| // Copyright 2018 Google Inc. All Rights Reserved. |
| // |
| // 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. |
| |
| import 'clock.dart'; |
| |
| /// The system's timer frequency in Hz. |
| /// |
| /// We can't really know how frequently the clock is updated, and that may not |
| /// even make sense for some implementations, so we just pretend we follow the |
| /// system's frequency. |
| final _frequency = new Stopwatch().frequency; |
| |
| /// A stopwatch that gets its notion of the current time from a [Clock]. |
| class ClockStopwatch implements Stopwatch { |
| /// The provider for this stopwatch's notion of the current time. |
| final Clock _clock; |
| |
| /// The number of elapsed microseconds that have been recorded from previous |
| /// runs of this stopwatch. |
| /// |
| /// This doesn't include the time between [_start] and the current time. |
| var _elapsed = 0; |
| |
| /// The point at which [start] was called most recently, or `null` if this |
| /// isn't active. |
| DateTime _start; |
| |
| ClockStopwatch(this._clock); |
| |
| int get frequency => _frequency; |
| int get elapsedTicks => (elapsedMicroseconds * frequency) ~/ 1000000; |
| Duration get elapsed => new Duration(microseconds: elapsedMicroseconds); |
| int get elapsedMilliseconds => elapsedMicroseconds ~/ 1000; |
| bool get isRunning => _start != null; |
| |
| int get elapsedMicroseconds => |
| _elapsed + |
| (_start == null ? 0 : _clock.now().difference(_start).inMicroseconds); |
| |
| void start() { |
| _start ??= _clock.now(); |
| } |
| |
| void stop() { |
| _elapsed = elapsedMicroseconds; |
| _start = null; |
| } |
| |
| void reset() { |
| _elapsed = 0; |
| if (_start != null) _start = _clock.now(); |
| } |
| } |