blob: 01e553063a3a451a4313d0f79283be0591699d19 [file] [log] [blame]
/*
Simple DirectMedia Layer
Copyright (C) 1997-2021 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_video.h"
#include "SDL_mouse.h"
#include "SDL_stdinc.h"
#include "../../events/SDL_events_c.h"
#include "SDL_waylandvideo.h"
#include "SDL_waylandevents_c.h"
#include "SDL_waylandwindow.h"
#include "SDL_waylandopengles.h"
#include "SDL_waylandmouse.h"
#include "SDL_waylandkeyboard.h"
#include "SDL_waylandtouch.h"
#include "SDL_waylandclipboard.h"
#include "SDL_waylandvulkan.h"
#include "SDL_hints.h"
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <xkbcommon/xkbcommon.h>
#include <wayland-util.h>
#include "xdg-shell-client-protocol.h"
#include "xdg-decoration-unstable-v1-client-protocol.h"
#include "keyboard-shortcuts-inhibit-unstable-v1-client-protocol.h"
#include "idle-inhibit-unstable-v1-client-protocol.h"
#include "xdg-activation-v1-client-protocol.h"
#include "text-input-unstable-v3-client-protocol.h"
#ifdef HAVE_LIBDECOR_H
#include <libdecor.h>
#endif
#define WAYLANDVID_DRIVER_NAME "wayland"
/* Initialization/Query functions */
static int
Wayland_VideoInit(_THIS);
static int
Wayland_GetDisplayBounds(_THIS, SDL_VideoDisplay *display, SDL_Rect *rect);
static int
Wayland_GetDisplayDPI(_THIS, SDL_VideoDisplay * sdl_display, float * ddpi, float * hdpi, float * vdpi);
static void
Wayland_VideoQuit(_THIS);
/* Find out what class name we should use
* Based on src/video/x11/SDL_x11video.c */
static char *
get_classname()
{
/* !!! FIXME: this is probably wrong, albeit harmless in many common cases. From protocol spec:
"The surface class identifies the general class of applications
to which the surface belongs. A common convention is to use the
file name (or the full path if it is a non-standard location) of
the application's .desktop file as the class." */
char *spot;
#if defined(__LINUX__) || defined(__FREEBSD__)
char procfile[1024];
char linkfile[1024];
int linksize;
#endif
/* First allow environment variable override */
spot = SDL_getenv("SDL_VIDEO_WAYLAND_WMCLASS");
if (spot) {
return SDL_strdup(spot);
} else {
/* Fallback to the "old" envvar */
spot = SDL_getenv("SDL_VIDEO_X11_WMCLASS");
if (spot) {
return SDL_strdup(spot);
}
}
/* Next look at the application's executable name */
#if defined(__LINUX__) || defined(__FREEBSD__)
#if defined(__LINUX__)
SDL_snprintf(procfile, SDL_arraysize(procfile), "/proc/%d/exe", getpid());
#elif defined(__FREEBSD__)
SDL_snprintf(procfile, SDL_arraysize(procfile), "/proc/%d/file",
getpid());
#else
#error Where can we find the executable name?
#endif
linksize = readlink(procfile, linkfile, sizeof(linkfile) - 1);
if (linksize > 0) {
linkfile[linksize] = '\0';
spot = SDL_strrchr(linkfile, '/');
if (spot) {
return SDL_strdup(spot + 1);
} else {
return SDL_strdup(linkfile);
}
}
#endif /* __LINUX__ || __FREEBSD__ */
/* Finally use the default we've used forever */
return SDL_strdup("SDL_App");
}
static const char *SDL_WAYLAND_surface_tag = "sdl-window";
static const char *SDL_WAYLAND_output_tag = "sdl-output";
void SDL_WAYLAND_register_surface(struct wl_surface *surface)
{
if (SDL_WAYLAND_HAVE_WAYLAND_CLIENT_1_18) {
wl_proxy_set_tag((struct wl_proxy *)surface, &SDL_WAYLAND_surface_tag);
}
}
void SDL_WAYLAND_register_output(struct wl_output *output)
{
if (SDL_WAYLAND_HAVE_WAYLAND_CLIENT_1_18) {
wl_proxy_set_tag((struct wl_proxy *)output, &SDL_WAYLAND_output_tag);
}
}
SDL_bool SDL_WAYLAND_own_surface(struct wl_surface *surface)
{
if (SDL_WAYLAND_HAVE_WAYLAND_CLIENT_1_18) {
return wl_proxy_get_tag((struct wl_proxy *) surface) == &SDL_WAYLAND_surface_tag;
}
return SDL_TRUE; /* For older clients we have to assume this is us... */
}
SDL_bool SDL_WAYLAND_own_output(struct wl_output *output)
{
if (SDL_WAYLAND_HAVE_WAYLAND_CLIENT_1_18) {
return wl_proxy_get_tag((struct wl_proxy *) output) == &SDL_WAYLAND_output_tag;
}
return SDL_TRUE; /* For older clients we have to assume this is us... */
}
static void
Wayland_DeleteDevice(SDL_VideoDevice *device)
{
SDL_VideoData *data = (SDL_VideoData *)device->driverdata;
if (data->display) {
WAYLAND_wl_display_flush(data->display);
WAYLAND_wl_display_disconnect(data->display);
}
SDL_free(data);
SDL_free(device);
SDL_WAYLAND_UnloadSymbols();
}
static SDL_VideoDevice *
Wayland_CreateDevice(int devindex)
{
SDL_VideoDevice *device;
SDL_VideoData *data;
struct wl_display *display;
if (!SDL_WAYLAND_LoadSymbols()) {
return NULL;
}
display = WAYLAND_wl_display_connect(NULL);
if (display == NULL) {
SDL_WAYLAND_UnloadSymbols();
return NULL;
}
data = SDL_calloc(1, sizeof(*data));
if (data == NULL) {
WAYLAND_wl_display_disconnect(display);
SDL_WAYLAND_UnloadSymbols();
SDL_OutOfMemory();
return NULL;
}
data->display = display;
/* Initialize all variables that we clean on shutdown */
device = SDL_calloc(1, sizeof(SDL_VideoDevice));
if (!device) {
SDL_free(data);
WAYLAND_wl_display_disconnect(display);
SDL_WAYLAND_UnloadSymbols();
SDL_OutOfMemory();
return NULL;
}
device->driverdata = data;
/* Set the function pointers */
device->VideoInit = Wayland_VideoInit;
device->VideoQuit = Wayland_VideoQuit;
device->GetDisplayBounds = Wayland_GetDisplayBounds;
device->GetDisplayDPI = Wayland_GetDisplayDPI;
device->GetWindowWMInfo = Wayland_GetWindowWMInfo;
device->SuspendScreenSaver = Wayland_SuspendScreenSaver;
device->PumpEvents = Wayland_PumpEvents;
device->GL_SwapWindow = Wayland_GLES_SwapWindow;
device->GL_GetSwapInterval = Wayland_GLES_GetSwapInterval;
device->GL_SetSwapInterval = Wayland_GLES_SetSwapInterval;
device->GL_GetDrawableSize = Wayland_GLES_GetDrawableSize;
device->GL_MakeCurrent = Wayland_GLES_MakeCurrent;
device->GL_CreateContext = Wayland_GLES_CreateContext;
device->GL_LoadLibrary = Wayland_GLES_LoadLibrary;
device->GL_UnloadLibrary = Wayland_GLES_UnloadLibrary;
device->GL_GetProcAddress = Wayland_GLES_GetProcAddress;
device->GL_DeleteContext = Wayland_GLES_DeleteContext;
device->CreateSDLWindow = Wayland_CreateWindow;
device->ShowWindow = Wayland_ShowWindow;
device->HideWindow = Wayland_HideWindow;
device->RaiseWindow = Wayland_RaiseWindow;
device->SetWindowFullscreen = Wayland_SetWindowFullscreen;
device->MaximizeWindow = Wayland_MaximizeWindow;
device->MinimizeWindow = Wayland_MinimizeWindow;
device->SetWindowMouseGrab = Wayland_SetWindowMouseGrab;
device->SetWindowKeyboardGrab = Wayland_SetWindowKeyboardGrab;
device->RestoreWindow = Wayland_RestoreWindow;
device->SetWindowBordered = Wayland_SetWindowBordered;
device->SetWindowResizable = Wayland_SetWindowResizable;
device->SetWindowSize = Wayland_SetWindowSize;
device->SetWindowMinimumSize = Wayland_SetWindowMinimumSize;
device->SetWindowMaximumSize = Wayland_SetWindowMaximumSize;
device->SetWindowModalFor = Wayland_SetWindowModalFor;
device->SetWindowTitle = Wayland_SetWindowTitle;
device->DestroyWindow = Wayland_DestroyWindow;
device->SetWindowHitTest = Wayland_SetWindowHitTest;
device->FlashWindow = Wayland_FlashWindow;
device->HasScreenKeyboardSupport = Wayland_HasScreenKeyboardSupport;
device->SetClipboardText = Wayland_SetClipboardText;
device->GetClipboardText = Wayland_GetClipboardText;
device->HasClipboardText = Wayland_HasClipboardText;
device->StartTextInput = Wayland_StartTextInput;
device->StopTextInput = Wayland_StopTextInput;
device->SetTextInputRect = Wayland_SetTextInputRect;
#if SDL_VIDEO_VULKAN
device->Vulkan_LoadLibrary = Wayland_Vulkan_LoadLibrary;
device->Vulkan_UnloadLibrary = Wayland_Vulkan_UnloadLibrary;
device->Vulkan_GetInstanceExtensions = Wayland_Vulkan_GetInstanceExtensions;
device->Vulkan_CreateSurface = Wayland_Vulkan_CreateSurface;
device->Vulkan_GetDrawableSize = Wayland_Vulkan_GetDrawableSize;
#endif
device->free = Wayland_DeleteDevice;
return device;
}
VideoBootStrap Wayland_bootstrap = {
WAYLANDVID_DRIVER_NAME, "SDL Wayland video driver",
Wayland_CreateDevice
};
static void
display_handle_geometry(void *data,
struct wl_output *output,
int x, int y,
int physical_width,
int physical_height,
int subpixel,
const char *make,
const char *model,
int transform)
{
SDL_WaylandOutputData *driverdata = data;
driverdata->x = x;
driverdata->y = y;
driverdata->physical_width = physical_width;
driverdata->physical_height = physical_height;
driverdata->placeholder.name = SDL_strdup(model);
driverdata->transform = transform;
}
static void
display_handle_mode(void *data,
struct wl_output *output,
uint32_t flags,
int width,
int height,
int refresh)
{
SDL_WaylandOutputData* driverdata = data;
SDL_DisplayMode mode;
if (flags & WL_OUTPUT_MODE_CURRENT) {
driverdata->width = width;
driverdata->height = height;
driverdata->refresh = refresh;
}
/* Note that the width/height are NOT multiplied by scale_factor!
* This is intentional and is designed to get the unscaled modes, which is
* important for high-DPI games intending to use the display mode as the
* target drawable size. The scaled desktop mode will be added at the end
* when display_handle_done is called (see below).
*/
SDL_zero(mode);
mode.format = SDL_PIXELFORMAT_RGB888;
if (driverdata->transform & WL_OUTPUT_TRANSFORM_90) {
mode.w = height;
mode.h = width;
} else {
mode.w = width;
mode.h = height;
}
mode.refresh_rate = refresh / 1000; /* mHz to Hz */
mode.driverdata = driverdata->output;
SDL_AddDisplayMode(&driverdata->placeholder, &mode);
}
static void
display_handle_done(void *data,
struct wl_output *output)
{
SDL_WaylandOutputData* driverdata = data;
SDL_DisplayMode mode;
if (driverdata->done)
return;
driverdata->done = SDL_TRUE;
SDL_zero(mode);
mode.format = SDL_PIXELFORMAT_RGB888;
if (driverdata->transform & WL_OUTPUT_TRANSFORM_90) {
mode.w = driverdata->height / driverdata->scale_factor;
mode.h = driverdata->width / driverdata->scale_factor;
driverdata->hdpi = driverdata->physical_height ?
(((float) driverdata->height) * 25.4f / driverdata->physical_height) :
0.0f;
driverdata->vdpi = driverdata->physical_width ?
(((float) driverdata->width) * 25.4f / driverdata->physical_width) :
0.0f;
driverdata->ddpi = SDL_ComputeDiagonalDPI(driverdata->height,
driverdata->width,
((float) driverdata->physical_height) / 25.4f,
((float) driverdata->physical_width) / 25.4f);
} else {
mode.w = driverdata->width / driverdata->scale_factor;
mode.h = driverdata->height / driverdata->scale_factor;
driverdata->hdpi = driverdata->physical_width ?
(((float) driverdata->width) * 25.4f / driverdata->physical_width) :
0.0f;
driverdata->vdpi = driverdata->physical_height ?
(((float) driverdata->height) * 25.4f / driverdata->physical_height) :
0.0f;
driverdata->ddpi = SDL_ComputeDiagonalDPI(driverdata->width,
driverdata->height,
((float) driverdata->physical_width) / 25.4f,
((float) driverdata->physical_height) / 25.4f);
}
mode.refresh_rate = driverdata->refresh / 1000; /* mHz to Hz */
mode.driverdata = driverdata->output;
SDL_AddDisplayMode(&driverdata->placeholder, &mode);
driverdata->placeholder.current_mode = mode;
driverdata->placeholder.desktop_mode = mode;
driverdata->placeholder.driverdata = driverdata;
SDL_AddVideoDisplay(&driverdata->placeholder, SDL_FALSE);
SDL_zero(driverdata->placeholder);
}
static void
display_handle_scale(void *data,
struct wl_output *output,
int32_t factor)
{
SDL_WaylandOutputData *driverdata = data;
driverdata->scale_factor = factor;
}
static const struct wl_output_listener output_listener = {
display_handle_geometry,
display_handle_mode,
display_handle_done,
display_handle_scale
};
static void
Wayland_add_display(SDL_VideoData *d, uint32_t id)
{
struct wl_output *output;
SDL_WaylandOutputData *data;
output = wl_registry_bind(d->registry, id, &wl_output_interface, 2);
if (!output) {
SDL_SetError("Failed to retrieve output.");
return;
}
data = SDL_malloc(sizeof *data);
SDL_zerop(data);
data->output = output;
data->scale_factor = 1.0;
wl_output_add_listener(output, &output_listener, data);
SDL_WAYLAND_register_output(output);
}
#ifdef SDL_VIDEO_DRIVER_WAYLAND_QT_TOUCH
static void
windowmanager_hints(void *data, struct qt_windowmanager *qt_windowmanager,
int32_t show_is_fullscreen)
{
}
static void
windowmanager_quit(void *data, struct qt_windowmanager *qt_windowmanager)
{
SDL_SendQuit();
}
static const struct qt_windowmanager_listener windowmanager_listener = {
windowmanager_hints,
windowmanager_quit,
};
#endif /* SDL_VIDEO_DRIVER_WAYLAND_QT_TOUCH */
static void
handle_ping_xdg_wm_base(void *data, struct xdg_wm_base *xdg, uint32_t serial)
{
xdg_wm_base_pong(xdg, serial);
}
static const struct xdg_wm_base_listener shell_listener_xdg = {
handle_ping_xdg_wm_base
};
#ifdef HAVE_LIBDECOR_H
static void
libdecor_error(struct libdecor *context,
enum libdecor_error error,
const char *message)
{
SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "libdecor error (%d): %s\n", error, message);
}
static struct libdecor_interface libdecor_interface = {
libdecor_error,
};
#endif
static void
display_handle_global(void *data, struct wl_registry *registry, uint32_t id,
const char *interface, uint32_t version)
{
SDL_VideoData *d = data;
/*printf("WAYLAND INTERFACE: %s\n", interface);*/
if (SDL_strcmp(interface, "wl_compositor") == 0) {
d->compositor = wl_registry_bind(d->registry, id, &wl_compositor_interface, SDL_min(3, version));
} else if (SDL_strcmp(interface, "wl_output") == 0) {
Wayland_add_display(d, id);
} else if (SDL_strcmp(interface, "wl_seat") == 0) {
Wayland_display_add_input(d, id, version);
} else if (SDL_strcmp(interface, "xdg_wm_base") == 0) {
d->shell.xdg = wl_registry_bind(d->registry, id, &xdg_wm_base_interface, 1);
xdg_wm_base_add_listener(d->shell.xdg, &shell_listener_xdg, NULL);
} else if (SDL_strcmp(interface, "wl_shm") == 0) {
d->shm = wl_registry_bind(registry, id, &wl_shm_interface, 1);
d->cursor_theme = WAYLAND_wl_cursor_theme_load(NULL, 32, d->shm);
} else if (SDL_strcmp(interface, "zwp_relative_pointer_manager_v1") == 0) {
Wayland_display_add_relative_pointer_manager(d, id);
} else if (SDL_strcmp(interface, "zwp_pointer_constraints_v1") == 0) {
Wayland_display_add_pointer_constraints(d, id);
} else if (SDL_strcmp(interface, "zwp_keyboard_shortcuts_inhibit_manager_v1") == 0) {
d->key_inhibitor_manager = wl_registry_bind(d->registry, id, &zwp_keyboard_shortcuts_inhibit_manager_v1_interface, 1);
} else if (SDL_strcmp(interface, "zwp_idle_inhibit_manager_v1") == 0) {
d->idle_inhibit_manager = wl_registry_bind(d->registry, id, &zwp_idle_inhibit_manager_v1_interface, 1);
} else if (SDL_strcmp(interface, "xdg_activation_v1") == 0) {
d->activation_manager = wl_registry_bind(d->registry, id, &xdg_activation_v1_interface, 1);
} else if (strcmp(interface, "zwp_text_input_manager_v3") == 0) {
Wayland_add_text_input_manager(d, id, version);
} else if (SDL_strcmp(interface, "wl_data_device_manager") == 0) {
Wayland_add_data_device_manager(d, id, version);
} else if (SDL_strcmp(interface, "zxdg_decoration_manager_v1") == 0) {
d->decoration_manager = wl_registry_bind(d->registry, id, &zxdg_decoration_manager_v1_interface, 1);
#ifdef SDL_VIDEO_DRIVER_WAYLAND_QT_TOUCH
} else if (SDL_strcmp(interface, "qt_touch_extension") == 0) {
Wayland_touch_create(d, id);
} else if (SDL_strcmp(interface, "qt_surface_extension") == 0) {
d->surface_extension = wl_registry_bind(registry, id,
&qt_surface_extension_interface, 1);
} else if (SDL_strcmp(interface, "qt_windowmanager") == 0) {
d->windowmanager = wl_registry_bind(registry, id,
&qt_windowmanager_interface, 1);
qt_windowmanager_add_listener(d->windowmanager, &windowmanager_listener, d);
#endif /* SDL_VIDEO_DRIVER_WAYLAND_QT_TOUCH */
}
}
static void
display_remove_global(void *data, struct wl_registry *registry, uint32_t id) {}
static const struct wl_registry_listener registry_listener = {
display_handle_global,
display_remove_global
};
int
Wayland_VideoInit(_THIS)
{
SDL_VideoData *data = (SDL_VideoData*)_this->driverdata;
data->xkb_context = WAYLAND_xkb_context_new(0);
if (!data->xkb_context) {
return SDL_SetError("Failed to create XKB context");
}
data->registry = wl_display_get_registry(data->display);
if (data->registry == NULL) {
return SDL_SetError("Failed to get the Wayland registry");
}
wl_registry_add_listener(data->registry, &registry_listener, data);
// First roundtrip to receive all registry objects.
WAYLAND_wl_display_roundtrip(data->display);
#ifdef HAVE_LIBDECOR_H
/* Don't have server-side decorations? Try client-side instead. */
if (!data->decoration_manager && SDL_WAYLAND_HAVE_WAYLAND_LIBDECOR && SDL_GetHintBoolean(SDL_HINT_VIDEO_WAYLAND_ALLOW_LIBDECOR, SDL_TRUE)) {
data->shell.libdecor = libdecor_new(data->display, &libdecor_interface);
/* If libdecor works, we don't need xdg-shell anymore. */
if (data->shell.libdecor && data->shell.xdg) {
xdg_wm_base_destroy(data->shell.xdg);
data->shell.xdg = NULL;
}
}
#endif
// Second roundtrip to receive all output events.
WAYLAND_wl_display_roundtrip(data->display);
Wayland_InitMouse();
/* Get the surface class name, usually the name of the application */
data->classname = get_classname();
WAYLAND_wl_display_flush(data->display);
Wayland_InitKeyboard(_this);
return 0;
}
static int
Wayland_GetDisplayBounds(_THIS, SDL_VideoDisplay *display, SDL_Rect *rect)
{
SDL_WaylandOutputData *driverdata = (SDL_WaylandOutputData *)display->driverdata;
rect->x = driverdata->x;
rect->y = driverdata->y;
rect->w = display->current_mode.w;
rect->h = display->current_mode.h;
return 0;
}
static int
Wayland_GetDisplayDPI(_THIS, SDL_VideoDisplay * sdl_display, float * ddpi, float * hdpi, float * vdpi)
{
SDL_WaylandOutputData *driverdata = (SDL_WaylandOutputData *)sdl_display->driverdata;
if (ddpi) {
*ddpi = driverdata->ddpi;
}
if (hdpi) {
*hdpi = driverdata->hdpi;
}
if (vdpi) {
*vdpi = driverdata->vdpi;
}
return driverdata->ddpi != 0.0f ? 0 : SDL_SetError("Couldn't get DPI");
}
void
Wayland_VideoQuit(_THIS)
{
SDL_VideoData *data = _this->driverdata;
int i, j;
Wayland_FiniMouse ();
for (i = 0; i < _this->num_displays; ++i) {
SDL_VideoDisplay *display = &_this->displays[i];
wl_output_destroy(((SDL_WaylandOutputData*)display->driverdata)->output);
SDL_free(display->driverdata);
display->driverdata = NULL;
for (j = display->num_display_modes; j--;) {
display->display_modes[j].driverdata = NULL;
}
display->desktop_mode.driverdata = NULL;
}
Wayland_display_destroy_input(data);
Wayland_display_destroy_pointer_constraints(data);
Wayland_display_destroy_relative_pointer_manager(data);
if (data->activation_manager)
xdg_activation_v1_destroy(data->activation_manager);
if (data->idle_inhibit_manager)
zwp_idle_inhibit_manager_v1_destroy(data->idle_inhibit_manager);
if (data->key_inhibitor_manager)
zwp_keyboard_shortcuts_inhibit_manager_v1_destroy(data->key_inhibitor_manager);
Wayland_QuitKeyboard(_this);
if (data->text_input_manager)
zwp_text_input_manager_v3_destroy(data->text_input_manager);
if (data->xkb_context) {
WAYLAND_xkb_context_unref(data->xkb_context);
data->xkb_context = NULL;
}
#ifdef SDL_VIDEO_DRIVER_WAYLAND_QT_TOUCH
if (data->windowmanager)
qt_windowmanager_destroy(data->windowmanager);
if (data->surface_extension)
qt_surface_extension_destroy(data->surface_extension);
Wayland_touch_destroy(data);
#endif /* SDL_VIDEO_DRIVER_WAYLAND_QT_TOUCH */
if (data->data_device_manager)
wl_data_device_manager_destroy(data->data_device_manager);
if (data->shm)
wl_shm_destroy(data->shm);
if (data->cursor_theme)
WAYLAND_wl_cursor_theme_destroy(data->cursor_theme);
if (data->shell.xdg)
xdg_wm_base_destroy(data->shell.xdg);
if (data->decoration_manager)
zxdg_decoration_manager_v1_destroy(data->decoration_manager);
#ifdef HAVE_LIBDECOR_H
if (data->shell.libdecor) {
libdecor_unref(data->shell.libdecor);
data->shell.libdecor = NULL;
}
#endif
if (data->compositor)
wl_compositor_destroy(data->compositor);
if (data->registry)
wl_registry_destroy(data->registry);
SDL_free(data->classname);
}
#endif /* SDL_VIDEO_DRIVER_WAYLAND */
/* vi: set ts=4 sw=4 expandtab: */