Add "assign" node type

Makefile

@@ -12,7 +12,7 @@ CPPFLAGS += $(shell pkg-config --cflags $(DEPS))
 LDLIBS += $(shell pkg-config --libs $(DEPS))
 INTERP ?=
 MAIN = main
-OBJS = main.o events.o processing.o graph.o config.o event_code_names.o hash_table.o module_registry.o event_predicate.o nodes/getchar.o nodes/print.o nodes/evdev.o nodes/tee.o nodes/router.o nodes/modifiers.o nodes/modify_predicate.o nodes/uinput.o
+OBJS = main.o events.o processing.o graph.o config.o event_code_names.o hash_table.o module_registry.o event_predicate.o nodes/getchar.o nodes/print.o nodes/evdev.o nodes/tee.o nodes/router.o nodes/modifiers.o nodes/modify_predicate.o nodes/uinput.o nodes/assign.o
 
 all: $(MAIN)
 

nodes/assign.c

@@ -0,0 +1,120 @@
+#include "../graph.h"
+#include "../module_registry.h"
+
+typedef struct {
+	GraphNode as_GraphNode;
+	bool has_ns, has_maj, has_min, has_payload;
+	EventData source;
+} AssignGraphNode;
+
+static bool
+handle_event(EventPositionBase * self, EventNode * event)
+{
+	AssignGraphNode *node = DOWNCAST(AssignGraphNode, GraphNode, DOWNCAST(GraphNode, EventPositionBase, self));
+	size_t count = node->as_GraphNode.outputs.length;
+	if (!count) {
+		event_destroy(event);
+		return true;
+	}
+
+	if (node->has_ns) {
+		event->data.code.ns = node->source.code.ns;
+	}
+	if (node->has_maj) {
+		event->data.code.major = node->source.code.major;
+	}
+	if (node->has_min) {
+		event->data.code.minor = node->source.code.minor;
+	}
+	if (node->has_payload) {
+		event->data.payload = node->source.payload;
+	}
+
+	if (count > 1) {
+		count = event_replicate(event, count - 1) + 1;
+	}
+	for (size_t i = 0; i < count; ++i) {
+		event->position = &node->as_GraphNode.outputs.elements[i]->as_EventPositionBase;
+		event = event->next;
+	}
+	return true;
+}
+
+static GraphNode *
+create(GraphNodeSpecification * spec, GraphNodeConfig * config, InitializationEnvironment * env)
+{
+	(void) config;
+	(void) env;
+	AssignGraphNode * node = T_ALLOC(1, AssignGraphNode);
+	if (!node) {
+		return NULL;
+	}
+
+	EventData source;
+	bool
+		has_ns = false,
+		has_maj = false,
+		has_min = false,
+		has_payload = false;
+	const config_setting_t *setting;
+
+	if ((setting = config_setting_get_member(config->options, "namespace"))) {
+		has_ns = true;
+		source.code.ns = env_resolve_constant(env, setting);
+	}
+	if ((setting = config_setting_get_member(config->options, "major"))) {
+		has_maj = true;
+		source.code.major = env_resolve_constant(env, setting);
+	}
+	if ((setting = config_setting_get_member(config->options, "minor"))) {
+		has_min = true;
+		source.code.minor = env_resolve_constant(env, setting);
+	}
+	if ((setting = config_setting_get_member(config->options, "payload"))) {
+		has_payload = true;
+		source.payload = env_resolve_constant(env, setting);
+	}
+
+	*node = (AssignGraphNode) {
+		.as_GraphNode = {
+			.as_EventPositionBase = {
+				.handle_event = &handle_event,
+				.waiting_new_event = false,
+			},
+			.specification = spec,
+			.inputs = EMPTY_GRAPH_CHANNEL_LIST,
+			.outputs = EMPTY_GRAPH_CHANNEL_LIST,
+		},
+		.has_ns = has_ns,
+		.has_maj = has_maj,
+		.has_min = has_min,
+		.has_payload = has_payload,
+		.source = source,
+	};
+	return &node->as_GraphNode;
+}
+
+static void destroy
+(GraphNodeSpecification * self, GraphNode * target)
+{
+	(void) self;
+	free(target);
+}
+
+GraphNodeSpecification nodespec_assign = (GraphNodeSpecification) {
+	.create = &create,
+	.destroy = &destroy,
+	.register_io = NULL,
+	.name = "assign",
+	.documentation = "Assigns field(s) in an event\nAccepts events on any connector\nSends events on all connectors"
+	                 "\nOption 'namespace' (optional): new event code namespace"
+	                 "\nOption 'major' (optional): new event code major"
+	                 "\nOption 'minor' (optional): new event code minor"
+	                 "\nOption 'payload' (optional): new event payload"
+	,
+};
+
+MODULE_CONSTRUCTOR(init)
+{
+	register_graph_node_specification(&nodespec_assign);
+}