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ndg/lib/lv_drivers/indev/libinput.c

492 lines
15 KiB
C

/**
* @file libinput.c
*
*/
/*********************
* INCLUDES
*********************/
#include "libinput_drv.h"
#if USE_LIBINPUT || USE_BSD_LIBINPUT
#include <stdio.h>
#include <unistd.h>
#include <linux/limits.h>
#include <fcntl.h>
#include <errno.h>
#include <stdbool.h>
#include <dirent.h>
#include <libinput.h>
#if USE_BSD_LIBINPUT
#include <dev/evdev/input.h>
#else
#include <linux/input.h>
#endif
/*********************
* DEFINES
*********************/
/**********************
* TYPEDEFS
**********************/
struct input_device {
libinput_capability capabilities;
char *path;
};
/**********************
* STATIC PROTOTYPES
**********************/
static bool rescan_devices(void);
static bool add_scanned_device(char *path, libinput_capability capabilities);
static void reset_scanned_devices(void);
static void read_pointer(libinput_drv_state_t *state, struct libinput_event *event);
static void read_keypad(libinput_drv_state_t *state, struct libinput_event *event);
static int open_restricted(const char *path, int flags, void *user_data);
static void close_restricted(int fd, void *user_data);
/**********************
* STATIC VARIABLES
**********************/
static struct input_device *devices = NULL;
static size_t num_devices = 0;
static libinput_drv_state_t default_state = { .most_recent_touch_point = { .x = 0, .y = 0 } };
static const int timeout = 0; // do not block
static const nfds_t nfds = 1;
static const struct libinput_interface interface = {
.open_restricted = open_restricted,
.close_restricted = close_restricted,
};
/**********************
* MACROS
**********************/
/**********************
* GLOBAL FUNCTIONS
**********************/
/**
* find connected input device with specific capabilities
* @param capabilities required device capabilities
* @param force_rescan erase the device cache (if any) and rescan the file system for available devices
* @return device node path (e.g. /dev/input/event0) for the first matching device or NULL if no device was found.
* The pointer is safe to use until the next forceful device search.
*/
char *libinput_find_dev(libinput_capability capabilities, bool force_rescan) {
char *path = NULL;
libinput_find_devs(capabilities, &path, 1, force_rescan);
return path;
}
/**
* find connected input devices with specific capabilities
* @param capabilities required device capabilities
* @param devices pre-allocated array to store the found device node paths (e.g. /dev/input/event0). The pointers are
* safe to use until the next forceful device search.
* @param count maximum number of devices to find (the devices array should be at least this long)
* @param force_rescan erase the device cache (if any) and rescan the file system for available devices
* @return number of devices that were found
*/
size_t libinput_find_devs(libinput_capability capabilities, char **found, size_t count, bool force_rescan) {
if ((!devices || force_rescan) && !rescan_devices()) {
return 0;
}
size_t num_found = 0;
for (size_t i = 0; i < num_devices && num_found < count; ++i) {
if (devices[i].capabilities & capabilities) {
found[num_found] = devices[i].path;
num_found++;
}
}
return num_found;
}
/**
* Reconfigure the device file for libinput using the default driver state. Use this function if you only want
* to connect a single device.
* @param dev_name input device node path (e.g. /dev/input/event0)
* @return true: the device file set complete
* false: the device file doesn't exist current system
*/
bool libinput_set_file(char* dev_name)
{
return libinput_set_file_state(&default_state, dev_name);
}
/**
* Reconfigure the device file for libinput using a specific driver state. Use this function if you want to
* connect multiple devices.
* @param state the driver state to configure
* @param dev_name input device node path (e.g. /dev/input/event0)
* @return true: the device file set complete
* false: the device file doesn't exist current system
*/
bool libinput_set_file_state(libinput_drv_state_t *state, char* dev_name)
{
// This check *should* not be necessary, yet applications crashes even on NULL handles.
// citing libinput.h:libinput_path_remove_device:
// > If no matching device exists, this function does nothing.
if (state->libinput_device) {
state->libinput_device = libinput_device_unref(state->libinput_device);
libinput_path_remove_device(state->libinput_device);
}
state->libinput_device = libinput_path_add_device(state->libinput_context, dev_name);
if(!state->libinput_device) {
perror("unable to add device to libinput context:");
return false;
}
state->libinput_device = libinput_device_ref(state->libinput_device);
if(!state->libinput_device) {
perror("unable to reference device within libinput context:");
return false;
}
state->button = LV_INDEV_STATE_REL;
state->key_val = 0;
return true;
}
/**
* Prepare for reading input via libinput using the default driver state. Use this function if you only want
* to connect a single device.
*/
void libinput_init(void)
{
libinput_init_state(&default_state, LIBINPUT_NAME);
}
/**
* Prepare for reading input via libinput using the a specific driver state. Use this function if you want to
* connect multiple devices.
* @param state driver state to initialize
* @param path input device node path (e.g. /dev/input/event0)
*/
void libinput_init_state(libinput_drv_state_t *state, char* path)
{
state->libinput_device = NULL;
state->libinput_context = libinput_path_create_context(&interface, NULL);
if(path == NULL || !libinput_set_file_state(state, path)) {
fprintf(stderr, "unable to add device \"%s\" to libinput context: %s\n", path ? path : "NULL", strerror(errno));
return;
}
state->fd = libinput_get_fd(state->libinput_context);
/* prepare poll */
state->fds[0].fd = state->fd;
state->fds[0].events = POLLIN;
state->fds[0].revents = 0;
#if USE_XKB
xkb_init_state(&(state->xkb_state));
#endif
}
/**
* Read available input events via libinput using the default driver state. Use this function if you only want
* to connect a single device.
* @param indev_drv driver object itself
* @param data store the libinput data here
*/
void libinput_read(lv_indev_drv_t * indev_drv, lv_indev_data_t * data)
{
libinput_read_state(&default_state, indev_drv, data);
}
/**
* Read available input events via libinput using a specific driver state. Use this function if you want to
* connect multiple devices.
* @param state the driver state to use
* @param indev_drv driver object itself
* @param data store the libinput data here
*/
void libinput_read_state(libinput_drv_state_t * state, lv_indev_drv_t * indev_drv, lv_indev_data_t * data)
{
struct libinput_event *event;
int rc = 0;
rc = poll(state->fds, nfds, timeout);
switch (rc){
case -1:
perror(NULL);
case 0:
goto report_most_recent_state;
default:
break;
}
libinput_dispatch(state->libinput_context);
while((event = libinput_get_event(state->libinput_context)) != NULL) {
switch (indev_drv->type) {
case LV_INDEV_TYPE_POINTER:
read_pointer(state, event);
break;
case LV_INDEV_TYPE_KEYPAD:
read_keypad(state, event);
break;
default:
break;
}
libinput_event_destroy(event);
}
report_most_recent_state:
data->point.x = state->most_recent_touch_point.x;
data->point.y = state->most_recent_touch_point.y;
data->state = state->button;
data->key = state->key_val;
}
/**********************
* STATIC FUNCTIONS
**********************/
/**
* rescan all attached evdev devices and store capable ones into the static devices array for quick later filtering
* @return true if the operation succeeded
*/
static bool rescan_devices(void) {
reset_scanned_devices();
DIR *dir;
struct dirent *ent;
if (!(dir = opendir("/dev/input"))) {
perror("unable to open directory /dev/input");
return false;
}
struct libinput *context = libinput_path_create_context(&interface, NULL);
while ((ent = readdir(dir))) {
if (strncmp(ent->d_name, "event", 5) != 0) {
continue;
}
/* 11 characters for /dev/input/ + length of name + 1 NUL terminator */
char *path = malloc((11 + strlen(ent->d_name) + 1) * sizeof(char));
if (!path) {
perror("could not allocate memory for device node path");
libinput_unref(context);
reset_scanned_devices();
return false;
}
strcpy(path, "/dev/input/");
strcat(path, ent->d_name);
struct libinput_device *device = libinput_path_add_device(context, path);
if(!device) {
perror("unable to add device to libinput context");
free(path);
continue;
}
/* The device pointer is guaranteed to be valid until the next libinput_dispatch. Since we're not dispatching events
* as part of this function, we don't have to increase its reference count to keep it alive.
* https://wayland.freedesktop.org/libinput/doc/latest/api/group__base.html#gaa797496f0150b482a4e01376bd33a47b */
libinput_capability capabilities = LIBINPUT_CAPABILITY_NONE;
if (libinput_device_has_capability(device, LIBINPUT_DEVICE_CAP_KEYBOARD)
&& (libinput_device_keyboard_has_key(device, KEY_ENTER) || libinput_device_keyboard_has_key(device, KEY_KPENTER)))
{
capabilities |= LIBINPUT_CAPABILITY_KEYBOARD;
}
if (libinput_device_has_capability(device, LIBINPUT_DEVICE_CAP_POINTER)) {
capabilities |= LIBINPUT_CAPABILITY_POINTER;
}
if (libinput_device_has_capability(device, LIBINPUT_DEVICE_CAP_TOUCH)) {
capabilities |= LIBINPUT_CAPABILITY_TOUCH;
}
libinput_path_remove_device(device);
if (capabilities == LIBINPUT_CAPABILITY_NONE) {
free(path);
continue;
}
if (!add_scanned_device(path, capabilities)) {
free(path);
libinput_unref(context);
reset_scanned_devices();
return false;
}
}
libinput_unref(context);
return true;
}
/**
* add a new scanned device to the static devices array, growing its size when necessary
* @param path device file path
* @param capabilities device input capabilities
* @return true if the operation succeeded
*/
static bool add_scanned_device(char *path, libinput_capability capabilities) {
/* Double array size every 2^n elements */
if ((num_devices & (num_devices + 1)) == 0) {
struct input_device *tmp = realloc(devices, (2 * num_devices + 1) * sizeof(struct input_device));
if (!tmp) {
perror("could not reallocate memory for devices array");
return false;
}
devices = tmp;
}
devices[num_devices].path = path;
devices[num_devices].capabilities = capabilities;
num_devices++;
return true;
}
/**
* reset the array of scanned devices and free any dynamically allocated memory
*/
static void reset_scanned_devices(void) {
if (!devices) {
return;
}
for (size_t i = 0; i < num_devices; ++i) {
free(devices[i].path);
}
free(devices);
devices = NULL;
num_devices = 0;
}
/**
* Handle libinput touch / pointer events
* @param state driver state to use
* @param event libinput event
*/
static void read_pointer(libinput_drv_state_t *state, struct libinput_event *event) {
struct libinput_event_touch *touch_event = NULL;
struct libinput_event_pointer *pointer_event = NULL;
enum libinput_event_type type = libinput_event_get_type(event);
/* We need to read unrotated display dimensions directly from the driver because libinput won't account
* for any rotation inside of LVGL */
lv_disp_drv_t *drv = lv_disp_get_default()->driver;
switch (type) {
case LIBINPUT_EVENT_TOUCH_MOTION:
case LIBINPUT_EVENT_TOUCH_DOWN:
touch_event = libinput_event_get_touch_event(event);
lv_coord_t x = libinput_event_touch_get_x_transformed(touch_event, drv->physical_hor_res > 0 ? drv->physical_hor_res : drv->hor_res) - drv->offset_x;
lv_coord_t y = libinput_event_touch_get_y_transformed(touch_event, drv->physical_ver_res > 0 ? drv->physical_ver_res : drv->ver_res) - drv->offset_y;
if (x < 0 || x > drv->hor_res || y < 0 || y > drv->ver_res) {
break; /* ignore touches that are out of bounds */
}
state->most_recent_touch_point.x = x;
state->most_recent_touch_point.y = y;
state->button = LV_INDEV_STATE_PR;
break;
case LIBINPUT_EVENT_TOUCH_UP:
state->button = LV_INDEV_STATE_REL;
break;
case LIBINPUT_EVENT_POINTER_MOTION:
pointer_event = libinput_event_get_pointer_event(event);
state->most_recent_touch_point.x += libinput_event_pointer_get_dx(pointer_event);
state->most_recent_touch_point.y += libinput_event_pointer_get_dy(pointer_event);
state->most_recent_touch_point.x = LV_CLAMP(0, state->most_recent_touch_point.x, drv->hor_res - 1);
state->most_recent_touch_point.y = LV_CLAMP(0, state->most_recent_touch_point.y, drv->ver_res - 1);
break;
case LIBINPUT_EVENT_POINTER_BUTTON:
pointer_event = libinput_event_get_pointer_event(event);
enum libinput_button_state button_state = libinput_event_pointer_get_button_state(pointer_event);
state->button = button_state == LIBINPUT_BUTTON_STATE_RELEASED ? LV_INDEV_STATE_REL : LV_INDEV_STATE_PR;
break;
default:
break;
}
}
/**
* Handle libinput keyboard events
* @param state driver state to use
* @param event libinput event
*/
static void read_keypad(libinput_drv_state_t *state, struct libinput_event *event) {
struct libinput_event_keyboard *keyboard_event = NULL;
enum libinput_event_type type = libinput_event_get_type(event);
switch (type) {
case LIBINPUT_EVENT_KEYBOARD_KEY:
keyboard_event = libinput_event_get_keyboard_event(event);
enum libinput_key_state key_state = libinput_event_keyboard_get_key_state(keyboard_event);
uint32_t code = libinput_event_keyboard_get_key(keyboard_event);
#if USE_XKB
state->key_val = xkb_process_key_state(&(state->xkb_state), code, key_state == LIBINPUT_KEY_STATE_PRESSED);
#else
switch(code) {
case KEY_BACKSPACE:
state->key_val = LV_KEY_BACKSPACE;
break;
case KEY_ENTER:
state->key_val = LV_KEY_ENTER;
break;
case KEY_PREVIOUS:
state->key_val = LV_KEY_PREV;
break;
case KEY_NEXT:
state->key_val = LV_KEY_NEXT;
break;
case KEY_UP:
state->key_val = LV_KEY_UP;
break;
case KEY_LEFT:
state->key_val = LV_KEY_LEFT;
break;
case KEY_RIGHT:
state->key_val = LV_KEY_RIGHT;
break;
case KEY_DOWN:
state->key_val = LV_KEY_DOWN;
break;
case KEY_TAB:
state->key_val = LV_KEY_NEXT;
break;
default:
state->key_val = 0;
break;
}
#endif /* USE_XKB */
if (state->key_val != 0) {
/* Only record button state when actual output is produced to prevent widgets from refreshing */
state->button = (key_state == LIBINPUT_KEY_STATE_RELEASED) ? LV_INDEV_STATE_REL : LV_INDEV_STATE_PR;
}
break;
default:
break;
}
}
static int open_restricted(const char *path, int flags, void *user_data)
{
LV_UNUSED(user_data);
int fd = open(path, flags);
return fd < 0 ? -errno : fd;
}
static void close_restricted(int fd, void *user_data)
{
LV_UNUSED(user_data);
close(fd);
}
#endif /* USE_LIBINPUT || USE_BSD_LIBINPUT */