FadeInImage works unexpectedly #94540
Description
When changing the image while the app is running, FadeInImage seems to work unexpectedly.
Steps to Reproduce:
Run the sample code (tested on Android and Linux, master and stable branches).
- A blue box appears, shortly later, it fades out and image 1 (mountains) fades in.
- Click on the image. Image 1 disappears, nothing appears for a while. Then the blue box appears and quickly fades out, fading in image 2 (bird).
- Click again. Image 2 disappears, and then (same as 2) occurs, fading in image 1.
- Click again. Image 2 appears immediately.
- Click again. (Same as 1) occurs.
- Click again. (Same as 4) occurs.
And then it loops between them.
Expected behavior:
- Expected.
- The blue box should be shown as a placeholder instead of nothing.
- Since image 1 is cached now, there should not be any loading, it should appear immediately. But looking at the download speed in the top bar, it can be seen that image 1 is getting downloaded every time (same on Linux).
- Expected
- Same as 3
- Expected
Video on OnePlus 7T running Android 11. Tested on Linux (details in flutter doctor) and got the same results.
21-12-02-23-45-23.mp4
sample code
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatefulWidget {
const MyApp({Key? key}) : super(key: key);
@override
State<MyApp> createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
bool img = false;
@override
Widget build(BuildContext context) {
return GestureDetector(
onTap: () {
setState(() {
img = !img;
});
},
child: FadeInImage(
placeholder: Image.network(
'http://jacksonmetalroof.com/wp-content/uploads/2016/06/metal-roofing-color-gallery-blue-180x180.png',
).image,
image: Image.network(
img
? 'https://wallup.net/wp-content/uploads/2019/09/07/762373-postcard-paper-poster-advertising-vintage-retro-antique-christmas.jpg'
: 'https://wallup.net/wp-content/uploads/2019/05/10/1003575-usa-parks-scenery-mountains-forests-california-clouds-kings-canyon-national-park-nature-wallpapers.jpg',
).image,
),
);
}
}flutter doctor
[✓] Flutter (Channel stable, 2.5.0, on Pop!_OS 20.04 LTS 5.13.0-7620-generic,
locale en_US.UTF-8)
• Flutter version 2.5.0 at /home/werain/soft/flutter
• Upstream repository https://github.com/flutter/flutter.git
• Framework revision 4cc385b4b8 (3 months ago), 2021-09-07 23:01:49 -0700
• Engine revision f0826da7ef
• Dart version 2.14.0
[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
• Android SDK at /home/werain/Android/Sdk
• Platform android-31, build-tools 31.0.0
• Java binary at: /snap/android-studio/current/android-studio/jre/bin/java
• Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7249189)
• All Android licenses accepted.
[✓] Chrome - develop for the web
• Chrome at google-chrome
[✓] Linux toolchain - develop for Linux desktop
• clang version 10.0.0-4ubuntu1
• cmake version 3.16.3
• ninja version 1.10.1
• pkg-config version 0.29.1
[✓] Android Studio (version 2020.3)
• Android Studio at /snap/android-studio/115/android-studio
• Flutter plugin version 62.0.1
• Dart plugin version 203.8452
• Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7249189)
[✓] Android Studio
• Android Studio at /snap/android-studio/current/android-studio
• Flutter plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/9212-flutter
• Dart plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/6351-dart
• android-studio-dir = /snap/android-studio/current/android-studio
• Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7249189)
[✓] VS Code
• VS Code at /snap/code/current
• Flutter extension version 3.29.0
[✓] Connected device (2 available)
• Linux (desktop) • linux • linux-x64 • Pop!_OS 20.04 LTS 5.13.0-7620-generic
• Chrome (web) • chrome • web-javascript • Google Chrome 96.0.4664.45