qt: Add xkbcommon keyboard support for Wayland

src/qt/xkbcommon_wl_keyboard.cpp

@@ -0,0 +1,236 @@
+/*
+ * 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 Wayland keyboard input module.
+ *
+ *          Heavily inspired by libxkbcommon interactive-wayland.c
+ *
+ *
+ *
+ * Authors: RichardG, <richardg867@gmail.com>
+ *
+ *          Copyright 2023 RichardG.
+ */
+extern "C" {
+#include <sys/mman.h>
+#include <unistd.h>
+#include <xkbcommon/xkbcommon.h>
+#include <86box/86box.h>
+};
+#include "xkbcommon_keyboard.hpp"
+#include <wayland-client.h>
+#include <wayland-util.h>
+
+#include <qpa/qplatformnativeinterface.h>
+#include <QtDebug>
+#include <QGuiApplication>
+
+typedef struct {
+    struct wl_seat *wl_seat;
+    struct wl_keyboard *wl_kbd;
+    uint32_t version;
+
+    struct xkb_keymap *keymap;
+
+    struct wl_list link;
+} seat_t;
+
+static bool wl_init_ok = false;
+static struct wl_list seats;
+static struct xkb_context *ctx;
+
+static void
+xkbcommon_wl_set_keymap()
+{
+    /* Grab keymap from the first seat with one. */
+    seat_t *seat, *tmp;
+    wl_list_for_each_safe(seat, tmp, &seats, link) {
+        if (seat->keymap) {
+            xkbcommon_init(seat->keymap);
+            return;
+        }
+    }
+    xkbcommon_close();
+}
+
+static void
+kbd_keymap(void *data, struct wl_keyboard *wl_kbd, uint32_t format,
+           int fd, uint32_t size)
+{
+    seat_t *seat = (seat_t *) data;
+
+    char *buf = (char *) mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0);
+    if (!buf) {
+        qWarning() << "XKB Keyboard: Failed to mmap keymap with error" << errno;
+        return;
+    }
+
+    seat->keymap = xkb_keymap_new_from_buffer(ctx, buf, size - 1,
+                                              XKB_KEYMAP_FORMAT_TEXT_V1,
+                                              XKB_KEYMAP_COMPILE_NO_FLAGS);
+    munmap(buf, size);
+    close(fd);
+    if (!seat->keymap) {
+        qWarning() << "XKB Keyboard: Keymap compilation failed";
+        return;
+    }
+
+    xkbcommon_wl_set_keymap();
+}
+
+static void
+kbd_enter(void *data, struct wl_keyboard *wl_kbd, uint32_t serial,
+          struct wl_surface *surf, struct wl_array *keys)
+{
+}
+
+static void
+kbd_leave(void *data, struct wl_keyboard *wl_kbd, uint32_t serial,
+          struct wl_surface *surf)
+{
+}
+
+static void
+kbd_key(void *data, struct wl_keyboard *wl_kbd, uint32_t serial, uint32_t time,
+        uint32_t key, uint32_t state)
+{
+}
+
+static void
+kbd_modifiers(void *data, struct wl_keyboard *wl_kbd, uint32_t serial,
+              uint32_t mods_depressed, uint32_t mods_latched,
+              uint32_t mods_locked, uint32_t group)
+{
+}
+
+static void
+kbd_repeat_info(void *data, struct wl_keyboard *wl_kbd, int32_t rate,
+                int32_t delay)
+{
+}
+
+static const struct wl_keyboard_listener kbd_listener = {
+    kbd_keymap,
+    kbd_enter,
+    kbd_leave,
+    kbd_key,
+    kbd_modifiers,
+    kbd_repeat_info
+};
+
+static void
+seat_capabilities(void *data, struct wl_seat *wl_seat, uint32_t caps)
+{
+    seat_t *seat = (seat_t *) data;
+
+    if (!seat->wl_kbd && (caps & WL_SEAT_CAPABILITY_KEYBOARD)) {
+        seat->wl_kbd = wl_seat_get_keyboard(seat->wl_seat);
+        wl_keyboard_add_listener(seat->wl_kbd, &kbd_listener, seat);
+    } else if (seat->wl_kbd && !(caps & WL_SEAT_CAPABILITY_KEYBOARD)) {
+        if (seat->version >= WL_SEAT_RELEASE_SINCE_VERSION)
+            wl_keyboard_release(seat->wl_kbd);
+        else
+            wl_keyboard_destroy(seat->wl_kbd);
+
+        static struct xkb_keymap *keymap = seat->keymap;
+        seat->keymap = NULL;
+        xkbcommon_wl_set_keymap();
+        xkb_keymap_unref(keymap);
+
+        seat->wl_kbd = NULL;
+    }
+}
+
+static void
+seat_name(void *data, struct wl_seat *wl_seat, const char *name)
+{
+}
+
+static const struct wl_seat_listener seat_listener = {
+    seat_capabilities,
+    seat_name
+};
+
+static void
+display_handle_global(void *data, struct wl_registry *wl_registry, uint32_t id,
+                      const char *interface, uint32_t version)
+{
+    if (!strcmp(interface, "wl_seat")) {
+        seat_t *seat = (seat_t *) malloc(sizeof(seat_t));
+        memset(seat, 0, sizeof(seat_t));
+
+        seat->wl_seat = (wl_seat *) wl_registry_bind(wl_registry, id, &wl_seat_interface, MIN(version, 5));
+        wl_seat_add_listener(seat->wl_seat, &seat_listener, seat);
+        wl_list_insert(&seats, &seat->link);
+    }
+}
+
+static void
+display_global_remove(void *data, struct wl_registry *wl_registry, uint32_t id)
+{
+    xkbcommon_close();
+
+    seat_t *seat, *tmp;
+    wl_list_for_each_safe(seat, tmp, &seats, link) {
+        if (seat->wl_kbd) {
+            if (seat->version >= WL_SEAT_RELEASE_SINCE_VERSION)
+                wl_keyboard_release(seat->wl_kbd);
+            else
+                wl_keyboard_destroy(seat->wl_kbd);
+
+            xkb_keymap_unref(seat->keymap);
+        }
+
+        if (seat->version >= WL_SEAT_RELEASE_SINCE_VERSION)
+            wl_seat_release(seat->wl_seat);
+        else
+            wl_seat_destroy(seat->wl_seat);
+
+        wl_list_remove(&seat->link);
+        free(seat);
+    }
+}
+
+static const struct wl_registry_listener registry_listener = {
+    display_handle_global,
+    display_global_remove
+};
+
+void
+xkbcommon_wl_init()
+{
+    if (wl_init_ok)
+        return;
+
+    wl_list_init(&seats);
+
+    ctx = xkb_context_new(XKB_CONTEXT_NO_FLAGS);
+    if (!ctx) {
+        qWarning() << "XKB Keyboard: XKB context creation failed";
+        return;
+    }
+
+    wl_display *display = (wl_display *) QGuiApplication::platformNativeInterface()->nativeResourceForIntegration("wl_display");
+    if (display) {
+        auto registry = wl_display_get_registry(display);
+        if (registry) {
+            wl_registry_add_listener(registry, &registry_listener, nullptr);
+            wl_display_roundtrip(display);
+            wl_display_roundtrip(display);
+        } else {
+            goto err_ctx;
+        }
+    } else {
+        goto err_ctx;
+    }
+    wl_init_ok = true;
+    return;
+
+err_ctx:
+    xkb_context_unref(ctx);
+}