buttons by taping one one then another using "Touch Up Inside" events.

I want to make them swap by swiping one in the direction of another and by dragging one on top of another. I haven't been able to figure out how to do this. Ive been looking in the Apple documentation for weeks but I really don't know how to make sense of it.

Can someone tell me what I need to dd to my code to do this?

Here is my code:

#import "squareViewController.h"
static UIButton *matrix[2][2];
static int firstButtonRow, firstButtonColumn, secondButtonRow, secondButtonColumn; 
static BOOL isFirstTouch = YES;
static  CGPoint gestureStartPoint;
@implementation squareViewController
@synthesize diamond;
@synthesize heart;
@synthesize spade;
@synthesize club;

- (void)viewDidLoad {


 matrix[0][0] = [diamond retain]; 
 matrix[0][1] = [heart retain]; 
 matrix[1][0] = [spade retain]; 
 matrix[1][1] = [club retain]; 

} 

- (void)ButtonTapped:(id)sender{
 int row = 0, column = 0; 
 for(row = 0; row < 2; row++){
  for(column = 0; column < 2; column++){
   if (matrix[row][column] == sender){ 
    if (isFirstTouch == YES){ 
     firstButtonRow = row; 
     firstButtonColumn = column; 
     isFirstTouch = NO;  
     return; 

    }
    else{
     secondButtonRow = row; 
     secondButtonColumn = column; 
     [self SwapButtons: firstButtonRow: 
     firstButtonColumn: 
       secondButtonRow: 
      secondButtonColumn]; 
     isFirstTouch = YES;  
     return; 



    }
   } 

  }
 }
}

- (void)ButtonSwiped:(id)sender {

 // ?????

}

- (void)ButtonDragged:(id)sender {

 // ?????

}

- (void)SwapButtons:(int)firstRow: (int)firstColumn: (int)secondRow: (int)secondColumn{
 UIButton *tempButton = [[[UIButton alloc] init] retain]; // allocate memory for tempButton
 UIButton *tempButtonOrig = tempButton;  // mirror tempButton to preserve adderess for release; 
 [UIView beginAnimations:@"main" context:nil];  
 tempButton.frame = matrix[firstRow][firstColumn].frame;
 matrix[firstRow][firstColumn].frame 
 = matrix[secondRow][secondColumn].frame;  
 matrix[secondRow][secondColumn].frame = tempButton.frame;  
 tempButton = matrix[firstRow][firstColumn];  
 matrix[firstRow][firstColumn] 
 = matrix[secondRow][secondColumn];  
 matrix[secondRow][secondColumn] = tempButton;  
 [tempButtonOrig release];   
 [UIView setAnimationDelegate:self]; 
 [UIView commitAnimations];   
}

Answer 1

Gestures like swipe and drag aren't handled for you; you pretty much have to do the work yourself. In my app, I've made a UIView subclass to do this. You'll want to override the following:

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

A few random tutorials on the subject here and here.