title: UIbutton stretch when clicked unexpectively
body: <p>I am trying to modify a frame work and have encountered the following problem. </p>
  
  <p>I have replaced one of the button image in the framework's xib file with my own one. The image itself is approximately 20Wx20H but I have set the button size to be 40Wx40H so that the clickable area is larger than the actual image. </p>
  
  <p>When the VC is displayed, I see the image to be normal 20x20 aspect ratio. However, when I clicked on the button, it stretches to 40x20 and goes back to default upon release. I was wondering if there is a UIButton parameter that I can disable which was enabled by the framework somewhere? I have done a search on the buttons in the code and could not find anything relating to stretching the button. So I am guessing somewhere in IB there is my solution?</p>
  
  <p>Below are the images for the button when touch down or not touched down. </p>
  
  <p><a href="https://i.stack.imgur.com/cgMvl.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/cgMvl.jpg" alt="button"></a></p>