How to remove empty spaces generated by grid view - flutter

Question

I want to apply categorise selection for my flutter app. I'm a beginner in flutter. I've tried to my very best to get here but I don't know how to remove these empty spaces.
In the body of the homescreen.dart I've written the following code.
Expanded(
child: Padding(
padding: const EdgeInsets.symmetric(horizontal: KDefaultPadding),
child: GridView.builder(
itemCount: products.length,
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 2,
childAspectRatio: 0.75,
mainAxisSpacing: KDefaultPadding,
crossAxisSpacing: KDefaultPadding,
),
itemBuilder: (context, index) => ItemCard(
product:
products[index].tag == "chicken" ? products[index] : null,
press: () => Navigator.push(
context,
MaterialPageRoute(
builder: (context) => DetailScreen(
product: products[index],
),
),
),
),
),
),
),
and in the item card.dart I've written the following.
class ItemCard extends StatelessWidget {
final Product product;
final Function press;
const ItemCard({
Key key,
this.product,
this.press,
}) : super(key: key);
#override
Widget build(BuildContext context) {
if (product != null) {
return GestureDetector(
onTap: press,
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Container(
padding: EdgeInsets.all(KDefaultPadding),
// height: 180,
// width: 160,
decoration: BoxDecoration(
color: product.color,
borderRadius: BorderRadius.circular(16),
),
child: Hero(
tag: "${product.id}",
child: Image.asset(
product.image,
)),
),
Padding(
padding:
const EdgeInsets.symmetric(vertical: KDefaultPadding / 4),
child: Text(
product.title,
style:
TextStyle(color: kTextColor, fontWeight: FontWeight.bold),
),
),
Text(
"$kCurrency${product.price}",
style: TextStyle(
color: kTextLightColor, fontWeight: FontWeight.bold),
)
],
),
);
} else {
return Container();
}
}
}
and the output I got is this.
initial is this...
Can someone help me out please?

Answer 1

Change this products.length to products.where((product) => product.tag == 'chicken').length to do not put unexpected product into GridView.