Grab key by mruby

Makefile

@@ -1,6 +1,7 @@
 current_dir := $(shell pwd)
 CSRCS := $(wildcard tools/xkremap/*.[ch])
-RBSRCS := $(wildcard mrblib/xkremap/*.rb)
+MRBSRCS := $(wildcard mrblib/xkremap/*.rb)
+MRBCSRCS := $(wildcard src/*.[ch])
 .PHONY: all
 
 all: xkremap
@@ -12,5 +13,5 @@ mruby:
 	curl -L --fail --retry 3 --retry-delay 1 https://github.com/mruby/mruby/archive/1.2.0.tar.gz -s -o - | tar zxf -
 	mv mruby-1.2.0 $@
 
-mruby/build/host/bin/xkremap: mruby build_config.rb $(CSRCS) $(RBSRCS)
+mruby/build/host/bin/xkremap: mruby build_config.rb $(CSRCS) $(MRBSRCS) $(MRBCSRCS)
 	cd mruby && MRUBY_CONFIG="$(current_dir)/build_config.rb" make

mrblib/xkremap/event_handler.rb

@@ -5,7 +5,7 @@ module Xkremap
     def initialize(config, display)
       @config  = config
       @display = display
-      # grab keys
+      XlibWrapper.grab_keys(@display)
     end
 
     def handle_key_press(keycode, state)

src/display.c

@@ -0,0 +1,45 @@
+#include <X11/Xlib.h>
+#include "mruby.h"
+#include "mruby/data.h"
+
+struct mrb_display {
+  Display *display;
+};
+
+static void
+mrb_display_free(mrb_state *mrb, void *ptr)
+{
+  struct mrb_display *display = (struct mrb_display *)ptr;
+  if (display != NULL) {
+    mrb_free(mrb, display);
+  }
+}
+
+struct mrb_data_type mrb_display_type = { "Display", mrb_display_free };
+
+mrb_value
+mrb_wrap_x_display(mrb_state *mrb, Display *display)
+{
+  struct RClass *mXkremap = mrb_module_get(mrb, "Xkremap");
+  struct RClass *cDisplay = mrb_class_get_under(mrb, mXkremap, "Display");
+
+  struct mrb_display *display_ptr = (struct mrb_display *)mrb_malloc(mrb, sizeof(struct mrb_display));
+  display_ptr->display = display;
+  mrb_value display_obj = mrb_obj_value(mrb_data_object_alloc(mrb, cDisplay, NULL, &mrb_display_type));
+  DATA_TYPE(display_obj) = &mrb_display_type;
+  DATA_PTR(display_obj)  = display_ptr;
+  return display_obj;
+}
+
+Display*
+extract_x_display(mrb_state *mrb, mrb_value display_obj)
+{
+  struct mrb_display *display_ptr = (struct mrb_display *)mrb_get_datatype(mrb, display_obj, &mrb_display_type);
+  return display_ptr->display;
+}
+
+void
+mrb_xkremap_display_init(mrb_state *mrb, struct RClass *mXkremap)
+{
+  mrb_define_class_under(mrb, mXkremap, "Display", mrb->object_class);
+}

src/xkremap_gem.c

@@ -0,0 +1,20 @@
+#include "mruby.h"
+
+extern void mrb_mruby_xkremap_gem_init(mrb_state *mrb);
+extern void mrb_xkremap_xlib_wrapper_init(mrb_state *mrb, struct RClass *mXkremap);
+extern void mrb_xkremap_display_init(mrb_state *mrb, struct RClass *mXkremap);
+
+void
+mrb_xkremap_gem_init(mrb_state *mrb)
+{
+  struct RClass *mXkremap = mrb_define_module(mrb, "Xkremap");
+
+  mrb_xkremap_xlib_wrapper_init(mrb, mXkremap);
+  mrb_xkremap_display_init(mrb, mXkremap);
+  mrb_gc_arena_restore(mrb, 0);
+}
+
+void
+mrb_xkremap_gem_final(mrb_state *mrb)
+{
+}

src/xlib_wrapper.c

@@ -0,0 +1,25 @@
+#include <X11/Xlib.h>
+#include <X11/keysym.h>
+#include "mruby.h"
+
+extern Display* extract_x_display(mrb_state *mrb, mrb_value display_obj);
+
+mrb_value
+mrb_xw_grab_keys(mrb_state *mrb, mrb_value self)
+{
+  mrb_value display_obj;
+  mrb_get_args(mrb, "o", &display_obj);
+  Display *display = extract_x_display(mrb, display_obj);
+
+  Window root = XDefaultRootWindow(display);
+  XGrabKey(display, XKeysymToKeycode(display, XK_b), ControlMask, root, True, GrabModeAsync, GrabModeAsync);
+
+  return mrb_nil_value();
+}
+
+void
+mrb_xkremap_xlib_wrapper_init(mrb_state *mrb, struct RClass *mXkremap)
+{
+  struct RClass *cXlibWrapper = mrb_define_class_under(mrb, mXkremap, "XlibWrapper", mrb->object_class);
+  mrb_define_class_method(mrb, cXlibWrapper, "grab_keys", mrb_xw_grab_keys, MRB_ARGS_REQ(1));
+}

tools/xkremap/event_handler.c

@@ -1,12 +1,15 @@
 #include <X11/Xlib.h>
 #include <mruby.h>
 
+extern mrb_value mrb_wrap_x_display(mrb_state *mrb, Display *display);
+
 mrb_value
 new_event_handler(mrb_state *mrb, mrb_value config, Display *display)
 {
   struct RClass *mXkremap = mrb_module_get(mrb, "Xkremap");
   struct RClass *cEventHandler = mrb_class_get_under(mrb, mXkremap, "EventHandler");
-  return mrb_funcall(mrb, mrb_obj_value(cEventHandler), "new", 2, config, mrb_nil_value());
+  mrb_value display_obj = mrb_wrap_x_display(mrb, display);
+  return mrb_funcall(mrb, mrb_obj_value(cEventHandler), "new", 2, config, display_obj);
 }
 
 void