add shm_buffer class

src/bar.hpp

@@ -0,0 +1,16 @@
+// somebar - dwl bar
+// See LICENSE file for copyright and license details.
+
+#pragma once
+#include <wayland-client.h>
+#include "wlr-layer-shell-unstable-v1-client-protocol.h"
+#include "common.hpp"
+#include "shm_buffer.hpp"
+
+class Bar {
+    wl_surface *_surface {nullptr};
+    zwlr_layer_surface_v1 *_layerSurface {nullptr};
+    ShmBuffer _bufs;
+public:
+    explicit Bar(wl_output *output);
+};