How to remove or increase selected decoration in NavigationBar

How can I remove or increase the decoration of the selected item in the NavigationBar in flutter?

NavigationBar(
        elevation: 0,
        selectedIndex: navIndex,
        onDestinationSelected: (index) => setState(() {
          navIndex = index;
        }),
        backgroundColor: Colors.transparent,
        labelBehavior: NavigationDestinationLabelBehavior.alwaysHide,
        destinations: const [
          NavigationDestination(
            icon: Text('Your subscriptions'),
            label: '',
          ),
          NavigationDestination(
            icon: Text('Upcoming bills'),
            label: '',
          ),
        ],
      ),

image of decoration

Typically, the NavigationDestination icon has to be an Icon() widget. But in your case, it's text. That's why the text exceeds the highlighted area.

NavigationDestination(
        icon: <This has to be a Icon>
        label: '',
),

Icon will use 'NavigationBarThemeData.iconTheme' , if 'NavigationBarThemeData' not present , icon will use 'IconThemeData'. In both cases, I couldn't find a way to change the size of the highlighted area.

You could do something like this, it will do the job but not that smooth.

  int _selectedIndex = 0; // local variable



      NavigationDestination(
        icon: Container(
            decoration: BoxDecoration(
                borderRadius: BorderRadius.all(Radius.circular(20)),
                color: _selectedIndex == 0 ? Colors.blue.shade100 : Colors.transparent,
                shape: BoxShape.rectangle),
            child: Padding(
              padding: const EdgeInsets.all(16.0),
              child: Text('Your subscriptions'),
            )),
        label: 'Your subscriptions',
      ),