From 4a5dc1a769712538baf68629047dd98426a35f25 Mon Sep 17 00:00:00 2001
From: Micah Morrison <micahmorrison95@gmail.com>
Date: Mon, 19 Aug 2019 16:46:58 -0400
Subject: [PATCH] Ensure that the progress update task stops when the sound
 stops (so that it's not running indefinitely)

---
 SoundBoard/Buttons.cs | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/SoundBoard/Buttons.cs b/SoundBoard/Buttons.cs
index 195b5a8..6607b55 100644
--- a/SoundBoard/Buttons.cs
+++ b/SoundBoard/Buttons.cs
@@ -608,6 +608,8 @@ private void ChooseSoundMenuItem_Click(object sender, RoutedEventArgs e)
 
         private void SoundStoppedHandler(object sender, StoppedEventArgs e)
         {
+            _progressBarCancellationToken?.Cancel();
+
             _audioFileReader.Position = 0;
 
             // Hide the additional buttons
@@ -922,8 +924,10 @@ public async void StartSound()
                 _player.Play();
 
                 // Begin updating progress bar
-                CancellationTokenSource tokenSource = new CancellationTokenSource();
-                await UpdateProgressTask(UpdateProgressAction, TimeSpan.FromMilliseconds(5), tokenSource.Token);
+                _progressBarCancellationToken?.Cancel();
+                _progressBarCancellationToken?.Dispose();
+                _progressBarCancellationToken = new CancellationTokenSource();
+                UpdateProgressTask(UpdateProgressAction, TimeSpan.FromMilliseconds(5), _progressBarCancellationToken.Token);
             }
             catch (Exception ex)
             {
@@ -1090,8 +1094,14 @@ private void SetDefaultText()
             SetUpContextMenu();
         }
 
-        private void UpdateProgressAction()
+        /// <summary>
+        /// Returns false as long as there is still processing to perform.
+        /// Returns true when progress no longer needs to be updated.
+        /// </summary>
+        private bool UpdateProgressAction()
         {
+            bool result = false;
+
             double maxSeconds = _audioFileReader.TotalTime.TotalMilliseconds;
             double curSeconds = _stopWatch.Elapsed.TotalMilliseconds;
 
@@ -1109,16 +1119,21 @@ private void UpdateProgressAction()
                 else
                 {
                     SoundProgressBar.Visibility = Visibility.Hidden;
+                    result = true;
                 }
             }
+
+            return result;
         }
 
-        private async Task UpdateProgressTask(Action action, TimeSpan interval, CancellationToken token)
+        private async void UpdateProgressTask(Func<bool> action, TimeSpan interval, CancellationToken token)
         {
-            while (true)
+            bool result = false;
+
+            while (token.IsCancellationRequested == false || result == false)
             {
-                action();
-                await Task.Delay(interval, token);
+                result = action();
+                await Task.Delay(interval);
             }
         }
 
@@ -1552,6 +1567,8 @@ private set
 
         private Point? _mouseDownPosition;
 
+        private CancellationTokenSource _progressBarCancellationToken;
+
         #endregion
 
         #region Private consts