scratcher

Scratch card widget which temporarily hides content from the user.

Version

Demo

Features

  • Supported platforms:
    • Android
    • iOS
    • Web (CanvasKit only)
  • Cover content with full color or custom image
  • Track the scratch progress and threshold
  • Fully configurable

Getting started

  1. First thing you need to do is adding the scratcher as a project dependency in pubspec.yaml:
dependencies:
 scratcher: "^2.5.0"
  1. Now you can install it by running flutter pub get or through code editor.

Setting up

  1. Import the library:
import 'package:scratcher/scratcher.dart';
  1. Cover desired widget with the scratch card:
Scratcher(
  brushSize: 30,
  threshold: 50,
  color: Colors.red,
  onChange: (value) => print("Scratch progress: $value%"),
  onThreshold: () => print("Threshold reached, you won!"),
  child: Container(
    height: 300,
    width: 300,
    color: Colors.blue,
  ),
)

Properties

Property Type Description
child Widget Widget rendered under the scratch area.
enabled bool Whether new scratches can be applied.
threshold double Percentage level of scratch area which should be revealed to complete.
brushSize double Size of the brush. The bigger it is the faster user can scratch the card.
accuracy ScratchAccuracy Determines how accurate the progress should be reported. Lower accuracy means higher performance.
color Color Color used to cover the child widget.
image Image Image widget used to cover the child widget.
rebuildOnResize bool Determines if the scratcher should rebuild itself when space constraints change (resize).
onChange Function Callback called when new part of area is revealed (min 0.1% difference).
onThreshold Function Callback called when threshold is reached (only when defined).
onScratchStart Function Callback called when scratching starts.
onScratchUpdate Function Callback called during scratching.
onScratchEnd Function Callback called when scratching ends.

Programmatic access

You can control the Scratcher programmatically by assigning the GlobalKey to the widget.

final scratchKey = GlobalKey<ScratcherState>();

Scratcher(
  key: scratchKey,
  // remaining properties
)

After assigning the key, you can call any exposed methods e.g.:

RaisedButton(
  child: const Text('Reset'),
  onPressed: () {
    scratchKey.currentState.reset(duration: Duration(milliseconds: 2000));
  },
);
Method Description
reset Resets the scratcher state to the initial values.
reveal Reveals the whole scratcher, so than only original child is displayed.

Example Project

There is a crazy example project in the example folder. Check it out to see most of the available options.

Resources

Libraries

painter
scratcher
utils
widgets