flame/doc/examples/gestures/lib/main.dart

import 'package:flame/game.dart';
import 'package:flutter/material.dart';
import 'package:flame/gestures.dart';
import 'package:flame/palette.dart';

void main() {
  runApp(
    GameWidget(
      game: MyGame(),
    ),
  );
}

/// Includes an example including basic detectors
class MyGame extends BaseGame
    with TapDetector, DoubleTapDetector, PanDetector, LongPressDetector {
  final _whitePaint = BasicPalette.white.paint;
  final _bluePaint = Paint()..color = const Color(0xFF0000FF);
  final _greenPaint = Paint()..color = const Color(0xFF00FF00);
  final _redPaint = Paint()..color = const Color(0xFFFF0000);

  @override
  Color backgroundColor() => const Color(0xFFF1F1F1);

  Paint _paint;

  Rect _rect = const Rect.fromLTWH(50, 50, 50, 50);

  MyGame() {
    _paint = _whitePaint;
  }

  @override
  void onTap() {
    _paint = _paint == _whitePaint ? _bluePaint : _whitePaint;
  }

  @override
  void onDoubleTap() {
    _paint = _greenPaint;
  }

  @override
  void onLongPress() {
    _paint = _redPaint;
  }

  @override
  void onPanUpdate(DragUpdateDetails details) {
    _rect = _rect.translate(details.delta.dx, details.delta.dy);
  }

  @override
  void render(Canvas canvas) {
    super.render(canvas);
    canvas.drawRect(_rect, _paint);
  }
}