扫描窗口管理器启动时需要管理的窗口

src/CMakeLists.txt

@@ -27,6 +27,7 @@ find_package(PkgConfig REQUIRED)
 pkg_check_modules(XCB REQUIRED
     xcb
     xcb-cursor
+    xcb-ewmh
     xcb-icccm
     xcb-keysyms
     xcb-util

src/include/xcb.h

@@ -2,6 +2,9 @@
 
 #include <stdbool.h>
 #include <stdint.h>
+#include <xcb/xproto.h>
+
+bool has_other_wm_running(void);
 
 typedef struct monitor_rect_t monitor_rect_t;
 struct monitor_rect_t {
@@ -11,6 +14,11 @@ struct monitor_rect_t {
   uint32_t height;
   monitor_rect_t *next;
 };
-
-bool has_other_wm_running(void);
 monitor_rect_t *detect_monitor_rect(void);
+
+typedef struct window_list_t {
+  uint32_t count;
+  xcb_window_t *list;
+} window_list_t;
+window_list_t *scan_window_list(void);
+void free_window_list(window_list_t *window_list);

src/main.c

@@ -21,5 +21,16 @@ int main(int argc, char *argv[]) {
     }
   }
 
+  window_list_t *window_list = scan_window_list();
+  if (window_list) {
+    for (uint32_t i = 0; i < window_list->count; i++) {
+      printf("window[%u]: 0x%x\n", i, window_list->list[i]);
+    }
+  } else {
+    printf("no window\n");
+  }
+
+  free_window_list(window_list);
+
   return 0;
 }

src/xcb/xcb-private.h

@@ -3,3 +3,4 @@
 #include <xcb/xcb.h>
 
 extern xcb_connection_t *conn;
+extern xcb_screen_t *screen;

src/xcb/xcb.c

@@ -1,13 +1,19 @@
 #include "xcb.h"
 
+#include <stdint.h>
+#include <stdlib.h>
 #include <xcb/xcb.h>
 #include <xcb/xcb_aux.h>
+#include <xcb/xcb_ewmh.h>
+#include <xcb/xcb_icccm.h>
 #include <xcb/xinerama.h>
+#include <xcb/xproto.h>
 
 #include "utils.h"
 #include "xcb-private.h"
 
 xcb_connection_t *conn = NULL;
+xcb_screen_t *screen = NULL;
 
 bool has_other_wm_running(void) {
   conn = xcb_connect(NULL, NULL);
@@ -17,7 +23,7 @@ bool has_other_wm_running(void) {
 
   const xcb_setup_t *setup = xcb_get_setup(conn);
   xcb_screen_iterator_t iter = xcb_setup_roots_iterator(setup);
-  xcb_screen_t *screen = iter.data;
+  screen = iter.data;
   uint32_t mask = XCB_CW_EVENT_MASK;
   xcb_params_cw_t params = {
     .event_mask = XCB_EVENT_MASK_LEAVE_WINDOW | XCB_EVENT_MASK_ENTER_WINDOW |
@@ -36,6 +42,14 @@ bool has_other_wm_running(void) {
   return false;
 }
 
+/**
+ * 使用 xinerama 扩展探测每个屏幕的配置信息
+ *
+ * @TODO: 后续考虑兼容无 xinerama 扩展或扩展未启用的情况
+ * 当前仅需函数在自己环境下能正常工作即可，先不考虑其他环境
+ *
+ * @note: 返回值使用完后记得释放其内存
+ */
 monitor_rect_t *detect_monitor_rect(void) {
   monitor_rect_t *list, *prev;
   xcb_xinerama_query_screens_cookie_t cookie = xcb_xinerama_query_screens(conn);
@@ -68,3 +82,73 @@ monitor_rect_t *detect_monitor_rect(void) {
 
   return list;
 }
+
+static xcb_ewmh_connection_t *ewmh = NULL;
+static void init_ewmh_extension(void) {
+  if (ewmh) return;
+
+  ewmh = ecalloc(1, sizeof(xcb_ewmh_connection_t));
+  xcb_intern_atom_cookie_t *cookie = xcb_ewmh_init_atoms(conn, ewmh);
+  if (!xcb_ewmh_init_atoms_replies(ewmh, cookie, NULL)) {
+    free(ewmh);
+    ewmh = NULL;
+    return;
+  }
+
+  screen = ewmh->screens[ewmh->nb_screens - 1];
+}
+
+/**
+ * 扫描窗口列表
+ * @returns 若无窗口，返回 NULL，否则返回窗口列表
+ * @note: 返回的窗口列表数据使用完后使用 free_window_list 释放
+ */
+window_list_t *scan_window_list(void) {
+  init_ewmh_extension();
+
+  xcb_query_tree_cookie_t cookie = xcb_query_tree(conn, screen->root);
+  xcb_query_tree_reply_t *reply = xcb_query_tree_reply(conn, cookie, NULL);
+  xcb_window_t *list = xcb_query_tree_children(reply);
+  int len = xcb_query_tree_children_length(reply);
+
+  uint32_t count = 0;
+  xcb_window_t temp_windoow_array[len];
+  for (int i = 0; i < len; i++) {
+    xcb_window_t window = list[i];
+
+    xcb_get_window_attributes_cookie_t wa_cookie =
+      xcb_get_window_attributes(conn, window);
+    xcb_get_window_attributes_reply_t *reply =
+      xcb_get_window_attributes_reply(conn, wa_cookie, NULL);
+    uint8_t override_redirect = reply->override_redirect;
+    uint8_t map_state = reply->map_state;
+    free(reply);
+    if (override_redirect || map_state != XCB_MAP_STATE_VIEWABLE) continue;
+
+    xcb_window_t transient_for = XCB_NONE;
+    xcb_get_property_cookie_t p_cookie =
+      xcb_icccm_get_wm_transient_for(conn, window);
+    xcb_icccm_get_wm_transient_for_reply(conn, p_cookie, &transient_for, NULL);
+    if (transient_for != XCB_NONE) continue;
+
+    temp_windoow_array[count] = window;
+    count++;
+  }
+
+  if (!count) return NULL;
+
+  xcb_window_t *window_list = ecalloc(count, sizeof(xcb_window_t));
+  for (uint32_t i = 0; i < count; i++) window_list[i] = temp_windoow_array[i];
+
+  window_list_t *r = ecalloc(1, sizeof(window_list_t));
+  r->count = count;
+  r->list = window_list;
+
+  return r;
+}
+
+void free_window_list(window_list_t *window_list) {
+  if (window_list == NULL) return;
+  free(window_list->list);
+  free(window_list);
+}