add notion of unavailable devices to ARDOUR::AudioBackend

gtk2_ardour/engine_dialog.cc

@@ -280,14 +280,29 @@ EngineControl::list_devices ()
 
 	/* now fill out devices, mark sample rates, buffer sizes insensitive */
 	    
-	vector<string> devices = backend->enumerate_devices ();
+	vector<ARDOUR::AudioBackend::DeviceStatus> all_devices = backend->enumerate_devices ();
 	
-	set_popdown_strings (interface_combo, devices);
-	interface_combo.set_active_text (devices.front());
-	set_popdown_strings (input_device_combo, devices);
-	input_device_combo.set_active_text (devices.front());
-	set_popdown_strings (output_device_combo, devices);
-	output_device_combo.set_active_text (devices.front());
+	/* NOTE: Ardour currently does not display the "available" field of the
+	 * returned devices.
+	 *
+	 * Doing so would require a different GUI widget than the combo
+	 * box/popdown that we currently use, since it has no way to list
+	 * items that are not selectable. Something more like a popup menu,
+	 * which could have unselectable items, would be appropriate.
+	 */
+
+	vector<string> available_devices;
+
+	for (vector<ARDOUR::AudioBackend::DeviceStatus>::const_iterator i = all_devices.begin(); i != all_devices.end(); ++i) {
+		available_devices.push_back (i->name);
+	}
+
+	set_popdown_strings (interface_combo, available_devices);
+	interface_combo.set_active_text (available_devices.front());
+	set_popdown_strings (input_device_combo, available_devices);
+	input_device_combo.set_active_text (available_devices.front());
+	set_popdown_strings (output_device_combo, available_devices);
+	output_device_combo.set_active_text (available_devices.front());
 	
 	interface_changed ();
 }

libs/ardour/ardour/audio_backend.h

@@ -95,12 +95,25 @@ class AudioBackend {
      */
     virtual int set_driver (const std::string& /*drivername*/) { return 0; }
 
-    /** Returns a collection of strings identifying devices known
-     * to this backend. Any of these strings may be used to identify a
+    /** used to list device names along with whether or not they are currently
+     *  available. 
+    */
+    struct DeviceStatus {
+	std::string name;
+	bool        available;
+
+	DeviceStatus (const std::string& s, bool avail) : name (s), available (avail) {}
+    };
+
+    /** Returns a collection of DeviceStatuses identifying devices discovered
+     * by this backend since the start of the process.
+     *
+     * Any of the names in each DeviceStatus may be used to identify a
      * device in other calls to the backend, though any of them may become
      * invalid at any time.
      */
-    virtual std::vector<std::string> enumerate_devices () const = 0;
+    virtual std::vector<DeviceStatus> enumerate_devices () const = 0;
+
     /** Returns a collection of float identifying sample rates that are
      * potentially usable with the hardware identified by @param device.
      * Any of these values may be supplied in other calls to this backend

libs/ardour/ardour/jack_audiobackend.h

@@ -23,6 +23,7 @@
 #include <string>
 #include <vector>
 #include <map>
+#include <set>
 
 #include <stdint.h>
 
@@ -53,7 +54,7 @@ class JACKAudioBackend : public AudioBackend {
     std::vector<std::string> enumerate_drivers () const;
     int set_driver (const std::string&);
 
-    std::vector<std::string> enumerate_devices () const;
+    std::vector<DeviceStatus> enumerate_devices () const;
 
     std::vector<float> available_sample_rates (const std::string& device) const;
     std::vector<uint32_t> available_buffer_sizes (const std::string& device) const;
@@ -173,6 +174,10 @@ class JACKAudioBackend : public AudioBackend {
     uint32_t _current_systemic_input_latency;
     uint32_t _current_systemic_output_latency;
 
+    typedef std::set<std::string> DeviceList;
+    typedef std::map<std::string,DeviceList> DriverDeviceMap;
+    
+    mutable DriverDeviceMap all_devices;
 };
 
 } // namespace

libs/ardour/jack_audiobackend.cc

@@ -97,9 +97,9 @@ JACKAudioBackend::requires_driver_selection() const
 vector<string>
 JACKAudioBackend::enumerate_drivers () const
 {
-	vector<string> s;
-	get_jack_audio_driver_names (s);
-	return s;
+	vector<string> currently_available;
+	get_jack_audio_driver_names (currently_available);
+	return currently_available;
 }
 
 int
@@ -109,10 +109,37 @@ JACKAudioBackend::set_driver (const std::string& name)
 	return 0;
 }
 
-vector<string>
+vector<AudioBackend::DeviceStatus>
 JACKAudioBackend::enumerate_devices () const
 {
-	return get_jack_device_names_for_audio_driver (_target_driver);
+	vector<string> currently_available = get_jack_device_names_for_audio_driver (_target_driver);
+	vector<DeviceStatus> statuses;
+
+	if (all_devices.find (_target_driver) == all_devices.end()) {
+		all_devices.insert (make_pair (_target_driver, std::set<string>()));
+	}
+	
+	/* store every device we've found, by driver name. 
+	 *
+	 * This is so we do not confuse ALSA, FFADO, netjack etc. devices
+	 * with each other.
+	 */
+
+	DeviceList& all (all_devices[_target_driver]);
+
+	for (vector<string>::const_iterator d = currently_available.begin(); d != currently_available.end(); ++d) {
+		all.insert (*d);
+	}
+	
+	for (DeviceList::const_iterator d = all.begin(); d != all.end(); ++d) {
+		if (find (currently_available.begin(), currently_available.end(), *d) == currently_available.end()) {
+			statuses.push_back (DeviceStatus (*d, false));
+		} else {
+			statuses.push_back (DeviceStatus (*d, false));
+		}
+	}
+	
+	return statuses;
 }
 
 vector<float>