Flesh out wayland backend somewhat, add example

backend/CMakeLists.txt

@@ -1 +1,14 @@
-add_subdirectory(wayland)
+include_directories(
+	${PROTOCOLS_INCLUDE_DIRS}
+	${WAYLAND_INCLUDE_DIR}
+)
+
+add_library(wlr-backend
+    wayland/backend.c
+    wayland/registry.c
+)
+
+target_link_libraries(wlr-backend
+    wlr-common
+    ${WAYLAND_LIBRARIES}
+)

backend/wayland/CMakeLists.txt

@@ -1,13 +0,0 @@
-include_directories(
-	${PROTOCOLS_INCLUDE_DIRS}
-	${WAYLAND_INCLUDE_DIR}
-    .
-)
-
-add_library(wlr-backend-wayland
-    backend.c
-)
-
-target_link_libraries(wlr-backend-wayland
-    ${WAYLAND_LIBRARIES}
-)

backend/wayland/backend.c

@@ -1,13 +1,49 @@
 #include <stdlib.h>
 #include <stdint.h>
 #include <wayland-server.h>
+#include <assert.h>
 #include "backend/wayland.h"
+#include "common/log.h"
 
-struct wlr_wayland_backend *wayland_backend_init(struct wl_display *display,
-		size_t outputs) {
-	struct wlr_wayland_backend *backend = calloc(
-			sizeof(struct wlr_wayland_backend), 1);
-	backend->local_display = display;
-	// TODO: obtain reference to remote display
-	return backend;
+void wlr_wl_backend_free(struct wlr_wl_backend *backend) {
+	if (!backend) {
+		return;
+	}
+	// TODO: free more shit
+	free(backend);
+}
+
+/*
+ * Initializes the wayland backend. Opens a connection to a remote wayland
+ * compositor and creates surfaces for each output, then registers globals on
+ * the specified display.
+ */
+struct wlr_wl_backend *wlr_wl_backend_init(
+		struct wl_display *display, size_t outputs) {
+	assert(display);
+	struct wlr_wl_backend *backend;
+	if (!(backend = calloc(sizeof(struct wlr_wl_backend), 1))) {
+		wlr_log(L_ERROR, "Could not allocate backend");
+		goto error;
+	}
+	if (!(backend->outputs = list_create())) {
+		wlr_log(L_ERROR, "Could not allocate output list");
+		goto error;
+	}
+	backend->local_display = display;
+	backend->remote_display = wl_display_connect(getenv("_WAYLAND_DISPLAY"));
+	if (!backend->remote_display) {
+		wlr_log(L_ERROR, "Could not connect to remote display");
+		goto error;
+	}
+	if (!(backend->remote_registry = wl_display_get_registry(
+			backend->remote_display))) {
+		wlr_log(L_ERROR, "Could not obtain reference to remote registry");
+		goto error;
+	}
+	wlr_wlb_registry_poll(backend);
+	return backend;
+error:
+	wlr_wl_backend_free(backend);
+	return NULL;
 }

backend/wayland/registry.c

@@ -0,0 +1,29 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <wayland-client.h>
+#include "backend/wayland.h"
+#include "common/log.h"
+
+static void registry_global(void *data, struct wl_registry *registry,
+		uint32_t name, const char *interface, uint32_t version) {
+	//struct wlr_wl_backend *backend = data;
+	wlr_log(L_DEBUG, "Remote wayland global: %s v%d", interface, version);
+	// TODO
+}
+
+static void registry_global_remove(void *data,
+		struct wl_registry *registry, uint32_t name) {
+	// TODO
+}
+
+static const struct wl_registry_listener registry_listener = {
+	.global = registry_global,
+	.global_remove = registry_global_remove
+};
+
+void wlr_wlb_registry_poll(struct wlr_wl_backend *backend) {
+	wl_registry_add_listener(backend->remote_registry,
+			&registry_listener, backend->remote_registry);
+	wl_display_dispatch(backend->remote_display);
+	wl_display_roundtrip(backend->remote_display);
+}