feat(backend): 添加光标支持

src/backend/x11/cursor.c

@@ -0,0 +1,51 @@
+#include <stddef.h>
+#include <xcb/xcb_cursor.h>
+#include <xcb/xproto.h>
+
+#include "base/macros.h"
+#include "base/memory.h"
+#include "internal.h"
+
+static const char *const cursor_name_map[] = {
+  [ZDWM_CURSOR_NORMAL] = "left_ptr",
+  [ZDWM_CURSOR_MOVE]   = "fleur",
+  [ZDWM_CURSOR_RESIZE] = "bottom_right_corner",
+};
+
+static xcb_cursor_context_t *get_xcb_cursor_context(backend_t *backend) {
+  if (backend->cursor_context) return backend->cursor_context;
+
+  auto conn   = backend->conn;
+  auto screen = backend->screen;
+  if (xcb_cursor_context_new(conn, screen, &backend->cursor_context) == 0) {
+    return backend->cursor_context;
+  }
+
+  return nullptr;
+}
+
+void cursor_init(backend_t *backend) {
+  auto ctx = get_xcb_cursor_context(backend);
+  if (!ctx) return;
+
+  for (size_t i = 0; i < countof(backend->cursors); ++i) {
+    auto cursor_name    = cursor_name_map[i];
+    backend->cursors[i] = xcb_cursor_load_cursor(ctx, cursor_name);
+  }
+}
+
+void cursor_cleanup(backend_t *backend) {
+  constexpr size_t count = countof(backend->cursors);
+  for (size_t i = 0; i < count; ++i) {
+    xcb_free_cursor(backend->conn, backend->cursors[i]);
+  }
+  p_clear(backend->cursors, count);
+  xcb_cursor_context_free(backend->cursor_context);
+  backend->cursor_context = nullptr;
+}
+
+xcb_cursor_t cursor_get_xcb_cursor(backend_t *backend, cursor_t cursor) {
+  if (backend->cursor_context == nullptr) return XCB_CURSOR_NONE;
+
+  return backend->cursors[cursor];
+}