title: Show CircularProgressIndicator in front in Flutter
body: <p>I want to display a circular bar like loading in front of other widgets. 
  Below is the code which i am currently using. It shows the Circular loading but its between other widget.</p>
  
  <p>It should be on top. Based on the suggestion I tried using Stack but it is still showing in between the widget. What am I doing wrong here?</p>
  
  <pre><code>class LoginPage extends StatefulWidget {
    @override
    _LoginPageState createState() =&gt; _LoginPageState();
  
  }
  
  class _LoginPageState extends State&lt;LoginPage&gt; {
  
   bool visible = true ; //Testing purpose it is true. Actually it is false.    
  @override
  
  Widget build(BuildContext context) {
  
  return Scaffold(
    key: _scaffoldKey,
    body: Stack(
          children: &lt;Widget&gt;[
            new Container(
              decoration: BoxDecoration(
            gradient: LinearGradient(
                begin: Alignment.topRight,
                end: FractionalOffset.bottomCenter,//Alignment.bottomLeft,
  
                colors: [Colors.green[900], Colors.lightBlueAccent]),
          ),
  
            ),SingleChildScrollView(
              child: new Form(
                key: _formKey,
                autovalidate: _autoValidate,
      child: Center(
      child: Column(
        children: &lt;Widget&gt;[
          Row(
                    children: &lt;Widget&gt;[
                      VerticalText(),
                      TextLogin(),                    
                    ],
                  ),
  
  
          Divider(),          
  
          Container(
          width: 280,
  
          ),
          Container(
          width: 280,
          child: TextFormField(
            style: TextStyle(
              color: Colors.white,
            ),
              decoration: InputDecoration(
              border: InputBorder.none,
              hintText: 'Enter Email',
              fillColor: Colors.lightBlueAccent,
              labelText: 'Email',
              labelStyle: TextStyle(
                color: Colors.white70,
                fontSize: 20,
              ),
              ),
              controller: emailController,
              autocorrect: true,
              validator: validateEmail,
              onSaved: (String val) {
                _email = val;
            },
            )
          ),
  
          Container(
          width: 280,
          child: TextFormField(
               style: TextStyle(
              color: Colors.white,
            ),
              decoration: InputDecoration(
              border: InputBorder.none,
              hintText: 'Enter Password',
              fillColor: Colors.lightBlueAccent,
              labelText: 'Password',
              labelStyle: TextStyle(
                color: Colors.white70,
                fontSize: 20,
              ),
              ),
              controller: passwordController,
              autocorrect: true,
              obscureText: true,
              validator: validatePassword,
                onSaved: (String val) {
                  _password = val;
            },
            )
          ),
  
          RaisedButton(
            onPressed: _validateInputs,
            color: Colors.green,
            textColor: Colors.white,
            padding: EdgeInsets.fromLTRB(10, 10, 10, 10),
            child: Text('Login'),
          ),
  
  
          Visibility(
            child: Center(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.center,
              children: &lt;Widget&gt;[
                SizedBox(
                  child: CircularProgressIndicator(
                    strokeWidth: 4.0,
                    valueColor : AlwaysStoppedAnimation(Colors.white),
                  ),
                  height: 200.0,
                  width: 200.0,
                ),
  
              ],
            ),
          ),
            visible: visible, 
        ),
        ],
      ),
    )
              )
    )
          ],
  ),
  );
  }
  </code></pre>
  
  <p>I have seen similar questions in SO but still getting hard time to resolve it.</p>
  
  <p><a href="https://stackoverflow.com/questions/47065098/how-to-work-with-progress-indicator-in-flutter">How to work with progress indicator in flutter?</a></p>
  
  <p><a href="https://stackoverflow.com/questions/48493319/flutter-how-to-get-a-circular-progress-indicator-working">flutter how to get a circular progress indicator working</a></p>
  
  <p><a href="https://stackoverflow.com/questions/58277766/flutter-create-an-overlay-progress-bar">Flutter : create an overlay progress bar</a></p>
  
  <p><a href="https://stackoverflow.com/questions/51952927/how-to-display-circularprogressindicator-on-top-of-all-widget-in-a-centre-of-the">How to display CircularProgressIndicator on top of all widget in a centre of the screen</a></p>