LoadingIndicator

A collection of out of the box loading animations written in pure dart, no extra dependency, inspired by loaders.css and NVActivityIndicatorView.

Now, you can click this site to preview.3D effect will be invalid in web.

Install the latest version from pub

Use the release helper from the latest master checkout to calculate the next version from the existing stable tags and update the root pubspec.yaml and CHANGELOG.md:

./scripts/prepare_release.sh --dry-run
./scripts/prepare_release.sh patch

patch, minor, and major are supported, as well as an explicit version such as 4.0.2. The helper refreshes tags from origin and ignores local tags that no longer exist remotely. It accepts a release tag that is either in the current history or fully represented by cherry-picked commits, and refuses to continue when the latest tag cannot be matched to the current history. For an automatic patch, it asks GitHub for notes before changing files and copies the returned Markdown into the dated changelog entry. A real patch run (not --dry-run) requires a clean master matching origin/master, updates only the root pubspec.yaml and CHANGELOG.md, commits them, pushes master, creates and pushes the next version tag, and invokes gh release create with the generated notes. It does not modify example/pubspec.yaml. gh must be installed and authenticated. The existing tag-triggered workflow safely skips release creation when the script has already created it. minor, major, and explicit versions update the local root pubspec.yaml and CHANGELOG.md with a placeholder, then print the release-notes command.

Simple but powerful parameters

LoadingIndicator(
  indicatorType: Indicator.ballPulse, // Required: animation type
  colors: const [Colors.white],        // Optional: color collection
  strokeWidth: 2,                      // Optional: stroke and line width
  backgroundColor: Colors.black,       // Optional: widget background
  pathBackgroundColor: Colors.black,   // Optional: stroke background
)

strokeWidth controls the bar width of lineScale, lineScaleParty, lineScalePulseOut, lineScalePulseOutRapid, and lineSpinFadeLoader. When omitted, these indicators keep their original size-derived bar width.

Without a controller, every indicator plays continuously. To control playback, create and dispose a LoadingIndicatorController with your widget:

late final LoadingIndicatorController _controller;

@override
void initState() {
  super.initState();
  _controller = LoadingIndicatorController();
}

@override
void dispose() {
  _controller.dispose();
  super.dispose();
}

@override
Widget build(BuildContext context) {
  return LoadingIndicator(
    indicatorType: Indicator.ballScaleMultiple,
    controller: _controller,
  );
}

The controller works with all 34 animation types:

_controller.pause(); // Freeze the current frame immediately.

await _controller.pauseAt(0.5); // Pause the next time progress reaches 50%.

await _controller.pauseAt(
  1.0,
  behavior: LoadingIndicatorPauseBehavior.jumpToTarget,
); // Advance the complete animation group to the target and pause now.

_controller.resume();

progress is the normalized position (0.0 to 1.0) of an indicator's reference animation track: 0.0 is the start of a loop and 1.0 is its final frame before reset. pauseAt completes only after the indicator has paused. Replacing a pending command or disposing the controller completes that Future with LoadingIndicatorCommandCanceled. One controller can be attached to only one LoadingIndicator at a time; the last command sent while detached is applied on the next attachment.

Version 4.0 removes the pause widget parameter. Replace it with a controller:

// 3.x
LoadingIndicator(indicatorType: Indicator.ballPulse, pause: isPaused);

// 4.0
LoadingIndicator(
  indicatorType: Indicator.ballPulse,
  controller: controller,
);

void setPaused(bool isPaused) {
  isPaused ? controller.pause() : controller.resume();
}

中文版

Copyright 2019 Tino Guo.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.