ewmh: correctly set _NET_CURRENT_DESKTOP to the number of the active workspace

include/ewmh.h

@@ -0,0 +1,23 @@
+/*
+ * vim:ts=8:expandtab
+ *
+ * i3 - an improved dynamic tiling window manager
+ *
+ * © 2009 Michael Stapelberg and contributors
+ *
+ * See file LICENSE for license information.
+ *
+ */
+#ifndef _EWMH_C
+#define _EWMH_C
+
+/**
+ * Updates _NET_CURRENT_DESKTOP with the current desktop number.
+ *
+ * EWMH: The index of the current desktop. This is always an integer between 0
+ * and _NET_NUMBER_OF_DESKTOPS - 1.
+ *
+ */
+void ewmh_update_current_desktop();
+
+#endif

include/i3.h

@@ -21,7 +21,7 @@
 #ifndef _I3_H
 #define _I3_H
 
-#define NUM_ATOMS 18
+#define NUM_ATOMS 19
 
 extern xcb_connection_t *global_conn;
 extern xcb_key_symbols_t *keysyms;

include/xcb.h

@@ -61,7 +61,8 @@ enum { _NET_SUPPORTED = 0,
         WM_DELETE_WINDOW,
         UTF8_STRING,
         WM_STATE,
-        WM_CLIENT_LEADER
+        WM_CLIENT_LEADER,
+        _NET_CURRENT_DESKTOP
 };
 
 extern unsigned int xcb_numlock_mask;

src/ewmh.c

@@ -0,0 +1,32 @@
+/*
+ * vim:ts=8:expandtab
+ *
+ * i3 - an improved dynamic tiling window manager
+ *
+ * © 2009 Michael Stapelberg and contributors
+ *
+ * See file LICENSE for license information.
+ *
+ * ewmh.c: Functions to get/set certain EWMH properties easily.
+ *
+ */
+#include <stdint.h>
+
+#include "data.h"
+#include "table.h"
+#include "i3.h"
+#include "xcb.h"
+
+/*
+ * Updates _NET_CURRENT_DESKTOP with the current desktop number.
+ *
+ * EWMH: The index of the current desktop. This is always an integer between 0
+ * and _NET_NUMBER_OF_DESKTOPS - 1.
+ *
+ */
+void ewmh_update_current_desktop() {
+        uint32_t current_desktop = c_ws->num;
+        xcb_change_property(global_conn, XCB_PROP_MODE_REPLACE, root,
+                            atoms[_NET_CURRENT_DESKTOP], CARDINAL, 32, 1,
+                            &current_desktop);
+}

src/mainx.c

@@ -248,6 +248,7 @@ int main(int argc, char *argv[], char *env[]) {
         REQUEST_ATOM(UTF8_STRING);
         REQUEST_ATOM(WM_STATE);
         REQUEST_ATOM(WM_CLIENT_LEADER);
+        REQUEST_ATOM(_NET_CURRENT_DESKTOP);
 
         /* TODO: this has to be more beautiful somewhen */
         int major, minor, error;
@@ -410,6 +411,7 @@ int main(int argc, char *argv[], char *env[]) {
         GET_ATOM(UTF8_STRING);
         GET_ATOM(WM_STATE);
         GET_ATOM(WM_CLIENT_LEADER);
+        GET_ATOM(_NET_CURRENT_DESKTOP);
 
         xcb_property_set_handler(&prophs, atoms[_NET_WM_WINDOW_TYPE], UINT_MAX, handle_window_type, NULL);
         /* TODO: In order to comply with EWMH, we have to watch _NET_WM_STRUT_PARTIAL */

src/util.c

@@ -32,6 +32,7 @@
 #include "xcb.h"
 #include "client.h"
 #include "log.h"
+#include "ewmh.h"
 
 static iconv_t conversion_descriptor = 0;
 struct keyvalue_table_head by_parent = TAILQ_HEAD_INITIALIZER(by_parent);
@@ -230,6 +231,7 @@ void set_focus(xcb_connection_t *conn, Client *client, bool set_anyways) {
         c_ws->current_row = current_row;
         c_ws->current_col = current_col;
         c_ws = client->workspace;
+        ewmh_update_current_desktop();
         /* Load current_col/current_row if we switch to a client without a container */
         current_col = c_ws->current_col;
         current_row = c_ws->current_row;