Handling Exposure-Events

i3bar/src/main.c

@@ -2,7 +2,9 @@
 #include <i3/ipc.h>
 #include <string.h>
 #include <unistd.h>
+#include <stdlib.h>
 #include <ev.h>
+#include <xcb/xcb.h>
 
 #include "ipc.h"
 #include "outputs.h"
@@ -10,6 +12,24 @@
 #include "common.h"
 #include "xcb.h"
 
+void ev_prepare_cb(struct ev_loop *loop, ev_prepare *w, int revents) {
+	xcb_flush(xcb_connection);
+}
+
+void ev_check_cb(struct ev_loop *loop, ev_check *w, int revents) {
+	xcb_generic_event_t *event;
+	if ((event = xcb_poll_for_event(xcb_connection)) != NULL) {
+		switch (event->response_type & ~0x80) {
+			case XCB_EXPOSE:
+				draw_buttons();
+		}
+		free(event);
+	}
+}
+
+void xcb_io_cb(struct ev_loop *loop, ev_io *w, int revents) {
+}
+
 int main(int argc, char **argv) {
 	main_loop = ev_default_loop(0);
 
@@ -18,11 +38,28 @@ int main(int argc, char **argv) {
 
 	subscribe_events();
 
+	ev_io *xcb_io = malloc(sizeof(ev_io));
+	ev_prepare *ev_prep = malloc(sizeof(ev_prepare));
+	ev_check *ev_chk = malloc(sizeof(ev_check));
+
+	ev_io_init(xcb_io, &xcb_io_cb, xcb_get_file_descriptor(xcb_connection), EV_READ);
+	ev_prepare_init(ev_prep, &ev_prepare_cb);
+	ev_check_init(ev_chk, &ev_check_cb);
+
+	ev_io_start(main_loop, xcb_io);
+	ev_prepare_start(main_loop, ev_prep);
+	ev_check_start(main_loop, ev_chk);
+
 	i3_send_msg(I3_IPC_MESSAGE_TYPE_GET_OUTPUTS, NULL);
 	i3_send_msg(I3_IPC_MESSAGE_TYPE_GET_WORKSPACES, NULL);
 
 	ev_loop(main_loop, 0);
 
+	ev_prepare_stop(main_loop, ev_prep);
+	ev_check_stop(main_loop, ev_chk);
+	FREE(ev_prep);
+	FREE(ev_chk);
+
 	ev_default_destroy();
 	clean_xcb();
 	free_outputs();

i3bar/src/xcb.c

@@ -19,6 +19,10 @@ uint32_t get_colorpixel(const char *s) {
 	return (r << 16 | g << 8 | b);
 }
 
+void handle_xcb_event(xcb_generic_event_t ev) {
+
+}
+
 void init_xcb() {
 	/* FIXME: xcb_connect leaks Memory */
 	xcb_connection = xcb_connect(NULL, NULL);
@@ -77,8 +81,9 @@ void create_windows() {
 		printf("Creating Window for output %s\n", walk->name);
 
 		walk->bar = xcb_generate_id(xcb_connection);
-		mask = XCB_CW_BACK_PIXEL;
+		mask = XCB_CW_BACK_PIXEL | XCB_CW_EVENT_MASK;
 		values[0] = xcb_screens->black_pixel;
+		values[1] = XCB_EVENT_MASK_EXPOSURE;
 		xcb_create_window(xcb_connection,
 				  xcb_screens->root_depth,
 				  walk->bar,