output/Interface: convert to class, make attributes private

src/output/Filtered.cxx

@@ -32,15 +32,15 @@
 bool
 FilteredAudioOutput::SupportsEnableDisable() const noexcept
 {
-	assert((output->plugin.enable == nullptr) == (output->plugin.disable == nullptr));
+	assert((output->GetPlugin().enable == nullptr) == (output->GetPlugin().disable == nullptr));
 
-	return output->plugin.enable != nullptr;
+	return output->GetPlugin().enable != nullptr;
 }
 
 bool
 FilteredAudioOutput::SupportsPause() const noexcept
 {
-	return output->plugin.pause != nullptr;
+	return output->GetPlugin().pause != nullptr;
 }
 
 void

src/output/Filtered.hxx

@@ -33,7 +33,7 @@ class Mixer;
 class MixerListener;
 struct MusicChunk;
 struct ConfigBlock;
-struct AudioOutput;
+class AudioOutput;
 struct ReplayGainConfig;
 struct Tag;
 

src/output/Init.cxx

@@ -55,7 +55,7 @@ FilteredAudioOutput::FilteredAudioOutput(AudioOutput &_output,
 	:output(&_output)
 {
 #ifndef NDEBUG
-	const auto &plugin = output->plugin;
+	const auto &plugin = output->GetPlugin();
 	assert(plugin.finish != nullptr);
 	assert(plugin.open != nullptr);
 	assert(plugin.close != nullptr);
@@ -172,7 +172,7 @@ FilteredAudioOutput::Configure(const ConfigBlock &block)
 	{
 		char buffer[64];
 		snprintf(buffer, sizeof(buffer), "\"%s\" (%s)",
-			 name, output->plugin.name);
+			 name, output->GetPlugin().name);
 		log_name = buffer;
 	}
 
@@ -207,7 +207,7 @@ FilteredAudioOutput::Setup(EventLoop &event_loop,
 			   MixerListener &mixer_listener,
 			   const ConfigBlock &block)
 {
-	if (output->need_fully_defined_audio_format &&
+	if (output->GetNeedFullyDefinedAudioFormat() &&
 	    !config_audio_format.IsFullyDefined())
 		throw std::runtime_error("Need full audio format specification");
 
@@ -233,7 +233,7 @@ FilteredAudioOutput::Setup(EventLoop &event_loop,
 
 	try {
 		mixer = audio_output_load_mixer(event_loop, *this, block,
-						output->plugin.mixer_plugin,
+						output->GetPlugin().mixer_plugin,
 						*prepared_filter,
 						mixer_listener);
 	} catch (const std::runtime_error &e) {

src/output/Interface.hxx

@@ -22,7 +22,7 @@
 
 struct AudioOutputPlugin;
 
-struct AudioOutput {
+class AudioOutput {
 	/**
 	 * The plugin which implements this output device.
 	 */
@@ -30,9 +30,18 @@ struct AudioOutput {
 
 	bool need_fully_defined_audio_format = false;
 
+public:
 	AudioOutput(const AudioOutputPlugin &_plugin)
 		:plugin(_plugin) {}
 
+	const AudioOutputPlugin &GetPlugin() const {
+		return plugin;
+	}
+
+	bool GetNeedFullyDefinedAudioFormat() const {
+		return need_fully_defined_audio_format;
+	}
+
 	/**
 	 * Plugins shall call this method if they require an
 	 * "audio_format" setting which evaluates

src/output/OutputPlugin.cxx

@@ -36,72 +36,72 @@ ao_plugin_init(EventLoop &event_loop,
 void
 ao_plugin_finish(AudioOutput *ao) noexcept
 {
-	ao->plugin.finish(ao);
+	ao->GetPlugin().finish(ao);
 }
 
 void
 ao_plugin_enable(AudioOutput &ao)
 {
-	if (ao.plugin.enable != nullptr)
+	if (ao.GetPlugin().enable != nullptr)
-		ao.plugin.enable(&ao);
+		ao.GetPlugin().enable(&ao);
 }
 
 void
 ao_plugin_disable(AudioOutput &ao) noexcept
 {
-	if (ao.plugin.disable != nullptr)
+	if (ao.GetPlugin().disable != nullptr)
-		ao.plugin.disable(&ao);
+		ao.GetPlugin().disable(&ao);
 }
 
 void
 ao_plugin_open(AudioOutput &ao, AudioFormat &audio_format)
 {
-	ao.plugin.open(&ao, audio_format);
+	ao.GetPlugin().open(&ao, audio_format);
 }
 
 void
 ao_plugin_close(AudioOutput &ao) noexcept
 {
-	ao.plugin.close(&ao);
+	ao.GetPlugin().close(&ao);
 }
 
 std::chrono::steady_clock::duration
 ao_plugin_delay(AudioOutput &ao) noexcept
 {
-	return ao.plugin.delay != nullptr
+	return ao.GetPlugin().delay != nullptr
-		? ao.plugin.delay(&ao)
+		? ao.GetPlugin().delay(&ao)
 		: std::chrono::steady_clock::duration::zero();
 }
 
 void
 ao_plugin_send_tag(AudioOutput &ao, const Tag &tag)
 {
-	if (ao.plugin.send_tag != nullptr)
+	if (ao.GetPlugin().send_tag != nullptr)
-		ao.plugin.send_tag(&ao, tag);
+		ao.GetPlugin().send_tag(&ao, tag);
 }
 
 size_t
 ao_plugin_play(AudioOutput &ao, const void *chunk, size_t size)
 {
-	return ao.plugin.play(&ao, chunk, size);
+	return ao.GetPlugin().play(&ao, chunk, size);
 }
 
 void
 ao_plugin_drain(AudioOutput &ao)
 {
-	if (ao.plugin.drain != nullptr)
+	if (ao.GetPlugin().drain != nullptr)
-		ao.plugin.drain(&ao);
+		ao.GetPlugin().drain(&ao);
 }
 
 void
 ao_plugin_cancel(AudioOutput &ao) noexcept
 {
-	if (ao.plugin.cancel != nullptr)
+	if (ao.GetPlugin().cancel != nullptr)
-		ao.plugin.cancel(&ao);
+		ao.GetPlugin().cancel(&ao);
 }
 
 bool
 ao_plugin_pause(AudioOutput &ao)
 {
-	return ao.plugin.pause != nullptr && ao.plugin.pause(&ao);
+	return ao.GetPlugin().pause != nullptr && ao.GetPlugin().pause(&ao);
 }

src/output/OutputPlugin.hxx

@@ -29,7 +29,7 @@
 struct ConfigBlock;
 struct AudioFormat;
 struct Tag;
-struct AudioOutput;
+class AudioOutput;
 struct MixerPlugin;
 class EventLoop;