检测显示器信息

src/CMakeLists.txt

@@ -1,6 +1,7 @@
 cmake_minimum_required(VERSION 3.24)
 
 set(APP_NAME "zswm")
+set(SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
 
 # generate compile_commands.json for clangd
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
@@ -14,7 +15,26 @@ project(${APP_NAME}
     LANGUAGES C
 )
 
-add_executable(${APP_NAME} main.c)
+add_executable(${APP_NAME} main.c utils.c)
 
 # use C17
 set_property(TARGET ${APP_NAME} PROPERTY C_STANDARD 17)
+
+target_include_directories(${APP_NAME} PRIVATE "${SOURCE_DIR}/include")
+
+find_package(PkgConfig REQUIRED)
+
+pkg_check_modules(XCB REQUIRED
+    xcb
+    xcb-cursor
+    xcb-icccm
+    xcb-keysyms
+    xcb-util
+    xcb-xfixes
+    xcb-xinerama
+    xcb-xrm
+)
+target_include_directories(${APP_NAME} SYSTEM PUBLIC ${XCB_INCLUDE_DIRS})
+
+add_subdirectory(xcb)
+target_link_libraries(${APP_NAME} ${LIB_XCB_NAME})

src/include/utils.h

@@ -0,0 +1,8 @@
+#pragma once
+
+#include <stddef.h>
+
+#define LENGTH(X) (sizeof(X) / sizeof(X)[0])
+
+void die(const char *format, ...);
+void *ecalloc(size_t number_of_member, size_t member_size);

src/include/xcb.h

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+
+typedef struct monitor_rect_t monitor_rect_t;
+struct monitor_rect_t {
+  int32_t x;
+  int32_t y;
+  uint32_t width;
+  uint32_t height;
+  monitor_rect_t *next;
+};
+
+bool has_other_wm_running(void);
+monitor_rect_t *detect_monitor_rect(void);

src/main.c

@@ -1 +1,25 @@
-int main(int argc, char *argv[]) { return 0; }
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "utils.h"
+#include "xcb.h"
+
+int main(int argc, char *argv[]) {
+  if (has_other_wm_running()) {
+    die("another window manager is already running");
+  }
+
+  {
+    monitor_rect_t *mr = detect_monitor_rect();
+    uint32_t i = 0;
+    while (mr) {
+      printf("mon[%u]: x: %d, y: %d, w: %u, h: %u\n", i, mr->x, mr->y,
+             mr->width, mr->height);
+      mr = mr->next;
+      free(mr);
+    }
+  }
+
+  return 0;
+}

src/utils.c

@@ -0,0 +1,32 @@
+#include "utils.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+void die(const char *fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  vfprintf(stderr, fmt, ap);
+  va_end(ap);
+
+  if (fmt[0] && fmt[strlen(fmt) - 1] == ':') {
+    fputc(' ', stderr);
+    perror(NULL);
+  } else {
+    fputc('\n', stderr);
+  }
+
+  exit(1);
+}
+
+void *ecalloc(size_t number_of_member, size_t member_size) {
+  void *p;
+
+  if (!(p = calloc(number_of_member, member_size))) {
+    die("calloc:");
+  }
+
+  return p;
+}

src/xcb/CMakeLists.txt

@@ -0,0 +1,9 @@
+set(LIB_XCB "zswm-xcb")
+set(LIB_XCB_NAME ${LIB_XCB} PARENT_SCOPE)
+
+add_library(${LIB_XCB} STATIC xcb.c)
+
+target_include_directories(${LIB_XCB} SYSTEM PUBLIC ${XCB_INCLUDE_DIRS})
+target_include_directories(${LIB_XCB} PUBLIC "${CMAKE_SOURCE_DIR}/include")
+
+target_link_libraries(${LIB_XCB} ${XCB_LIBRARIES})

src/xcb/xcb-private.h

@@ -0,0 +1,5 @@
+#pragma once
+
+#include <xcb/xcb.h>
+
+extern xcb_connection_t *conn;

src/xcb/xcb.c

@@ -0,0 +1,70 @@
+#include "xcb.h"
+
+#include <xcb/xcb.h>
+#include <xcb/xcb_aux.h>
+#include <xcb/xinerama.h>
+
+#include "utils.h"
+#include "xcb-private.h"
+
+xcb_connection_t *conn = NULL;
+
+bool has_other_wm_running(void) {
+  conn = xcb_connect(NULL, NULL);
+  if (!conn || xcb_connection_has_error(conn)) {
+    die("connection:");
+  }
+
+  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;
+  uint32_t mask = XCB_CW_EVENT_MASK;
+  xcb_params_cw_t params = {
+    .event_mask = XCB_EVENT_MASK_LEAVE_WINDOW | XCB_EVENT_MASK_ENTER_WINDOW |
+                  XCB_EVENT_MASK_POINTER_MOTION |
+                  XCB_EVENT_MASK_SUBSTRUCTURE_REDIRECT |
+                  XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY,
+  };
+  xcb_void_cookie_t cookie =
+    xcb_aux_change_window_attributes(conn, screen->root, mask, &params);
+  xcb_generic_error_t *error = xcb_request_check(conn, cookie);
+  if (error) {
+    xcb_disconnect(conn);
+    return true;
+  }
+
+  return false;
+}
+
+monitor_rect_t *detect_monitor_rect(void) {
+  monitor_rect_t *list, *prev;
+  xcb_xinerama_query_screens_cookie_t cookie = xcb_xinerama_query_screens(conn);
+  xcb_xinerama_query_screens_reply_t *reply =
+    xcb_xinerama_query_screens_reply(conn, cookie, NULL);
+  xcb_xinerama_screen_info_t *screen_info =
+    xcb_xinerama_query_screens_screen_info(reply);
+
+  if (screen_info == NULL) {
+    die("no monitor finded");
+  }
+
+  int count = xcb_xinerama_query_screens_screen_info_length(reply);
+  for (int i = 0; i < count; i++) {
+    monitor_rect_t *m = ecalloc(1, sizeof(monitor_rect_t));
+    xcb_xinerama_screen_info_t info = screen_info[i];
+    m->x = info.x_org;
+    m->y = info.y_org;
+    m->width = info.width;
+    m->height = info.height;
+    m->next = NULL;
+
+    if (i == 0) {
+      list = m;
+    } else {
+      prev->next = m;
+    }
+    prev = m;
+  }
+
+  return list;
+}