title: multiple bitmaps versus drawables - performance and memory impact
body: <p>As you can see on the screenshot, I'm showing thumbnails in the ListView on the left side. Those thumbs are generated asynchronously. Anyway, the result for each row/item is a new Bitmap. </p>
  
  <p><img src="https://i.stack.imgur.com/uB9YO.jpg" alt="climbing wall management"></p>
  
  <p>But I wonder if that's the best practise. This is because very often the background image (the climbing wall) is the same. Therefore I could generate a LayeredDrawable consisting of the background bitmap - which is the same for each row - and an own implementation of a Drawable which then draws the climbing route in its draw(Canvas) method.</p>
  
  <p>Option 1: generate a new bitmap for each row/item.</p>
  
  <p>Option 2: use a LayeredDrawable with the background bitmap and a dynamic Drawable.</p>
  
  <p>Which option is best in terms of memory and CPU usage?</p>