54 lines
1.4 KiB
Dart
54 lines
1.4 KiB
Dart
import 'dart:async';
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import 'package:flutter/material.dart';
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import "package:photos/models/typedefs.dart";
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class Debouncer {
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final Duration _duration;
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final ValueNotifier<bool> _debounceActiveNotifier = ValueNotifier(false);
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/// If executionInterval is not null, then the debouncer will execute the
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/// current callback it has in run() method repeatedly in the given interval.
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final int? executionInterval;
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Timer? _debounceTimer;
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Debouncer(this._duration, {this.executionInterval});
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final Stopwatch _stopwatch = Stopwatch();
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void run(FutureVoidCallback fn) {
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if (executionInterval != null) {
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runCallbackIfIntervalTimeElapses(fn);
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}
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if (isActive()) {
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_debounceTimer!.cancel();
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}
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_debounceTimer = Timer(_duration, () async {
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await fn();
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_debounceActiveNotifier.value = false;
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});
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_debounceActiveNotifier.value = true;
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}
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void cancelDebounce() {
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if (_debounceTimer != null) {
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_debounceTimer!.cancel();
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}
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}
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runCallbackIfIntervalTimeElapses(FutureVoidCallback fn) {
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_stopwatch.isRunning ? null : _stopwatch.start();
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if (_stopwatch.elapsedMilliseconds > executionInterval!) {
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_stopwatch.reset();
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fn();
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}
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}
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bool isActive() => _debounceTimer != null && _debounceTimer!.isActive;
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ValueNotifier<bool> get debounceActiveNotifier {
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return _debounceActiveNotifier;
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}
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}
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