title: Flutter - Paste text over other text already written in a TextField
body: <p>I have a program that copies and pastes text in flutter, the problem is that when I copy the text and paste it, it replaces the one that was previously written, in this case I want to write over the text already written before and that it is pasted with a space, like a normal copy and paste.
  I hope your help, thank you.</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>TextEditingController textEditingController;
  String paste = '';
  
  _textField() {
      return SliverToBoxAdapter(
        child: Padding(
          padding: EdgeInsets.all(30.0),
          child: TextFormField(
           
            controller: textEditingController,
          
          ),
        ),
      );
    }
  
  _buttons() {
      return SliverToBoxAdapter(
        child: Column(
          children: [
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: &lt;Widget&gt;[
                IconButton(
                  icon: Icon(Icons.content_copy),
                  onPressed: () async {
                    await FlutterClipboard.copy(textEditingController.text);
  
                    Scaffold.of(context).showSnackBar(
                      SnackBar(content: Text('✓   Copied to Clipboard')),
                    );
                  },
                ),
                IconButton(
                  icon: Icon(Icons.paste),
                  onPressed: () async {
                    final value = await FlutterClipboard.paste();
  
                    setState(() {
                      this.paste = value;
                    });
                  },
                )
              ],
            ),
            SizedBox(
              height: 20,
            ),
            Text(
              'Clipboard Text',
              style: TextStyle(fontSize: 20),
            )
          ],
        ),
      );
    }</code></pre>
  </div>
  </div>
  </p>