showToolbar method

void showToolbar ()

Shows the toolbar by inserting it into the context's overlay.

Implementation 

void showToolbar() {
  assert(_toolbar == null);
  _toolbar = OverlayEntry(builder: _buildToolbar);
  Overlay.of(context, debugRequiredFor: debugRequiredFor).insert(_toolbar);
  _toolbarController.forward(from: 0.0);
}