From 4f26d6f2a1a0efb7fa15999f9cc00d8673220e97 Mon Sep 17 00:00:00 2001
From: Michael Stapelberg <michael@stapelberg.de>
Date: Fri, 20 Jan 2012 10:52:45 +0000
Subject: [PATCH] Bugfix: Setup the _NET_SUPPORTING_WM_CHECK atom in a
 standards-compliant way

This makes chrome (and probably other apps, too) receive changes of the
_NET_ACTIVE_WINDOW and thus show its bookmark dialog properly.

Fixes: #544
---
 include/ewmh.h |  6 ++++++
 src/ewmh.c     | 38 ++++++++++++++++++++++++++++++++++++++
 src/main.c     | 11 +----------
 3 files changed, 45 insertions(+), 10 deletions(-)

diff --git a/include/ewmh.h b/include/ewmh.h
index bde8f319..aacd1510 100644
--- a/include/ewmh.h
+++ b/include/ewmh.h
@@ -40,4 +40,10 @@ void ewmh_update_active_window(xcb_window_t window);
  */
 void ewmh_update_client_list_stacking(xcb_window_t *stack, int num_windows);
 
+/**
+ * Set up the EWMH hints on the root window.
+ *
+ */
+void ewmh_setup_hints();
+
 #endif
diff --git a/src/ewmh.c b/src/ewmh.c
index 92ad88b8..a11d4658 100644
--- a/src/ewmh.c
+++ b/src/ewmh.c
@@ -126,3 +126,41 @@ void ewmh_update_client_list_stacking(xcb_window_t *stack, int num_windows) {
         num_windows,
         stack);
 }
+
+/*
+ * Set up the EWMH hints on the root window.
+ *
+ */
+void ewmh_setup_hints() {
+    xcb_atom_t supported_atoms[] = {
+#define xmacro(atom) A_ ## atom,
+#include "atoms.xmacro"
+#undef xmacro
+    };
+
+    /* Set up the window manager’s name. According to EWMH, section "Root Window
+     * Properties", to indicate that an EWMH-compliant window manager is
+     * present, a child window has to be created (and kept alive as long as the
+     * window manager is running) which has the _NET_SUPPORTING_WM_CHECK and
+     * _NET_WM_ATOMS. */
+    xcb_window_t child_window = xcb_generate_id(conn);
+    xcb_create_window(
+        conn,
+        XCB_COPY_FROM_PARENT, /* depth */
+        child_window, /* window id */
+        root, /* parent */
+        0, 0, 1, 1, /* dimensions (x, y, w, h) */
+        0, /* border */
+        XCB_WINDOW_CLASS_INPUT_ONLY, /* window class */
+        XCB_COPY_FROM_PARENT, /* visual */
+        0,
+        NULL);
+    xcb_change_property(conn, XCB_PROP_MODE_REPLACE, child_window, A__NET_SUPPORTING_WM_CHECK, XCB_ATOM_WINDOW, 32, 1, &child_window);
+    xcb_change_property(conn, XCB_PROP_MODE_REPLACE, child_window, A__NET_WM_NAME, A_UTF8_STRING, 8, strlen("i3"), "i3");
+    xcb_change_property(conn, XCB_PROP_MODE_REPLACE, root, A__NET_SUPPORTING_WM_CHECK, XCB_ATOM_WINDOW, 32, 1, &child_window);
+
+    /* I’m not entirely sure if we need to keep _NET_WM_NAME on root. */
+    xcb_change_property(conn, XCB_PROP_MODE_REPLACE, root, A__NET_WM_NAME, A_UTF8_STRING, 8, strlen("i3"), "i3");
+
+    xcb_change_property(conn, XCB_PROP_MODE_REPLACE, root, A__NET_SUPPORTED, XCB_ATOM_ATOM, 32, 16, supported_atoms);
+}
diff --git a/src/main.c b/src/main.c
index 062a4862..5a3468da 100644
--- a/src/main.c
+++ b/src/main.c
@@ -544,16 +544,7 @@ int main(int argc, char *argv[]) {
 
     property_handlers_init();
 
-    /* Set up the atoms we support */
-    xcb_atom_t supported_atoms[] = {
-#define xmacro(atom) A_ ## atom,
-#include "atoms.xmacro"
-#undef xmacro
-    };
-    xcb_change_property(conn, XCB_PROP_MODE_REPLACE, root, A__NET_SUPPORTED, XCB_ATOM_ATOM, 32, 16, supported_atoms);
-    /* Set up the window manager’s name */
-    xcb_change_property(conn, XCB_PROP_MODE_REPLACE, root, A__NET_SUPPORTING_WM_CHECK, XCB_ATOM_WINDOW, 32, 1, &root);
-    xcb_change_property(conn, XCB_PROP_MODE_REPLACE, root, A__NET_WM_NAME, A_UTF8_STRING, 8, strlen("i3"), "i3");
+    ewmh_setup_hints();
 
     keysyms = xcb_key_symbols_alloc(conn);
 
-- 
2.39.5