title: How to center flutter text with other widgets in row
body: <p>I created a row with a BackButton and a TextWidget.
  I want to center the text to the middle of the screen. Actually flutter centeres the text to the containers width, but the containers width isnt the same as the screen width, because there is the backbutton. How do i fix that?</p>
  
  <pre><code>  Expanded getTitle() {
      return new Expanded(
          child: new Text("Einloggen", style: new TextStyle(fontSize: 18.0), textAlign: TextAlign.center)
      );
    }
  
    BackButton getBackButton() {
      return new BackButton(
  
      );
    }
  
    Row getHeader() {
      return new Row(
        children: &lt;Widget&gt;[
          getBackButton(),
          getTitle()
        ],
      );
    }
    @override
    Widget build(BuildContext context) {
      final double statusBarHeight = MediaQuery.of(context).padding.top;
      return new Material(
        child: new Container(
          padding: new EdgeInsets.fromLTRB(0.0, statusBarHeight, 0.0, 0.0),
          child: new Column(
            children: &lt;Widget&gt;[
              getHeader()
            ],
          ),
        ),
      );
    }
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/Tou8y.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Tou8y.png" alt="enter image description here"></a></p>