59 lines
1.6 KiB
Dart
59 lines
1.6 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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///in milliseconds
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final ValueNotifier<bool> _debounceActiveNotifier = ValueNotifier(false);
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/// If executionIntervalInSeconds 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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/// This is useful for example when you want to execute a callback every 5 seconds
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final int? executionIntervalInMilliSeconds;
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Timer? _debounceTimer;
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Debouncer(this._duration, {this.executionIntervalInMilliSeconds});
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final Stopwatch _stopwatch = Stopwatch();
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void run(FutureVoidCallback fn) {
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bool shouldRunImmediately = false;
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if (executionIntervalInMilliSeconds != null) {
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// ensure the stop watch is running
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_stopwatch.start();
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if (_stopwatch.elapsedMilliseconds > executionIntervalInMilliSeconds!) {
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shouldRunImmediately = true;
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_stopwatch.stop();
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_stopwatch.reset();
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}
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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 =
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Timer(shouldRunImmediately ? Duration.zero : _duration, () async {
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_stopwatch.stop();
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_stopwatch.reset();
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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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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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