feat(tray): 添加 tray 相关接口并融入现有启动流程

src/backend/x11/backend.c

@@ -774,7 +774,8 @@ void backend_scan_result_destroy(backend_scan_result_t *result) {
 backend_bar_window_t backend_create_bar_window(
   backend_t *backend,
   rect_t geometry,
-  uint32_t bg_pixel
+  uint32_t bg_pixel,
+  bool enable_tray
 ) {
   auto conn = backend->conn;
   auto root = backend->screen->root;

src/interface/backend.h

@@ -5,6 +5,7 @@
 
 #include "interface/effect.h"
 #include "interface/event.h"
+#include "interface/tray.h"
 #include "interface/types.h"
 
 typedef struct backend_t backend_t;
@@ -69,11 +70,13 @@ void backend_scan_result_destroy(backend_scan_result_t *result);
 typedef struct backend_bar_window_t {
   window_id_t window_id;
   cairo_t *cr;
+  tray_t tray;
 } backend_bar_window_t;
 
 backend_bar_window_t backend_create_bar_window(
   backend_t *backend,
   rect_t geometry,
-  uint32_t bg_pixel
+  uint32_t bg_pixel,
+  bool enable_tray
 );
 void backend_flush(backend_t *backend);

src/interface/tray.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "interface/types.h"
+
+typedef void (*tray_icons_change_cb_t)(void *user_data);
+
+typedef struct tray_api_t {
+  /**
+   * @brief 获取 tray 当前挂载的 bar window id
+   *
+   * @detail    如果返回的 window_id 是 ZDWM_WINDOW_ID_INVALID 则表示 tray
+   *            功能未开启，无 tray 需要挂载
+   */
+  window_id_t (*host_window)(void *handle);
+  /* 获取当前 icon 数量 */
+  size_t (*icon_count)(void *handle);
+  /* 获取每个 icon 的边长， icon 长宽一样，都等于 bar_height */
+  int32_t (*icon_size)(void *handle);
+  /* 将 tray 的 icon 容器窗口起点放到 bar 中 x 这个位置 */
+  void (*place)(void *handle, int32_t x);
+  /* 设置 icon 数量变化回调 */
+  void (*set_listener)(
+    void *handle,
+    tray_icons_change_cb_t cb,
+    void *user_data
+  );
+} tray_api_t;
+
+typedef struct tray_t {
+  tray_api_t api;
+  void *handle;
+} tray_t;

src/runtime/runtime.c

@@ -121,7 +121,8 @@ static void runtime_init_bar(runtime_t *runtime) {
       .height = bar_height,
     };
     auto color = bar->palette.bg.argb;
-    auto bar_window = backend_create_bar_window(backend, bar_rect, color);
+    auto bar_window =
+      backend_create_bar_window(backend, bar_rect, color, false);
     auto bar_output = &bar->bars[i];
     bar_output->cr = bar_window.cr;
     bar_output->window_id = bar_window.window_id;