title: Creating a custom progress bar with images
body: <p>Pretty much what I am trying to do, is create the following image:
  <img src="https://i.stack.imgur.com/iAijM.png" alt="enter image description here"></p>
  
  <p>So this is a progress bar, which will show how many votes the client get in that option. How can I do that? I was wondering if I can use a mask (as I would in flex), but all the masking implementations that I found on the web are doing masks for <code>UIImage</code>s, and not for <code>UIImageView</code>. I cannot do the mask in the <code>UIImage</code>, because the two images have the same dimensions. I have to use the X and Y of the images to crop them?! So, any suggestions?</p>
  
  <p>Here are the two images that I have to create that progress bar:</p>
  
  <p><img src="https://i.stack.imgur.com/5Ocv5.png" alt="enter image description here">
  <img src="https://i.stack.imgur.com/8OC0s.png" alt="enter image description here"></p>
  
  <p>Cheers.</p>