kmx git

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2022 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/

#include "../../SDL_internal.h"

#if SDL_VIDEO_DRIVER_WAYLAND

#include "SDL_stdinc.h"
#include "SDL_timer.h"
#include "SDL_hints.h"

#include "../../core/unix/SDL_poll.h"
#include "../../events/SDL_events_c.h"
#include "../../events/scancodes_xfree86.h"
#include "../SDL_sysvideo.h"

#include "SDL_waylandvideo.h"
#include "SDL_waylandevents_c.h"
#include "SDL_waylandwindow.h"

#include "pointer-constraints-unstable-v1-client-protocol.h"
#include "relative-pointer-unstable-v1-client-protocol.h"
#include "xdg-shell-client-protocol.h"
#include "keyboard-shortcuts-inhibit-unstable-v1-client-protocol.h"
#include "text-input-unstable-v3-client-protocol.h"
#include "tablet-unstable-v2-client-protocol.h"

#ifdef HAVE_LIBDECOR_H
#include <libdecor.h>
#endif

#ifdef SDL_INPUT_LINUXEV
#include <linux/input.h>
#else
#define BTN_LEFT    (0x110)
#define BTN_RIGHT   (0x111)
#define BTN_MIDDLE  (0x112)
#define BTN_SIDE    (0x113)
#define BTN_EXTRA   (0x114)
#endif
#include <sys/select.h>
#include <sys/mman.h>
#include <poll.h>
#include <unistd.h>
#include <errno.h>
#include <xkbcommon/xkbcommon.h>
#include <xkbcommon/xkbcommon-compose.h>
#include "../../events/imKStoUCS.h"

/* Weston uses a ratio of 10 units per scroll tick */
#define WAYLAND_WHEEL_AXIS_UNIT 10

static const struct {
    xkb_keysym_t keysym;
    SDL_KeyCode keycode;
} KeySymToSDLKeyCode[] = {
    { XKB_KEY_Shift_L, SDLK_LSHIFT },
    { XKB_KEY_Shift_R, SDLK_RSHIFT },
    { XKB_KEY_Control_L, SDLK_LCTRL },
    { XKB_KEY_Control_R, SDLK_RCTRL },
    { XKB_KEY_Caps_Lock, SDLK_CAPSLOCK },
    { XKB_KEY_Alt_L, SDLK_LALT },
    { XKB_KEY_Alt_R, SDLK_RALT },
    { XKB_KEY_Meta_L, SDLK_LGUI },
    { XKB_KEY_Meta_R, SDLK_RGUI },
    { XKB_KEY_Super_L, SDLK_LGUI },
    { XKB_KEY_Super_R, SDLK_RGUI },
    { XKB_KEY_Hyper_L, SDLK_LGUI },
    { XKB_KEY_Hyper_R, SDLK_RGUI },
    { XKB_KEY_BackSpace, SDLK_BACKSPACE },
};

struct SDL_WaylandTouchPoint {
    SDL_TouchID id;
    float x;
    float y;
    struct wl_surface* surface;

    struct SDL_WaylandTouchPoint* prev;
    struct SDL_WaylandTouchPoint* next;
};

struct SDL_WaylandTouchPointList {
    struct SDL_WaylandTouchPoint* head;
    struct SDL_WaylandTouchPoint* tail;
};

static struct SDL_WaylandTouchPointList touch_points = {NULL, NULL};

static SDL_KeyCode
Wayland_KeySymToSDLKeyCode(xkb_keysym_t keysym)
{
    int i;

    for (i = 0; i < SDL_arraysize(KeySymToSDLKeyCode); ++i) {
        if (keysym == KeySymToSDLKeyCode[i].keysym) {
            return KeySymToSDLKeyCode[i].keycode;
        }
    }
    return SDLK_UNKNOWN;
}

static void
touch_add(SDL_TouchID id, float x, float y, struct wl_surface *surface)
{
    struct SDL_WaylandTouchPoint* tp = SDL_malloc(sizeof(struct SDL_WaylandTouchPoint));

    tp->id = id;
    tp->x = x;
    tp->y = y;
    tp->surface = surface;

    if (touch_points.tail) {
        touch_points.tail->next = tp;
        tp->prev = touch_points.tail;
    } else {
        touch_points.head = tp;
        tp->prev = NULL;
    }

    touch_points.tail = tp;
    tp->next = NULL;
}

static void
touch_update(SDL_TouchID id, float x, float y)
{
    struct SDL_WaylandTouchPoint* tp = touch_points.head;

    while (tp) {
        if (tp->id == id) {
            tp->x = x;
            tp->y = y;
        }

        tp = tp->next;
    }
}

static void
touch_del(SDL_TouchID id, float* x, float* y, struct wl_surface **surface)
{
    struct SDL_WaylandTouchPoint* tp = touch_points.head;

    while (tp) {
        if (tp->id == id) {
            *x = tp->x;
            *y = tp->y;
            *surface = tp->surface;

            if (tp->prev) {
                tp->prev->next = tp->next;
            } else {
                touch_points.head = tp->next;
            }

            if (tp->next) {
                tp->next->prev = tp->prev;
            } else {
                touch_points.tail = tp->prev;
            }

            {
                struct SDL_WaylandTouchPoint *next = tp->next;
                SDL_free(tp);
                tp = next;
            }
        } else {
            tp = tp->next;
        }
    }
}

static struct wl_surface*
touch_surface(SDL_TouchID id)
{
    struct SDL_WaylandTouchPoint* tp = touch_points.head;

    while (tp) {
        if (tp->id == id) {
            return tp->surface;
        }

        tp = tp->next;
    }

    return NULL;
}

/* Returns SDL_TRUE if a key repeat event was due */
static SDL_bool
keyboard_repeat_handle(SDL_WaylandKeyboardRepeat* repeat_info, uint32_t elapsed)
{
    SDL_bool ret = SDL_FALSE;
    while ((elapsed - repeat_info->next_repeat_ms) < 0x80000000U) {
        if (repeat_info->scancode != SDL_SCANCODE_UNKNOWN) {
            SDL_SendKeyboardKey(SDL_PRESSED, repeat_info->scancode);
        }
        if (repeat_info->text[0]) {
            SDL_SendKeyboardText(repeat_info->text);
        }
        repeat_info->next_repeat_ms += 1000 / repeat_info->repeat_rate;
        ret = SDL_TRUE;
    }
    return ret;
}

static void
keyboard_repeat_clear(SDL_WaylandKeyboardRepeat* repeat_info) {
    if (!repeat_info->is_initialized) {
        return;
    }
    repeat_info->is_key_down = SDL_FALSE;
}

static void
keyboard_repeat_set(SDL_WaylandKeyboardRepeat* repeat_info, uint32_t wl_press_time,
                    uint32_t scancode, SDL_bool has_text, char text[8]) {
    if (!repeat_info->is_initialized || !repeat_info->repeat_rate) {
        return;
    }
    repeat_info->is_key_down = SDL_TRUE;
    repeat_info->wl_press_time = wl_press_time;
    repeat_info->sdl_press_time = SDL_GetTicks();
    repeat_info->next_repeat_ms = repeat_info->repeat_delay;
    repeat_info->scancode = scancode;
    if (has_text) {
        SDL_memcpy(repeat_info->text, text, 8);
    } else {
        repeat_info->text[0] = '\0';
    }
}

static SDL_bool keyboard_repeat_is_set(SDL_WaylandKeyboardRepeat* repeat_info) {
    return repeat_info->is_initialized && repeat_info->is_key_down;
}

void
Wayland_SendWakeupEvent(_THIS, SDL_Window *window)
{
    SDL_VideoData *d = _this->driverdata;

    /* TODO: Maybe use a pipe to avoid the compositor roundtrip? */
    wl_display_sync(d->display);
    WAYLAND_wl_display_flush(d->display);
}

int
Wayland_WaitEventTimeout(_THIS, int timeout)
{
    SDL_VideoData *d = _this->driverdata;
    struct SDL_WaylandInput *input = d->input;
    SDL_bool key_repeat_active = SDL_FALSE;

    WAYLAND_wl_display_flush(d->display);

#ifdef SDL_USE_IME
    if (d->text_input_manager == NULL && SDL_GetEventState(SDL_TEXTINPUT) == SDL_ENABLE) {
        SDL_IME_PumpEvents();
    }
#endif

    /* If key repeat is active, we'll need to cap our maximum wait time to handle repeats */
    if (input && keyboard_repeat_is_set(&input->keyboard_repeat)) {
        uint32_t elapsed = SDL_GetTicks() - input->keyboard_repeat.sdl_press_time;
        if (keyboard_repeat_handle(&input->keyboard_repeat, elapsed)) {
            /* A repeat key event was already due */
            return 1;
        } else {
            uint32_t next_repeat_wait_time = (input->keyboard_repeat.next_repeat_ms - elapsed) + 1;
            if (timeout >= 0) {
                timeout = SDL_min(timeout, next_repeat_wait_time);
            } else {
                timeout = next_repeat_wait_time;
            }
            key_repeat_active = SDL_TRUE;
        }
    }

#ifdef HAVE_LIBDECOR_H
    if (d->shell.libdecor) {
        libdecor_dispatch(d->shell.libdecor, timeout);
    }
#endif

    /* wl_display_prepare_read() will return -1 if the default queue is not empty.
     * If the default queue is empty, it will prepare us for our SDL_IOReady() call. */
    if (WAYLAND_wl_display_prepare_read(d->display) == 0) {
        /* Use SDL_IOR_NO_RETRY to ensure SIGINT will break us out of our wait */
        int err = SDL_IOReady(WAYLAND_wl_display_get_fd(d->display), SDL_IOR_READ | SDL_IOR_NO_RETRY, timeout);
        if (err > 0) {
            /* There are new events available to read */
            WAYLAND_wl_display_read_events(d->display);
            WAYLAND_wl_display_dispatch_pending(d->display);
            return 1;
        } else if (err == 0) {
            /* No events available within the timeout */
            WAYLAND_wl_display_cancel_read(d->display);

            /* If key repeat is active, we might have woken up to generate a key event */
            if (key_repeat_active) {
                uint32_t elapsed = SDL_GetTicks() - input->keyboard_repeat.sdl_press_time;
                if (keyboard_repeat_handle(&input->keyboard_repeat, elapsed)) {
                    return 1;
                }
            }

            return 0;
        } else {
            /* Error returned from poll()/select() */
            WAYLAND_wl_display_cancel_read(d->display);

            if (errno == EINTR) {
                /* If the wait was interrupted by a signal, we may have generated a
                 * SDL_QUIT event. Let the caller know to call SDL_PumpEvents(). */
                return 1;
            } else {
                return err;
            }
        }
    } else {
        /* We already had pending events */
        WAYLAND_wl_display_dispatch_pending(d->display);
        return 1;
    }
}

void
Wayland_PumpEvents(_THIS)
{
    SDL_VideoData *d = _this->driverdata;
    struct SDL_WaylandInput *input = d->input;
    int err;

    WAYLAND_wl_display_flush(d->display);

#ifdef SDL_USE_IME
    if (d->text_input_manager == NULL && SDL_GetEventState(SDL_TEXTINPUT) == SDL_ENABLE) {
        SDL_IME_PumpEvents();
    }
#endif

    /* wl_display_prepare_read() will return -1 if the default queue is not empty.
     * If the default queue is empty, it will prepare us for our SDL_IOReady() call. */
    if (WAYLAND_wl_display_prepare_read(d->display) == 0) {
        if (SDL_IOReady(WAYLAND_wl_display_get_fd(d->display), SDL_IOR_READ, 0) > 0) {
            WAYLAND_wl_display_read_events(d->display);
        } else {
            WAYLAND_wl_display_cancel_read(d->display);
        }
    }

    /* Dispatch any pre-existing pending events or new events we may have read */
    err = WAYLAND_wl_display_dispatch_pending(d->display);

    if (input && keyboard_repeat_is_set(&input->keyboard_repeat)) {
        uint32_t elapsed = SDL_GetTicks() - input->keyboard_repeat.sdl_press_time;
        keyboard_repeat_handle(&input->keyboard_repeat, elapsed);
    }

    if (err == -1 && !d->display_disconnected) {
        /* Something has failed with the Wayland connection -- for example,
         * the compositor may have shut down and closed its end of the socket,
         * or there is a library-specific error. No recovery is possible. */
        d->display_disconnected = 1;
        /* Only send a single quit message, as application shutdown might call
         * SDL_PumpEvents */
        SDL_SendQuit();
    }
}

static void
pointer_handle_motion(void *data, struct wl_pointer *pointer,
                      uint32_t time, wl_fixed_t sx_w, wl_fixed_t sy_w)
{
    struct SDL_WaylandInput *input = data;
    SDL_WindowData *window = input->pointer_focus;
    input->sx_w = sx_w;
    input->sy_w = sy_w;
    if (input->pointer_focus) {
        const float sx_f = (float)wl_fixed_to_double(sx_w);
        const float sy_f = (float)wl_fixed_to_double(sy_w);
        const int   sx   = (int)SDL_floorf(sx_f * window->pointer_scale_x);
        const int   sy   = (int)SDL_floorf(sy_f * window->pointer_scale_y);
        SDL_SendMouseMotion(window->sdlwindow, 0, 0, sx, sy);
    }
}

static void
pointer_handle_enter(void *data, struct wl_pointer *pointer,
                     uint32_t serial, struct wl_surface *surface,
                     wl_fixed_t sx_w, wl_fixed_t sy_w)
{
    struct SDL_WaylandInput *input = data;
    SDL_WindowData *window;

    if (!surface) {
        /* enter event for a window we've just destroyed */
        return;
    }

    /* check that this surface belongs to one of the SDL windows */
    if (!SDL_WAYLAND_own_surface(surface)) {
        return;
    }

    /* This handler will be called twice in Wayland 1.4
     * Once for the window surface which has valid user data
     * and again for the mouse cursor surface which does not have valid user data
     * We ignore the later
     */

    window = (SDL_WindowData *)wl_surface_get_user_data(surface);

    if (window) {
        input->pointer_focus = window;
        input->pointer_enter_serial = serial;
        SDL_SetMouseFocus(window->sdlwindow);
        /* In the case of e.g. a pointer confine warp, we may receive an enter
         * event with no following motion event, but with the new coordinates
         * as part of the enter event. */
        pointer_handle_motion(data, pointer, serial, sx_w, sy_w);
        /* If the cursor was changed while our window didn't have pointer
         * focus, we might need to trigger another call to
         * wl_pointer_set_cursor() for the new cursor to be displayed. */
        SDL_SetCursor(NULL);
    }
}

static void
pointer_handle_leave(void *data, struct wl_pointer *pointer,
                     uint32_t serial, struct wl_surface *surface)
{
    struct SDL_WaylandInput *input = data;

    if (!surface || !SDL_WAYLAND_own_surface(surface)) {
        return;
    }

    if (input->pointer_focus) {
        SDL_SetMouseFocus(NULL);
        input->pointer_focus = NULL;
    }
}

static SDL_bool
ProcessHitTest(struct SDL_WaylandInput *input, uint32_t serial)
{
    SDL_WindowData *window_data = input->pointer_focus;
    SDL_Window *window = window_data->sdlwindow;

    if (window->hit_test) {
        const SDL_Point point = { wl_fixed_to_int(input->sx_w), wl_fixed_to_int(input->sy_w) };
        const SDL_HitTestResult rc = window->hit_test(window, &point, window->hit_test_data);

        static const uint32_t directions[] = {
            XDG_TOPLEVEL_RESIZE_EDGE_TOP_LEFT, XDG_TOPLEVEL_RESIZE_EDGE_TOP,
            XDG_TOPLEVEL_RESIZE_EDGE_TOP_RIGHT, XDG_TOPLEVEL_RESIZE_EDGE_RIGHT,
            XDG_TOPLEVEL_RESIZE_EDGE_BOTTOM_RIGHT, XDG_TOPLEVEL_RESIZE_EDGE_BOTTOM,
            XDG_TOPLEVEL_RESIZE_EDGE_BOTTOM_LEFT, XDG_TOPLEVEL_RESIZE_EDGE_LEFT
        };

#ifdef HAVE_LIBDECOR_H
        static const uint32_t directions_libdecor[] = {
            LIBDECOR_RESIZE_EDGE_TOP_LEFT, LIBDECOR_RESIZE_EDGE_TOP,
            LIBDECOR_RESIZE_EDGE_TOP_RIGHT, LIBDECOR_RESIZE_EDGE_RIGHT,
            LIBDECOR_RESIZE_EDGE_BOTTOM_RIGHT, LIBDECOR_RESIZE_EDGE_BOTTOM,
            LIBDECOR_RESIZE_EDGE_BOTTOM_LEFT, LIBDECOR_RESIZE_EDGE_LEFT
        };
#endif

        switch (rc) {
            case SDL_HITTEST_DRAGGABLE:
#ifdef HAVE_LIBDECOR_H
                if (window_data->shell_surface_type == WAYLAND_SURFACE_LIBDECOR) {
                    if (window_data->shell_surface.libdecor.frame) {
                        libdecor_frame_move(window_data->shell_surface.libdecor.frame, input->seat, serial);
                    }
                } else
#endif
                if (window_data->shell_surface_type == WAYLAND_SURFACE_XDG_TOPLEVEL) {
                    if (window_data->shell_surface.xdg.roleobj.toplevel) {
                        xdg_toplevel_move(window_data->shell_surface.xdg.roleobj.toplevel,
                                          input->seat,
                                          serial);
                    }
                }
                return SDL_TRUE;

            case SDL_HITTEST_RESIZE_TOPLEFT:
            case SDL_HITTEST_RESIZE_TOP:
            case SDL_HITTEST_RESIZE_TOPRIGHT:
            case SDL_HITTEST_RESIZE_RIGHT:
            case SDL_HITTEST_RESIZE_BOTTOMRIGHT:
            case SDL_HITTEST_RESIZE_BOTTOM:
            case SDL_HITTEST_RESIZE_BOTTOMLEFT:
            case SDL_HITTEST_RESIZE_LEFT:
#ifdef HAVE_LIBDECOR_H
                if (window_data->shell_surface_type == WAYLAND_SURFACE_LIBDECOR) {
                    if (window_data->shell_surface.libdecor.frame) {
                        libdecor_frame_resize(window_data->shell_surface.libdecor.frame, input->seat, serial, directions_libdecor[rc - SDL_HITTEST_RESIZE_TOPLEFT]);
                    }
                } else
#endif
                if (window_data->shell_surface_type == WAYLAND_SURFACE_XDG_TOPLEVEL) {
                    if (window_data->shell_surface.xdg.roleobj.toplevel) {
                        xdg_toplevel_resize(window_data->shell_surface.xdg.roleobj.toplevel,
                                            input->seat,
                                            serial,
                                            directions[rc - SDL_HITTEST_RESIZE_TOPLEFT]);
                    }
                }
                return SDL_TRUE;

            default: return SDL_FALSE;
        }
    }

    return SDL_FALSE;
}

static void
pointer_handle_button_common(struct SDL_WaylandInput *input, uint32_t serial,
                             uint32_t time, uint32_t button, uint32_t state_w)
{
    SDL_WindowData *window = input->pointer_focus;
    enum wl_pointer_button_state state = state_w;
    uint32_t sdl_button;

    if (window) {
        switch (button) {
            case BTN_LEFT:
                sdl_button = SDL_BUTTON_LEFT;
                if (ProcessHitTest(input, serial)) {
                    return;  /* don't pass this event on to app. */
                }
                break;
            case BTN_MIDDLE:
                sdl_button = SDL_BUTTON_MIDDLE;
                break;
            case BTN_RIGHT:
                sdl_button = SDL_BUTTON_RIGHT;
                break;
            case BTN_SIDE:
                sdl_button = SDL_BUTTON_X1;
                break;
            case BTN_EXTRA:
                sdl_button = SDL_BUTTON_X2;
                break;
            default:
                return;
        }

        /* Wayland won't let you "capture" the mouse, but it will
           automatically track the mouse outside the window if you
           drag outside of it, until you let go of all buttons (even
           if you add or remove presses outside the window, as long
           as any button is still down, the capture remains) */
        if (state) {  /* update our mask of currently-pressed buttons */
            input->buttons_pressed |= SDL_BUTTON(sdl_button);
        } else {
            input->buttons_pressed &= ~(SDL_BUTTON(sdl_button));
        }

        if (input->buttons_pressed != 0) {
            window->sdlwindow->flags |= SDL_WINDOW_MOUSE_CAPTURE;
        } else {
            window->sdlwindow->flags &= ~SDL_WINDOW_MOUSE_CAPTURE;
        }

        Wayland_data_device_set_serial(input->data_device, serial);

        SDL_SendMouseButton(window->sdlwindow, 0,
                            state ? SDL_PRESSED : SDL_RELEASED, sdl_button);
    }
}

static void
pointer_handle_button(void *data, struct wl_pointer *pointer, uint32_t serial,
                      uint32_t time, uint32_t button, uint32_t state_w)
{
    struct SDL_WaylandInput *input = data;

    pointer_handle_button_common(input, serial, time, button, state_w);
}

static void
pointer_handle_axis_common_v1(struct SDL_WaylandInput *input,
                              uint32_t time, uint32_t axis, wl_fixed_t value)
{
    SDL_WindowData *window = input->pointer_focus;
    enum wl_pointer_axis a = axis;
    float x, y;

    if (input->pointer_focus) {
        switch (a) {
            case WL_POINTER_AXIS_VERTICAL_SCROLL:
                x = 0;
                y = 0 - (float)wl_fixed_to_double(value);
                break;
            case WL_POINTER_AXIS_HORIZONTAL_SCROLL:
                x = (float)wl_fixed_to_double(value);
                y = 0;
                break;
            default:
                return;
        }

        x /= WAYLAND_WHEEL_AXIS_UNIT;
        y /= WAYLAND_WHEEL_AXIS_UNIT;

        SDL_SendMouseWheel(window->sdlwindow, 0, x, y, SDL_MOUSEWHEEL_NORMAL);
    }
}

static void
pointer_handle_axis_common(struct SDL_WaylandInput *input, SDL_bool discrete,
                           uint32_t axis, wl_fixed_t value)
{
    enum wl_pointer_axis a = axis;

    if (input->pointer_focus) {
        switch (a) {
            case WL_POINTER_AXIS_VERTICAL_SCROLL:
                if (discrete) {
                    /* this is a discrete axis event so we process it and flag
                     * to ignore future continuous axis events in this frame */
                    input->pointer_curr_axis_info.is_y_discrete = SDL_TRUE;
                } else if(input->pointer_curr_axis_info.is_y_discrete) {
                    /* this is a continuous axis event and we have already
                     * processed a discrete axis event before so we ignore it */
                    break;
                }
                input->pointer_curr_axis_info.y = 0 - (float)wl_fixed_to_double(value);
                break;
            case WL_POINTER_AXIS_HORIZONTAL_SCROLL:
                if (discrete) {
                    /* this is a discrete axis event so we process it and flag
                     * to ignore future continuous axis events in this frame */
                    input->pointer_curr_axis_info.is_x_discrete = SDL_TRUE;
                } else if(input->pointer_curr_axis_info.is_x_discrete) {
                    /* this is a continuous axis event and we have already
                     * processed a discrete axis event before so we ignore it */
                    break;
                }
                input->pointer_curr_axis_info.x = (float)wl_fixed_to_double(value);
                break;
        }
    }
}

static void
pointer_handle_axis(void *data, struct wl_pointer *pointer,
                    uint32_t time, uint32_t axis, wl_fixed_t value)
{
    struct SDL_WaylandInput *input = data;

    if(wl_seat_get_version(input->seat) >= 5)
        pointer_handle_axis_common(input, SDL_FALSE, axis, value);
    else
        pointer_handle_axis_common_v1(input, time, axis, value);
}

static void
pointer_handle_frame(void *data, struct wl_pointer *pointer)
{
    struct SDL_WaylandInput *input = data;
    SDL_WindowData *window = input->pointer_focus;
    float x, y;

    if (input->pointer_curr_axis_info.is_x_discrete)
        x = input->pointer_curr_axis_info.x;
    else
        x = input->pointer_curr_axis_info.x / WAYLAND_WHEEL_AXIS_UNIT;

    if (input->pointer_curr_axis_info.is_y_discrete)
        y = input->pointer_curr_axis_info.y;
    else
        y = input->pointer_curr_axis_info.y / WAYLAND_WHEEL_AXIS_UNIT;

    /* clear pointer_curr_axis_info for next frame */
    SDL_memset(&input->pointer_curr_axis_info, 0, sizeof input->pointer_curr_axis_info);

    if(x == 0.0f && y == 0.0f)
        return;
    else
        SDL_SendMouseWheel(window->sdlwindow, 0, x, y, SDL_MOUSEWHEEL_NORMAL);
}

static void
pointer_handle_axis_source(void *data, struct wl_pointer *pointer,
                           uint32_t axis_source)
{
    /* unimplemented */
}

static void
pointer_handle_axis_stop(void *data, struct wl_pointer *pointer,
                         uint32_t time, uint32_t axis)
{
    /* unimplemented */
}

static void
pointer_handle_axis_discrete(void *data, struct wl_pointer *pointer,
                             uint32_t axis, int32_t discrete)
{
    struct SDL_WaylandInput *input = data;

    pointer_handle_axis_common(input, SDL_TRUE, axis, wl_fixed_from_int(discrete));
}


static const struct wl_pointer_listener pointer_listener = {
    pointer_handle_enter,
    pointer_handle_leave,
    pointer_handle_motion,
    pointer_handle_button,
    pointer_handle_axis,
    pointer_handle_frame,           // Version 5
    pointer_handle_axis_source,     // Version 5
    pointer_handle_axis_stop,       // Version 5
    pointer_handle_axis_discrete,   // Version 5
};

static void
touch_handler_down(void *data, struct wl_touch *touch, unsigned int serial,
                   unsigned int timestamp, struct wl_surface *surface,
                   int id, wl_fixed_t fx, wl_fixed_t fy)
{
    SDL_WindowData *window_data = (SDL_WindowData *)wl_surface_get_user_data(surface);
    const double dblx = wl_fixed_to_double(fx) * window_data->pointer_scale_x;
    const double dbly = wl_fixed_to_double(fy) * window_data->pointer_scale_y;
    const float x = dblx / window_data->sdlwindow->w;
    const float y = dbly / window_data->sdlwindow->h;

    touch_add(id, x, y, surface);

    SDL_SendTouch((SDL_TouchID)(intptr_t)touch, (SDL_FingerID)id, window_data->sdlwindow, SDL_TRUE, x, y, 1.0f);
}

static void
touch_handler_up(void *data, struct wl_touch *touch, unsigned int serial,
                 unsigned int timestamp, int id)
{
    float x = 0, y = 0;
    struct wl_surface *surface = NULL;
    SDL_Window *window = NULL;

    touch_del(id, &x, &y, &surface);

    if (surface) {
        SDL_WindowData *window_data = (SDL_WindowData *)wl_surface_get_user_data(surface);
        window = window_data->sdlwindow;
    }

    SDL_SendTouch((SDL_TouchID)(intptr_t)touch, (SDL_FingerID)id, window, SDL_FALSE, x, y, 0.0f);
}

static void
touch_handler_motion(void *data, struct wl_touch *touch, unsigned int timestamp,
                     int id, wl_fixed_t fx, wl_fixed_t fy)
{
    SDL_WindowData *window_data = (SDL_WindowData *)wl_surface_get_user_data(touch_surface(id));
    const double dblx = wl_fixed_to_double(fx) * window_data->pointer_scale_x;
    const double dbly = wl_fixed_to_double(fy) * window_data->pointer_scale_y;
    const float x = dblx / window_data->sdlwindow->w;
    const float y = dbly / window_data->sdlwindow->h;

    touch_update(id, x, y);
    SDL_SendTouchMotion((SDL_TouchID)(intptr_t)touch, (SDL_FingerID)id, window_data->sdlwindow, x, y, 1.0f);
}

static void
touch_handler_frame(void *data, struct wl_touch *touch)
{

}

static void
touch_handler_cancel(void *data, struct wl_touch *touch)
{

}

static const struct wl_touch_listener touch_listener = {
    touch_handler_down,
    touch_handler_up,
    touch_handler_motion,
    touch_handler_frame,
    touch_handler_cancel,
    NULL, /* shape */
    NULL, /* orientation */
};

static void
keyboard_handle_keymap(void *data, struct wl_keyboard *keyboard,
                       uint32_t format, int fd, uint32_t size)
{
    struct SDL_WaylandInput *input = data;
    char *map_str;
    const char *locale;

    if (!data) {
        close(fd);
        return;
    }

    if (format != WL_KEYBOARD_KEYMAP_FORMAT_XKB_V1) {
        close(fd);
        return;
    }

    map_str = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0);
    if (map_str == MAP_FAILED) {
        close(fd);
        return;
    }

    input->xkb.keymap = WAYLAND_xkb_keymap_new_from_string(input->display->xkb_context,
                                                map_str,
                                                XKB_KEYMAP_FORMAT_TEXT_V1,
                                                0);
    munmap(map_str, size);
    close(fd);

    if (!input->xkb.keymap) {
        fprintf(stderr, "failed to compile keymap\n");
        return;
    }

    #define GET_MOD_INDEX(mod) \
        WAYLAND_xkb_keymap_mod_get_index(input->xkb.keymap, XKB_MOD_NAME_##mod)
    input->xkb.idx_shift = 1 << GET_MOD_INDEX(SHIFT);
    input->xkb.idx_ctrl = 1 << GET_MOD_INDEX(CTRL);
    input->xkb.idx_alt = 1 << GET_MOD_INDEX(ALT);
    input->xkb.idx_gui = 1 << GET_MOD_INDEX(LOGO);
    input->xkb.idx_num = 1 << GET_MOD_INDEX(NUM);
    input->xkb.idx_caps = 1 << GET_MOD_INDEX(CAPS);
    #undef GET_MOD_INDEX

    input->xkb.state = WAYLAND_xkb_state_new(input->xkb.keymap);
    if (!input->xkb.state) {
        fprintf(stderr, "failed to create XKB state\n");
        WAYLAND_xkb_keymap_unref(input->xkb.keymap);
        input->xkb.keymap = NULL;
        return;
    }

    /*
     * See https://blogs.s-osg.org/compose-key-support-weston/
     * for further explanation on dead keys in Wayland.
     */

    /* Look up the preferred locale, falling back to "C" as default */
    if (!(locale = SDL_getenv("LC_ALL"))) {
        if (!(locale = SDL_getenv("LC_CTYPE"))) {
            if (!(locale = SDL_getenv("LANG"))) {
                locale = "C";
            }
        }
    }

    /* Set up XKB compose table */
    input->xkb.compose_table = WAYLAND_xkb_compose_table_new_from_locale(input->display->xkb_context,
                                              locale, XKB_COMPOSE_COMPILE_NO_FLAGS);
    if (input->xkb.compose_table) {
        /* Set up XKB compose state */
        input->xkb.compose_state = WAYLAND_xkb_compose_state_new(input->xkb.compose_table,
                                              XKB_COMPOSE_STATE_NO_FLAGS);
        if (!input->xkb.compose_state) {
            fprintf(stderr, "could not create XKB compose state\n");
            WAYLAND_xkb_compose_table_unref(input->xkb.compose_table);
            input->xkb.compose_table = NULL;
        }
    }
}

static void
keyboard_handle_enter(void *data, struct wl_keyboard *keyboard,
                      uint32_t serial, struct wl_surface *surface,
                      struct wl_array *keys)
{
    struct SDL_WaylandInput *input = data;
    SDL_WindowData *window;

    if (!surface) {
        /* enter event for a window we've just destroyed */
        return;
    }

    if (!SDL_WAYLAND_own_surface(surface)) {
        return;
    }

    window = wl_surface_get_user_data(surface);

    if (window) {
        input->keyboard_focus = window;
        window->keyboard_device = input;
        SDL_SetKeyboardFocus(window->sdlwindow);
    }
#ifdef SDL_USE_IME
    if (!input->text_input) {
        SDL_IME_SetFocus(SDL_TRUE);
    }
#endif
}

static void
keyboard_handle_leave(void *data, struct wl_keyboard *keyboard,
                      uint32_t serial, struct wl_surface *surface)
{
    struct SDL_WaylandInput *input = data;
    SDL_WindowData *window;

    if (!surface || !SDL_WAYLAND_own_surface(surface)) {
        return;
    }

    window = wl_surface_get_user_data(surface);
    if (window) {
        window->sdlwindow->flags &= ~SDL_WINDOW_MOUSE_CAPTURE;
    }

    /* Stop key repeat before clearing keyboard focus */
    keyboard_repeat_clear(&input->keyboard_repeat);

    /* This will release any keys still pressed */
    SDL_SetKeyboardFocus(NULL);

#ifdef SDL_USE_IME
    if (!input->text_input) {
        SDL_IME_SetFocus(SDL_FALSE);
    }
#endif
}

static SDL_bool
keyboard_input_get_text(char text[8], const struct SDL_WaylandInput *input, uint32_t key, Uint8 state, SDL_bool *handled_by_ime)
{
    SDL_WindowData *window = input->keyboard_focus;
    const xkb_keysym_t *syms;
    xkb_keysym_t sym;

    if (!window || window->keyboard_device != input || !input->xkb.state) {
        return SDL_FALSE;
    }

    // TODO can this happen?
    if (WAYLAND_xkb_state_key_get_syms(input->xkb.state, key + 8, &syms) != 1) {
        return SDL_FALSE;
    }
    sym = syms[0];

#ifdef SDL_USE_IME
    if (SDL_IME_ProcessKeyEvent(sym, key + 8, state)) {
        *handled_by_ime = SDL_TRUE;
        return SDL_TRUE;
    }
#endif

    if (state == SDL_RELEASED) {
        return SDL_FALSE;
    }

    if (input->xkb.compose_state && WAYLAND_xkb_compose_state_feed(input->xkb.compose_state, sym) == XKB_COMPOSE_FEED_ACCEPTED) {
        switch(WAYLAND_xkb_compose_state_get_status(input->xkb.compose_state)) {
            case XKB_COMPOSE_COMPOSING:
                *handled_by_ime = SDL_TRUE;
                return SDL_TRUE;
            case XKB_COMPOSE_CANCELLED:
            default:
                sym = XKB_KEY_NoSymbol;
                break;
            case XKB_COMPOSE_NOTHING:
                break;
            case XKB_COMPOSE_COMPOSED:
                sym = WAYLAND_xkb_compose_state_get_one_sym(input->xkb.compose_state);
                break;
        }
    }

    return WAYLAND_xkb_keysym_to_utf8(sym, text, 8) > 0;
}

static void
keyboard_handle_key(void *data, struct wl_keyboard *keyboard,
                    uint32_t serial, uint32_t time, uint32_t key,
                    uint32_t state_w)
{
    struct SDL_WaylandInput *input = data;
    enum wl_keyboard_key_state state = state_w;
    uint32_t scancode = SDL_SCANCODE_UNKNOWN;
    char text[8];
    SDL_bool has_text = SDL_FALSE;
    SDL_bool handled_by_ime = SDL_FALSE;

    if (state == WL_KEYBOARD_KEY_STATE_PRESSED) {
        has_text = keyboard_input_get_text(text, input, key, SDL_PRESSED, &handled_by_ime);
    } else {
        if (keyboard_repeat_is_set(&input->keyboard_repeat)) {
            // Send any due key repeat events before stopping the repeat and generating the key up event
            // Compute time based on the Wayland time, as it reports when the release event happened
            // Using SDL_GetTicks would be wrong, as it would report when the release event is processed,
            // which may be off if the application hasn't pumped events for a while
            keyboard_repeat_handle(&input->keyboard_repeat, time - input->keyboard_repeat.wl_press_time);
            keyboard_repeat_clear(&input->keyboard_repeat);
        }
        keyboard_input_get_text(text, input, key, SDL_RELEASED, &handled_by_ime);
    }

    if (!handled_by_ime && key < SDL_arraysize(xfree86_scancode_table2)) {
        scancode = xfree86_scancode_table2[key];

        if (scancode != SDL_SCANCODE_UNKNOWN) {
            SDL_SendKeyboardKey(state == WL_KEYBOARD_KEY_STATE_PRESSED ?
                                SDL_PRESSED : SDL_RELEASED, scancode);
        }
    }

    if (state == WL_KEYBOARD_KEY_STATE_PRESSED) {
        if (has_text && !(SDL_GetModState() & KMOD_CTRL)) {
            Wayland_data_device_set_serial(input->data_device, serial);
            if (!handled_by_ime) {
                SDL_SendKeyboardText(text);
            }
        }
        if (input->xkb.keymap && WAYLAND_xkb_keymap_key_repeats(input->xkb.keymap, key + 8)) {
            keyboard_repeat_set(&input->keyboard_repeat, time, scancode, has_text, text);
        }
    }
}

typedef struct Wayland_Keymap
{
    xkb_layout_index_t layout;
    SDL_Keycode keymap[SDL_NUM_SCANCODES];
} Wayland_Keymap;

static void
Wayland_keymap_iter(struct xkb_keymap *keymap, xkb_keycode_t key, void *data)
{
    const xkb_keysym_t *syms;
    Wayland_Keymap *sdlKeymap = (Wayland_Keymap *)data;

    if ((key - 8) < SDL_arraysize(xfree86_scancode_table2)) {
        SDL_Scancode scancode = xfree86_scancode_table2[key - 8];
        if (scancode == SDL_SCANCODE_UNKNOWN) {
            return;
        }

        if (WAYLAND_xkb_keymap_key_get_syms_by_level(keymap, key, sdlKeymap->layout, 0, &syms) > 0) {
            uint32_t keycode = SDL_KeySymToUcs4(syms[0]);

            if (!keycode) {
                keycode = Wayland_KeySymToSDLKeyCode(syms[0]);
            }

            if (keycode) {
                sdlKeymap->keymap[scancode] = keycode;
            } else {
                switch (scancode) {
                    case SDL_SCANCODE_RETURN:
                        sdlKeymap->keymap[scancode] = SDLK_RETURN;
                        break;
                    case SDL_SCANCODE_ESCAPE:
                        sdlKeymap->keymap[scancode] = SDLK_ESCAPE;
                        break;
                    case SDL_SCANCODE_BACKSPACE:
                        sdlKeymap->keymap[scancode] = SDLK_BACKSPACE;
                        break;
                    case SDL_SCANCODE_TAB:
                        sdlKeymap->keymap[scancode] = SDLK_TAB;
                        break;
                    case SDL_SCANCODE_DELETE:
                        sdlKeymap->keymap[scancode] = SDLK_DELETE;
                        break;
                    default:
                        sdlKeymap->keymap[scancode] = SDL_SCANCODE_TO_KEYCODE(scancode);
                        break;
                }
            }
        }
    }
}

static void
keyboard_handle_modifiers(void *data, struct wl_keyboard *keyboard,
                          uint32_t serial, uint32_t mods_depressed,
                          uint32_t mods_latched, uint32_t mods_locked,
                          uint32_t group)
{
    struct SDL_WaylandInput *input = data;
    Wayland_Keymap keymap;
    uint32_t modstate = (mods_depressed | mods_latched | mods_locked);

    WAYLAND_xkb_state_update_mask(input->xkb.state, mods_depressed, mods_latched,
                          mods_locked, 0, 0, group);

    SDL_ToggleModState(KMOD_SHIFT, modstate & input->xkb.idx_shift);
    SDL_ToggleModState(KMOD_CTRL, modstate & input->xkb.idx_ctrl);
    SDL_ToggleModState(KMOD_ALT, modstate & input->xkb.idx_alt);
    SDL_ToggleModState(KMOD_GUI, modstate & input->xkb.idx_gui);
    SDL_ToggleModState(KMOD_NUM, modstate & input->xkb.idx_num);
    SDL_ToggleModState(KMOD_CAPS, modstate & input->xkb.idx_caps);

    if (group == input->xkb.current_group) {
        return;
    }

    /* The layout changed, remap and fire an event */
    input->xkb.current_group = group;
    keymap.layout = group;
    SDL_GetDefaultKeymap(keymap.keymap);
    WAYLAND_xkb_keymap_key_for_each(input->xkb.keymap,
                                    Wayland_keymap_iter,
                                    &keymap);
    SDL_SetKeymap(0, keymap.keymap, SDL_NUM_SCANCODES, SDL_TRUE);
}

static void
keyboard_handle_repeat_info(void *data, struct wl_keyboard *wl_keyboard,
                            int32_t rate, int32_t delay)
{
    struct SDL_WaylandInput *input = data;
    input->keyboard_repeat.repeat_rate = SDL_clamp(rate, 0, 1000);
    input->keyboard_repeat.repeat_delay = delay;
    input->keyboard_repeat.is_initialized = SDL_TRUE;
}

static const struct wl_keyboard_listener keyboard_listener = {
    keyboard_handle_keymap,
    keyboard_handle_enter,
    keyboard_handle_leave,
    keyboard_handle_key,
    keyboard_handle_modifiers,
    keyboard_handle_repeat_info,    // Version 4
};

static void
seat_handle_capabilities(void *data, struct wl_seat *seat,
                         enum wl_seat_capability caps)
{
    struct SDL_WaylandInput *input = data;

    if ((caps & WL_SEAT_CAPABILITY_POINTER) && !input->pointer) {
        input->pointer = wl_seat_get_pointer(seat);
        SDL_memset(&input->pointer_curr_axis_info, 0, sizeof input->pointer_curr_axis_info);
        input->display->pointer = input->pointer;
        wl_pointer_set_user_data(input->pointer, input);
        wl_pointer_add_listener(input->pointer, &pointer_listener,
                                input);
    } else if (!(caps & WL_SEAT_CAPABILITY_POINTER) && input->pointer) {
        wl_pointer_destroy(input->pointer);
        input->pointer = NULL;
        input->display->pointer = NULL;
    }

    if ((caps & WL_SEAT_CAPABILITY_TOUCH) && !input->touch) {
        input->touch = wl_seat_get_touch(seat);
        SDL_AddTouch((SDL_TouchID)(intptr_t)input->touch, SDL_TOUCH_DEVICE_DIRECT, "wayland_touch");
        wl_touch_set_user_data(input->touch, input);
        wl_touch_add_listener(input->touch, &touch_listener,
                                 input);
    } else if (!(caps & WL_SEAT_CAPABILITY_TOUCH) && input->touch) {
        SDL_DelTouch((SDL_TouchID)(intptr_t)input->touch);
        wl_touch_destroy(input->touch);
        input->touch = NULL;
    }

    if ((caps & WL_SEAT_CAPABILITY_KEYBOARD) && !input->keyboard) {
        input->keyboard = wl_seat_get_keyboard(seat);
        wl_keyboard_set_user_data(input->keyboard, input);
        wl_keyboard_add_listener(input->keyboard, &keyboard_listener,
                                 input);
    } else if (!(caps & WL_SEAT_CAPABILITY_KEYBOARD) && input->keyboard) {
        wl_keyboard_destroy(input->keyboard);
        input->keyboard = NULL;
    }
}

static void
seat_handle_name(void *data, struct wl_seat *wl_seat, const char *name)
{
    /* unimplemented */
}

static const struct wl_seat_listener seat_listener = {
    seat_handle_capabilities,
    seat_handle_name,           // Version 2
};

static void
data_source_handle_target(void *data, struct wl_data_source *wl_data_source,
                          const char *mime_type)
{
}

static void
data_source_handle_send(void *data, struct wl_data_source *wl_data_source,
                        const char *mime_type, int32_t fd)
{
    Wayland_data_source_send((SDL_WaylandDataSource *)data, mime_type, fd);
}

static void
data_source_handle_cancelled(void *data, struct wl_data_source *wl_data_source)
{
    Wayland_data_source_destroy(data);
}

static void
data_source_handle_dnd_drop_performed(void *data, struct wl_data_source *wl_data_source)
{
}

static void
data_source_handle_dnd_finished(void *data, struct wl_data_source *wl_data_source)
{
}

static void
data_source_handle_action(void *data, struct wl_data_source *wl_data_source,
                          uint32_t dnd_action)
{
}

static const struct wl_data_source_listener data_source_listener = {
    data_source_handle_target,
    data_source_handle_send,
    data_source_handle_cancelled,
    data_source_handle_dnd_drop_performed, // Version 3
    data_source_handle_dnd_finished,       // Version 3
    data_source_handle_action,             // Version 3
};

SDL_WaylandDataSource*
Wayland_data_source_create(_THIS)
{
    SDL_WaylandDataSource *data_source = NULL;
    SDL_VideoData *driver_data = NULL;
    struct wl_data_source *id = NULL;

    if (_this == NULL || _this->driverdata == NULL) {
        SDL_SetError("Video driver uninitialized");
    } else {
        driver_data = _this->driverdata;

        if (driver_data->data_device_manager != NULL) {
            id = wl_data_device_manager_create_data_source(
                     driver_data->data_device_manager);
        }

        if (id == NULL) {
            SDL_SetError("Wayland unable to create data source");
        } else {
            data_source = SDL_calloc(1, sizeof *data_source);
            if (data_source == NULL) {
                SDL_OutOfMemory();
                wl_data_source_destroy(id);
            } else {
                WAYLAND_wl_list_init(&(data_source->mimes));
                data_source->source = id;
                wl_data_source_set_user_data(id, data_source);
                wl_data_source_add_listener(id, &data_source_listener,
                                            data_source);
            }
        }
    }
    return data_source;
}

static void
data_offer_handle_offer(void *data, struct wl_data_offer *wl_data_offer,
                        const char *mime_type)
{
    SDL_WaylandDataOffer *offer = data;
    Wayland_data_offer_add_mime(offer, mime_type);
}

static void
data_offer_handle_source_actions(void *data, struct wl_data_offer *wl_data_offer,
                                 uint32_t source_actions)
{
}

static void
data_offer_handle_actions(void *data, struct wl_data_offer *wl_data_offer,
                          uint32_t dnd_action)
{
}

static const struct wl_data_offer_listener data_offer_listener = {
    data_offer_handle_offer,
    data_offer_handle_source_actions, // Version 3
    data_offer_handle_actions,        // Version 3
};

static void
data_device_handle_data_offer(void *data, struct wl_data_device *wl_data_device,
                              struct wl_data_offer *id)
{
    SDL_WaylandDataOffer *data_offer = NULL;

    data_offer = SDL_calloc(1, sizeof *data_offer);
    if (data_offer == NULL) {
        SDL_OutOfMemory();
    } else {
        data_offer->offer = id;
        data_offer->data_device = data;
        WAYLAND_wl_list_init(&(data_offer->mimes));
        wl_data_offer_set_user_data(id, data_offer);
        wl_data_offer_add_listener(id, &data_offer_listener, data_offer);
    }
}

static void
data_device_handle_enter(void *data, struct wl_data_device *wl_data_device,
                         uint32_t serial, struct wl_surface *surface,
                         wl_fixed_t x, wl_fixed_t y, struct wl_data_offer *id)
{
    SDL_WaylandDataDevice *data_device = data;
    SDL_bool has_mime = SDL_FALSE;
    uint32_t dnd_action = WL_DATA_DEVICE_MANAGER_DND_ACTION_NONE;

    data_device->drag_serial = serial;

    if (id != NULL) {
        data_device->drag_offer = wl_data_offer_get_user_data(id);

        /* TODO: SDL Support more mime types */
        has_mime = Wayland_data_offer_has_mime(
            data_device->drag_offer, FILE_MIME);

        /* If drag_mime is NULL this will decline the offer */
        wl_data_offer_accept(id, serial,
                             (has_mime == SDL_TRUE) ? FILE_MIME : NULL);

        /* SDL only supports "copy" style drag and drop */
        if (has_mime == SDL_TRUE) {
            dnd_action = WL_DATA_DEVICE_MANAGER_DND_ACTION_COPY;
        }
        if (wl_data_offer_get_version(data_device->drag_offer->offer) >= 3) {
            wl_data_offer_set_actions(data_device->drag_offer->offer,
                                      dnd_action, dnd_action);
        }
    }
}

static void
data_device_handle_leave(void *data, struct wl_data_device *wl_data_device)
{
    SDL_WaylandDataDevice *data_device = data;
    SDL_WaylandDataOffer *offer = NULL;

    if (data_device->selection_offer != NULL) {
        data_device->selection_offer = NULL;
        Wayland_data_offer_destroy(offer);
    }
}

static void
data_device_handle_motion(void *data, struct wl_data_device *wl_data_device,
                          uint32_t time, wl_fixed_t x, wl_fixed_t y)
{
}

/* Decodes URI escape sequences in string buf of len bytes
   (excluding the terminating NULL byte) in-place. Since
   URI-encoded characters take three times the space of
   normal characters, this should not be an issue.

   Returns the number of decoded bytes that wound up in
   the buffer, excluding the terminating NULL byte.

   The buffer is guaranteed to be NULL-terminated but
   may contain embedded NULL bytes.

   On error, -1 is returned.

   FIXME: This was shamelessly copied from SDL_x11events.c
 */
static int Wayland_URIDecode(char *buf, int len) {
    int ri, wi, di;
    char decode = '\0';
    if (buf == NULL || len < 0) {
        errno = EINVAL;
        return -1;
    }
    if (len == 0) {
        len = SDL_strlen(buf);
    }
    for (ri = 0, wi = 0, di = 0; ri < len && wi < len; ri += 1) {
        if (di == 0) {
            /* start decoding */
            if (buf[ri] == '%') {
                decode = '\0';
                di += 1;
                continue;
            }
            /* normal write */
            buf[wi] = buf[ri];
            wi += 1;
            continue;
        } else if (di == 1 || di == 2) {
            char off = '\0';
            char isa = buf[ri] >= 'a' && buf[ri] <= 'f';
            char isA = buf[ri] >= 'A' && buf[ri] <= 'F';
            char isn = buf[ri] >= '0' && buf[ri] <= '9';
            if (!(isa || isA || isn)) {
                /* not a hexadecimal */
                int sri;
                for (sri = ri - di; sri <= ri; sri += 1) {
                    buf[wi] = buf[sri];
                    wi += 1;
                }
                di = 0;
                continue;
            }
            /* itsy bitsy magicsy */
            if (isn) {
                off = 0 - '0';
            } else if (isa) {
                off = 10 - 'a';
            } else if (isA) {
                off = 10 - 'A';
            }
            decode |= (buf[ri] + off) << (2 - di) * 4;
            if (di == 2) {
                buf[wi] = decode;
                wi += 1;
                di = 0;
            } else {
                di += 1;
            }
            continue;
        }
    }
    buf[wi] = '\0';
    return wi;
}

/* Convert URI to local filename
   return filename if possible, else NULL

   FIXME: This was shamelessly copied from SDL_x11events.c
*/
static char* Wayland_URIToLocal(char* uri) {
    char *file = NULL;
    SDL_bool local;

    if (SDL_memcmp(uri,"file:/",6) == 0) uri += 6;      /* local file? */
    else if (SDL_strstr(uri,":/") != NULL) return file; /* wrong scheme */

    local = uri[0] != '/' || (uri[0] != '\0' && uri[1] == '/');

    /* got a hostname? */
    if (!local && uri[0] == '/' && uri[2] != '/') {
      char* hostname_end = SDL_strchr(uri+1, '/');
      if (hostname_end != NULL) {
          char hostname[ 257 ];
          if (gethostname(hostname, 255) == 0) {
            hostname[ 256 ] = '\0';
            if (SDL_memcmp(uri+1, hostname, hostname_end - (uri+1)) == 0) {
                uri = hostname_end + 1;
                local = SDL_TRUE;
            }
          }
      }
    }
    if (local) {
      file = uri;
      /* Convert URI escape sequences to real characters */
      Wayland_URIDecode(file, 0);
      if (uri[1] == '/') {
          file++;
      } else {
          file--;
      }
    }
    return file;
}

static void
data_device_handle_drop(void *data, struct wl_data_device *wl_data_device)
{
    SDL_WaylandDataDevice *data_device = data;

    if (data_device->drag_offer != NULL) {
        /* TODO: SDL Support more mime types */
        size_t length;
        void *buffer = Wayland_data_offer_receive(data_device->drag_offer,
                                                  &length, FILE_MIME, SDL_FALSE);
        if (buffer) {
            char *saveptr = NULL;
            char *token = SDL_strtokr((char *) buffer, "\r\n", &saveptr);
            while (token != NULL) {
                char *fn = Wayland_URIToLocal(token);
                if (fn) {
                    SDL_SendDropFile(NULL, fn); /* FIXME: Window? */
                }
                token = SDL_strtokr(NULL, "\r\n", &saveptr);
            }
            SDL_SendDropComplete(NULL); /* FIXME: Window? */
            SDL_free(buffer);
        }
    }
}

static void
data_device_handle_selection(void *data, struct wl_data_device *wl_data_device,
                             struct wl_data_offer *id)
{
    SDL_WaylandDataDevice *data_device = data;
    SDL_WaylandDataOffer *offer = NULL;

    if (id != NULL) {
        offer = wl_data_offer_get_user_data(id);
    }

    if (data_device->selection_offer != offer) {
        Wayland_data_offer_destroy(data_device->selection_offer);
        data_device->selection_offer = offer;
    }

    SDL_SendClipboardUpdate();
}

static const struct wl_data_device_listener data_device_listener = {
    data_device_handle_data_offer,
    data_device_handle_enter,
    data_device_handle_leave,
    data_device_handle_motion,
    data_device_handle_drop,
    data_device_handle_selection
};

static void
text_input_enter(void *data,
                 struct zwp_text_input_v3 *zwp_text_input_v3,
                 struct wl_surface *surface)
{
    /* No-op */
}

static void
text_input_leave(void *data,
                 struct zwp_text_input_v3 *zwp_text_input_v3,
                 struct wl_surface *surface)
{
    /* No-op */
}

static void
text_input_preedit_string(void *data,
                          struct zwp_text_input_v3 *zwp_text_input_v3,
                          const char *text,
                          int32_t cursor_begin,
                          int32_t cursor_end)
{
    SDL_WaylandTextInput *text_input = data;
    char buf[SDL_TEXTEDITINGEVENT_TEXT_SIZE];
    text_input->has_preedit = SDL_TRUE;
    if (text) {
        if (SDL_GetHintBoolean(SDL_HINT_IME_SUPPORT_EXTENDED_TEXT, SDL_FALSE)) {
            int cursor_begin_utf8 = cursor_begin >= 0 ? (int)SDL_utf8strnlen(text, cursor_begin) : -1;
            int cursor_end_utf8 = cursor_end >= 0 ? (int)SDL_utf8strnlen(text, cursor_end) : -1;
            int cursor_size_utf8;
            if (cursor_end_utf8 >= 0) {
                if (cursor_begin_utf8 >= 0) {
                    cursor_size_utf8 = cursor_end_utf8 - cursor_begin_utf8;
                } else {
                    cursor_size_utf8 = cursor_end_utf8;
                }
            } else {
                cursor_size_utf8 = -1;
            }
            SDL_SendEditingText(text, cursor_begin_utf8, cursor_size_utf8);
        } else {
            int text_bytes = (int)SDL_strlen(text), i = 0;
            int cursor = 0;
            do {
                const int sz = (int)SDL_utf8strlcpy(buf, text+i, sizeof(buf));
                const int chars = (int)SDL_utf8strlen(buf);
    
                SDL_SendEditingText(buf, cursor, chars);
    
                i += sz;
                cursor += chars;
            } while (i < text_bytes);
        }
    } else {
        buf[0] = '\0';
        SDL_SendEditingText(buf, 0, 0);
    }
}

static void
text_input_commit_string(void *data,
                         struct zwp_text_input_v3 *zwp_text_input_v3,
                         const char *text)
{
    if (text && *text) {
        char buf[SDL_TEXTINPUTEVENT_TEXT_SIZE];
        size_t text_bytes = SDL_strlen(text), i = 0;

        while (i < text_bytes) {
            size_t sz = SDL_utf8strlcpy(buf, text+i, sizeof(buf));
            SDL_SendKeyboardText(buf);

            i += sz;
        }
    }
}

static void
text_input_delete_surrounding_text(void *data,
                                   struct zwp_text_input_v3 *zwp_text_input_v3,
                                   uint32_t before_length,
                                   uint32_t after_length)
{
    /* FIXME: Do we care about this event? */
}

static void
text_input_done(void *data,
                struct zwp_text_input_v3 *zwp_text_input_v3,
                uint32_t serial)
{
    SDL_WaylandTextInput *text_input = data;
    if (!text_input->has_preedit) {
        SDL_SendEditingText("", 0, 0);
    }
    text_input->has_preedit = SDL_FALSE;
}

static const struct zwp_text_input_v3_listener text_input_listener = {
    text_input_enter,
    text_input_leave,
    text_input_preedit_string,
    text_input_commit_string,
    text_input_delete_surrounding_text,
    text_input_done
};

static void
Wayland_create_data_device(SDL_VideoData *d)
{
    SDL_WaylandDataDevice *data_device = NULL;

    data_device = SDL_calloc(1, sizeof *data_device);
    if (data_device == NULL) {
        return;
    }

    data_device->data_device = wl_data_device_manager_get_data_device(
        d->data_device_manager, d->input->seat
    );
    data_device->video_data = d;

    if (data_device->data_device == NULL) {
        SDL_free(data_device);
    } else {
        wl_data_device_set_user_data(data_device->data_device, data_device);
        wl_data_device_add_listener(data_device->data_device,
                                    &data_device_listener, data_device);
        d->input->data_device = data_device;
    }
}

static void
Wayland_create_text_input(SDL_VideoData *d)
{
    SDL_WaylandTextInput *text_input = NULL;

    text_input = SDL_calloc(1, sizeof *text_input);
    if (text_input == NULL) {
        return;
    }

    text_input->text_input = zwp_text_input_manager_v3_get_text_input(
        d->text_input_manager, d->input->seat
    );

    if (text_input->text_input == NULL) {
        SDL_free(text_input);
    } else {
        zwp_text_input_v3_set_user_data(text_input->text_input, text_input);
        zwp_text_input_v3_add_listener(text_input->text_input,
                                       &text_input_listener, text_input);
        d->input->text_input = text_input;
    }
}

void
Wayland_add_data_device_manager(SDL_VideoData *d, uint32_t id, uint32_t version)
{
    d->data_device_manager = wl_registry_bind(d->registry, id, &wl_data_device_manager_interface, SDL_min(3, version));

    if (d->input != NULL) {
        Wayland_create_data_device(d);
    }
}

void
Wayland_add_text_input_manager(SDL_VideoData *d, uint32_t id, uint32_t version)
{
    d->text_input_manager = wl_registry_bind(d->registry, id, &zwp_text_input_manager_v3_interface, 1);

    if (d->input != NULL) {
        Wayland_create_text_input(d);
    }
}

static void
tablet_tool_handle_type(void* data, struct zwp_tablet_tool_v2* tool, uint32_t type)
{
    /* unimplemented */
}

static void
tablet_tool_handle_hardware_serial(void* data, struct zwp_tablet_tool_v2* tool, uint32_t serial_hi, uint32_t serial_lo)
{
    /* unimplemented */
}

static void
tablet_tool_handle_hardware_id_wacom(void* data, struct zwp_tablet_tool_v2* tool, uint32_t id_hi, uint32_t id_lo)
{
    /* unimplemented */
}

static void
tablet_tool_handle_capability(void* data, struct zwp_tablet_tool_v2* tool, uint32_t capability)
{
    /* unimplemented */
}

static void
tablet_tool_handle_done(void* data, struct zwp_tablet_tool_v2* tool)
{
    /* unimplemented */
}

static void
tablet_tool_handle_removed(void* data, struct zwp_tablet_tool_v2* tool)
{
    /* unimplemented */
}

static void
tablet_tool_handle_proximity_in(void* data, struct zwp_tablet_tool_v2* tool, uint32_t serial, struct zwp_tablet_v2* tablet, struct wl_surface* surface)
{
    struct SDL_WaylandTabletInput* input = data;
    SDL_WindowData* window;

    if (!surface) {
        return;
    }

    if (!SDL_WAYLAND_own_surface(surface)) {
        return;
    }

    window = (SDL_WindowData*)wl_surface_get_user_data(surface);

    if (window) {
        input->tool_focus = window;
        input->tool_prox_serial = serial;

        input->is_down = SDL_FALSE;

        input->btn_stylus = SDL_FALSE;
        input->btn_stylus2 = SDL_FALSE;
        input->btn_stylus3 = SDL_FALSE;

        SDL_SetMouseFocus(window->sdlwindow);
        SDL_SetCursor(NULL);
    }
}

static void
tablet_tool_handle_proximity_out(void* data, struct zwp_tablet_tool_v2* tool)
{
    struct SDL_WaylandTabletInput* input = data;

    if (input->tool_focus) {
        SDL_SetMouseFocus(NULL);
        input->tool_focus = NULL;
    }
}

uint32_t
tablet_tool_btn_to_sdl_button(struct SDL_WaylandTabletInput* input)
{
    unsigned int tool_btn = input->btn_stylus3 << 2 | input->btn_stylus2 << 1 | input->btn_stylus << 0;
    switch (tool_btn) {
        case 0b000:
            return SDL_BUTTON_LEFT;
        case 0b001:
            return SDL_BUTTON_RIGHT;
        case 0b010:
            return SDL_BUTTON_MIDDLE;
        case 0b100:
            return SDL_BUTTON_X1;
        default:
            return SDL_BUTTON_LEFT;
    }
}

static void
tablet_tool_handle_down(void* data, struct zwp_tablet_tool_v2* tool, uint32_t serial)
{
    struct SDL_WaylandTabletInput* input = data;
    SDL_WindowData* window = input->tool_focus;
    input->is_down = SDL_TRUE;
    if (!window) {
        /* tablet_tool_handle_proximity_out gets called when moving over the libdecoration csd.
         * that sets input->tool_focus (window) to NULL, but handle_{down,up} events are still
         * received. To prevent SIGSEGV this returns when this is the case.
         */
        return;
    }

    SDL_SendMouseButton(window->sdlwindow, 0, SDL_PRESSED, tablet_tool_btn_to_sdl_button(input));
}

static void
tablet_tool_handle_up(void* data, struct zwp_tablet_tool_v2* tool)
{
    struct SDL_WaylandTabletInput* input = data;
    SDL_WindowData* window = input->tool_focus;

    input->is_down = SDL_FALSE;

    if (!window) {
        /* tablet_tool_handle_proximity_out gets called when moving over the libdecoration csd.
         * that sets input->tool_focus (window) to NULL, but handle_{down,up} events are still
         * received. To prevent SIGSEGV this returns when this is the case.
         */
        return;
    }

    SDL_SendMouseButton(window->sdlwindow, 0, SDL_RELEASED, tablet_tool_btn_to_sdl_button(input));
}

static void
tablet_tool_handle_motion(void* data, struct zwp_tablet_tool_v2* tool, wl_fixed_t sx_w, wl_fixed_t sy_w)
{
    struct SDL_WaylandTabletInput* input = data;
    SDL_WindowData* window = input->tool_focus;

    input->sx_w = sx_w;
    input->sy_w = sy_w;
    if (input->tool_focus) {
        const float sx_f = (float)wl_fixed_to_double(sx_w);
        const float sy_f = (float)wl_fixed_to_double(sy_w);
        const int   sx   = (int)SDL_floorf(sx_f * window->pointer_scale_x);
        const int   sy   = (int)SDL_floorf(sy_f * window->pointer_scale_y);
        SDL_SendMouseMotion(window->sdlwindow, 0, 0, sx, sy);
    }
}

static void
tablet_tool_handle_pressure(void* data, struct zwp_tablet_tool_v2* tool, uint32_t pressure)
{
    /* unimplemented */
}

static void
tablet_tool_handle_distance(void* data, struct zwp_tablet_tool_v2* tool, uint32_t distance)
{
    /* unimplemented */
}

static void
tablet_tool_handle_tilt(void* data, struct zwp_tablet_tool_v2* tool, wl_fixed_t xtilt, wl_fixed_t ytilt)
{
    /* unimplemented */
}

static void
tablet_tool_handle_button(void* data, struct zwp_tablet_tool_v2* tool, uint32_t serial, uint32_t button, uint32_t state)
{
    struct SDL_WaylandTabletInput* input = data;

    if (input->is_down) {
        tablet_tool_handle_up(data, tool);
        input->is_down = SDL_TRUE;
    }

    switch (button) {
        /* see %{_includedir}/linux/input-event-codes.h */
        case 0x14b: /* BTN_STYLUS */
            input->btn_stylus = state == ZWP_TABLET_PAD_V2_BUTTON_STATE_PRESSED ? SDL_TRUE : SDL_FALSE;
            break;
        case 0x14c: /* BTN_STYLUS2 */
            input->btn_stylus2 = state == ZWP_TABLET_PAD_V2_BUTTON_STATE_PRESSED ? SDL_TRUE : SDL_FALSE;
            break;
        case 0x149: /* BTN_STYLUS3 */
            input->btn_stylus3 = state == ZWP_TABLET_PAD_V2_BUTTON_STATE_PRESSED ? SDL_TRUE : SDL_FALSE;
            break;
    }

    if (input->is_down) {
        tablet_tool_handle_down(data, tool, serial);
    }
}

static void
tablet_tool_handle_rotation(void* data, struct zwp_tablet_tool_v2* tool, wl_fixed_t degrees)
{
    /* unimplemented */
}

static void
tablet_tool_handle_slider(void* data, struct zwp_tablet_tool_v2* tool, int32_t position)
{
    /* unimplemented */
}

static void
tablet_tool_handle_wheel(void* data, struct zwp_tablet_tool_v2* tool, int32_t degrees, int32_t clicks)
{
    /* unimplemented */
}

static void
tablet_tool_handle_frame(void* data, struct zwp_tablet_tool_v2* tool, uint32_t time)
{
    /* unimplemented */
}


static const struct zwp_tablet_tool_v2_listener tablet_tool_listener = {
    tablet_tool_handle_type,
    tablet_tool_handle_hardware_serial,
    tablet_tool_handle_hardware_id_wacom,
    tablet_tool_handle_capability,
    tablet_tool_handle_done,
    tablet_tool_handle_removed,
    tablet_tool_handle_proximity_in,
    tablet_tool_handle_proximity_out,
    tablet_tool_handle_down,
    tablet_tool_handle_up,
    tablet_tool_handle_motion,
    tablet_tool_handle_pressure,
    tablet_tool_handle_distance,
    tablet_tool_handle_tilt,
    tablet_tool_handle_rotation,
    tablet_tool_handle_slider,
    tablet_tool_handle_wheel,
    tablet_tool_handle_button,
    tablet_tool_handle_frame
};

struct SDL_WaylandTabletObjectListNode*
tablet_object_list_new_node(void* object)
{
    struct SDL_WaylandTabletObjectListNode* node;

    node = SDL_calloc(1, sizeof *node);
    if (node == NULL) {
        return NULL;
    }

    node->next = NULL;
    node->object = object;

    return node;
}

void tablet_object_list_append(struct SDL_WaylandTabletObjectListNode* head, void* object)
{
    if (head->object == NULL) {
        head->object = object;
        return;
    }

    while (head->next) {
        head = head->next;
    }

    head->next = tablet_object_list_new_node(object);
}

void tablet_object_list_destroy(struct SDL_WaylandTabletObjectListNode* head, void (*deleter)(void* object))
{
    while (head) {
        struct SDL_WaylandTabletObjectListNode* next = head->next;
        if (head->object) {
            (*deleter)(head->object);
        }
        SDL_free(head);
        head = next;
    }
}


static void
tablet_seat_handle_tablet_added(void* data, struct zwp_tablet_seat_v2* seat, struct zwp_tablet_v2* tablet)
{
    struct SDL_WaylandTabletInput* input = data;

    tablet_object_list_append(input->tablets, tablet);
}

static void
tablet_seat_handle_tool_added(void* data, struct zwp_tablet_seat_v2* seat, struct zwp_tablet_tool_v2* tool)
{
    struct SDL_WaylandTabletInput* input = data;

    zwp_tablet_tool_v2_add_listener(tool, &tablet_tool_listener, data);
    zwp_tablet_tool_v2_set_user_data(tool, data);

    tablet_object_list_append(input->tools, tool);
}

static void
tablet_seat_handle_pad_added(void* data, struct zwp_tablet_seat_v2* seat, struct zwp_tablet_pad_v2* pad)
{
    struct SDL_WaylandTabletInput* input = data;

    tablet_object_list_append(input->pads, pad);
}

static const struct zwp_tablet_seat_v2_listener tablet_seat_listener = {
    tablet_seat_handle_tablet_added,
    tablet_seat_handle_tool_added,
    tablet_seat_handle_pad_added
};

void
Wayland_input_add_tablet(struct SDL_WaylandInput *input, struct SDL_WaylandTabletManager* tablet_manager)
{
    struct SDL_WaylandTabletInput* tablet_input;

    if (!tablet_manager || !input || !input->seat) {
        return;
    }

    tablet_input = SDL_calloc(1, sizeof *tablet_input);
    if (tablet_input == NULL) {
        return;
    }

    input->tablet = tablet_input;

    tablet_input->seat = (struct SDL_WaylandTabletSeat*)zwp_tablet_manager_v2_get_tablet_seat((struct zwp_tablet_manager_v2*)tablet_manager, input->seat);

    tablet_input->tablets = tablet_object_list_new_node(NULL);
    tablet_input->tools = tablet_object_list_new_node(NULL);
    tablet_input->pads = tablet_object_list_new_node(NULL);

    zwp_tablet_seat_v2_add_listener((struct zwp_tablet_seat_v2*)tablet_input->seat, &tablet_seat_listener, tablet_input);
}

#define TABLET_OBJECT_LIST_DELETER(fun) (void (*)(void*))fun
void
Wayland_input_destroy_tablet(struct SDL_WaylandInput* input)
{
    tablet_object_list_destroy(input->tablet->pads, TABLET_OBJECT_LIST_DELETER(zwp_tablet_pad_v2_destroy));
    tablet_object_list_destroy(input->tablet->tools, TABLET_OBJECT_LIST_DELETER(zwp_tablet_tool_v2_destroy));
    tablet_object_list_destroy(input->tablet->tablets, TABLET_OBJECT_LIST_DELETER(zwp_tablet_v2_destroy));

    zwp_tablet_seat_v2_destroy((struct zwp_tablet_seat_v2*)input->tablet->seat);

    SDL_free(input->tablet);
    input->tablet = NULL;
}

void
Wayland_display_add_input(SDL_VideoData *d, uint32_t id, uint32_t version)
{
    struct SDL_WaylandInput *input;

    input = SDL_calloc(1, sizeof *input);
    if (input == NULL)
        return;

    input->display = d;
    input->seat = wl_registry_bind(d->registry, id, &wl_seat_interface, SDL_min(5, version));
    input->sx_w = wl_fixed_from_int(0);
    input->sy_w = wl_fixed_from_int(0);
    input->xkb.current_group = ~0;
    d->input = input;

    if (d->data_device_manager != NULL) {
        Wayland_create_data_device(d);
    }
    if (d->text_input_manager != NULL) {
        Wayland_create_text_input(d);
    }

    wl_seat_add_listener(input->seat, &seat_listener, input);
    wl_seat_set_user_data(input->seat, input);

    if (d->tablet_manager) {
        Wayland_input_add_tablet(input, d->tablet_manager);
    }

    WAYLAND_wl_display_flush(d->display);
}

void Wayland_display_destroy_input(SDL_VideoData *d)
{
    struct SDL_WaylandInput *input = d->input;

    if (!input)
        return;

    if (input->data_device != NULL) {
        Wayland_data_device_clear_selection(input->data_device);
        if (input->data_device->selection_offer != NULL) {
            Wayland_data_offer_destroy(input->data_device->selection_offer);
        }
        if (input->data_device->drag_offer != NULL) {
            Wayland_data_offer_destroy(input->data_device->drag_offer);
        }
        if (input->data_device->data_device != NULL) {
            wl_data_device_release(input->data_device->data_device);
        }
        SDL_free(input->data_device);
    }

    if (input->text_input != NULL) {
        zwp_text_input_v3_destroy(input->text_input->text_input);
        SDL_free(input->text_input);
    }

    if (input->keyboard)
        wl_keyboard_destroy(input->keyboard);

    if (input->pointer)
        wl_pointer_destroy(input->pointer);

    if (input->touch) {
        SDL_DelTouch(1);
        wl_touch_destroy(input->touch);
    }

    if (input->tablet) {
        Wayland_input_destroy_tablet(input);
    }

    if (input->seat)
        wl_seat_destroy(input->seat);

    if (input->xkb.compose_state)
        WAYLAND_xkb_compose_state_unref(input->xkb.compose_state);

    if (input->xkb.compose_table)
        WAYLAND_xkb_compose_table_unref(input->xkb.compose_table);

    if (input->xkb.state)
        WAYLAND_xkb_state_unref(input->xkb.state);

    if (input->xkb.keymap)
        WAYLAND_xkb_keymap_unref(input->xkb.keymap);

    SDL_free(input);
    d->input = NULL;
}

/* !!! FIXME: just merge these into display_handle_global(). */
void Wayland_display_add_relative_pointer_manager(SDL_VideoData *d, uint32_t id)
{
    d->relative_pointer_manager =
        wl_registry_bind(d->registry, id,
                         &zwp_relative_pointer_manager_v1_interface, 1);
}

void Wayland_display_destroy_relative_pointer_manager(SDL_VideoData *d)
{
    if (d->relative_pointer_manager)
        zwp_relative_pointer_manager_v1_destroy(d->relative_pointer_manager);
}

void Wayland_display_add_pointer_constraints(SDL_VideoData *d, uint32_t id)
{
    d->pointer_constraints =
        wl_registry_bind(d->registry, id,
                         &zwp_pointer_constraints_v1_interface, 1);
}

void Wayland_display_destroy_pointer_constraints(SDL_VideoData *d)
{
    if (d->pointer_constraints)
        zwp_pointer_constraints_v1_destroy(d->pointer_constraints);
}

static void
relative_pointer_handle_relative_motion(void *data,
                                        struct zwp_relative_pointer_v1 *pointer,
                                        uint32_t time_hi,
                                        uint32_t time_lo,
                                        wl_fixed_t dx_w,
                                        wl_fixed_t dy_w,
                                        wl_fixed_t dx_unaccel_w,
                                        wl_fixed_t dy_unaccel_w)
{
    struct SDL_WaylandInput *input = data;
    SDL_VideoData *d = input->display;
    SDL_WindowData *window = input->pointer_focus;
    double dx_unaccel;
    double dy_unaccel;
    double dx;
    double dy;

    dx_unaccel = wl_fixed_to_double(dx_unaccel_w);
    dy_unaccel = wl_fixed_to_double(dy_unaccel_w);

    /* Add left over fraction from last event. */
    dx_unaccel += input->dx_frac;
    dy_unaccel += input->dy_frac;

    input->dx_frac = modf(dx_unaccel, &dx);
    input->dy_frac = modf(dy_unaccel, &dy);

    if (input->pointer_focus && d->relative_mouse_mode) {
        SDL_SendMouseMotion(window->sdlwindow, 0, 1, (int)dx, (int)dy);
    }
}

static const struct zwp_relative_pointer_v1_listener relative_pointer_listener = {
    relative_pointer_handle_relative_motion,
};

static void
locked_pointer_locked(void *data,
                      struct zwp_locked_pointer_v1 *locked_pointer)
{
}

static void
locked_pointer_unlocked(void *data,
                        struct zwp_locked_pointer_v1 *locked_pointer)
{
}

static const struct zwp_locked_pointer_v1_listener locked_pointer_listener = {
    locked_pointer_locked,
    locked_pointer_unlocked,
};

static void
lock_pointer_to_window(SDL_Window *window,
                       struct SDL_WaylandInput *input)
{
    SDL_WindowData *w = window->driverdata;
    SDL_VideoData *d = input->display;
    struct zwp_locked_pointer_v1 *locked_pointer;

    if (w->locked_pointer)
        return;

    locked_pointer =
        zwp_pointer_constraints_v1_lock_pointer(d->pointer_constraints,
                                                w->surface,
                                                input->pointer,
                                                NULL,
                                                ZWP_POINTER_CONSTRAINTS_V1_LIFETIME_PERSISTENT);
    zwp_locked_pointer_v1_add_listener(locked_pointer,
                                       &locked_pointer_listener,
                                       window);

    w->locked_pointer = locked_pointer;
}

static void pointer_confine_destroy(SDL_Window *window)
{
    SDL_WindowData *w = window->driverdata;
    if (w->confined_pointer) {
        zwp_confined_pointer_v1_destroy(w->confined_pointer);
        w->confined_pointer = NULL;
    }
}

int Wayland_input_lock_pointer(struct SDL_WaylandInput *input)
{
    SDL_VideoDevice *vd = SDL_GetVideoDevice();
    SDL_VideoData *d = input->display;
    SDL_Window *window;
    struct zwp_relative_pointer_v1 *relative_pointer;

    if (!d->relative_pointer_manager)
        return -1;

    if (!d->pointer_constraints)
        return -1;

    if (!input->pointer)
        return -1;

    /* If we have a pointer confine active, we must destroy it here because
     * creating a locked pointer otherwise would be a protocol error. */
    for (window = vd->windows; window; window = window->next)
        pointer_confine_destroy(window);

    if (!input->relative_pointer) {
        relative_pointer =
            zwp_relative_pointer_manager_v1_get_relative_pointer(
                d->relative_pointer_manager,
                input->pointer);
        zwp_relative_pointer_v1_add_listener(relative_pointer,
                                             &relative_pointer_listener,
                                             input);
        input->relative_pointer = relative_pointer;
    }

    for (window = vd->windows; window; window = window->next)
        lock_pointer_to_window(window, input);

    d->relative_mouse_mode = 1;

    return 0;
}

int Wayland_input_unlock_pointer(struct SDL_WaylandInput *input)
{
    SDL_VideoDevice *vd = SDL_GetVideoDevice();
    SDL_VideoData *d = input->display;
    SDL_Window *window;
    SDL_WindowData *w;

    for (window = vd->windows; window; window = window->next) {
        w = window->driverdata;
        if (w->locked_pointer)
            zwp_locked_pointer_v1_destroy(w->locked_pointer);
        w->locked_pointer = NULL;
    }

    zwp_relative_pointer_v1_destroy(input->relative_pointer);
    input->relative_pointer = NULL;

    d->relative_mouse_mode = 0;

    for (window = vd->windows; window; window = window->next)
        Wayland_input_confine_pointer(input, window);

    return 0;
}

static void
confined_pointer_confined(void *data,
                          struct zwp_confined_pointer_v1 *confined_pointer)
{
}

static void
confined_pointer_unconfined(void *data,
                            struct zwp_confined_pointer_v1 *confined_pointer)
{
}

static const struct zwp_confined_pointer_v1_listener confined_pointer_listener = {
    confined_pointer_confined,
    confined_pointer_unconfined,
};

int Wayland_input_confine_pointer(struct SDL_WaylandInput *input, SDL_Window *window)
{
    SDL_WindowData *w = window->driverdata;
    SDL_VideoData *d = input->display;
    struct zwp_confined_pointer_v1 *confined_pointer;
    struct wl_region *confine_rect;

    if (!d->pointer_constraints)
        return -1;

    if (!input->pointer)
        return -1;

    /* A confine may already be active, in which case we should destroy it and
     * create a new one. */
    pointer_confine_destroy(window);

    /* We cannot create a confine if the pointer is already locked. Defer until
     * the pointer is unlocked. */
    if (d->relative_mouse_mode)
        return 0;

    if (SDL_RectEmpty(&window->mouse_rect)) {
        confine_rect = NULL;
    } else {
        SDL_Rect scaled_mouse_rect;

        scaled_mouse_rect.x = (int)SDL_floorf((float)window->mouse_rect.x / w->pointer_scale_x);
        scaled_mouse_rect.y = (int)SDL_floorf((float)window->mouse_rect.y / w->pointer_scale_y);
        scaled_mouse_rect.w = (int)SDL_ceilf((float)window->mouse_rect.w / w->pointer_scale_x);
        scaled_mouse_rect.h = (int)SDL_ceilf((float)window->mouse_rect.h / w->pointer_scale_y);

        confine_rect = wl_compositor_create_region(d->compositor);
        wl_region_add(confine_rect,
                      scaled_mouse_rect.x,
                      scaled_mouse_rect.y,
                      scaled_mouse_rect.w,
                      scaled_mouse_rect.h);
    }

    confined_pointer =
        zwp_pointer_constraints_v1_confine_pointer(d->pointer_constraints,
                                                   w->surface,
                                                   input->pointer,
                                                   confine_rect,
                                                   ZWP_POINTER_CONSTRAINTS_V1_LIFETIME_PERSISTENT);
    zwp_confined_pointer_v1_add_listener(confined_pointer,
                                         &confined_pointer_listener,
                                         window);

    if (confine_rect != NULL) {
        wl_region_destroy(confine_rect);
    }

    w->confined_pointer = confined_pointer;
    return 0;
}

int Wayland_input_unconfine_pointer(struct SDL_WaylandInput *input, SDL_Window *window)
{
    pointer_confine_destroy(window);
    return 0;
}

int Wayland_input_grab_keyboard(SDL_Window *window, struct SDL_WaylandInput *input)
{
    SDL_WindowData *w = window->driverdata;
    SDL_VideoData *d = input->display;

    if (!d->key_inhibitor_manager)
        return -1;

    if (w->key_inhibitor)
        return 0;

    w->key_inhibitor =
        zwp_keyboard_shortcuts_inhibit_manager_v1_inhibit_shortcuts(d->key_inhibitor_manager,
                                                                    w->surface,
                                                                    input->seat);

    return 0;
}

int Wayland_input_ungrab_keyboard(SDL_Window *window)
{
    SDL_WindowData *w = window->driverdata;

    if (w->key_inhibitor) {
        zwp_keyboard_shortcuts_inhibitor_v1_destroy(w->key_inhibitor);
        w->key_inhibitor = NULL;
    }

    return 0;
}

#endif /* SDL_VIDEO_DRIVER_WAYLAND */

/* vi: set ts=4 sw=4 expandtab: */
kc3-lang/SDL/src/video/wayland/SDL_waylandevents.c

Commit

src/video/wayland/SDL_waylandevents.c
