From dfeb19b0a83b8ce57d28bf94a4f8d129993d1064 Mon Sep 17 00:00:00 2001
From: Joel Klinghed <the_jk@opera.com>
Date: Mon, 12 Jan 2026 23:06:20 +0100
Subject: Initial commit

---
 src/xcb_xkb.cc | 167 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 167 insertions(+)
 create mode 100644 src/xcb_xkb.cc

(limited to 'src/xcb_xkb.cc')

diff --git a/src/xcb_xkb.cc b/src/xcb_xkb.cc
new file mode 100644
index 0000000..3d00537
--- /dev/null
+++ b/src/xcb_xkb.cc
@@ -0,0 +1,167 @@
+#include "xcb_xkb.hh"
+
+#include <cstdint>
+#include <memory>
+#include <string>
+#include <xcb/xcb.h>
+#include <xcb/xcb_event.h>
+#define explicit dont_use_cxx_explicit
+#include <xcb/xkb.h>
+#undef explicit
+#include <utility>
+#include <xcb/xproto.h>
+#include <xkbcommon/xkbcommon-x11.h>
+#include <xkbcommon/xkbcommon.h>
+
+namespace xcb {
+
+namespace {
+
+struct KeymapDeleter {
+  void operator()(xkb_keymap* keymap) const {
+    if (keymap)
+      xkb_keymap_unref(keymap);
+  }
+};
+
+struct StateDeleter {
+  void operator()(xkb_state* state) const {
+    if (state)
+      xkb_state_unref(state);
+  }
+};
+
+struct ContextDeleter {
+  void operator()(xkb_context* context) const {
+    if (context)
+      xkb_context_unref(context);
+  }
+};
+
+class KeyboardImpl : public Keyboard {
+ public:
+  KeyboardImpl() = default;
+
+  bool init(xcb_connection_t* conn) {
+    if (!xkb_x11_setup_xkb_extension(
+            conn, XKB_X11_MIN_MAJOR_XKB_VERSION, XKB_X11_MIN_MINOR_XKB_VERSION,
+            XKB_X11_SETUP_XKB_EXTENSION_NO_FLAGS, nullptr, nullptr,
+            &first_xkb_event_, nullptr))
+      return false;
+
+    ctx_.reset(xkb_context_new(XKB_CONTEXT_NO_FLAGS));
+    if (!ctx_)
+      return false;
+    device_id_ = xkb_x11_get_core_keyboard_device_id(conn);
+    if (device_id_ == -1)
+      return false;
+    if (!update_keymap(conn))
+      return false;
+    select_events(conn);
+    return true;
+  }
+
+  bool handle_event(xcb_connection_t* conn,
+                    xcb_generic_event_t* event) override {
+    if (XCB_EVENT_RESPONSE_TYPE(event) == first_xkb_event_) {
+      auto* xkb_event = reinterpret_cast<xkb_generic_event_t*>(event);
+      if (std::cmp_equal(xkb_event->deviceID, device_id_)) {
+        switch (xkb_event->xkbType) {
+          case XCB_XKB_NEW_KEYBOARD_NOTIFY: {
+            auto* e =
+                reinterpret_cast<xcb_xkb_new_keyboard_notify_event_t*>(event);
+            if (e->changed & XCB_XKB_NKN_DETAIL_KEYCODES)
+              update_keymap(conn);
+            break;
+          }
+          case XCB_XKB_MAP_NOTIFY:
+            update_keymap(conn);
+            break;
+          case XCB_XKB_STATE_NOTIFY: {
+            auto* e = reinterpret_cast<xcb_xkb_state_notify_event_t*>(event);
+            xkb_state_update_mask(state_.get(), e->baseMods, e->latchedMods,
+                                  e->lockedMods, e->baseGroup, e->latchedGroup,
+                                  e->lockedGroup);
+            break;
+          }
+          default:
+            break;
+        }
+      }
+      return true;
+    }
+    return false;
+  }
+
+  std::string get_utf8(xcb_key_press_event_t* event) override {
+    char tmp[16];
+    xkb_state_key_get_utf8(state_.get(), event->detail, tmp, sizeof(tmp));
+    return {tmp};
+  }
+
+ private:
+  struct xkb_generic_event_t {
+    uint8_t response_type;
+    uint8_t xkbType;
+    uint16_t sequence;
+    xcb_timestamp_t time;
+    uint8_t deviceID;
+  };
+
+  bool update_keymap(xcb_connection_t* conn) {
+    auto* keymap = xkb_x11_keymap_new_from_device(ctx_.get(), conn, device_id_,
+                                                  XKB_KEYMAP_COMPILE_NO_FLAGS);
+    if (!keymap)
+      return false;
+    auto* state = xkb_x11_state_new_from_device(keymap, conn, device_id_);
+    if (!state) {
+      xkb_keymap_unref(keymap);
+      return false;
+    }
+    keymap_.reset(keymap);
+    state_.reset(state);
+    return true;
+  }
+
+  void select_events(xcb_connection_t* conn) const {
+    static const uint16_t new_keyboard_details = XCB_XKB_NKN_DETAIL_KEYCODES;
+    static const uint16_t map_parts =
+        XCB_XKB_MAP_PART_KEY_TYPES | XCB_XKB_MAP_PART_KEY_SYMS |
+        XCB_XKB_MAP_PART_MODIFIER_MAP | XCB_XKB_MAP_PART_EXPLICIT_COMPONENTS |
+        XCB_XKB_MAP_PART_KEY_ACTIONS | XCB_XKB_MAP_PART_VIRTUAL_MODS |
+        XCB_XKB_MAP_PART_VIRTUAL_MOD_MAP;
+    static const uint16_t state_details =
+        XCB_XKB_STATE_PART_MODIFIER_BASE | XCB_XKB_STATE_PART_MODIFIER_LATCH |
+        XCB_XKB_STATE_PART_MODIFIER_LOCK | XCB_XKB_STATE_PART_GROUP_BASE |
+        XCB_XKB_STATE_PART_GROUP_LATCH | XCB_XKB_STATE_PART_GROUP_LOCK;
+
+    xcb_xkb_select_events_details_t details = {};
+    details.affectNewKeyboard = new_keyboard_details;
+    details.newKeyboardDetails = new_keyboard_details;
+    details.affectState = state_details;
+    details.stateDetails = state_details;
+
+    xcb_xkb_select_events_aux(conn, device_id_,
+                              XCB_XKB_EVENT_TYPE_NEW_KEYBOARD_NOTIFY |
+                                  XCB_XKB_EVENT_TYPE_MAP_NOTIFY |
+                                  XCB_XKB_EVENT_TYPE_STATE_NOTIFY,
+                              0, 0, map_parts, map_parts, &details);
+  }
+
+  std::unique_ptr<xkb_context, ContextDeleter> ctx_;
+  std::unique_ptr<xkb_keymap, KeymapDeleter> keymap_;
+  std::unique_ptr<xkb_state, StateDeleter> state_;
+  uint8_t first_xkb_event_;
+  int32_t device_id_;
+};
+
+}  // namespace
+
+std::unique_ptr<Keyboard> Keyboard::create(xcb_connection_t* conn) {
+  auto ret = std::make_unique<KeyboardImpl>();
+  if (ret->init(conn))
+    return ret;
+  return nullptr;
+}
+
+}  // namespace xcb
-- 
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