UISlider that snaps to a fixed number of steps (like Text Size in the iOS 7 Settings app)

Question

I\'m trying to create a UISlider that lets you choose from an array of numbers. Each slider position should be equidistant and the slider should snap to each po

Answer 1

The answer is essentially the same at this answer to UISlider with increments of 5

To modify it to work for your case, you'll need to create a rounding function that returns only the values you want. For example, you could do something simple (though hacky) like this:

-(int)roundSliderValue:(float)x {
    if (x < -1.5) {
        return -3;
    } else if (x < 1.0) {
        return 0;
    } else if (x < 3.0) {
        return 2;
    } else if (x < 5.5) {
        return 4;
    } else if (x < 8.5) {
        return 7;
    } else if (x < 11.0) {
        return 10;
    } else {
        return 12;
    }
}

Now use the answer from the previous post to round the value.

slider.continuous = YES;
[slider addTarget:self
      action:@selector(valueChanged:) 
      forControlEvents:UIControlEventValueChanged];

Finally, implement the changes:

-(void)valueChanged:(id)slider {
    [slider setValue:[self roundSliderValue:slider.value] animated:NO];
}