fix(policy): 新增窗口后通知原焦点窗口状态变更

新增 window_get_showing_title，按 title → instance_name →
class_name → app_id 优先级取显示标题，窗口快照改用该函数，
避免标题缺失时显示为空。

.clangd

@@ -2,3 +2,4 @@
 
 Completion:
   ArgumentLists: None
+  HeaderInsertion: Never

Makefile

@@ -1,16 +1,11 @@
 MAKEFILE_ABS_PATH := $(abspath $(lastword $(MAKEFILE_LIST)))
 MAKEFILE_DIR := $(dir $(MAKEFILE_ABS_PATH))
-PWD_DIR := $(CURDIR)/
 BUILD_DIR := $(addprefix $(MAKEFILE_DIR),build)
 SRC_DIR := $(addprefix $(MAKEFILE_DIR),/)
 
 TARGET_NAME := zdwm
 TARGET := $(addprefix $(MAKEFILE_DIR),$(TARGET_NAME))
 
-ifneq ($(PWD_DIR),$(MAKEFILE_DIR))
-	TARGET := $(addprefix $(MAKEFILE_DIR),$(TARGET_NAME))
-endif
-
 
 $(TARGET_NAME): build
 
@@ -19,10 +14,10 @@ clean:
 	${RM} -r $(BUILD_DIR)
 
 run:
-	-$(shell Xephyr :3 -screen 1920x1080 -dpi `xrdb -get Xft.dpi` &)
+	Xephyr :3 -screen 1920x1080 -dpi `xrdb -get Xft.dpi`
 
 run_multiple_screen:
-	-$(shell Xephyr :3 -screen 1920x1080 -screen 1920x1080 +xinerama -dpi `xrdb -get Xft.dpi` &)
+	Xephyr :3 -screen 1920x1080 -screen 1920x1080 +xinerama -dpi `xrdb -get Xft.dpi`
 
 wm: $(TARGET_NAME)
 	DISPLAY=:3 $(TARGET)

src/backend/x11/backend.c

@@ -195,6 +195,8 @@ backend_t *backend_create(const char *display_name) {
 void backend_destroy(backend_t *backend) {
   if (!backend) return;
 
+  tray_cleanup(backend);
+
   p_delete(&backend->config_list.cfgs);
   p_clear(&backend->config_list, 1);
 
@@ -556,6 +558,7 @@ static void backend_merge_effects(
     switch (e->type) {
     case ZDWM_EFFECT_MAP_WINDOW:
       window_list_push(&backend->map, e->as.map.window);
+      window_list_push(&backend->configure, e->as.map.window);
       break;
     case ZDWM_EFFECT_UNMAP_WINDOW:
       window_list_push(&backend->unmap, e->as.unmap.window);
@@ -610,6 +613,9 @@ static void backend_merge_effects(
     case ZDWM_EFFECT_CONFIGURE_WINDOW:
       merge_window_configure_params(backend, &e->as.configure);
       break;
+    case ZDWM_EFFECT_CONFIGURE_NOTIFY:
+      window_list_push(&backend->configure, e->as.configure_notify.window);
+      break;
     case ZDWM_EFFECT_CHANGE_BORDER_COLOR: {
       xcb_change_window_attributes_value_list_t value = {
         .border_pixel = e->as.change_border_color.color->argb
@@ -641,6 +647,46 @@ static void backend_merge_effects(
   }
 }
 
+static void batch_send_configure_notify(
+  xcb_connection_t *conn,
+  xcb_window_t *windows,
+  size_t count
+) {
+  if (count == 0) return;
+
+  auto cookie_list = p_new(xcb_get_geometry_cookie_t, count);
+
+  for (size_t i = 0; i < count; ++i) {
+    auto window = windows[i];
+    cookie_list[i] = xcb_get_geometry(conn, window);
+  }
+
+  uint32_t event_mask = XCB_EVENT_MASK_STRUCTURE_NOTIFY;
+  for (size_t i = 0; i < count; ++i) {
+    auto window = windows[i];
+    auto cookie = cookie_list[i];
+    auto reply = xcb_get_geometry_reply(conn, cookie, nullptr);
+    if (!reply) continue;
+
+    xcb_configure_notify_event_t ev = {
+      .response_type = XCB_CONFIGURE_NOTIFY,
+      .event = window,
+      .window = window,
+      .above_sibling = XCB_WINDOW_NONE,
+      .x = reply->x,
+      .y = reply->y,
+      .width = reply->width,
+      .height = reply->height,
+      .border_width = reply->border_width,
+      .override_redirect = false,
+    };
+    xcb_send_event(conn, false, window, event_mask, (char *)&ev);
+    p_delete(&reply);
+  }
+
+  p_delete(&cookie_list);
+}
+
 static void backend_batch_apply_effects(backend_t *backend) {
   xcb_connection_t *conn = backend->conn;
   if (backend->unmap.count) {
@@ -670,6 +716,12 @@ static void backend_batch_apply_effects(backend_t *backend) {
 
   backend_apply_window_configure_list(backend);
 
+  {
+    auto windows = backend->configure.windows;
+    auto count = backend->configure.count;
+    batch_send_configure_notify(conn, windows, count);
+  }
+
   if (backend->update_focus) {
     backend_focus_window(backend, backend->focus_window);
   }
@@ -685,6 +737,7 @@ bool backend_apply_effect(
   window_list_reset(&backend->unmap);
   window_list_reset(&backend->map);
   window_list_reset(&backend->kill);
+  window_list_reset(&backend->configure);
 
   backend_merge_effects(backend, effects, effect_count);
   backend_batch_apply_effects(backend);
@@ -846,7 +899,15 @@ backend_bar_window_t backend_create_bar_window(
     fatal("cannot create cairo context: %s", cairo_status_to_string(statue));
   }
 
-  if (enable_tray) tray_init(backend, window_id, width, height);
+  if (enable_tray) {
+    tray_host_window_t host_window = {
+      .window = window_id,
+      .width = width,
+      .height = height,
+      .bg_pixel = bg_pixel,
+    };
+    tray_init(backend, host_window);
+  }
 
   return (backend_bar_window_t){
     .window_id = window_id,

src/backend/x11/event.c

@@ -10,6 +10,7 @@
 #include <xcb/xproto.h>
 
 #include "backend/x11/common.h"
+#include "backend/x11/tray.h"
 #include "backend/x11/window.h"
 #include "base/memory.h"
 #include "interface/backend.h"
@@ -189,6 +190,8 @@ static bool handle_map_request(
   event_t *event,
   const xcb_map_request_event_t *xcb_event
 ) {
+  if (tray_handle_map_request(backend, xcb_event)) return false;
+
   event->type = ZDWM_EVENT_WINDOW_MAP_REQUEST;
   return populate_window_event(
     backend,
@@ -202,6 +205,8 @@ static bool handle_unmap_notify(
   event_t *event,
   const xcb_unmap_notify_event_t *xcb_event
 ) {
+  if (tray_handle_unmap_notify(backend, xcb_event)) return false;
+
   event->type = ZDWM_EVENT_WINDOW_REMOVE;
   event->as.window_remove.window = xcb_event->window;
   if (XCB_EVENT_SENT(xcb_event)) {
@@ -218,6 +223,8 @@ static bool handle_destroy_notify(
   event_t *event,
   const xcb_destroy_notify_event_t *xcb_event
 ) {
+  if (tray_handle_destroy_notify(backend, xcb_event)) return false;
+
   event->type = ZDWM_EVENT_WINDOW_REMOVE;
   event->as.window_remove.window = xcb_event->window;
   event->as.window_remove.reason = ZDWM_WINDOW_REMOVE_DESTROY;
@@ -230,6 +237,8 @@ static bool handle_configure_request(
   event_t *event,
   const xcb_configure_request_event_t *xcb_event
 ) {
+  if (tray_handle_configure_request(backend, xcb_event)) return false;
+
   event->type = ZDWM_EVENT_CONFIGURE_REQUEST;
   auto data = &event->as.configure_request;
   data->window = xcb_event->window;
@@ -341,6 +350,8 @@ static bool handle_property_notify(
   event_t *event,
   const xcb_property_notify_event_t *xcb_event
 ) {
+  if (tray_handle_property_notify(backend, xcb_event)) return false;
+
   auto window_id = xcb_event->window;
   if (
     xcb_event->atom == backend->atoms.WM_NAME ||
@@ -419,6 +430,8 @@ static bool handle_client_message(
   event_t *event,
   const xcb_client_message_event_t *xcb_event
 ) {
+  if (tray_handle_client_message(backend, xcb_event)) return false;
+
   auto atoms = &backend->atoms;
 
   if (xcb_event->type == atoms->_NET_ACTIVE_WINDOW) {

src/backend/x11/internal.h

@@ -47,6 +47,8 @@
 
 #define ATOM_LIST(X)          \
   X(MANAGER)                  \
+  X(_NET_SYSTEM_TRAY_OPCODE)  \
+  X(_XEMBED)                  \
                               \
   X(COMPOUND_TEXT)            \
   X(UTF8_STRING)              \
@@ -113,6 +115,7 @@ typedef struct backend_t {
   window_list_t unmap;
   window_list_t map;
   window_list_t kill;
+  window_list_t configure;
 
   tray_host_t *tray;
 } backend_t;

src/backend/x11/tray.c

@@ -1,13 +1,16 @@
 #include "backend/x11/tray.h"
 
+#include <assert.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <xcb/xcb.h>
+#include <xcb/xcb_aux.h>
 #include <xcb/xproto.h>
 #include <zdwm/types.h>
 
 #include "backend/x11/window.h"
+#include "base/array.h"
 #include "base/log.h"
 #include "base/macros.h"
 #include "base/memory.h"
@@ -15,6 +18,24 @@
 #include "interface/types.h"
 #include "internal.h"
 
+typedef enum tray_opcode_t {
+  SYSTEM_TRAY_REQUEST_DOCK = 0,
+  SYSTEM_TRAY_BEGIN_MESSAGE = 1,
+  SYSTEM_TRAY_CANCEL_MESSAGE = 2,
+} tray_opcode_t;
+
+typedef enum xembed_message_t {
+  XEMBED_EMBEDDED_NOTIFY = 0,
+} xembed_message_t;
+
+static constexpr auto XEMBED_VERSION = 0;
+
+typedef struct tray_icon_t {
+  xcb_window_t window;
+  int32_t natural_width;
+  int32_t natural_height;
+} tray_icon_t;
+
 typedef struct tray_host_t {
   bool enabled;
   bool initialized;
@@ -22,7 +43,11 @@ typedef struct tray_host_t {
   xcb_window_t host_window;
   xcb_window_t container;
   int32_t icon_size;
+
+  tray_icon_t *icons;
   size_t icon_count;
+  size_t icon_capacity;
+
   tray_icons_change_cb_t icon_change_cb;
   void *cb_user_data;
 } tray_host_t;
@@ -37,6 +62,118 @@ static tray_host_t *get_tray_host(void *handle) {
   return tray;
 }
 
+static size_t tray_find_icon(tray_host_t *tray, xcb_window_t window) {
+  for (size_t i = 0; i < tray->icon_count; ++i) {
+    if (tray->icons[i].window == window) return i;
+  }
+
+  return SIZE_MAX;
+}
+
+static tray_icon_t *tray_get_icon(tray_host_t *tray, xcb_window_t window) {
+  for (size_t i = 0; i < tray->icon_count; ++i) {
+    auto icon = &tray->icons[i];
+    if (icon->window == window) return icon;
+  }
+
+  return nullptr;
+}
+
+static inline void tray_dispatch_callback(tray_host_t *tray) {
+  assert(tray);
+  if (tray->icon_change_cb) tray->icon_change_cb(tray->cb_user_data);
+}
+
+static void tray_release_icon_window(backend_t *backend, tray_icon_t *icon) {
+  if (!icon || icon->window == XCB_WINDOW_NONE) return;
+
+  auto tray = get_tray_host(backend);
+  if (!tray || !tray->initialized) return;
+
+  auto conn = backend->conn;
+  auto root = backend->screen->root;
+  auto window = icon->window;
+  auto mask = XCB_CW_EVENT_MASK;
+  xcb_params_cw_t params = {.event_mask = XCB_EVENT_MASK_NO_EVENT};
+  xcb_change_save_set(conn, XCB_SET_MODE_DELETE, window);
+  xcb_aux_change_window_attributes(conn, window, mask, &params);
+  xcb_reparent_window(conn, window, root, 0, 0);
+}
+
+static void tray_remove_icon_by_index(
+  backend_t *backend,
+  size_t index,
+  bool release_window
+) {
+  auto tray = backend->tray;
+  if (index >= tray->icon_count) return;
+
+  auto icon = &tray->icons[index];
+  if (release_window) tray_release_icon_window(backend, icon);
+
+  array_erase(tray->icons, tray->icon_count, index);
+  tray_dispatch_callback(tray);
+}
+
+static zdwm_size_t tray_get_icon_size(tray_host_t *tray, size_t index) {
+  auto target_size = MAX(tray->icon_size, (int32_t)1);
+  auto natural_width = tray->icons[index].natural_width;
+  auto natural_height = tray->icons[index].natural_height;
+
+  if (natural_width == 0) natural_width = target_size;
+  if (natural_height == 0) natural_height = target_size;
+
+  double width_scale = (double)target_size / (double)natural_width;
+  double height_scale = (double)target_size / (double)natural_height;
+  auto scale = MIN(width_scale, height_scale);
+  zdwm_size_t size = {
+    .width = (int32_t)(natural_width * scale),
+    .height = (int32_t)(natural_height * scale),
+  };
+  return size;
+}
+
+static void tray_layout_icons(backend_t *backend, int32_t start_x) {
+  auto tray = get_tray_host(backend);
+  if (!tray || !tray->initialized) return;
+  if (tray->container == XCB_WINDOW_NONE) return;
+
+  auto conn = backend->conn;
+  if (tray->icon_count == 0) {
+    xcb_unmap_window(conn, tray->container);
+    return;
+  }
+
+  auto height = tray->icon_size;
+  auto width = height * (int32_t)tray->icon_count;
+  xcb_configure_window_value_list_t value_list = {
+    .x = start_x,
+    .y = 0,
+    .width = (uint32_t)width,
+    .height = (uint32_t)height,
+  };
+  uint16_t value_mask = XCB_CONFIG_WINDOW_X | XCB_CONFIG_WINDOW_Y |
+                        XCB_CONFIG_WINDOW_WIDTH | XCB_CONFIG_WINDOW_HEIGHT;
+  xcb_configure_window_aux(conn, tray->container, value_mask, &value_list);
+  xcb_map_window(conn, tray->container);
+
+  for (size_t i = 0; i < tray->icon_count; ++i) {
+    auto window = tray->icons[i].window;
+    auto icon_size = tray_get_icon_size(tray, i);
+    value_mask |= XCB_CONFIG_WINDOW_BORDER_WIDTH;
+    auto offset_x = height * (int32_t)i;
+    value_list = (xcb_configure_window_value_list_t){
+      .x = offset_x + (icon_size.width - height) / 2,
+      .y = (icon_size.height - height) / 2,
+      .width = icon_size.width,
+      .height = icon_size.height,
+      .border_width = 0,
+    };
+    xcb_configure_window_aux(conn, window, value_mask, &value_list);
+    xcb_map_window(conn, window);
+  }
+}
+
 static window_id_t tray_host_window(void *handle) {
   auto tray = get_tray_host(handle);
   if (!tray) return ZDWM_WINDOW_ID_INVALID;
@@ -60,10 +197,7 @@ static void tray_place(void *handle, int32_t x) {
   auto tray = get_tray_host(handle);
   if (!tray) return;
 
-  auto conn = ((backend_t *)handle)->conn;
+  tray_layout_icons((backend_t *)handle, x);
-  uint16_t value_mask = XCB_CONFIG_WINDOW_X;
-  xcb_configure_window_value_list_t value_list = {.x = x};
-  xcb_configure_window_aux(conn, tray->container, value_mask, &value_list);
 }
 
 static void
@@ -104,12 +238,6 @@ static bool tray_intern_selection_atom(tray_host_t *tray, backend_t *backend) {
   return true;
 }
 
-typedef struct tray_host_window_t {
-  xcb_window_t window;
-  int32_t width;
-  int32_t height;
-} tray_host_window_t;
-
 static bool tray_create_container_window(
   tray_host_t *tray,
   backend_t *backend,
@@ -117,15 +245,31 @@ static bool tray_create_container_window(
 ) {
   auto conn = backend->conn;
   auto window_id = xcb_generate_id(conn);
+  auto depth = backend->screen->root_depth;
+  auto visual_id = backend->screen->root_visual;
 
+  static xcb_colormap_t colormap = XCB_NONE;
+  if (colormap == XCB_NONE) {
+    colormap = xcb_generate_id(conn);
+    auto root = backend->screen->root;
+    uint8_t alloc = XCB_COLORMAP_ALLOC_NONE;
+    xcb_create_colormap(conn, alloc, colormap, root, visual_id);
+  }
+
+  uint32_t value_mask = XCB_CW_BACK_PIXEL | XCB_CW_BORDER_PIXEL |
+                        XCB_CW_OVERRIDE_REDIRECT | XCB_CW_EVENT_MASK |
+                        XCB_CW_COLORMAP;
   xcb_create_window_value_list_t value_list = {
+    .background_pixel = host_window.bg_pixel,
+    .border_pixel = 0,
     .override_redirect = true,
     .event_mask =
-      XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY | XCB_EVENT_MASK_STRUCTURE_NOTIFY
+      XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY | XCB_EVENT_MASK_STRUCTURE_NOTIFY,
+    .colormap = colormap,
   };
   auto cookie = xcb_create_window_aux_checked(
     conn,
-    XCB_COPY_FROM_PARENT,
+    depth,
     window_id,
     host_window.window,
     (int16_t)host_window.width,
@@ -134,8 +278,8 @@ static bool tray_create_container_window(
     (uint16_t)MAX(1, host_window.height),
     0,
     XCB_WINDOW_CLASS_INPUT_OUTPUT,
-    XCB_COPY_FROM_PARENT,
+    visual_id,
-    XCB_CW_OVERRIDE_REDIRECT | XCB_CW_EVENT_MASK,
+    value_mask,
     &value_list
   );
 
@@ -210,12 +354,7 @@ static void tray_broadcast_manager(tray_host_t *tray, backend_t *backend) {
   xcb_send_event(conn, false, root, event_mask, (char *)&event);
 }
 
-void tray_init(
+void tray_init(backend_t *backend, tray_host_window_t host_window) {
-  backend_t *backend,
-  xcb_window_t host_window,
-  int32_t host_width,
-  int32_t host_height
-) {
   auto tray = get_tray_host(backend);
   if (!tray) {
     tray = p_new(tray_host_t, 1);
@@ -226,20 +365,242 @@ void tray_init(
 
   if (!tray_intern_selection_atom(tray, backend)) return;
 
-  tray_host_window_t host_window_params = {
+  if (!tray_create_container_window(tray, backend, host_window)) return;
-    .window = host_window,
-    .width = host_width,
-    .height = host_height
-  };
-  if (!tray_create_container_window(tray, backend, host_window_params)) return;
   if (!tray_take_selection_owner(tray, backend)) {
-    /* TODO: cleanup tray */
+    tray_cleanup(backend);
     return;
   }
 
   tray->enabled = true;
   tray->initialized = true;
+  tray->host_window = host_window.window;
+  tray->icon_size = host_window.height;
 
   tray_broadcast_manager(tray, backend);
+  tray_layout_icons(backend, host_window.width);
   xcb_flush(backend->conn);
 }
+
+void tray_cleanup(backend_t *backend) {
+  auto tray = backend->tray;
+  if (!tray) return;
+
+  for (size_t i = 0; i < tray->icon_count; ++i) {
+    tray_release_icon_window(backend, &tray->icons[i]);
+  }
+  p_delete(&tray->icons);
+  tray->icon_count = 0;
+  tray->icon_capacity = 0;
+
+  auto conn = backend->conn;
+
+  auto atom = tray->selection_atom;
+  if (atom != XCB_ATOM_NONE) {
+    xcb_set_selection_owner(conn, XCB_WINDOW_NONE, atom, XCB_CURRENT_TIME);
+  }
+
+  if (tray->container != XCB_WINDOW_NONE) {
+    xcb_destroy_window(conn, tray->container);
+  }
+
+  p_clear(backend->tray, 1);
+  p_delete(&backend->tray);
+}
+
+static void
+tray_select_icon_events(xcb_connection_t *conn, xcb_window_t window) {
+  xcb_params_cw_t params = {
+    .event_mask =
+      XCB_EVENT_MASK_STRUCTURE_NOTIFY | XCB_EVENT_MASK_PROPERTY_CHANGE,
+  };
+  uint32_t mask = XCB_CW_EVENT_MASK;
+  xcb_aux_change_window_attributes(conn, window, mask, &params);
+  xcb_clear_area(conn, false, window, 0, 0, 0, 0);
+}
+
+/* reference:
+ * https://specifications.freedesktop.org/xembed/latest-single/#id-1.7.4 */
+typedef struct xembed_message_data_t {
+  uint32_t message; /* message opcode */
+  uint32_t detail;  /* message detail */
+  uint32_t data1;   /* message data 1 */
+  uint32_t data2;   /* message data 2 */
+} xembed_message_data_t;
+
+static void tray_send_xembed_message(
+  backend_t *backend,
+  xcb_window_t window,
+  xembed_message_data_t message
+) {
+  auto conn = backend->conn;
+  auto message_type = backend->atoms._XEMBED;
+
+  xcb_client_message_event_t event = {
+    .response_type = XCB_CLIENT_MESSAGE,
+    .format = 32,
+    .window = window,
+    .type = message_type,
+    .data.data32 = {
+      [0] = XCB_CURRENT_TIME,
+      [1] = message.message,
+      [2] = message.detail,
+      [3] = message.data1,
+      [4] = message.data2,
+    },
+  };
+  uint32_t event_mask = XCB_EVENT_MASK_NO_EVENT;
+  xcb_send_event(conn, false, window, event_mask, (char *)&event);
+}
+
+static void tray_add_icon(backend_t *backend, xcb_window_t window) {
+  if (window == XCB_WINDOW_NONE) return;
+
+  auto tray = get_tray_host(backend);
+  if (!tray || !tray->initialized || tray_get_icon(tray, window)) return;
+
+  rect_t geometry = {0};
+  if (!window_get_geometry(backend, window, &geometry)) return;
+
+  auto icon = array_push(tray->icons, tray->icon_count, tray->icon_capacity);
+  *icon = (tray_icon_t){
+    .window = window,
+    .natural_width = geometry.width,
+    .natural_height = geometry.height,
+  };
+
+  auto conn = backend->conn;
+  auto container = tray->container;
+  xembed_message_data_t message = {
+    .message = XEMBED_EMBEDDED_NOTIFY,
+    .detail = 0,
+    .data1 = container,
+    .data2 = XEMBED_VERSION,
+  };
+  xcb_change_save_set(conn, XCB_SET_MODE_INSERT, window);
+  xcb_reparent_window(conn, window, tray->container, 0, 0);
+  tray_select_icon_events(conn, window);
+  tray_send_xembed_message(backend, window, message);
+  xcb_map_window(conn, window);
+  tray_dispatch_callback(tray);
+}
+
+bool tray_handle_client_message(
+  backend_t *backend,
+  const xcb_client_message_event_t *ev
+) {
+  auto tray = get_tray_host(backend);
+  if (!tray || !tray->enabled || !tray->initialized) return false;
+  if (ev->window != tray->container && ev->window != backend->screen->root) {
+    return false;
+  }
+
+  auto opcode = ev->data.data32[1];
+  switch (opcode) {
+  case SYSTEM_TRAY_REQUEST_DOCK:
+    auto window = ev->data.data32[2];
+    tray_add_icon(backend, window);
+    break;
+  case SYSTEM_TRAY_BEGIN_MESSAGE:
+  case SYSTEM_TRAY_CANCEL_MESSAGE:
+  default:
+    break;
+  }
+
+  xcb_flush(backend->conn);
+
+  return true;
+}
+
+bool tray_handle_configure_request(
+  backend_t *backend,
+  const xcb_configure_request_event_t *ev
+) {
+  auto tray = get_tray_host(backend);
+  if (!tray || !tray->initialized) return false;
+
+  if (ev->window == tray->container) {
+    tray_dispatch_callback(tray);
+    return true;
+  }
+
+  auto icon = tray_get_icon(tray, ev->window);
+  if (!icon) return false;
+
+  if ((ev->value_mask & XCB_CONFIG_WINDOW_WIDTH) && ev->width > 0) {
+    icon->natural_width = (int32_t)ev->width;
+  }
+  if ((ev->value_mask & XCB_CONFIG_WINDOW_HEIGHT) && ev->height > 0) {
+    icon->natural_height = (int32_t)ev->height;
+  }
+
+  tray_dispatch_callback(tray);
+  return true;
+}
+
+bool tray_handle_map_request(
+  backend_t *backend,
+  const xcb_map_request_event_t *ev
+) {
+  auto tray = get_tray_host(backend);
+  if (!tray || !tray->initialized) return false;
+
+  auto conn = backend->conn;
+  if (ev->window == tray->container) {
+    tray_dispatch_callback(tray);
+    return true;
+  }
+
+  auto icon = tray_get_icon(tray, ev->window);
+  if (!icon && ev->parent != tray->container) return false;
+
+  xcb_map_window(conn, ev->window);
+  xcb_flush(conn);
+
+  tray_dispatch_callback(tray);
+  return true;
+}
+
+bool tray_handle_property_notify(
+  backend_t *backend,
+  const xcb_property_notify_event_t *ev
+) {
+  auto tray = get_tray_host(backend);
+  if (!tray || !tray->initialized) return false;
+
+  if (ev->window == XCB_WINDOW_NONE) return false;
+  if (ev->window == tray->container) return true;
+  return tray_get_icon(tray, ev->window) != nullptr;
+}
+
+bool tray_handle_unmap_notify(
+  backend_t *backend,
+  const xcb_unmap_notify_event_t *ev
+) {
+  auto tray = get_tray_host(backend);
+  if (!tray || !tray->initialized) return false;
+
+  auto index = tray_find_icon(tray, ev->window);
+  if (index == SIZE_MAX) return ev->window == tray->container;
+
+  tray_remove_icon_by_index(backend, index, true);
+  return true;
+}
+
+bool tray_handle_destroy_notify(
+  backend_t *backend,
+  const xcb_destroy_notify_event_t *ev
+) {
+  auto tray = get_tray_host(backend);
+  if (!tray || !tray->initialized) return false;
+
+  if (ev->window == tray->container) {
+    tray_cleanup(backend);
+    return true;
+  }
+
+  auto index = tray_find_icon(tray, ev->window);
+  if (index == SIZE_MAX) return false;
+
+  tray_remove_icon_by_index(backend, index, false);
+  return true;
+}

src/backend/x11/tray.h

@@ -9,9 +9,37 @@ extern const tray_api_t tray_api;
 
 typedef struct backend_t backend_t;
 
-void tray_init(
+typedef struct tray_host_window_t {
+  xcb_window_t window;
+  int32_t width;
+  int32_t height;
+  uint32_t bg_pixel;
+} tray_host_window_t;
+
+void tray_init(backend_t *backend, tray_host_window_t host_window);
+void tray_cleanup(backend_t *backend);
+
+bool tray_handle_client_message(
   backend_t *backend,
-  xcb_window_t host_window,
+  const xcb_client_message_event_t *ev
-  int32_t host_width,
+);
-  int32_t host_height
+bool tray_handle_configure_request(
+  backend_t *backend,
+  const xcb_configure_request_event_t *ev
+);
+bool tray_handle_map_request(
+  backend_t *backend,
+  const xcb_map_request_event_t *ev
+);
+bool tray_handle_property_notify(
+  backend_t *backend,
+  const xcb_property_notify_event_t *ev
+);
+bool tray_handle_unmap_notify(
+  backend_t *backend,
+  const xcb_unmap_notify_event_t *ev
+);
+bool tray_handle_destroy_notify(
+  backend_t *backend,
+  const xcb_destroy_notify_event_t *ev
 );

src/config/defaults.c

@@ -122,7 +122,7 @@ bool config_defaults_build(
   RAISE_OR_RUN(default_mode, Super("e"), editor);
   RAISE_OR_RUN(default_mode, Super("q"), browser);
   RAISE_OR_RUN(default_mode, Super("a"), chrome);
-  BIND_DEFAULT(Super("f"), {.type = ZDWM_ACTION_WINDOW_TOGGLE_FLOATING});
+  BIND_DEFAULT(Super("f"), {.type = ZDWM_ACTION_WINDOW_TOGGLE_FULLSCREEN});
   BIND_DEFAULT(Super("m"), {.type = ZDWM_ACTION_WINDOW_TOGGLE_MAXIMIZE});
   BIND_DEFAULT(
     Super("Control+space"),

src/core/command.h

@@ -11,6 +11,7 @@ typedef enum command_type_t {
   ZDWM_COMMAND_RAISE_WINDOW,
   ZDWM_COMMAND_WITHDRAW_WINDOW,
   ZDWM_COMMAND_CONFIGURE_WINDOW,
+  ZDWM_COMMAND_NOTIFY_CONFIGURE,
   ZDWM_COMMAND_CHANGE_WINDOW_STATE,
   ZDWM_COMMAND_START_MOVE_WINDOW,
   ZDWM_COMMAND_STOP_MOVE_WINDOW,
@@ -102,6 +103,7 @@ typedef struct command_t {
     only_window_data_t raise;
     only_window_data_t withdraw;
     configure_data_t configure;
+    only_window_data_t notify_configure;
     window_state_change_command_t state_change;
     start_interaction_command_t move;
     start_interaction_command_t resize;

src/core/listeners.c

@@ -5,6 +5,7 @@
 #include "core/binding.h"
 #include "core/layout.h"
 #include "core/state.h"
+#include "core/window.h"
 
 #define FOR_EACH_LISTENER(FIELD, BODY)         \
   do {                                         \
@@ -117,7 +118,7 @@ static bool listeners_window_snapshot(
   *out = (zdwm_window_t){
     .workspace = window->workspace_id,
     .id = window->id,
-    .title = window->title,
+    .title = window_get_showing_title(window),
     .focused = workspace->focused_window_id == window->id,
     .urgent = window->urgent,
     .skip_taskbar = window->skip_taskbar,

src/core/plan.c

@@ -121,6 +121,16 @@ void plan_push_resize_effect(plan_t *plan, window_id_t window_id) {
   plan_push_effect(plan, &effect);
 }
 
+void plan_push_configure_notify_effect(plan_t *plan, window_id_t window_id) {
+  if (window_id_invalid(window_id)) return;
+
+  effect_t effect = {
+    .type = ZDWM_EFFECT_CONFIGURE_NOTIFY,
+    .as.configure_notify.window = window_id,
+  };
+  plan_push_effect(plan, &effect);
+}
+
 void plan_push_fullscreen_effect(
   plan_t *plan,
   window_id_t window_id,

src/core/plan.h

@@ -26,6 +26,7 @@ void plan_push_kill_effect(plan_t *plan, window_id_t window_id);
 void plan_push_withdraw_effect(plan_t *plan, window_id_t window_id);
 void plan_push_move_effect(plan_t *plan, window_id_t window_id);
 void plan_push_resize_effect(plan_t *plan, window_id_t window_id);
+void plan_push_configure_notify_effect(plan_t *plan, window_id_t window_id);
 void plan_push_fullscreen_effect(
   plan_t *plan,
   window_id_t window_id,

src/core/policy.c

@@ -771,6 +771,15 @@ static void route_window_state_request(
   command_buffer_push(out, &change_window_state_cmd);
 }
 
+static void
+add_notify_configure_command(command_buffer_t *out, window_id_t window) {
+  command_t notify_cmd = {
+    .type = ZDWM_COMMAND_NOTIFY_CONFIGURE,
+    .as.notify_configure = {.window = window},
+  };
+  command_buffer_push(out, &notify_cmd);
+}
+
 static void route_configure_request(
   state_t *state,
   const configure_data_t *data,
@@ -788,6 +797,7 @@ static void route_configure_request(
   }
 
   if (!state_workspace_show(state, window->workspace_id)) return;
+  add_notify_configure_command(out, data->window);
   if (window_need_layout(window)) return;
   auto workspace = state_workspace_get(state, window->workspace_id);
   if (layout_get(layouts, workspace->layout_id)) return;
@@ -938,10 +948,13 @@ static void manage_window(
   auto window = state_window_add(state, &command->info);
   auto window_id = window->id;
   auto workspace_id = command->workspace;
+  auto workspace = state_workspace_get(state, workspace_id);
+  auto old_focused_window = workspace->focused_window_id;
   state_window_set_workspace(state, window_id, workspace_id);
   set_foucs_window(ctx, workspace_id, window_id, plan);
   plan_push_grab_button_effect(plan, window_id);
   push_window_list_effect(state, plan);
+  listeners_notify_window_updated(ctx->listeners, state, old_focused_window);
   listeners_notify_window_added(ctx->listeners, state, window_id);
 
   if (window_should_fix_size(window)) {
@@ -950,7 +963,6 @@ static void manage_window(
     state_window_set_floating(state, window_id, command->floating);
   }
 
-  auto workspace = state_workspace_get(state, workspace_id);
   auto need_layout = window_need_layout(window);
   auto layout_func = layout_get(ctx->layouts, workspace->layout_id);
 
@@ -1690,6 +1702,9 @@ void policy_apply_command(
     case ZDWM_COMMAND_CONFIGURE_WINDOW:
       configure_window(state, &cmd->as.configure, plan);
       break;
+    case ZDWM_COMMAND_NOTIFY_CONFIGURE:
+      plan_push_configure_notify_effect(plan, cmd->as.notify_configure.window);
+      break;
     case ZDWM_COMMAND_CHANGE_WINDOW_STATE:
       change_window_state(ctx, &cmd->as.state_change, plan);
       break;

src/core/window.c

@@ -145,3 +145,11 @@ bool window_can_resize(const window_t *window) {
 
   return true;
 }
+
+const char *window_get_showing_title(const window_t *window) {
+  if (window->title) return window->title;
+  if (window->instance_name) return window->instance_name;
+  if (window->class_name) return window->class_name;
+  if (window->app_id) return window->app_id;
+  return nullptr;
+}

src/core/window.h

@@ -67,3 +67,4 @@ bool window_need_resize(const window_t *window, int32_t width, int32_t height);
 bool window_should_has_border(const window_t *window);
 bool window_should_fix_size(const window_t *window);
 bool window_can_resize(const window_t *window);
+const char *window_get_showing_title(const window_t *window);

src/interface/effect.h

@@ -17,6 +17,7 @@ typedef enum effect_type_t {
   ZDWM_EFFECT_MAXIMIZE_WINDOW,
   ZDWM_EFFECT_FULLSCREEN_WINDOW,
   ZDWM_EFFECT_CONFIGURE_WINDOW,
+  ZDWM_EFFECT_CONFIGURE_NOTIFY,
   ZDWM_EFFECT_CHANGE_BORDER_COLOR,
   ZDWM_EFFECT_CHANGE_WINDOW_LIST,
   ZDWM_EFFECT_RESTACK_WINDOWS,
@@ -86,6 +87,7 @@ typedef struct effect_t {
     effect_bool_window_t maximize;
     effect_bool_window_t fullscreen;
     configure_data_t configure;
+    only_window_data_t configure_notify;
     effect_change_border_color_t change_border_color;
     effect_window_list_t change_window_list;
     effect_window_list_t restack_windows;