title: Flutter - how to populate GridView items in columns, not in rows
body: <p>Currently this is order in which items are added to the <code>GridView.builder</code>:</p>
  
  <p><a href="https://i.stack.imgur.com/3zUTY.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3zUTY.jpg" alt="current behaviour"></a></p>
  
  <p>My question is -- how to make them added in <strong>this</strong> order?</p>
  
  <p><a href="https://i.stack.imgur.com/gp32i.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/gp32i.png" alt="desired behaviour"></a></p>
  
  <p>GridView's scroll direction must remain vertical.</p>
  
  <p>Here's example of <code>GridView</code> I'm using:</p>
  
  <pre><code>Widget gridViewBuilder () {
    return GridView.builder(
       gridDelegate: 
          new SliverGridDelegateWithFixedCrossAxisCount(
            crossAxisCount: 2,
            mainAxisSpacing: 1,
          ),
         itemCount: 3,
         itemBuilder: (BuildContext context, int i) {
            itemForGridview(i, context);
    );
  }
  </code></pre>