Add "modifiers" 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
+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
 
 all: $(MAIN)
 

config.cfg

@@ -1,3 +1,7 @@
+constants = {
+	my_modifier = 9;
+};
+
 enums = {
 	namespaces: ["stdin", "clickpad"];
 };
@@ -42,7 +46,21 @@ nodes = {
 	select_key_events = {
 		type = "router";
 		options = {
-			predicates = ["key_event"];
+			predicates = (
+				"key_event",
+				{
+					type = "or";
+					inverted = 1;
+					args = ["key_event"];
+				}
+			);
+		};
+	};
+	set_modifier = {
+		type = "modifiers";
+		options = {
+			operation = "set";
+			modifiers = ["my_modifier"];
 		};
 	};
 };
@@ -55,7 +73,13 @@ channels = ({
 	to: ("select_key_events", 1);
 }, {
 	from: ("select_key_events", 0);
+	to: ("set_modifier", 0);
+}, {
+	from: ("set_modifier", 0);
 	to: ("print", 0);
+}, {
+	from: ("select_key_events", 1);
+	to: ("print", 1);
 });
 
 // vim: ft=libconfig

nodes/modifiers.c

@@ -0,0 +1,99 @@
+#include "../graph.h"
+#include "../module_registry.h"
+
+typedef struct {
+	GraphNode as_GraphNode;
+	ModifierSet modifiers;
+	ModifierOperation operation;
+} ModifiersGraphNode;
+
+static bool
+handle_event(EventPositionBase * self, EventNode * event)
+{
+	ModifiersGraphNode *node = DOWNCAST(ModifiersGraphNode, GraphNode, DOWNCAST(GraphNode, EventPositionBase, self));
+	size_t count = node->as_GraphNode.outputs.length;
+	if (!count) {
+		event_destroy(event);
+		return true;
+	}
+	modifier_set_operation_from(&event->data.modifiers, node->modifiers, node->operation);
+	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;
+	ModifiersGraphNode * node = T_ALLOC(1, ModifiersGraphNode);
+	if (!node) {
+		return NULL;
+	}
+
+	const char *operation_name;
+	config_setting_lookup_string(config->options, "operation", &operation_name);
+	ModifierOperation op = modifier_operation_parse(operation_name);
+	if (op < 0) {
+		free(node);
+		return NULL;
+	}
+
+	config_setting_t *modifiers_setting = config_setting_get_member(config->options, "modifiers");
+	if (!modifiers_setting) {
+		free(node);
+		return NULL;
+	}
+
+	ModifierSet modifier_set = EMPTY_MODIFIER_SET;
+	size_t length = config_setting_length(modifiers_setting);
+	for (size_t i = 0; i < length; ++i) {
+		long long mod = env_resolve_constant_or(env, config_setting_get_elem(modifiers_setting, i), -1);
+		if (mod < 0 || mod > MODIFIER_MAX) {
+			continue;
+		}
+		modifier_set_set(&modifier_set, mod);
+	}
+
+	*node = (ModifiersGraphNode) {
+		.as_GraphNode = {
+			.as_EventPositionBase = {
+				.handle_event = &handle_event,
+				.waiting_new_event = false,
+			},
+			.specification = spec,
+			.inputs = EMPTY_GRAPH_CHANNEL_LIST,
+			.outputs = EMPTY_GRAPH_CHANNEL_LIST,
+		},
+		.modifiers = modifier_set,
+		.operation = op,
+	};
+	return &node->as_GraphNode;
+}
+
+static void destroy
+(GraphNodeSpecification * self, GraphNode * target)
+{
+	(void) self;
+	ModifiersGraphNode * node = DOWNCAST(ModifiersGraphNode, GraphNode, target);
+	modifier_set_destruct(&node->modifiers);
+	free(target);
+}
+
+GraphNodeSpecification nodespec_modifiers = (GraphNodeSpecification) {
+	.create = &create,
+	.destroy = &destroy,
+	.register_io = NULL,
+	.name = "modifiers",
+};
+
+MODULE_CONSTRUCTOR(init)
+{
+	register_graph_node_specification(&nodespec_modifiers);
+}