title: Catch pinch-zoom in browser
body: <p>I have a web application that is basically a canvas you can draw on. I'm handling the drawing - either by mouse or by single finger touch - and it's working well.</p>
  
  <p>The canvas is larger than the screen, and I need to implement my own zooming mechanism (because I only want to zoom the canvas, not the entire screen). I've added a handler to the <code>wheel</code> event, and I process Control-Wheels properly. Now I need to handle pinch-zooms.</p>
  
  <p>My canvas as a <code>track-action: pinch-zoom</code> CSS settings. This enables two finger swipes for scrolling, which is excellent. I want to let the browser handle pinch-zooms, too, but I want to handle the zooming logic myself (like I do with the mouse wheel).</p>
  
  <p>Is there any way to catch the pinch-zoom event and override the zooming behavior?</p>
  
  <p>I'm using Chrome on Android, but this technique should also work with Safari on iOS.</p>