title: Flutter sliding container into another container to show or hide some icons like with toolbar
body: <p>in container you suppose i have <code>AppBar()</code> witch that i want to have another invisible container, like with this screen shot:</p>
  
  <p><a href="https://i.stack.imgur.com/IRa9l.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/IRa9l.png" alt="enter image description here"></a></p>
  
  <p>in that two other container are invisible and i want to show them by sliding from top to bottom or bottom to top for change visibility on visible or invisible</p>
  
  <p><strong>sliding from top to bottom to show or sliding that to top to hide</strong></p>
  
  <p><a href="https://i.stack.imgur.com/zKo36.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zKo36.png" alt="enter image description here"></a></p>
  
  <p><strong>sliding from bottom to top to show or sliding that to bottom to hide</strong></p>
  
  <p><a href="https://i.stack.imgur.com/DW4oo.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DW4oo.png" alt="enter image description here"></a></p>
  
  <p>is any library to implementing this sliding animation?</p>