Add "modify_predicate" node type

Change "enabled" and "inverted" predicate flags when received events
satisfy other predicates

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
+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
 
 all: $(MAIN)
 

config.cfg

@@ -23,6 +23,31 @@ predicates = {
 			}
 		);
 	};
+	btn_touch_event = {
+		type = "and";
+		args = (
+			"key_event",
+			{
+				type = "code_minor";
+				min = "button_event.TOUCH";
+				max = "button_event.TOUCH";
+			}
+		);
+	};
+	payload_zero = {
+		type = "payload";
+		min = 0;
+		max = 0;
+	};
+	payload_one = {
+		type = "payload";
+		min = 1;
+		max = 1;
+	};
+	touch_held = {
+		type = "accept";
+		inverted = 1;
+	};
 };
 
 nodes = {
@@ -63,6 +88,20 @@ nodes = {
 			modifiers = ["my_modifier"];
 		};
 	};
+	update_touch_held = {
+		type = "modify_predicate";
+		options = {
+			target = "touch_held";
+			uninvert_on = {type: "and", args: ["btn_touch_event", "payload_one"]};
+			invert_on = {type: "and", args: ["btn_touch_event", "payload_zero"]};
+		};
+	};
+	while_touch_held = {
+		type = "router";
+		options = {
+			predicates = ["touch_held"];
+		};
+	};
 };
 
 channels = ({
@@ -79,7 +118,13 @@ channels = ({
 	to: ("print", 0);
 }, {
 	from: ("select_key_events", 1);
+	to: ("while_touch_held", 0);
+}, {
+	from: ("while_touch_held", 0);
 	to: ("print", 1);
+}, {
+	from: ("clickpad", 1);
+	to: ("update_touch_held", 0);
 });
 
 // vim: ft=libconfig

nodes/modify_predicate.c

@@ -0,0 +1,102 @@
+#include "../graph.h"
+#include "../module_registry.h"
+
+typedef struct {
+	GraphNode as_GraphNode;
+	EventPredicateHandle target;
+	EventPredicateHandle enable_on, disable_on, invert_on, uninvert_on;
+} ModifyPredicateGraphNode;
+
+static bool
+handle_event(EventPositionBase * self, EventNode * event)
+{
+	ModifyPredicateGraphNode *node = DOWNCAST(ModifyPredicateGraphNode, GraphNode, DOWNCAST(GraphNode, EventPositionBase, self));
+	bool
+		  should_enable = false,
+		  should_disable = false,
+		  should_invert = false,
+		  should_uninvert = false;
+	EventPredicateHandle target = node->target;
+	EventPredicate target_state = event_predicate_get(target);
+
+	if (target_state.enabled) {
+		should_disable = event_predicate_apply(node->disable_on, event) == EVPREDRES_ACCEPTED;
+	} else {
+		should_enable = event_predicate_apply(node->enable_on, event) == EVPREDRES_ACCEPTED;
+	}
+	if (target_state.inverted) {
+		should_uninvert = event_predicate_apply(node->uninvert_on, event) == EVPREDRES_ACCEPTED;
+	} else {
+		should_invert = event_predicate_apply(node->invert_on, event) == EVPREDRES_ACCEPTED;
+	}
+
+	if (should_enable) {
+		event_predicate_set_enabled(target, true);
+	}
+	if (should_disable) {
+		event_predicate_set_enabled(target, false);
+	}
+	if (should_invert) {
+		event_predicate_set_inverted(target, true);
+	}
+	if (should_uninvert) {
+		event_predicate_set_inverted(target, false);
+	}
+
+	event_destroy(event);
+	return true;
+}
+
+static GraphNode *
+create(GraphNodeSpecification * spec, GraphNodeConfig * config, InitializationEnvironment * env)
+{
+	(void) config;
+	(void) env;
+	ModifyPredicateGraphNode * node = T_ALLOC(1, ModifyPredicateGraphNode);
+	if (!node) {
+		return NULL;
+	}
+
+	EventPredicateHandle target = env_resolve_event_predicate(env, config_setting_get_member(config->options, "target"));
+	if (target < 0) {
+		free(node);
+		return NULL;
+	}
+
+	*node = (ModifyPredicateGraphNode) {
+		.as_GraphNode = {
+			.as_EventPositionBase = {
+				.handle_event = &handle_event,
+				.waiting_new_event = false,
+			},
+			.specification = spec,
+			.inputs = EMPTY_GRAPH_CHANNEL_LIST,
+			.outputs = EMPTY_GRAPH_CHANNEL_LIST,
+		},
+		.target = target,
+		.enable_on = env_resolve_event_predicate(env, config_setting_get_member(config->options, "enable_on")),
+		.disable_on = env_resolve_event_predicate(env, config_setting_get_member(config->options, "disable_on")),
+		.invert_on = env_resolve_event_predicate(env, config_setting_get_member(config->options, "invert_on")),
+		.uninvert_on = env_resolve_event_predicate(env, config_setting_get_member(config->options, "uninvert_on")),
+	};
+	return &node->as_GraphNode;
+}
+
+static void destroy
+(GraphNodeSpecification * self, GraphNode * target)
+{
+	(void) self;
+	free(target);
+}
+
+GraphNodeSpecification nodespec_modify_predicate = (GraphNodeSpecification) {
+	.create = &create,
+	.destroy = &destroy,
+	.register_io = NULL,
+	.name = "modify_predicate",
+};
+
+MODULE_CONSTRUCTOR(init)
+{
+	register_graph_node_specification(&nodespec_modify_predicate);
+}