title: How to open DropdownButton when other widget is tapped, in Flutter?
body: <p>I need to have a <code>DropdownButton</code>'s list of options open/show programmatically when some other widget is tapped. I know that this may not be UI-best-practice and all, but I need this behavior:</p>
  
  <p>As an example, in a structure like the one below, I may need to have taping <code>Text("every")</code> to open the neighboring <code>DropdownButton</code>'s dropdown list, behaviors similar to clicking a <code>&lt;select&gt;</code>'s label in HTML.</p>
  
  <pre class="lang-dart prettyprint-override"><code>Row(children: [
    Padding(
      padding: const EdgeInsets.only(right: 16),
      child: Text('every'),
    ),
    Expanded(
      child: DropdownButton&lt;String&gt;(
        value: _data['every'],
        onChanged: (String val) =&gt; setState(() =&gt; _data['every'] = val),
        items: _every_options.map&lt;DropdownMenuItem&lt;String&gt;&gt;(
          (String value) {
            return DropdownMenuItem&lt;String&gt;(
              value: value,
              child: Text(value),
            );
          },
        ).toList(),
        isExpanded: true,
      ),
    ),
  ]);
  </code></pre>
  
  <p><strong>NOTE:</strong> I am in need though of the <em>general solution to this problem</em>, not just how to make that <code>Text</code> behave somewhat "like a HTML label" in the tree below. It may need to be triggered to open by maybe a further away button etc.</p>