Remove Padding on CupertinoSliverNavigationBar

Issue

I am trying to use CupertinoSliverNavigationBar, actually it’s great, but for some reason I can’t place the trailing right on the end of navigation bar. I looked up and I (guess, I) found that there’s Padding inside it

this is my code

   new CupertinoPageScaffold(
        child: new CustomScrollView(
          slivers: <Widget>[
            new CupertinoSliverNavigationBar(
              largeTitle: new Text('Tasks'),
              trailing: new CupertinoButton(
                child: new Icon(AdditionalCupertinoIcons.compose, size: 32.0),
                onPressed: () {
                  showDialog(
                      context: context,
                      builder: (BuildContext context) {
                        return new CupertinoAlertDialog();
                      });
                },
                padding: EdgeInsets.all(0.0),
              ),
            )
          ],
        ),
      ),

Solution

Sadly, no can-do.

Looking at this line of source code, you can see that they are using a Padding at the end, which is _kNavBarEdgePadding, i.e. 16.0. Same for the start.

This means that with the CupertinoSliverNavigationBar you will not be able to remove that Padding because there is no access point to change it. You will have to create your own widget for that.

The _CupertinoPersistentNavigationBar widget contains the Padding and is used by CupertinoSliverNavigationBar, as can be seen here and for completion here.

Answered By – creativecreatorormaybenot

Answer Checked By – Gilberto Lyons (FlutterFixes Admin)