Open Radar

 
Summary:
The default UISlider element can jump when you touch the thumb knob. This is most noticeable when the thumb knob is all the way at the max value. There is a workaround, which is not desired. The workaround includes using a custom thumb image and setting it like: 

`slider.setThumbImage(UIImage(named: "thumb"), forState: .Normal)`

I’ve included a sample project that demonstrates the broken functionality and a workaround. 

Steps to Reproduce:
1. Run sample project
2. Slide top slider to the max value
3. Touch down (or click in simulator) on the top slider thumb knob. 

Expected Results:
The expected result is that the thumb/slider value shouldn’t jump when tapped/clicked. 

Actual Results:
The thumb knob jumps noticeably to the left. 

Regression:
Describe circumstances where the problem occurs or does not occur, such as software versions and/or hardware configurations.

Notes:
There is a workaround. You can set your own thumb image. This is not optimal since not everyone should have to create their own thumb image for UISliders in order to get the correct functionality out of the UISlider control.