title: Adding UIImage's as "Tick Marks" to UISlider
body: <p>To sum up my question beforehand: I'm trying to determine where on the slider I can place the image based upon knowing only the UISlider's duration, and having an array of times to loop through, placing the images accordingly.</p>
  
  <p>I've been reading through the Apple Docs on UISlider, and it appears that there is no native way to add "Tick marks" on a UISlider based upon an array of floats. "Tick marks" meaning lines upon a slider, such as those used to place advertisements on scrubbers. Here is a visualization:
  <img src="https://i.stack.imgur.com/z2PHq.png" alt="enter image description here"></p>
  
  <p>Now, I have an array full of floats; Floats in which I will use to drop the tick marks based upon the UISlider's value. The values of the floats in the array will be different every time. I would like to loop through the .value property of my UISlider, dropping the UIImages accordingly. The UIImage's are the tick marks that are just little png's assets I created. What I cannot figure out is the logic behind looping through the .value property of the UISlider and placing the UIImage in accordance with the UISlider's future position. The values of the floats in the array will be different every time, so I can't place them statically. Does anyone know where to start? I'm still a little new to Objective-C programming. </p>
  
  <p>I know that it may be possible utilize retrieving the slider's beginning X coordinate on the screen, like so:</p>
  
  <pre><code>- (float)xPositionFromSliderValue:(UISlider *)aSlider;
  {
      float sliderRange = aSlider.frame.size.width - aSlider.currentThumbImage.size.width;
      float sliderOrigin = aSlider.frame.origin.x + (aSlider.currentThumbImage.size.width / 2.0);
  
      float sliderValueToPixels = (((aSlider.value-aSlider.minimumValue)/(aSlider.maximumValue-aSlider.minimumValu‌​e)) * sliderRange) + sliderOrigin);
  
      return sliderValueToPixels;
  }
  </code></pre>
  
  <p>Maybe I could add in a calculation in the for loop to place the image in accordance to that instead. I'm just not too sure where even to begin here... </p>