Split out the ALSA-specific parts from MIDIMapper into a new class MIDIDevice.

[nageru] / nageru / midi_device.h

diff --git a/nageru/midi_device.h b/nageru/midi_device.h
new file mode 100644 (file)
index 0000000..3c1e6b2
--- /dev/null
+++ b/nageru/midi_device.h
@@ -0,0 +1,56 @@
+#ifndef _MIDI_DEVICE_H
+#define _MIDI_DEVICE_H 1
+
+// MIDIDevice is a class that pools incoming MIDI messages from
+// all MIDI devices in the system, decodes them and sends them on.
+
+#include <atomic>
+#include <map>
+#include <mutex>
+#include <set>
+#include <thread>
+
+typedef struct snd_seq_addr snd_seq_addr_t;
+typedef struct snd_seq_event snd_seq_event_t;
+typedef struct _snd_seq snd_seq_t;
+
+class MIDIReceiver {
+public:
+       virtual ~MIDIReceiver() {}
+       virtual void controller_received(int controller, int value) = 0;
+       virtual void note_on_received(int note) = 0;
+       virtual void update_num_subscribers(unsigned num_subscribers) = 0;
+};
+
+class MIDIDevice {
+public:
+       MIDIDevice(MIDIReceiver *receiver);
+       ~MIDIDevice();
+       void start_thread();
+
+       void update_lights(const std::set<unsigned> &active_lights)
+       {
+               std::lock_guard<std::mutex> lock(mu);
+               update_lights_lock_held(active_lights);
+       }
+
+private:
+       void thread_func();
+       void handle_event(snd_seq_t *seq, snd_seq_event_t *event);
+       void subscribe_to_port_lock_held(snd_seq_t *seq, const snd_seq_addr_t &addr);
+       void update_lights_lock_held(const std::set<unsigned> &active_lights);
+
+       std::atomic<bool> should_quit{false};
+       int should_quit_fd;
+
+       mutable std::mutex mu;
+       MIDIReceiver *receiver;  // Under <mu>.
+
+       std::thread midi_thread;
+       std::map<unsigned, bool> current_light_status;  // Keyed by note number. Under <mu>.
+       snd_seq_t *alsa_seq{nullptr};  // Under <mu>.
+       int alsa_queue_id{-1};  // Under <mu>.
+       std::atomic<int> num_subscribed_ports{0};
+};
+
+#endif  // !defined(_MIDI_DEVICE_H)