Bring back PortAudio support on Windows (#4770)

Population of the PortAudio setup widget has been delayed until it is shown, as it was causing crashes on some systems.

CMakeLists.txt

@@ -88,7 +88,6 @@ IF(LMMS_BUILD_WIN32)
 	SET(WANT_ALSA OFF)
 	SET(WANT_JACK OFF)
 	SET(WANT_PULSEAUDIO OFF)
-	SET(WANT_PORTAUDIO OFF)
 	SET(WANT_SNDIO OFF)
 	SET(WANT_SOUNDIO OFF)
 	SET(WANT_WINMM ON)
@@ -96,7 +95,6 @@ IF(LMMS_BUILD_WIN32)
 	SET(STATUS_ALSA "<not supported on this platform>")
 	SET(STATUS_JACK "<not supported on this platform>")
 	SET(STATUS_PULSEAUDIO "<not supported on this platform>")
-	SET(STATUS_PORTAUDIO "<disabled on this platform>")
 	SET(STATUS_SOUNDIO "<disabled in this release>")
 	SET(STATUS_WINMM "OK")
 	SET(STATUS_APPLEMIDI "<not supported on this platform>")

include/AudioPortAudio.h

@@ -34,6 +34,7 @@ class AudioPortAudioSetupUtil : public QObject
 {
 	Q_OBJECT
 public slots:
+	void updateBackends();
 	void updateDevices();
 	void updateChannels();
 
@@ -87,6 +88,7 @@ public:
 		virtual ~setupWidget();
 
 		virtual void saveSettings();
+		virtual void show();
 
 	private:
 		ComboBox * m_backend;

src/core/audio/AudioPortAudio.cpp

@@ -27,6 +27,10 @@
 #include "AudioPortAudio.h"
 
 #ifndef LMMS_HAVE_PORTAUDIO
+void AudioPortAudioSetupUtil::updateBackends()
+{
+}
+
 void AudioPortAudioSetupUtil::updateDevices()
 {
 }
@@ -328,6 +332,28 @@ int AudioPortAudio::_process_callback(
 
 
 
+
+void AudioPortAudioSetupUtil::updateBackends()
+{
+	PaError err = Pa_Initialize();
+	if( err != paNoError ) {
+		printf( "Couldn't initialize PortAudio: %s\n", Pa_GetErrorText( err ) );
+		return;
+	}
+
+	const PaHostApiInfo * hi;
+	for( int i = 0; i < Pa_GetHostApiCount(); ++i )
+	{
+		hi = Pa_GetHostApiInfo( i );
+		m_backendModel.addItem( hi->name );
+	}
+
+	Pa_Terminate();
+}
+
+
+
+
 void AudioPortAudioSetupUtil::updateDevices()
 {
 	PaError err = Pa_Initialize();
@@ -409,37 +435,6 @@ AudioPortAudio::setupWidget::setupWidget( QWidget * _parent ) :
 	m_channels->setLabel( tr( "CHANNELS" ) );
 	m_channels->move( 308, 20 );*/
 
-	// Setup models
-	PaError err = Pa_Initialize();
-	if( err != paNoError ) {
-		printf( "Couldn't initialize PortAudio: %s\n", Pa_GetErrorText( err ) );
-		return;
-	}
-	
-	// todo: setup backend model
-	const PaHostApiInfo * hi;
-	for( int i = 0; i < Pa_GetHostApiCount(); ++i )
-	{
-		hi = Pa_GetHostApiInfo( i );
-		m_setupUtil.m_backendModel.addItem( hi->name );
-	}
-
-	Pa_Terminate();
-
-
-	const QString& backend = ConfigManager::inst()->value( "audioportaudio",
-		"backend" );
-	const QString& device = ConfigManager::inst()->value( "audioportaudio",
-		"device" );
-	
-	int i = qMax( 0, m_setupUtil.m_backendModel.findText( backend ) );
-	m_setupUtil.m_backendModel.setValue( i );
-	
-	m_setupUtil.updateDevices();
-	
-	i = qMax( 0, m_setupUtil.m_deviceModel.findText( device ) );
-	m_setupUtil.m_deviceModel.setValue( i );
-
 	connect( &m_setupUtil.m_backendModel, SIGNAL( dataChanged() ),
 			&m_setupUtil, SLOT( updateDevices() ) );
 			
@@ -478,6 +473,33 @@ void AudioPortAudio::setupWidget::saveSettings()
 }
 
 
+
+
+void AudioPortAudio::setupWidget::show()
+{
+	if( m_setupUtil.m_backendModel.size() == 0 )
+	{
+		// populate the backend model the first time we are shown
+		m_setupUtil.updateBackends();
+
+		const QString& backend = ConfigManager::inst()->value(
+			"audioportaudio", "backend" );
+		const QString& device = ConfigManager::inst()->value(
+			"audioportaudio", "device" );
+		
+		int i = qMax( 0, m_setupUtil.m_backendModel.findText( backend ) );
+		m_setupUtil.m_backendModel.setValue( i );
+		
+		m_setupUtil.updateDevices();
+		
+		i = qMax( 0, m_setupUtil.m_deviceModel.findText( device ) );
+		m_setupUtil.m_deviceModel.setValue( i );
+	}
+
+	AudioDeviceSetupWidget::show();
+}
+
+
 #endif