title: Canvas within a scrollable browser window (grab position)
body: <p>I have an issue when drawing in a canvas within a browser window that has a vertical scrollbar.</p>
  
  <p>The figures is at the correct position, and is possible to grab it around the canvas and make the connections, but this is only possible with the vertical scrollbar (of the browser window) fully up.</p>
  
  <p>When the window is scrolled down, the nodes can't be dragged any more, and even the cursor doest change when its hovering the node.
  I figured out that its possible to drag the node when scrolled down. Somehow, the "grabbing area" of the node doesn't change its position, as if this area had a fixed position according to the browser window.</p>
  
  <p>What I'm doing wrong?</p>
  
  <p>obs.: Cant post images :(, I don't have enough reputation.</p>
  
  <p>Thanks in advance!</p>