How to enable “tap and slide” in a UISlider?

I’m not sure if you are still looking for an answer for this, but I was just looking at this myself today; and I managed to get it to work for me.

The key to it, is using a UILongPressGestureRecognizer instead of just a UITapGestureRecognizer, we can then set the minimumPressDuration of the recognizer to 0; making it act as a tap recognizer, except you can now actually check its state.

Putting what ali59a suggested will work for you, just by replacing the UITapGestureRecognizer with a UILongPressGestureRecognizer. However, I found that this didn’t seem to quite put the thumbRect directly under my thumb. It appeared a bit off to me.

I created my own UISlider subclass for my project, and here is how I implemented the “tap and slide feature” for me.

In my init method:

UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(tapAndSlide:)];
longPress.minimumPressDuration = 0;
[self addGestureRecognizer:longPress];

Then my tapAndSlide: method:

- (void)tapAndSlide:(UILongPressGestureRecognizer*)gesture
{
    CGPoint pt = [gesture locationInView: self];
    CGFloat thumbWidth = [self thumbRect].size.width;
    CGFloat value;

    if(pt.x <= [self thumbRect].size.width/2.0)
        value = self.minimumValue;
    else if(pt.x >= self.bounds.size.width - thumbWidth/2.0)
        value = self.maximumValue;
    else {
        CGFloat percentage = (pt.x - thumbWidth/2.0)/(self.bounds.size.width - thumbWidth);
        CGFloat delta = percentage * (self.maximumValue - self.minimumValue);
        value = self.minimumValue + delta;
    }

    if(gesture.state == UIGestureRecognizerStateBegan){
        [UIView animateWithDuration:0.35 delay:0 options:UIViewAnimationOptionCurveEaseInOut animations:^{
            [self setValue:value animated:YES];
            [super sendActionsForControlEvents:UIControlEventValueChanged];
        } completion:nil];
    }
    else [self setValue:value];

    if(gesture.state == UIGestureRecognizerStateChanged)
        [super sendActionsForControlEvents:UIControlEventValueChanged];
}

Where I also used a method to return the frame of my custom thumbRect:

- (CGRect)thumbRect {
    CGRect trackRect = [self trackRectForBounds:self.bounds];
    return [self thumbRectForBounds:self.bounds trackRect:trackRect value:self.value];
}

I also have my slider animate to the position where the user first taps, over 0.35 seconds. Which I reckon looks pretty sweet, so I included that in that code.
If you don’t want that, simply try this:

- (void)tapAndSlide:(UILongPressGestureRecognizer*)gesture
{
    CGPoint pt = [gesture locationInView: self];
    CGFloat thumbWidth = [self thumbRect].size.width;
    CGFloat value;

    if(pt.x <= [self thumbRect].size.width/2.0)
        value = self.minimumValue;
    else if(pt.x >= self.bounds.size.width - thumbWidth/2.0)
        value = self.maximumValue;
    else {
        CGFloat percentage = (pt.x - thumbWidth/2.0)/(self.bounds.size.width - thumbWidth);
        CGFloat delta = percentage * (self.maximumValue - self.minimumValue);
        value = self.minimumValue + delta;
    }

    [self setValue:value];

    if(gesture.state == UIGestureRecognizerStateChanged)
        [super sendActionsForControlEvents:UIControlEventValueChanged];
}

I hope that makes sense, and helps you.