title: Add image to list Flutter
body: <p>I would like to do something like this. First there is a  button in the <code>listView</code>. When the  button is clicked, it will allow user to select image from gallery. </p>
  
  <p><a href="https://i.stack.imgur.com/pm1CQ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/pm1CQ.png" alt="enter image description here"></a></p>
  
  <p>After select, the selected image will be placed to <code>ListView</code>, and the  button will moved to another item like image below.</p>
  
  <p><a href="https://i.stack.imgur.com/FChq4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FChq4.png" alt="enter image description here"></a></p>
  
  <p>This is my output.</p>
  
  <p>Before</p>
  
  <p><a href="https://i.stack.imgur.com/bfGdb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/bfGdb.png" alt="enter image description here"></a></p>
  
  <p>After</p>
  
  <p><a href="https://i.stack.imgur.com/XwzhP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XwzhP.png" alt="enter image description here"></a></p>
  
  <p>My code</p>
  
  <pre><code> Container(
                    child: StreamBuilder&lt;List&lt;Asset&gt;&gt;(
                        stream: _bloc.uploadImageStream,
                        builder: (context, snapshot) {
                          if (snapshot.hasData) {
                            return Column(
                              mainAxisAlignment: MainAxisAlignment.center,
                              crossAxisAlignment: CrossAxisAlignment.center,
                              children: &lt;Widget&gt;[
                                images == null
                                    ? new Container(
                                        height: 300.0,
                                        width: 300.0,
                                        child: new Icon(
                                          Icons.image,
                                          size: 250.0,
                                          color: Theme.of(context).primaryColor,
                                        ),
                                      )
                                    : new SizedBox(
                                        height: 200.0,
                                        width: double.infinity,
                                        child: new ListView.builder(
                                          scrollDirection: Axis.horizontal,
                                          itemCount: snapshot.data.length,
                                          itemBuilder: (BuildContext context,
                                                  int index) =&gt;
                                              new Padding(
                                                  padding:
                                                      const EdgeInsets.all(5.0),
                                                  child: AssetThumb(
                                                    height: 200,
                                                    width: 200,
                                                    asset: snapshot.data[index],
                                                  )),
                                        ),
                                      ),
                                IconButton(
                                    icon: Center(
                                      child: Icon(
                                        Icons.camera,
                                        size: 30.0,
                                      ),
                                    ),
                                    onPressed: () {
                                      _bloc.getImage();
                                    })
                              ],
                            );
                          } else {
                            return IconButton(
                                icon: Center(
                                  child: Icon(
                                    Icons.camera,
                                    size: 30.0,
                                  ),
                                ),
                                onPressed: () {
                                  _bloc.getImage();
                                });
                          }
                        }))
  </code></pre>