How to detect the drawer is closed on flutter?

Question

As title. It since that we can detect the drawer is opened, but is this possible to check it is closed or not? Thanks.

Answer 1

I have added this feature in Flutter 2.0.0. Make sure you are using Flutter SDK version >= 2.0.0 to use this.

Simply use a callback in Scaffold

return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      drawer: NavDrawer(),
      onDrawerChanged: (isOpen) {
        // write your callback implementation here
        print('drawer callback isOpen=$isOpen');
      },
      endDrawer: NavDrawerEnd(),
      onEndDrawerChanged: (isOpen) {
        // write your callback implementation here
        print('end drawer callback isOpen=$isOpen');
      },
      body:
      ...

Pull request merged in 2.0.0: https://github.com/flutter/flutter/pull/67249

Happy coding!

Answer 2

Declare a GlobalKey to reference your drawer:

GlobalKey _drawerKey = GlobalKey();

Put the key in your Drawer:

 drawer: Drawer(
                  key: _drawerKey,

Check if your drawer is visible:

 final RenderBox box = _drawerKey.currentContext?.findRenderObject();
 if (box != null){
    //is visible
 } else {
   //not visible  
}