Establish multi backend support

1 files changed, 107 insertions, 0 deletions

diff --git a/backend/multi/backend.c b/backend/multi/backend.c
new file mode 100644
index 00000000..e3d87ccc
--- /dev/null
+++ b/backend/multi/backend.c
@@ -0,0 +1,107 @@
+#include <stdbool.h>
+#include <stdlib.h>
+#include <wlr/backend/interface.h>
+#include <wlr/common/log.h>
+#include "backend/multi.h"
+#include "common/log.h"
+
+struct subbackend_state {
+	struct wlr_backend *backend;
+	struct wlr_backend *container;
+	struct wl_listener input_add;
+	struct wl_listener input_remove;
+	struct wl_listener output_add;
+	struct wl_listener output_remove;
+};
+
+static bool multi_backend_init(struct wlr_backend_state *state) {
+	for (size_t i = 0; i < state->backends->length; ++i) {
+		struct subbackend_state *sub = state->backends->items[i];
+		if (!wlr_backend_init(sub->backend)) {
+			wlr_log(L_ERROR, "Failed to initialize backend %zd", i);
+			return false;
+		}
+	}
+	return true;
+}
+
+static void multi_backend_destroy(struct wlr_backend_state *state) {
+	for (size_t i = 0; i < state->backends->length; ++i) {
+		struct subbackend_state *sub = state->backends->items[i];
+		wlr_backend_destroy(sub->backend);
+		free(sub);
+	}
+	list_free(state->backends);
+	free(state);
+}
+
+struct wlr_backend_impl backend_impl = {
+	.init = multi_backend_init,
+	.destroy = multi_backend_destroy
+};
+
+struct wlr_backend *wlr_multi_backend_create() {
+	struct wlr_backend_state *state =
+		calloc(1, sizeof(struct wlr_backend_state));
+	if (!state) {
+		wlr_log(L_ERROR, "Backend allocation failed");
+		return NULL;
+	}
+	state->backends = list_create();
+	if (!state->backends) {
+		free(state);
+		wlr_log(L_ERROR, "Backend allocation failed");
+		return NULL;
+	}
+	struct wlr_backend *backend = wlr_backend_create(&backend_impl, state);
+	state->backend = backend;
+	return backend;
+}
+
+static void input_add_reemit(struct wl_listener *listener, void *data) {
+	struct subbackend_state *state = wl_container_of(listener,
+			state, input_add);
+	wl_signal_emit(&state->container->events.input_add, data);
+}
+
+static void input_remove_reemit(struct wl_listener *listener, void *data) {
+	struct subbackend_state *state = wl_container_of(listener,
+			state, input_remove);
+	wl_signal_emit(&state->container->events.input_remove, data);
+}
+
+static void output_add_reemit(struct wl_listener *listener, void *data) {
+	struct subbackend_state *state = wl_container_of(listener,
+			state, output_add);
+	wl_signal_emit(&state->container->events.output_add, data);
+}
+
+static void output_remove_reemit(struct wl_listener *listener, void *data) {
+	struct subbackend_state *state = wl_container_of(listener,
+			state, output_remove);
+	wl_signal_emit(&state->container->events.output_remove, data);
+}
+
+void wlr_multi_backend_add(struct wlr_backend *multi,
+		struct wlr_backend *backend) {
+	struct subbackend_state *sub = calloc(1, sizeof(struct subbackend_state));
+	sub->backend = backend;
+	sub->container = multi;
+
+	sub->input_add.notify = input_add_reemit;
+	sub->input_remove.notify = input_remove_reemit;
+	sub->output_add.notify = output_add_reemit;
+	sub->output_remove.notify = output_remove_reemit;
+
+	wl_list_init(&sub->input_add.link);
+	wl_list_init(&sub->input_remove.link);
+	wl_list_init(&sub->output_add.link);
+	wl_list_init(&sub->output_remove.link);
+
+	wl_signal_add(&backend->events.input_add, &sub->input_add);
+	wl_signal_add(&backend->events.input_remove, &sub->input_remove);
+	wl_signal_add(&backend->events.output_add, &sub->output_add);
+	wl_signal_add(&backend->events.output_remove, &sub->output_remove);
+
+	list_add(multi->state->backends, sub);
+}