title: Flutter/dart capture entire partially OFFSCREEN widget as image
body: <p>Some comments on <a href="https://stackoverflow.com/a/50351442/6047611">this answer</a> suggest that it is possible to capture every pixel of a widget, even if it is partially offscreen. Comments in <a href="https://stackoverflow.com/a/51118092/6047611">this answer</a> suggest the opposite. I haven't been able to figure it out, I've only started messing with it today. Here's the code I have so far:</p>
  
  <pre><code>RenderRepaintBoundary boundary = globalKey.currentContext.findRenderObject();
  ui.Image image = await boundary.toImage();
  ByteData byteData = await image.toByteData(format: ui.ImageByteFormat.png);
  Uint8List pngBytes = byteData.buffer.asUint8List();
  </code></pre>
  
  <p>Anyone know how to modify this so it will capture the full widget? Or does this only work with the portions of the widget that are on-screen?</p>