title: How to take screenshot of widget beyond the screen in flutter?
body: <p>I am using <strong>RepaintBoundary</strong> to take the screenshot of the current widget which is a <strong>listView</strong>. But it only captures the content which is visible on the screen at the time.</p>
  
  <pre><code>RepaintBoundary(
                  key: src,
                  child: ListView(padding: EdgeInsets.only(left: 10.0),
                    scrollDirection: Axis.horizontal,
                    children: &lt;Widget&gt;[
                      Align(
                          alignment: Alignment(-0.8, -0.2),
                          child: Column(
                            mainAxisAlignment: MainAxisAlignment.center,
                            children: listLabel(orientation),
                          )
                      ),
  
                      Padding(padding: EdgeInsets.all(5.0)),
  
                      Align(
                          alignment: FractionalOffset(0.3, 0.5),
                          child: Container(
                              height: orientation == Orientation.portrait? 430.0: 430.0*0.7,
                              decoration: BoxDecoration(
                                  border: Border(left: BorderSide(color: Colors.black))
                              ),
                              //width: 300.0,
                              child:
                              Wrap(
                                direction: Axis.vertical,
                                //runSpacing: 10.0,
                                children: colWidget(orientation),
                              )
                          )
                      ),
                      Padding(padding: EdgeInsets.all(5.0)),
                      Column(
                        mainAxisAlignment: MainAxisAlignment.center,
                        children: listLabel(orientation),
                      )
                    ],
                  ),
                );
  </code></pre>
  
  <p>screenshot function:</p>
  
  <pre><code>Future screenshot() async {
      RenderRepaintBoundary boundary = src.currentContext.findRenderObject();
      ui.Image image = await boundary.toImage();
      ByteData byteData = await image.toByteData(format: ui.ImageByteFormat.png);
      Uint8List pngBytes = byteData.buffer.asUint8List();
      print(pngBytes);
      final directory = (await getExternalStorageDirectory()).path;
  File imgFile =new File('$directory/layout2.pdf');
  imgFile.writeAsBytes(pngBytes);
    }
  </code></pre>
  
  <p>Is there any way, so that I can capture the whole listView, i.e., not only the content which is not visible on the screen but the scrollable content also. Or maybe if the whole widget is too large to fit in a picture, it can be captured in multiple images.</p>