qt: Initial xkbcommon keyboard support for X11

src/qt/xkbcommon_x11_keyboard.cpp

@@ -0,0 +1,85 @@
+/*
+ * 86Box    A hypervisor and IBM PC system emulator that specializes in
+ *          running old operating systems and software designed for IBM
+ *          PC systems and compatibles from 1981 through fairly recent
+ *          system designs based on the PCI bus.
+ *
+ *          This file is part of the 86Box distribution.
+ *
+ *          xkbcommon-x11 keyboard input module.
+ *
+ *          Heavily inspired by libxkbcommon interactive-x11.c
+ *
+ *
+ *
+ * Authors: RichardG, <richardg867@gmail.com>
+ *
+ *          Copyright 2023 RichardG.
+ */
+extern "C" {
+/* xkb.h has identifiers named "explicit", which is a C++ keyword now... */
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wkeyword-macro"
+#endif
+#define explicit explicit_
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
+#include <xcb/xkb.h>
+#undef explicit
+
+#include <xkbcommon/xkbcommon-x11.h>
+};
+#include "xkbcommon_keyboard.hpp"
+
+#include <QtDebug>
+
+void
+xkbcommon_x11_init()
+{
+    xcb_connection_t *conn;
+    struct xkb_context *ctx;
+    int32_t core_kbd_device_id;
+    struct xkb_keymap *keymap;
+
+    conn = xcb_connect(NULL, NULL);
+    if (!conn || xcb_connection_has_error(conn)) {
+        qWarning() << "XKB Keyboard: X server connection failed with error" << (conn ? xcb_connection_has_error(conn) : -1);
+        return;
+    }
+
+    int ret = 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,
+                                          NULL, NULL, NULL, NULL);
+    if (!ret) {
+        qWarning() << "XKB Keyboard: XKB extension setup failed";
+        goto err_conn;
+    }
+
+    ctx = xkb_context_new(XKB_CONTEXT_NO_FLAGS);
+    if (!ctx) {
+        qWarning() << "XKB Keyboard: XKB context creation failed";
+        goto err_conn;
+    }
+
+    core_kbd_device_id = xkb_x11_get_core_keyboard_device_id(conn);
+    if (core_kbd_device_id == -1) {
+        qWarning() << "XKB Keyboard: Core keyboard device not found";
+        goto err_ctx;
+    }
+
+    keymap = xkb_x11_keymap_new_from_device(ctx, conn, core_kbd_device_id, XKB_KEYMAP_COMPILE_NO_FLAGS);
+    if (!keymap) {
+        qWarning() << "XKB Keyboard: Keymap loading failed";
+        goto err_ctx;
+    }
+
+    xkbcommon_init(keymap);
+
+err_ctx:
+    xkb_context_unref(ctx);
+err_conn:
+    xcb_disconnect(conn);
+}