Shrink container to smaller child rather than expanding to fill parent

wrapping a Container in a Row() widget makes the container shrinks to the Container's child size as mentioned here,, https://github.com/flutter/flutter/issues/4949

Row(
 mainAxisAlignment: MainAxisAlignment.center,
 crossAxisAlignment: CrossAxisAlignment.center,
   children: [
     Container(
       child:button()   
     ),
   ]
),

To get the container not to take up the entire parent, you need to tell it where it should be placed within the parent - by default, it doesn't know where to go so it fills the parent =D.

The simplest ways of doing this are to use an Align or a Center widget. I believe you want to put it around your Container in this case, but I'm not 100% sure.