Lint that helps users realize that `&` is often the best way to create rectangles.

[jacob314]

This lint is for users of the Flutter framework to help them discover that the & operator often provides a cleaner way to define rectangles..

Examples

Rect.fromLTWH(offset.dx, offset.dy, size.width, size.height)

Should generate a lint hint that you should write

offset & size

instead.

Additional context It is hard for users to discover that the & operator is often the right way to create a Rect instance. Autocomplete in Dart doesn't suggest operators and for autocomplete to ever help in this case, users would need to know to start with the offset. What we want is some way to suggest a lint or autocomplete style hint whenever a user creates a Rectangle that could be more easily created with & that they should.

[a14n]

You can also +1 dart-lang/sdk#32174 :)

[dnfield]

This might be unfortunate in the case where the Rect could have been const, but operators won't allow that.

For example:

const Rect rect = Rect.fromLTWH(offset.dx, offset.dy, size.dx, size.dy);

Is valid if offset and size are const, but

const Rect rect = offset & size;

Is not valid.

[jacob314]

I can't reproduce that case.

const Offset offset = Offset(3.0, 4.0);
const Size size = Size(4.0, 5.0);
const Rect rect = Rect.fromLTWH(offset.dx, offset.dy, size.width, size.height);

Fails with the error: "error: Arguments of a constant creation must be constant expressions. (const_with_non_constant_argument at...."

[dnfield]

Yeah, I edited it to fix - you have to use the .dx and .dy properties, since width and height are getters.

[jacob314]

Do you mean ._dx and .dy for size? ._dx and ._dy are private on the size object so I'm not clear how those can be used unless your code is in package:flutter

[dnfield]

Ahh ok - I guess this is impossible then. I don't know why I thought I had done it.