[PATCH V2] weston_wm: Implement _NET_ACTIVE_WINDOW

[Benoit Gschwind]

I updated the patch taking in account remarks from Bryce. But after a quick check
I found that on the top the current master the _NET_ACTIVE_WINDOW is not clear
when all X11 window lost the focus. I will investigate to fix this case.

Best regards

---
 xwayland/window-manager.c | 23 ++++++++++++++++++++++-
 xwayland/xwayland.h       |  2 ++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/xwayland/window-manager.c b/xwayland/window-manager.c
index db6b437..984143f 100644
--- a/xwayland/window-manager.c
+++ b/xwayland/window-manager.c
@@ -163,6 +163,9 @@ static struct weston_wm_window *
 get_wm_window(struct weston_surface *surface);
 
 static void
+weston_wm_set_net_active_window(struct weston_wm *wm, xcb_window_t window);
+
+static void
 weston_wm_window_schedule_repaint(struct weston_wm_window *window);
 
 static void
@@ -782,6 +785,12 @@ weston_wm_window_activate(struct wl_listener *listener, void *data)
 		window = get_wm_window(surface);
 	}
 
+	if (window) {
+		weston_wm_set_net_active_window(wm, window->id);
+	} else {
+		weston_wm_set_net_active_window(wm, XCB_WINDOW_NONE);
+	}
+
 	weston_wm_send_focus_window(wm, window);
 
 	if (wm->focus_window) {
@@ -1986,6 +1995,13 @@ weston_wm_handle_event(int fd, uint32_t mask, void *data)
 }
 
 static void
+weston_wm_set_net_active_window(struct weston_wm *wm, xcb_window_t window) {
+	xcb_change_property(wm->conn, XCB_PROP_MODE_REPLACE,
+			wm->screen->root, wm->atom.net_active_window,
+			wm->atom.window, 32, 1, &window);
+}
+
+static void
 weston_wm_get_visual_and_colormap(struct weston_wm *wm)
 {
 	xcb_depth_iterator_t d_iter;
@@ -2061,6 +2077,7 @@ weston_wm_get_resources(struct weston_wm *wm)
 		{ "_NET_SUPPORTING_WM_CHECK",
 					F(atom.net_supporting_wm_check) },
 		{ "_NET_SUPPORTED",     F(atom.net_supported) },
+		{ "_NET_ACTIVE_WINDOW",     F(atom.net_active_window) },
 		{ "_MOTIF_WM_HINTS",	F(atom.motif_wm_hints) },
 		{ "CLIPBOARD",		F(atom.clipboard) },
 		{ "CLIPBOARD_MANAGER",	F(atom.clipboard_manager) },
@@ -2074,6 +2091,7 @@ weston_wm_get_resources(struct weston_wm *wm)
 		{ "COMPOUND_TEXT",	F(atom.compound_text) },
 		{ "TEXT",		F(atom.text) },
 		{ "STRING",		F(atom.string) },
+		{ "WINDOW",		F(atom.window) },
 		{ "text/plain;charset=utf-8",	F(atom.text_plain_utf8) },
 		{ "text/plain",		F(atom.text_plain) },
 		{ "XdndSelection",	F(atom.xdnd_selection) },
@@ -2213,7 +2231,7 @@ weston_wm_create(struct weston_xserver *wxs, int fd)
 	struct wl_event_loop *loop;
 	xcb_screen_iterator_t s;
 	uint32_t values[1];
-	xcb_atom_t supported[5];
+	xcb_atom_t supported[6];
 
 	wm = zalloc(sizeof *wm);
 	if (wm == NULL)
@@ -2266,6 +2284,7 @@ weston_wm_create(struct weston_xserver *wxs, int fd)
 	supported[2] = wm->atom.net_wm_state_fullscreen;
 	supported[3] = wm->atom.net_wm_state_maximized_vert;
 	supported[4] = wm->atom.net_wm_state_maximized_horz;
+	supported[5] = wm->atom.net_active_window;
 	xcb_change_property(wm->conn,
 			    XCB_PROP_MODE_REPLACE,
 			    wm->screen->root,
@@ -2274,6 +2293,8 @@ weston_wm_create(struct weston_xserver *wxs, int fd)
 			    32, /* format */
 			    ARRAY_LENGTH(supported), supported);
 
+	weston_wm_set_net_active_window(wm, XCB_WINDOW_NONE);
+
 	weston_wm_selection_init(wm);
 
 	weston_wm_dnd_init(wm);
diff --git a/xwayland/xwayland.h b/xwayland/xwayland.h
index 7f4c5b1..bace079 100644
--- a/xwayland/xwayland.h
+++ b/xwayland/xwayland.h
@@ -129,6 +129,7 @@ struct weston_wm {
 		xcb_atom_t		 net_wm_moveresize;
 		xcb_atom_t		 net_supporting_wm_check;
 		xcb_atom_t		 net_supported;
+		xcb_atom_t		 net_active_window;
 		xcb_atom_t		 motif_wm_hints;
 		xcb_atom_t		 clipboard;
 		xcb_atom_t		 clipboard_manager;
@@ -141,6 +142,7 @@ struct weston_wm {
 		xcb_atom_t		 compound_text;
 		xcb_atom_t		 text;
 		xcb_atom_t		 string;
+		xcb_atom_t		 window;
 		xcb_atom_t		 text_plain_utf8;
 		xcb_atom_t		 text_plain;
 		xcb_atom_t		 xdnd_selection;
-- 
2.4.9