prefer_transform_over_container

v0.4.0 Warning Fix Widget Replacement

Flags Container widgets that only use the transform parameter (plus optional key and child). When Container is used solely for a transform, the Transform widget is a lighter, more descriptive alternative.

Why use this rule

Container is a convenience widget that composes many lower-level widgets internally. When you only need a matrix transform, using Transform directly avoids the overhead and clearly communicates your intent. It also gives you access to Transform’s named constructors like Transform.rotate and Transform.scale.

See also: Transform | Container

Don’t

// Container with only transform parameter
Container(
  transform: Matrix4.skewY(0.3)..rotateZ(-math.pi / 12.0),
  child: const Text('Skewed'),
);

// Container with only transform and key
Container(
  key: const ValueKey('rotated'),
  transform: Matrix4.rotationZ(math.pi / 4),
  child: const Text('Rotated'),
);

Do

// Use Transform directly
Transform(
  transform: Matrix4.skewY(0.3)..rotateZ(-math.pi / 12.0),
  child: const Text('Skewed'),
);

// Container with transform and other parameters is fine
Container(
  transform: Matrix4.rotationZ(math.pi / 4),
  alignment: Alignment.topRight,
  child: const Text('Rotated with alignment'),
);

Configuration

To disable this rule:

plugins:
  many_lints:
    diagnostics:
      prefer_transform_over_container: false