Add wayvncctl get-outputs command

Signed-off-by: Jim Ramsay <i.am@jimramsay.com>

include/ctl-server.h

@@ -27,6 +27,14 @@ struct ctl_server_vnc_client {
 	char username[256];
 };
 
+struct ctl_server_output {
+	char name[65];
+	char description[128];
+	unsigned height;
+	unsigned width;
+	bool captured;
+};
+
 struct ctl_server_actions {
 	void* userdata;
 	struct cmd_response* (*on_output_cycle)(struct ctl*,
@@ -39,6 +47,12 @@ struct ctl_server_actions {
 	// Receiver will free(clients) when done.
 	int (*get_client_list)(struct ctl*,
 			struct ctl_server_vnc_client** clients);
+
+	// Return number of elements created
+	// Allocate 'outputs' array or set to NULL if none
+	// Receiver will free(outputs) when done.
+	int (*get_output_list)(struct ctl*,
+			struct ctl_server_output** outputs);
 };
 
 struct ctl* ctl_server_new(const char* socket_path,

src/ctl-client.c

@@ -412,6 +412,29 @@ static void pretty_client_list(json_t* data)
 	}
 }
 
+static void pretty_output_list(json_t* data)
+{
+	int n = json_array_size(data);
+	printf("There %s %d output%s%s\n", (n == 1) ? "is" : "are",
+			n, (n == 1) ? "" : "s", (n > 0) ? ":" : ".");
+	int i;
+	json_t* value;
+	json_array_foreach(data, i, value) {
+		char* name = NULL;
+		char* description = NULL;
+		int height = -1;
+		int width = -1;
+		int captured = false;
+		json_unpack(value, "{s:s, s:s, s:i, s:i, s:b}", "name", &name, 
+				"description", &description,
+				"height", &height,
+				"width", &width,
+				"captured", &captured);
+		printf("%s output[%s]: %s (%dx%d)\n",
+				captured ? "*" : " ", name, description, width,
+				height);
+	}
+}
 static void pretty_print(json_t* data,
 		struct jsonipc_request* request)
 {
@@ -422,6 +445,8 @@ static void pretty_print(json_t* data,
 		pretty_version(data);
 	else if (strcmp(method, "get-clients") == 0)
 		pretty_client_list(data);
+	else if (strcmp(method, "get-outputs") == 0)
+		pretty_output_list(data);
 	else
 		json_dumpf(data, stdout, JSON_INDENT(2));
 }

src/ctl-server.c

@@ -47,6 +47,7 @@ enum cmd_type {
 	CMD_EVENT_RECEIVE,
 	CMD_SET_OUTPUT,
 	CMD_GET_CLIENTS,
+	CMD_GET_OUTPUTS,
 	CMD_UNKNOWN,
 };
 #define CMD_LIST_LEN CMD_UNKNOWN
@@ -99,7 +100,10 @@ static struct cmd_info cmd_list[] = {
 		"Return a list of all currently connected  VNC sessions",
 		{{NULL, NULL}}
 	},
-
+	[CMD_GET_OUTPUTS] = { "get-outputs",
+		"Return a list of all currently detected Wayland outputs",
+		{{NULL, NULL}}
+	},
 };
 
 #define CLIENT_EVENT_PARAMS(including) \
@@ -290,6 +294,7 @@ static struct cmd* parse_command(struct jsonipc_request* ipc,
 	case CMD_VERSION:
 	case CMD_EVENT_RECEIVE:
 	case CMD_GET_CLIENTS:
+	case CMD_GET_OUTPUTS:
 		cmd = calloc(1, sizeof(*cmd));
 		cmd->type = cmd_type;
 		break;
@@ -448,6 +453,25 @@ static struct cmd_response* generate_vnc_client_list(struct ctl* self)
 	return response;
 }
 
+static struct cmd_response* generate_output_list(struct ctl* self)
+{
+	struct ctl_server_output* outputs;
+	size_t num_outputs = self->actions.get_output_list(self, &outputs);
+	struct cmd_response* response = cmd_ok();
+
+	response->data = json_array();
+	for (int i = 0; i < num_outputs; ++i)
+		json_array_append_new(response->data, json_pack(
+					"{s:s, s:s, s:i, s:i, s:b}",
+				"name", outputs[i].name,
+				"description", outputs[i].description,
+				"height", outputs[i].height,
+				"width", outputs[i].width,
+				"captured", outputs[i].captured));
+	free(outputs);
+	return response;
+}
+
 static struct cmd_response* ctl_server_dispatch_cmd(struct ctl* self,
 		struct ctl_client* client, struct cmd* cmd)
 {
@@ -479,6 +503,9 @@ static struct cmd_response* ctl_server_dispatch_cmd(struct ctl* self,
 	case CMD_GET_CLIENTS:
 		response = generate_vnc_client_list(self);
 		break;
+	case CMD_GET_OUTPUTS:
+		response = generate_output_list(self);
+		break;
 	case CMD_UNKNOWN:
 		break;
 	}

src/main.c

@@ -493,6 +493,30 @@ static int get_client_list(struct ctl* ctl,
 	return self->nr_clients;
 }
 
+static int get_output_list(struct ctl* ctl,
+		struct ctl_server_output** outputs)
+{
+	struct wayvnc* self = ctl_server_userdata(ctl);
+	int n = wl_list_length(&self->outputs);
+	if (n == 0) {
+		*outputs = NULL;
+		return 0;
+	}
+	*outputs = calloc(n, sizeof(**outputs));
+	struct output* output;
+	struct ctl_server_output* item = *outputs;
+	wl_list_for_each(output, &self->outputs, link) {
+		strlcpy(item->name, output->name, sizeof(item->name));
+		strlcpy(item->description, output->description,
+				sizeof(item->description));
+		item->height = output->height;
+		item->width = output->width;
+		item->captured = (output->id == self->selected_output->id);
+		item++;
+	}
+	return n;
+}
+
 int init_main_loop(struct wayvnc* self)
 {
 	struct aml* loop = aml_get_default();
@@ -1335,6 +1359,7 @@ int main(int argc, char* argv[])
 		.on_output_cycle = on_output_cycle,
 		.on_output_switch = on_output_switch,
 		.get_client_list = get_client_list,
+		.get_output_list = get_output_list,
 	};
 	self.ctl = ctl_server_new(socket_path, &ctl_actions);
 	if (!self.ctl)

wayvnc.scd

@@ -68,11 +68,15 @@ is also possible to run wayvnc without a physical display attached.
 
 ## MULTIPLE OUTPUTS
 
-If the Wayland session consists of  multiple outputs, only one will be captured.
+If the Wayland session consists of multiple outputs, only one will be captured.
 By default this will be the first one, but can be specified by the _-o_ command
 line argument. The argument accepts the short name such as _eDP-1_ or _DP-4_.
 Running wayvnc in verbose mode (_-v_) will display the names of all outputs on
-startup.
+startup, or you can query them at runtime via the *wayvncctl get-outputs*
+command.
+
+You can also change which output is being captured on the fly via the *wayvncctl
+set-output* command.
 
 # CONFIGURATION
 
@@ -204,6 +208,11 @@ _GET-CLIENTS_
 The *get-clients* command retrieves a list of all VNC clients currently
 connected to wayvnc.
 
+_GET-OUTPUTS_
+
+The *get-outputs* command retrieves a list of all outputs known to wayvnc and
+whether or not each one is currently being captured.
+
 ## IPC EVENTS
 
 _CLIENT-CONNECTED_