avoid-incorrect-image-opacity

Group: Correctness
Path: lint/correctness/avoid-incorrect-image-opacity
Default: Off, opt in
Origin: Falcon
Domain: flutter
Rule: 73 of 512

flutter

Flags Opacity directly wrapping a Flutter Image, including named constructors. Prefer Image.opacity (or image color blending) to compositing the whole widget.

Invalid

example.dartdart

import 'package:flutter/widgets.dart';
import 'package:flutter/widgets.dart' as f;
typedef I = Image;
void callback() {}
void examples(Widget child, dynamic image, dynamic color, double size, String label) {
  Opacity(opacity: .5, child: Image(image: image));
  Opacity(opacity: .2, child: Image.asset("a"));
  const Opacity(opacity: .5, child: Image());
  f.Opacity(opacity: .5, child: f.Image.network("a"));
  new Opacity(opacity: .5, child: I.asset("a"));
}

Apply opacity directly to the Image instead of wrapping it in Opacity.

5void examples(Widget child, dynamic image, dynamic color, double size, String label) {

6 Opacity(opacity: .5, child: Image(image: image));

∙

Apply opacity directly to the Image instead of wrapping it in Opacity.

6 Opacity(opacity: .5, child: Image(image: image));

7 Opacity(opacity: .2, child: Image.asset("a"));

∙

Apply opacity directly to the Image instead of wrapping it in Opacity.

7 Opacity(opacity: .2, child: Image.asset("a"));

8 const Opacity(opacity: .5, child: Image());

∙

Apply opacity directly to the Image instead of wrapping it in Opacity.

8 const Opacity(opacity: .5, child: Image());

9 f.Opacity(opacity: .5, child: f.Image.network("a"));

∙

Apply opacity directly to the Image instead of wrapping it in Opacity.

9 f.Opacity(opacity: .5, child: f.Image.network("a"));

10 new Opacity(opacity: .5, child: I.asset("a"));

∙

Valid

example.dartdart

import 'package:flutter/widgets.dart';
import 'package:flutter/widgets.dart' as f;
typedef I = Image;
void callback() {}
void examples(Widget child, dynamic image, dynamic color, double size, String label) {
  Opacity(opacity: .5, child: SizedBox());
  Image(image: image, opacity: image);
  Opacity(opacity: .5);
  Opacity(opacity: .5, child: Container(child: Image()));
  Opacity(opacity: .5, child: child);
}

Configure avoid-incorrect-image-opacity

Set its severity in falcon.json. See the configuration guide.

falcon.jsonjson

{
  "linter": {
    "rules": {
      "correctness": {
        "avoid-incorrect-image-opacity": "error"
      }
    }
  }
}

Or silence one occurrence with a suppression comment; the reason is required.

example.dartdart

// falcon-ignore lint/correctness/avoid-incorrect-image-opacity: <reason>

avoid-inherited-widget-in-initstaterecommendedflutter
Avoid inherited-widget subscriptions during initState.
avoid-instantiating-in-value-providerprovider
Value providers borrow existing instances; newly constructed values need create.
avoid-late-contextrecommendedflutter
Avoid storing BuildContext in late fields or reading it in late initializers.
avoid-missing-completer-stack-trace
Preserve error origins when calling SDK Completer.completeError.
avoid-missing-controllerflutter
Require Flutter text fields to expose their updated value.
avoid-missing-enum-constant-in-map
Require enum-keyed map literals to include every declared enum value.
avoid-missing-interpolationrecommended
Flags missing interpolation around visible String variables or member accesses and calls.
avoid-misused-hooksrecommendedflutter_hooks
Flags confirmed Flutter hooks called directly in non-hook Flutter widget builds.

Invalid

Valid

Configure avoid-incorrect-image-opacity

More correctness rules