use_dedicated_media_query_methods

v0.1.0 Warning Fix Widget Best Practices

This rule flags calls like MediaQuery.of(context).size and suggests using the dedicated aspect methods like MediaQuery.sizeOf(context) instead. The dedicated methods subscribe only to the specific property you need, so your widget does not rebuild when unrelated MediaQuery properties change.

Why use this rule

MediaQuery.of(context) subscribes to the entire MediaQueryData. That means your widget rebuilds whenever any media property changes — orientation, padding, text scale, view insets, and more. If you only need size, using MediaQuery.sizeOf(context) ensures rebuilds happen only when the size actually changes. This is a significant performance win for widgets that appear in frequently-rebuilt subtrees.

See also: MediaQuery

Don’t

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // Subscribes to ALL MediaQuery changes
    final size = MediaQuery.of(context).size;
    final padding = MediaQuery.of(context).padding;
    return SizedBox(width: size.width, height: size.height - padding.top);
  }
}

Do

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // Only rebuilds when size or padding changes
    final size = MediaQuery.sizeOf(context);
    final padding = MediaQuery.paddingOf(context);
    return SizedBox(width: size.width, height: size.height - padding.top);
  }
}

Configuration

This rule is in the recommended preset, so it is on with preset: recommended or preset: opinionated. Add it to preset: core with use_dedicated_media_query_methods: true.

To turn it off:

many_lints.yaml

rules:
  use_dedicated_media_query_methods: false

To keep the rule on but skip certain paths, use per-rule exclude.

Related rules

• always_pass_global_key — Don’t create a GlobalKey inside build.
• avoid_conditional_hooks — Never call hooks inside conditionals, loops, or ternaries.
• avoid_deep_widget_nesting — Keep a widget tree within a nesting budget.
• avoid_flexible_outside_flex — Only use Flexible and Expanded as direct children of Row, Column, or Flex.