minui/events.cpp - android_bootable_recovery - Gitiles

 /*
  * Copyright (C) 2007 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <linux/input.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/epoll.h>
 #include <sys/inotify.h>
 #include <sys/ioctl.h>
 #include <sys/types.h>
 #include <unistd.h>

 #include <functional>
 #include <memory>
 #include <string>

 #include <android-base/strings.h>
 #include <android-base/unique_fd.h>

 #include "minui/minui.h"

 constexpr const char* INPUT_DEV_DIR = "/dev/input";

 constexpr size_t MAX_DEVICES = 16;
 constexpr size_t MAX_MISC_FDS = 16;

 constexpr size_t BITS_PER_LONG = sizeof(unsigned long) * 8;
 constexpr size_t BITS_TO_LONGS(size_t bits) {
   return ((bits + BITS_PER_LONG - 1) / BITS_PER_LONG);
 }

 struct FdInfo {
   android::base::unique_fd fd;
   ev_callback cb;
 #ifdef TW_USE_MINUI_WITH_DATA
   void* data;
 #endif
 };

 static bool g_allow_touch_inputs = true;
 static ev_callback g_saved_input_cb;
 static android::base::unique_fd g_epoll_fd;
 static epoll_event g_polled_events[MAX_DEVICES + MAX_MISC_FDS];
 static int g_polled_events_count;

 static FdInfo ev_fdinfo[MAX_DEVICES + MAX_MISC_FDS];

 static size_t g_ev_count = 0;
 static size_t g_ev_dev_count = 0;
 static size_t g_ev_misc_count = 0;

 static bool test_bit(size_t bit, unsigned long* array) { // NOLINT
   return (array[bit / BITS_PER_LONG] & (1UL << (bit % BITS_PER_LONG))) != 0;
 }

 #ifdef TW_USE_MINUI_WITH_OPTIONAL_TOUCH_EVENTS
 static bool should_add_input_device(int fd, bool allow_touch_inputs) {
   // Use unsigned long to match ioctl's parameter type.
   unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)];  // NOLINT

   // Read the evbits of the input device.
   if (ioctl(fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
     return false;
   }

   // We assume that only EV_KEY, EV_REL, and EV_SW event types are ever needed. EV_ABS is also
   // allowed if allow_touch_inputs is set.
   if (!test_bit(EV_KEY, ev_bits) && !test_bit(EV_REL, ev_bits) && !test_bit(EV_SW, ev_bits)) {
     if (!allow_touch_inputs || !test_bit(EV_ABS, ev_bits)) {
       return false;
     }
   }

   return true;
 }

 static int inotify_cb(int fd, __unused uint32_t epevents) {
   if (g_saved_input_cb == nullptr) return -1;

   // The inotify will put one or several complete events.
   // Should not read part of one event.
   int event_len_int;
   int ret = ioctl(fd, FIONREAD, &event_len_int);
   if (ret != 0) return -1;
   if (event_len_int < 0) return -1;
   size_t event_len = event_len_int;

   std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(INPUT_DEV_DIR), closedir);
   if (!dir) {
     return -1;
   }

   std::vector<int8_t> buf(event_len);

   ssize_t r = TEMP_FAILURE_RETRY(read(fd, buf.data(), event_len));
   if (r != event_len) {
     return -1;
   }

   size_t offset = 0;
   while (offset < event_len) {
     struct inotify_event* pevent = reinterpret_cast<struct inotify_event*>(buf.data() + offset);
     if (offset + sizeof(inotify_event) + pevent->len > event_len) {
       // The pevent->len is too large and buffer will over flow.
       // In general, should not happen, just make more stable.
       return -1;
     }
     offset += sizeof(inotify_event) + pevent->len;

     std::string event_name(pevent->name, pevent->len);
     if (!android::base::StartsWith(event_name, "event")) {
       continue;
     }

     android::base::unique_fd dfd(openat(dirfd(dir.get()), event_name.c_str(), O_RDONLY));
     if (dfd == -1) {
       break;
     }

     if (!should_add_input_device(dfd, g_allow_touch_inputs)) {
       continue;
     }

     // Only add, we assume the user will not plug out and plug in USB device again and again :)
     ev_add_fd(std::move(dfd), g_saved_input_cb);
   }

   return 0;
 }

 int ev_init(ev_callback input_cb, bool allow_touch_inputs) {
 #else
 #ifdef TW_USE_MINUI_WITH_DATA
 int ev_init(ev_callback input_cb, void* data) {
 #else
 int ev_init(ev_callback input_cb) {
 #endif
   bool allow_touch_inputs = false;
 #endif
   g_epoll_fd.reset();

   android::base::unique_fd epoll_fd(epoll_create1(EPOLL_CLOEXEC));
   if (epoll_fd == -1) {
     return -1;
   }

   android::base::unique_fd inotify_fd(inotify_init1(IN_CLOEXEC));
   if (inotify_fd.get() == -1) {
     return -1;
   }

   if (inotify_add_watch(inotify_fd, INPUT_DEV_DIR, IN_CREATE) < 0) {
     return -1;
   }

   std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(INPUT_DEV_DIR), closedir);
   if (!dir) {
     return -1;
   }

   bool epoll_ctl_failed = false;
   dirent* de;
   while ((de = readdir(dir.get())) != nullptr) {
     if (strncmp(de->d_name, "event", 5)) continue;
     android::base::unique_fd fd(openat(dirfd(dir.get()), de->d_name, O_RDONLY | O_CLOEXEC));
     if (fd == -1) continue;

 #ifdef TW_USE_MINUI_WITH_OPTIONAL_TOUCH_EVENTS
     if (!should_add_input_device(fd, allow_touch_inputs)) {
       continue;
     }
 #endif

     epoll_event ev;
     ev.events = EPOLLIN | EPOLLWAKEUP;
     ev.data.ptr = &ev_fdinfo[g_ev_count];
     if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &ev) == -1) {
       epoll_ctl_failed = true;
       continue;
     }

     ev_fdinfo[g_ev_count].fd.reset(fd.release());
     ev_fdinfo[g_ev_count].cb = input_cb;
     g_ev_count++;
     g_ev_dev_count++;
     if (g_ev_dev_count == MAX_DEVICES) break;
   }

   if (epoll_ctl_failed && !g_ev_count) {
     return -1;
   }

   g_epoll_fd.reset(epoll_fd.release());

   g_saved_input_cb = input_cb;
   g_allow_touch_inputs = allow_touch_inputs;
 #ifdef TW_USE_MINUI_WITH_OPTIONAL_TOUCH_EVENTS
   ev_add_fd(std::move(inotify_fd), inotify_cb);
 #endif

   return 0;
 }

 int ev_get_epollfd(void) {
   return g_epoll_fd.get();
 }

 int ev_add_fd(android::base::unique_fd&& fd, ev_callback cb) {
   if (g_ev_misc_count == MAX_MISC_FDS || cb == nullptr) {
     return -1;
   }

   epoll_event ev;
   ev.events = EPOLLIN | EPOLLWAKEUP;
   ev.data.ptr = static_cast<void*>(&ev_fdinfo[g_ev_count]);
   int ret = epoll_ctl(g_epoll_fd, EPOLL_CTL_ADD, fd, &ev);
   if (!ret) {
     ev_fdinfo[g_ev_count].fd.reset(fd.release());
     ev_fdinfo[g_ev_count].cb = std::move(cb);
     g_ev_count++;
     g_ev_misc_count++;
   }

   return ret;
 }

 void ev_exit(void) {
   while (g_ev_count > 0) {
     ev_fdinfo[--g_ev_count].fd.reset();
   }
   g_ev_misc_count = 0;
   g_ev_dev_count = 0;
   g_saved_input_cb = nullptr;
   g_epoll_fd.reset();
 }

 int ev_wait(int timeout) {
   g_polled_events_count = epoll_wait(g_epoll_fd, g_polled_events, g_ev_count, timeout);
   if (g_polled_events_count <= 0) {
     return -1;
   }
   return 0;
 }

 void ev_dispatch(void) {
   for (int n = 0; n < g_polled_events_count; n++) {
     FdInfo* fdi = static_cast<FdInfo*>(g_polled_events[n].data.ptr);
     const ev_callback& cb = fdi->cb;
     if (cb) {
       cb(fdi->fd, g_polled_events[n].events);
     }
   }
 }

 int ev_get_input(int fd, uint32_t epevents, input_event* ev) {
   if (epevents & EPOLLIN) {
     ssize_t r = TEMP_FAILURE_RETRY(read(fd, ev, sizeof(*ev)));
     if (r == sizeof(*ev)) {
       return 0;
     }
   }
   if (epevents & EPOLLHUP) {
     // Delete this watch
     epoll_ctl(g_epoll_fd, EPOLL_CTL_DEL, fd, nullptr);
   }
   return -1;
 }

 #ifdef TW_USE_MINUI_WITH_DATA
 int ev_sync_key_state(ev_set_key_callback set_key_cb, void* data) {
 #else
 int ev_sync_key_state(const ev_set_key_callback& set_key_cb) {
 #endif
   // Use unsigned long to match ioctl's parameter type.
   unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)];    // NOLINT
   unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)];  // NOLINT

   for (size_t i = 0; i < g_ev_dev_count; ++i) {
     memset(ev_bits, 0, sizeof(ev_bits));
     memset(key_bits, 0, sizeof(key_bits));

     if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
       continue;
     }
     if (!test_bit(EV_KEY, ev_bits)) {
       continue;
     }
     if (ioctl(ev_fdinfo[i].fd, EVIOCGKEY(sizeof(key_bits)), key_bits) == -1) {
       continue;
     }

     for (int code = 0; code <= KEY_MAX; code++) {
       if (test_bit(code, key_bits)) {
 #ifdef TW_USE_MINUI_WITH_DATA
         set_key_cb(code, 1, data);
 #else
         set_key_cb(code, 1);
 #endif
       }
     }
   }

   return 0;
 }

 void ev_iterate_available_keys(const std::function<void(int)>& f) {
   // Use unsigned long to match ioctl's parameter type.
   unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)];    // NOLINT
   unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)];  // NOLINT

   for (size_t i = 0; i < g_ev_dev_count; ++i) {
     memset(ev_bits, 0, sizeof(ev_bits));
     memset(key_bits, 0, sizeof(key_bits));

     // Does this device even have keys?
     if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
       continue;
     }
     if (!test_bit(EV_KEY, ev_bits)) {
       continue;
     }

     if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(EV_KEY, KEY_MAX), key_bits) == -1) {
       continue;
     }

     for (int key_code = 0; key_code <= KEY_MAX; ++key_code) {
       if (test_bit(key_code, key_bits)) {
         f(key_code);
       }
     }
   }
 }

 #ifdef TW_USE_MINUI_WITH_OPTIONAL_TOUCH_EVENTS
 void ev_iterate_touch_inputs(const std::function<void(int)>& action) {
   for (size_t i = 0; i < g_ev_dev_count; ++i) {
     // Use unsigned long to match ioctl's parameter type.
     unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)] = {};  // NOLINT
     if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
       continue;
     }
     if (!test_bit(EV_ABS, ev_bits)) {
       continue;
     }

     unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)] = {};  // NOLINT
     if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(EV_ABS, KEY_MAX), key_bits) == -1) {
       continue;
     }

     for (int key_code = 0; key_code <= KEY_MAX; ++key_code) {
       if (test_bit(key_code, key_bits)) {
         action(key_code);
       }
     }
   }
 }
 #endif
	/*
	* Copyright (C) 2007 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <dirent.h>
	#include <errno.h>
	#include <fcntl.h>
	#include <linux/input.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/epoll.h>
	#include <sys/inotify.h>
	#include <sys/ioctl.h>
	#include <sys/types.h>
	#include <unistd.h>

	#include <functional>
	#include <memory>
	#include <string>

	#include <android-base/strings.h>
	#include <android-base/unique_fd.h>

	#include "minui/minui.h"

	constexpr const char* INPUT_DEV_DIR = "/dev/input";

	constexpr size_t MAX_DEVICES = 16;
	constexpr size_t MAX_MISC_FDS = 16;

	constexpr size_t BITS_PER_LONG = sizeof(unsigned long) * 8;
	constexpr size_t BITS_TO_LONGS(size_t bits) {
	return ((bits + BITS_PER_LONG - 1) / BITS_PER_LONG);
	}

	struct FdInfo {
	android::base::unique_fd fd;
	ev_callback cb;
	#ifdef TW_USE_MINUI_WITH_DATA
	void* data;
	#endif
	};

	static bool g_allow_touch_inputs = true;
	static ev_callback g_saved_input_cb;
	static android::base::unique_fd g_epoll_fd;
	static epoll_event g_polled_events[MAX_DEVICES + MAX_MISC_FDS];
	static int g_polled_events_count;

	static FdInfo ev_fdinfo[MAX_DEVICES + MAX_MISC_FDS];

	static size_t g_ev_count = 0;
	static size_t g_ev_dev_count = 0;
	static size_t g_ev_misc_count = 0;

	static bool test_bit(size_t bit, unsigned long* array) { // NOLINT
	return (array[bit / BITS_PER_LONG] & (1UL << (bit % BITS_PER_LONG))) != 0;
	}

	#ifdef TW_USE_MINUI_WITH_OPTIONAL_TOUCH_EVENTS
	static bool should_add_input_device(int fd, bool allow_touch_inputs) {
	// Use unsigned long to match ioctl's parameter type.
	unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)]; // NOLINT

	// Read the evbits of the input device.
	if (ioctl(fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
	return false;
	}

	// We assume that only EV_KEY, EV_REL, and EV_SW event types are ever needed. EV_ABS is also
	// allowed if allow_touch_inputs is set.
	if (!test_bit(EV_KEY, ev_bits) && !test_bit(EV_REL, ev_bits) && !test_bit(EV_SW, ev_bits)) {
	if (!allow_touch_inputs \|\| !test_bit(EV_ABS, ev_bits)) {
	return false;
	}
	}

	return true;
	}

	static int inotify_cb(int fd, __unused uint32_t epevents) {
	if (g_saved_input_cb == nullptr) return -1;

	// The inotify will put one or several complete events.
	// Should not read part of one event.
	int event_len_int;
	int ret = ioctl(fd, FIONREAD, &event_len_int);
	if (ret != 0) return -1;
	if (event_len_int < 0) return -1;
	size_t event_len = event_len_int;

	std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(INPUT_DEV_DIR), closedir);
	if (!dir) {
	return -1;
	}

	std::vector<int8_t> buf(event_len);

	ssize_t r = TEMP_FAILURE_RETRY(read(fd, buf.data(), event_len));
	if (r != event_len) {
	return -1;
	}

	size_t offset = 0;
	while (offset < event_len) {
	struct inotify_event* pevent = reinterpret_cast<struct inotify_event*>(buf.data() + offset);
	if (offset + sizeof(inotify_event) + pevent->len > event_len) {
	// The pevent->len is too large and buffer will over flow.
	// In general, should not happen, just make more stable.
	return -1;
	}
	offset += sizeof(inotify_event) + pevent->len;

	std::string event_name(pevent->name, pevent->len);
	if (!android::base::StartsWith(event_name, "event")) {
	continue;
	}

	android::base::unique_fd dfd(openat(dirfd(dir.get()), event_name.c_str(), O_RDONLY));
	if (dfd == -1) {
	break;
	}

	if (!should_add_input_device(dfd, g_allow_touch_inputs)) {
	continue;
	}

	// Only add, we assume the user will not plug out and plug in USB device again and again :)
	ev_add_fd(std::move(dfd), g_saved_input_cb);
	}

	return 0;
	}

	int ev_init(ev_callback input_cb, bool allow_touch_inputs) {
	#else
	#ifdef TW_USE_MINUI_WITH_DATA
	int ev_init(ev_callback input_cb, void* data) {
	#else
	int ev_init(ev_callback input_cb) {
	#endif
	bool allow_touch_inputs = false;
	#endif
	g_epoll_fd.reset();

	android::base::unique_fd epoll_fd(epoll_create1(EPOLL_CLOEXEC));
	if (epoll_fd == -1) {
	return -1;
	}

	android::base::unique_fd inotify_fd(inotify_init1(IN_CLOEXEC));
	if (inotify_fd.get() == -1) {
	return -1;
	}

	if (inotify_add_watch(inotify_fd, INPUT_DEV_DIR, IN_CREATE) < 0) {
	return -1;
	}

	std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(INPUT_DEV_DIR), closedir);
	if (!dir) {
	return -1;
	}

	bool epoll_ctl_failed = false;
	dirent* de;
	while ((de = readdir(dir.get())) != nullptr) {
	if (strncmp(de->d_name, "event", 5)) continue;
	android::base::unique_fd fd(openat(dirfd(dir.get()), de->d_name, O_RDONLY \| O_CLOEXEC));
	if (fd == -1) continue;

	#ifdef TW_USE_MINUI_WITH_OPTIONAL_TOUCH_EVENTS
	if (!should_add_input_device(fd, allow_touch_inputs)) {
	continue;
	}
	#endif

	epoll_event ev;
	ev.events = EPOLLIN \| EPOLLWAKEUP;
	ev.data.ptr = &ev_fdinfo[g_ev_count];
	if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &ev) == -1) {
	epoll_ctl_failed = true;
	continue;
	}

	ev_fdinfo[g_ev_count].fd.reset(fd.release());
	ev_fdinfo[g_ev_count].cb = input_cb;
	g_ev_count++;
	g_ev_dev_count++;
	if (g_ev_dev_count == MAX_DEVICES) break;
	}

	if (epoll_ctl_failed && !g_ev_count) {
	return -1;
	}

	g_epoll_fd.reset(epoll_fd.release());

	g_saved_input_cb = input_cb;
	g_allow_touch_inputs = allow_touch_inputs;
	#ifdef TW_USE_MINUI_WITH_OPTIONAL_TOUCH_EVENTS
	ev_add_fd(std::move(inotify_fd), inotify_cb);
	#endif

	return 0;
	}

	int ev_get_epollfd(void) {
	return g_epoll_fd.get();
	}

	int ev_add_fd(android::base::unique_fd&& fd, ev_callback cb) {
	if (g_ev_misc_count == MAX_MISC_FDS \|\| cb == nullptr) {
	return -1;
	}

	epoll_event ev;
	ev.events = EPOLLIN \| EPOLLWAKEUP;
	ev.data.ptr = static_cast<void*>(&ev_fdinfo[g_ev_count]);
	int ret = epoll_ctl(g_epoll_fd, EPOLL_CTL_ADD, fd, &ev);
	if (!ret) {
	ev_fdinfo[g_ev_count].fd.reset(fd.release());
	ev_fdinfo[g_ev_count].cb = std::move(cb);
	g_ev_count++;
	g_ev_misc_count++;
	}

	return ret;
	}

	void ev_exit(void) {
	while (g_ev_count > 0) {
	ev_fdinfo[--g_ev_count].fd.reset();
	}
	g_ev_misc_count = 0;
	g_ev_dev_count = 0;
	g_saved_input_cb = nullptr;
	g_epoll_fd.reset();
	}

	int ev_wait(int timeout) {
	g_polled_events_count = epoll_wait(g_epoll_fd, g_polled_events, g_ev_count, timeout);
	if (g_polled_events_count <= 0) {
	return -1;
	}
	return 0;
	}

	void ev_dispatch(void) {
	for (int n = 0; n < g_polled_events_count; n++) {
	FdInfo* fdi = static_cast<FdInfo*>(g_polled_events[n].data.ptr);
	const ev_callback& cb = fdi->cb;
	if (cb) {
	cb(fdi->fd, g_polled_events[n].events);
	}
	}
	}

	int ev_get_input(int fd, uint32_t epevents, input_event* ev) {
	if (epevents & EPOLLIN) {
	ssize_t r = TEMP_FAILURE_RETRY(read(fd, ev, sizeof(*ev)));
	if (r == sizeof(*ev)) {
	return 0;
	}
	}
	if (epevents & EPOLLHUP) {
	// Delete this watch
	epoll_ctl(g_epoll_fd, EPOLL_CTL_DEL, fd, nullptr);
	}
	return -1;
	}

	#ifdef TW_USE_MINUI_WITH_DATA
	int ev_sync_key_state(ev_set_key_callback set_key_cb, void* data) {
	#else
	int ev_sync_key_state(const ev_set_key_callback& set_key_cb) {
	#endif
	// Use unsigned long to match ioctl's parameter type.
	unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)]; // NOLINT
	unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)]; // NOLINT

	for (size_t i = 0; i < g_ev_dev_count; ++i) {
	memset(ev_bits, 0, sizeof(ev_bits));
	memset(key_bits, 0, sizeof(key_bits));

	if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
	continue;
	}
	if (!test_bit(EV_KEY, ev_bits)) {
	continue;
	}
	if (ioctl(ev_fdinfo[i].fd, EVIOCGKEY(sizeof(key_bits)), key_bits) == -1) {
	continue;
	}

	for (int code = 0; code <= KEY_MAX; code++) {
	if (test_bit(code, key_bits)) {
	#ifdef TW_USE_MINUI_WITH_DATA
	set_key_cb(code, 1, data);
	#else
	set_key_cb(code, 1);
	#endif
	}
	}
	}

	return 0;
	}

	void ev_iterate_available_keys(const std::function<void(int)>& f) {
	// Use unsigned long to match ioctl's parameter type.
	unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)]; // NOLINT
	unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)]; // NOLINT

	for (size_t i = 0; i < g_ev_dev_count; ++i) {
	memset(ev_bits, 0, sizeof(ev_bits));
	memset(key_bits, 0, sizeof(key_bits));

	// Does this device even have keys?
	if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
	continue;
	}
	if (!test_bit(EV_KEY, ev_bits)) {
	continue;
	}

	if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(EV_KEY, KEY_MAX), key_bits) == -1) {
	continue;
	}

	for (int key_code = 0; key_code <= KEY_MAX; ++key_code) {
	if (test_bit(key_code, key_bits)) {
	f(key_code);
	}
	}
	}
	}

	#ifdef TW_USE_MINUI_WITH_OPTIONAL_TOUCH_EVENTS
	void ev_iterate_touch_inputs(const std::function<void(int)>& action) {
	for (size_t i = 0; i < g_ev_dev_count; ++i) {
	// Use unsigned long to match ioctl's parameter type.
	unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)] = {}; // NOLINT
	if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits) == -1) {
	continue;
	}
	if (!test_bit(EV_ABS, ev_bits)) {
	continue;
	}

	unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)] = {}; // NOLINT
	if (ioctl(ev_fdinfo[i].fd, EVIOCGBIT(EV_ABS, KEY_MAX), key_bits) == -1) {
	continue;
	}

	for (int key_code = 0; key_code <= KEY_MAX; ++key_code) {
	if (test_bit(key_code, key_bits)) {
	action(key_code);
	}
	}
	}
	}
	#endif