From c324de804c961986ce0f5d09070f5b483c1cbd5a Mon Sep 17 00:00:00 2001
From: itsmattkc <itsmattkc@gmail.com>
Date: Fri, 26 Jun 2020 00:21:34 +1000
Subject: [PATCH] audiomanager: create and delete future watchers when
 necessary

---
 app/audio/audiomanager.cpp | 38 +++++++++++++++++++++++++++++---------
 app/audio/audiomanager.h   |  4 ++--
 2 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/app/audio/audiomanager.cpp b/app/audio/audiomanager.cpp
index 4a8ac8435..f5a1a866d 100644
--- a/app/audio/audiomanager.cpp
+++ b/app/audio/audiomanager.cpp
@@ -48,18 +48,31 @@ AudioManager *AudioManager::instance()
 
 void AudioManager::RefreshDevices()
 {
-  output_watcher_.setFuture(QtConcurrent::run(QAudioDeviceInfo::availableDevices, QAudio::AudioOutput));
-  input_watcher_.setFuture(QtConcurrent::run(QAudioDeviceInfo::availableDevices, QAudio::AudioInput));
+  if (!is_refreshing_outputs_) {
+    QFutureWatcher< QList<QAudioDeviceInfo> >* output_watcher = new QFutureWatcher< QList<QAudioDeviceInfo> >();
+    connect(output_watcher, &QFutureWatcher< QList<QAudioDeviceInfo> >::finished, this, &AudioManager::OutputDevicesRefreshed);
+    output_watcher->setFuture(QtConcurrent::run(QAudioDeviceInfo::availableDevices, QAudio::AudioOutput));
+
+    is_refreshing_outputs_ = true;
+  }
+
+  if (!is_refreshing_inputs_) {
+    QFutureWatcher< QList<QAudioDeviceInfo> >* input_watcher = new QFutureWatcher< QList<QAudioDeviceInfo> >();
+    connect(input_watcher, &QFutureWatcher< QList<QAudioDeviceInfo> >::finished, this, &AudioManager::InputDevicesRefreshed);
+    input_watcher->setFuture(QtConcurrent::run(QAudioDeviceInfo::availableDevices, QAudio::AudioInput));
+
+    is_refreshing_inputs_ = true;
+  }
 }
 
 bool AudioManager::IsRefreshingOutputs()
 {
-  return output_watcher_.isRunning();
+  return is_refreshing_outputs_;
 }
 
 bool AudioManager::IsRefreshingInputs()
 {
-  return input_watcher_.isRunning();
+  return is_refreshing_inputs_;
 }
 
 void AudioManager::PushToOutput(const QByteArray &samples)
@@ -200,6 +213,8 @@ void AudioManager::ReverseBuffer(char *buffer, int buffer_size, int sample_size)
 }
 
 AudioManager::AudioManager() :
+  is_refreshing_inputs_(false),
+  is_refreshing_outputs_(false),
   output_is_set_(false),
   input_(nullptr),
   input_file_(nullptr)
@@ -210,9 +225,6 @@ AudioManager::AudioManager() :
   output_manager_.moveToThread(&output_thread_);
 
   connect(&output_manager_, &AudioOutputManager::OutputNotified, this, &AudioManager::OutputNotified);
-
-  connect(&output_watcher_, &QFutureWatcher< QList<QAudioDeviceInfo> >::finished, this, &AudioManager::OutputDevicesRefreshed);
-  connect(&input_watcher_, &QFutureWatcher< QList<QAudioDeviceInfo> >::finished, this, &AudioManager::InputDevicesRefreshed);
 }
 
 AudioManager::~AudioManager()
@@ -224,7 +236,11 @@ AudioManager::~AudioManager()
 
 void AudioManager::OutputDevicesRefreshed()
 {
-  output_devices_ = output_watcher_.result();
+  QFutureWatcher< QList<QAudioDeviceInfo> >* watcher = static_cast<QFutureWatcher< QList<QAudioDeviceInfo> >*>(sender());
+
+  output_devices_ = watcher->result();
+  watcher->deleteLater();
+  is_refreshing_outputs_ = false;
 
   QString preferred_audio_output = Config::Current()["PreferredAudioOutput"].toString();
 
@@ -247,7 +263,11 @@ void AudioManager::OutputDevicesRefreshed()
 
 void AudioManager::InputDevicesRefreshed()
 {
-  input_devices_ = input_watcher_.result();
+  QFutureWatcher< QList<QAudioDeviceInfo> >* watcher = static_cast<QFutureWatcher< QList<QAudioDeviceInfo> >*>(sender());
+
+  input_devices_ = watcher->result();
+  watcher->deleteLater();
+  is_refreshing_inputs_ = false;
 
   QString preferred_audio_input = Config::Current()["PreferredAudioInput"].toString();
 
diff --git a/app/audio/audiomanager.h b/app/audio/audiomanager.h
index 07a5fb9a1..f0c6c7db0 100644
--- a/app/audio/audiomanager.h
+++ b/app/audio/audiomanager.h
@@ -102,8 +102,8 @@ private:
   QList<QAudioDeviceInfo> input_devices_;
   QList<QAudioDeviceInfo> output_devices_;
 
-  QFutureWatcher< QList<QAudioDeviceInfo> > input_watcher_;
-  QFutureWatcher< QList<QAudioDeviceInfo> > output_watcher_;
+  bool is_refreshing_inputs_;
+  bool is_refreshing_outputs_;
 
   static AudioManager* instance_;