使用 _NET_WM_DESKTOP 保存和恢复 client 所在 tag

src/atoms-list.txt

@@ -11,6 +11,7 @@ COMPOUND_TEXT
 
 _NET_ACTIVE_WINDOW
 _NET_CLIENT_LIST
+_NET_WM_DESKTOP
 _NET_WM_NAME
 _NET_WM_ICON_NAME
 _NET_SUPPORTING_WM_CHECK

src/client.c

@@ -77,6 +77,8 @@ task_in_tag_t *client_get_previous_task_in_tag(client_t *client, tag_t *tag) {
 static void client_add_to_tag(client_t *client, tag_t *tag) {
   if (client_get_task_in_tag(client, tag)) return;
 
+  xwindow_set_wm_desktop(client->window, tag->index);
+
   task_in_tag_t *task = p_new(task_in_tag_t, 1);
   task->client = client;
   task->next = tag->task_list;
@@ -145,6 +147,20 @@ static inline void client_init_geometry(client_t *c) {
   client_change_border_width(c, wm.border_width);
 }
 
+static void client_init_tag_by_wm_desktop(client_t *client) {
+  uint32_t tag_index = 0;
+  if (!xwindow_get_wm_desktop(client->window, &tag_index)) return;
+  for (monitor_t *m = wm.monitor_list; m; m = m->next) {
+    for (tag_t *tag = m->tag_list; tag; tag = tag->next) {
+      if (tag->index == tag_index) {
+        client->monitor = m;
+        client->tags = tag->mask;
+        return;
+      }
+    }
+  }
+}
+
 void client_manage(xcb_window_t window,
                    xcb_get_geometry_reply_t *geometry_reply) {
   client_t *c = p_new(client_t, 1);
@@ -198,6 +214,7 @@ void client_manage(xcb_window_t window,
     }
 
     client_init_geometry(c);
+    client_init_tag_by_wm_desktop(c);
     client_tags_apply(c);
   }
 

src/xwindow.c

@@ -206,6 +206,25 @@ void xwindow_get_text_property(xcb_window_t window, xcb_atom_t property,
   p_delete(&reply);
 }
 
+void xwindow_set_wm_desktop(xcb_window_t window, uint32_t desktop) {
+  xcb_change_property(wm.xcb_conn, XCB_PROP_MODE_REPLACE, window,
+                      _NET_WM_DESKTOP, XCB_ATOM_CARDINAL, 32, 1, &desktop);
+}
+
+bool xwindow_get_wm_desktop(xcb_window_t window, uint32_t *desktop) {
+  xcb_get_property_cookie_t cookie = xcb_get_property_unchecked(
+    wm.xcb_conn, false, window, _NET_WM_DESKTOP, XCB_ATOM_CARDINAL, 0, 1);
+  xcb_get_property_reply_t *reply =
+    xcb_get_property_reply(wm.xcb_conn, cookie, nullptr);
+  if (!reply) return false;
+
+  bool success = reply->type == XCB_ATOM_CARDINAL && reply->format == 32;
+  if (success) *desktop = *(uint32_t *)xcb_get_property_value(reply);
+
+  p_delete(&reply);
+  return success;
+}
+
 xcb_window_t xwindow_get_transient_for(xcb_window_t window) {
   xcb_connection_t *conn = wm.xcb_conn;
   xcb_window_t t_window = XCB_WINDOW_NONE;

src/xwindow.h

@@ -20,6 +20,9 @@ bool xwindow_send_event(xcb_window_t window, xcb_atom_t atom);
 void xwindow_focus(xcb_window_t window);
 void xwindow_get_text_property(xcb_window_t window, xcb_atom_t property,
                                char **out);
+void xwindow_set_wm_desktop(xcb_window_t window, uint32_t desktop);
+bool xwindow_get_wm_desktop(xcb_window_t window, uint32_t *desktop);
+
 xcb_window_t xwindow_get_transient_for(xcb_window_t window);
 int32_t xwindow_get_state(xcb_window_t window);
 xcb_get_geometry_reply_t *xwindow_get_geometry_reply(xcb_window_t window);