Simultaneous Button Press

Question

I am trying to build an app where two buttons need to be pressed simultaneously.

if (self->button1.touchInside && self->button2.touchInside) {
    NSLog(@"Two buttons pressed");
    }
else if (!self->button1.touchInside | !self->button2.touchInside){
    NSLog(@"One button pressed");
    }

Both buttons are attached to the View Controller using the 'Touch Down' gesture option. When I press both buttons at the same time (with one press) the console window prints:

One button pressed
Two buttons pressed

This interferes with how my application works. I only want the console to print

Two buttons pressed

Thanks

Well, there's always going to be a delay from the first button press to the second. You can either add your own timer check and treat two presses within N milliseconds as "simultaneous", or wait for the first "touch up" and see if two buttons were down. — Hot Licks, Jul 25 '14 at 20:40
This may be a duplicate question, please check the following link http://stackoverflow.com/questions/24964104/simultaneous-button-press — jsedano, Jul 25 '14 at 20:54
http://stackoverflow.com/questions/9039115/two-button-simultaneous-press-input?rq=1 — u_ser722345, Jul 25 '14 at 20:56
Again, it is not worth my time look up the messy details of how to do it. You should do some research on your own. — Hot Licks, Jul 25 '14 at 21:32

score 1 · Accepted Answer · answered Jul 26 '14 at 02:21

What i understand is you need to take some action when both the buttons are pressed. Watever you try, there is going to be a lag between the touches of these buttons. A better approach would be to check if press on both buttons is finished. Hope following works for you -

    @property(nonatomic, assign) BOOL firstButtonPressed;

    @property(nonatomic, assign) BOOL secondButtonPressed;

    //in init or viewDidLoad or any view delegates
       _firstButtonPressed = NO;
        _secondButtonPressed = NO;

    //Connect following IBActions to Touch Down events of both buttons
    - (IBAction)firstButtonPressed:(UIButton *)sender {
         _firstButtonPressed = YES;
          [self checkForButtonPress]; 
    }

    - (IBAction)secondButtonPressed:(UIButton *)sender {
         _ secondButtonPressed = YES; 
         [self checkForButtonPress];    
    }

    - (void)checkForButtonPress {
        if (_firstButtonPressed && _secondButtonPressed) {
            NSlog(@"Two buttons pressed");
        }
    }

score 0 · Answer 2 · answered Jul 25 '14 at 20:59

You can do it using two boolean flags like this:

@property(nonatomic, assign) BOOL firstButtonPressed;
@property(nonatomic, assign) BOOL secondButtonPressed;

- (void)firstButtonTouchDown:(id)sender
{
    _firstButtonPressed = YES;

    if (_secondButtonPressed)
    {
        // Both buttons pressed.
    }
}


- (void)secondButtonTouchDown:(id)sender
{
    _secondButtonPressed = YES;

    if (_firstButtonPressed)
    {
        // Both buttons pressed.
    }
}


- (void)firstButtonTouchCancelled:(id)sender
{
    _firstButtonPressed = NO;
}


- (void)secondButtonTouchCancelled:(id)sender
{
    _secondButtonPressed = NO;
}

Alternatively, you can also start a timer when a touch is down and check if the second touch happens during time interval you specify.

Nothing wrong with this, don't see the need for the previous blatant down vote. +1 — Brian Tracy, Jul 26 '14 at 02:29

Simultaneous Button Press

2 Answers2