Waybar/src/modules/battery.cpp

730 lines
27 KiB
C++

#include "modules/battery.hpp"
#include <algorithm>
#if defined(__FreeBSD__)
#include <sys/sysctl.h>
#endif
#include <spdlog/spdlog.h>
#include <iostream>
waybar::modules::Battery::Battery(const std::string& id, const Bar& bar, const Json::Value& config)
: ALabel(config, "battery", id, "{capacity}%", 60), bar_(bar) {
#if defined(__linux__)
battery_watch_fd_ = inotify_init1(IN_CLOEXEC);
if (battery_watch_fd_ == -1) {
throw std::runtime_error("Unable to listen batteries.");
}
global_watch_fd_ = inotify_init1(IN_CLOEXEC);
if (global_watch_fd_ == -1) {
throw std::runtime_error("Unable to listen batteries.");
}
// Watch the directory for any added or removed batteries
global_watch = inotify_add_watch(global_watch_fd_, data_dir_.c_str(), IN_CREATE | IN_DELETE);
if (global_watch < 0) {
throw std::runtime_error("Could not watch for battery plug/unplug");
}
#endif
worker();
}
waybar::modules::Battery::~Battery() {
#if defined(__linux__)
std::lock_guard<std::mutex> guard(battery_list_mutex_);
if (global_watch >= 0) {
inotify_rm_watch(global_watch_fd_, global_watch);
}
close(global_watch_fd_);
for (auto it = batteries_.cbegin(), next_it = it; it != batteries_.cend(); it = next_it) {
++next_it;
auto watch_id = (*it).second;
if (watch_id >= 0) {
inotify_rm_watch(battery_watch_fd_, watch_id);
}
batteries_.erase(it);
}
close(battery_watch_fd_);
#endif
}
void waybar::modules::Battery::worker() {
#if defined(__FreeBSD__)
thread_timer_ = [this] {
dp.emit();
thread_timer_.sleep_for(interval_);
};
#else
thread_timer_ = [this] {
// Make sure we eventually update the list of batteries even if we miss an
// inotify event for some reason
refreshBatteries();
dp.emit();
thread_timer_.sleep_for(interval_);
};
thread_ = [this] {
struct inotify_event event = {0};
int nbytes = read(battery_watch_fd_, &event, sizeof(event));
if (nbytes != sizeof(event) || event.mask & IN_IGNORED) {
thread_.stop();
return;
}
dp.emit();
};
thread_battery_update_ = [this] {
struct inotify_event event = {0};
int nbytes = read(global_watch_fd_, &event, sizeof(event));
if (nbytes != sizeof(event) || event.mask & IN_IGNORED) {
thread_.stop();
return;
}
refreshBatteries();
dp.emit();
};
#endif
}
void waybar::modules::Battery::refreshBatteries() {
#if defined(__linux__)
std::lock_guard<std::mutex> guard(battery_list_mutex_);
// Mark existing list of batteries as not necessarily found
std::map<fs::path, bool> check_map;
for (auto const& bat : batteries_) {
check_map[bat.first] = false;
}
try {
for (auto& node : fs::directory_iterator(data_dir_)) {
if (!fs::is_directory(node)) {
continue;
}
auto dir_name = node.path().filename();
auto bat_defined = config_["bat"].isString();
bool bat_compatibility = config_["bat-compatibility"].asBool();
if (((bat_defined && dir_name == config_["bat"].asString()) || !bat_defined) &&
(fs::exists(node.path() / "capacity") || fs::exists(node.path() / "charge_now")) &&
fs::exists(node.path() / "uevent") &&
(fs::exists(node.path() / "status") || bat_compatibility) &&
fs::exists(node.path() / "type")) {
std::string type;
std::ifstream(node.path() / "type") >> type;
if (!type.compare("Battery")) {
// Ignore non-system power supplies unless explicitly requested
if (!bat_defined && fs::exists(node.path() / "scope")) {
std::string scope;
std::ifstream(node.path() / "scope") >> scope;
if (g_ascii_strcasecmp(scope.data(), "device") == 0) {
continue;
}
}
check_map[node.path()] = true;
auto search = batteries_.find(node.path());
if (search == batteries_.end()) {
// We've found a new battery save it and start listening for events
auto event_path = (node.path() / "uevent");
auto wd = inotify_add_watch(battery_watch_fd_, event_path.c_str(), IN_ACCESS);
if (wd < 0) {
throw std::runtime_error("Could not watch events for " + node.path().string());
}
batteries_[node.path()] = wd;
}
}
}
auto adap_defined = config_["adapter"].isString();
if (((adap_defined && dir_name == config_["adapter"].asString()) || !adap_defined) &&
(fs::exists(node.path() / "online") || fs::exists(node.path() / "status"))) {
adapter_ = node.path();
}
}
} catch (fs::filesystem_error& e) {
throw std::runtime_error(e.what());
}
if (warnFirstTime_ && batteries_.empty()) {
if (config_["bat"].isString()) {
spdlog::warn("No battery named {0}", config_["bat"].asString());
} else {
spdlog::warn("No batteries.");
}
warnFirstTime_ = false;
}
// Remove any batteries that are no longer present and unwatch them
for (auto const& check : check_map) {
if (!check.second) {
auto watch_id = batteries_[check.first];
if (watch_id >= 0) {
inotify_rm_watch(battery_watch_fd_, watch_id);
}
batteries_.erase(check.first);
}
}
#endif
}
// Unknown > Full > Not charging > Discharging > Charging
static bool status_gt(const std::string& a, const std::string& b) {
if (a == b)
return false;
else if (a == "Unknown")
return true;
else if (a == "Full" && b != "Unknown")
return true;
else if (a == "Not charging" && b != "Unknown" && b != "Full")
return true;
else if (a == "Discharging" && b != "Unknown" && b != "Full" && b != "Not charging")
return true;
return false;
}
const std::tuple<uint8_t, float, std::string, float> waybar::modules::Battery::getInfos() {
std::lock_guard<std::mutex> guard(battery_list_mutex_);
try {
#if defined(__FreeBSD__)
/* Allocate state of battery units reported via ACPI. */
int battery_units = 0;
size_t battery_units_size = sizeof battery_units;
if (sysctlbyname("hw.acpi.battery.units", &battery_units, &battery_units_size, NULL, 0) != 0) {
throw std::runtime_error("sysctl hw.acpi.battery.units failed");
}
if (battery_units < 0) {
throw std::runtime_error("No battery units");
}
int capacity;
size_t size_capacity = sizeof capacity;
if (sysctlbyname("hw.acpi.battery.life", &capacity, &size_capacity, NULL, 0) != 0) {
throw std::runtime_error("sysctl hw.acpi.battery.life failed");
}
int time;
size_t size_time = sizeof time;
if (sysctlbyname("hw.acpi.battery.time", &time, &size_time, NULL, 0) != 0) {
throw std::runtime_error("sysctl hw.acpi.battery.time failed");
}
int rate;
size_t size_rate = sizeof rate;
if (sysctlbyname("hw.acpi.battery.rate", &rate, &size_rate, NULL, 0) != 0) {
throw std::runtime_error("sysctl hw.acpi.battery.rate failed");
}
auto status = getAdapterStatus(capacity);
// Handle full-at
if (config_["full-at"].isUInt()) {
auto full_at = config_["full-at"].asUInt();
if (full_at < 100) {
capacity = 100.f * capacity / full_at;
}
}
if (capacity > 100.f) {
// This can happen when the battery is calibrating and goes above 100%
// Handle it gracefully by clamping at 100%
capacity = 100.f;
}
uint8_t cap = round(capacity);
if (cap == 100 && status == "Plugged") {
// If we've reached 100% just mark as full as some batteries can stay
// stuck reporting they're still charging but not yet done
status = "Full";
}
// spdlog::info("{} {} {} {}", capacity,time,status,rate);
return {capacity, time / 60.0, status, rate};
#elif defined(__linux__)
uint32_t total_power = 0; // μW
bool total_power_exists = false;
uint32_t total_energy = 0; // μWh
bool total_energy_exists = false;
uint32_t total_energy_full = 0;
bool total_energy_full_exists = false;
uint32_t total_energy_full_design = 0;
bool total_energy_full_design_exists = false;
uint32_t total_capacity = 0;
bool total_capacity_exists = false;
uint32_t time_to_empty_now = 0;
bool time_to_empty_now_exists = false;
uint32_t time_to_full_now = 0;
bool time_to_full_now_exists = false;
std::string status = "Unknown";
for (auto const& item : batteries_) {
auto bat = item.first;
std::string _status;
/* Check for adapter status if battery is not available */
if (!std::ifstream(bat / "status")) {
std::getline(std::ifstream(adapter_ / "status"), _status);
} else {
std::getline(std::ifstream(bat / "status"), _status);
}
// Some battery will report current and charge in μA/μAh.
// Scale these by the voltage to get μW/μWh.
uint32_t capacity = 0;
bool capacity_exists = false;
if (fs::exists(bat / "capacity")) {
capacity_exists = true;
std::ifstream(bat / "capacity") >> capacity;
}
uint32_t current_now = 0;
bool current_now_exists = false;
if (fs::exists(bat / "current_now")) {
current_now_exists = true;
std::ifstream(bat / "current_now") >> current_now;
} else if (fs::exists(bat / "current_avg")) {
current_now_exists = true;
std::ifstream(bat / "current_avg") >> current_now;
}
if (fs::exists(bat / "time_to_empty_now")) {
time_to_empty_now_exists = true;
std::ifstream(bat / "time_to_empty_now") >> time_to_empty_now;
}
if (fs::exists(bat / "time_to_full_now")) {
time_to_full_now_exists = true;
std::ifstream(bat / "time_to_full_now") >> time_to_full_now;
}
uint32_t voltage_now = 0;
bool voltage_now_exists = false;
if (fs::exists(bat / "voltage_now")) {
voltage_now_exists = true;
std::ifstream(bat / "voltage_now") >> voltage_now;
} else if (fs::exists(bat / "voltage_avg")) {
voltage_now_exists = true;
std::ifstream(bat / "voltage_avg") >> voltage_now;
}
uint32_t charge_full = 0;
bool charge_full_exists = false;
if (fs::exists(bat / "charge_full")) {
charge_full_exists = true;
std::ifstream(bat / "charge_full") >> charge_full;
}
uint32_t charge_full_design = 0;
bool charge_full_design_exists = false;
if (fs::exists(bat / "charge_full_design")) {
charge_full_design_exists = true;
std::ifstream(bat / "charge_full_design") >> charge_full_design;
}
uint32_t charge_now = 0;
bool charge_now_exists = false;
if (fs::exists(bat / "charge_now")) {
charge_now_exists = true;
std::ifstream(bat / "charge_now") >> charge_now;
}
uint32_t power_now = 0;
bool power_now_exists = false;
if (fs::exists(bat / "power_now")) {
power_now_exists = true;
std::ifstream(bat / "power_now") >> power_now;
}
uint32_t energy_now = 0;
bool energy_now_exists = false;
if (fs::exists(bat / "energy_now")) {
energy_now_exists = true;
std::ifstream(bat / "energy_now") >> energy_now;
}
uint32_t energy_full = 0;
bool energy_full_exists = false;
if (fs::exists(bat / "energy_full")) {
energy_full_exists = true;
std::ifstream(bat / "energy_full") >> energy_full;
}
uint32_t energy_full_design = 0;
bool energy_full_design_exists = false;
if (fs::exists(bat / "energy_full_design")) {
energy_full_design_exists = true;
std::ifstream(bat / "energy_full_design") >> energy_full_design;
}
if (!voltage_now_exists) {
if (power_now_exists && current_now_exists && current_now != 0) {
voltage_now_exists = true;
voltage_now = 1000000 * (uint64_t)power_now / (uint64_t)current_now;
} else if (energy_full_design_exists && charge_full_design_exists &&
charge_full_design != 0) {
voltage_now_exists = true;
voltage_now = 1000000 * (uint64_t)energy_full_design / (uint64_t)charge_full_design;
} else if (energy_now_exists) {
if (charge_now_exists && charge_now != 0) {
voltage_now_exists = true;
voltage_now = 1000000 * (uint64_t)energy_now / (uint64_t)charge_now;
} else if (capacity_exists && charge_full_exists) {
charge_now_exists = true;
charge_now = (uint64_t)charge_full * (uint64_t)capacity / 100;
if (charge_full != 0 && capacity != 0) {
voltage_now_exists = true;
voltage_now =
1000000 * (uint64_t)energy_now * 100 / (uint64_t)charge_full / (uint64_t)capacity;
}
}
} else if (energy_full_exists) {
if (charge_full_exists && charge_full != 0) {
voltage_now_exists = true;
voltage_now = 1000000 * (uint64_t)energy_full / (uint64_t)charge_full;
} else if (charge_now_exists && capacity_exists) {
if (capacity != 0) {
charge_full_exists = true;
charge_full = 100 * (uint64_t)charge_now / (uint64_t)capacity;
}
if (charge_now != 0) {
voltage_now_exists = true;
voltage_now =
10000 * (uint64_t)energy_full * (uint64_t)capacity / (uint64_t)charge_now;
}
}
}
}
if (!capacity_exists) {
if (charge_now_exists && charge_full_exists && charge_full != 0) {
capacity_exists = true;
capacity = 100 * (uint64_t)charge_now / (uint64_t)charge_full;
} else if (energy_now_exists && energy_full_exists && energy_full != 0) {
capacity_exists = true;
capacity = 100 * (uint64_t)energy_now / (uint64_t)energy_full;
} else if (charge_now_exists && energy_full_exists && voltage_now_exists) {
if (!charge_full_exists && voltage_now != 0) {
charge_full_exists = true;
charge_full = 1000000 * (uint64_t)energy_full / (uint64_t)voltage_now;
}
if (energy_full != 0) {
capacity_exists = true;
capacity = (uint64_t)charge_now * (uint64_t)voltage_now / 10000 / (uint64_t)energy_full;
}
} else if (charge_full_exists && energy_now_exists && voltage_now_exists) {
if (!charge_now_exists && voltage_now != 0) {
charge_now_exists = true;
charge_now = 1000000 * (uint64_t)energy_now / (uint64_t)voltage_now;
}
if (voltage_now != 0 && charge_full != 0) {
capacity_exists = true;
capacity = 100 * 1000000 * (uint64_t)energy_now / (uint64_t)voltage_now /
(uint64_t)charge_full;
}
}
}
if (!energy_now_exists && voltage_now_exists) {
if (charge_now_exists) {
energy_now_exists = true;
energy_now = (uint64_t)charge_now * (uint64_t)voltage_now / 1000000;
} else if (capacity_exists && charge_full_exists) {
charge_now_exists = true;
charge_now = (uint64_t)capacity * (uint64_t)charge_full / 100;
energy_now_exists = true;
energy_now =
(uint64_t)voltage_now * (uint64_t)capacity * (uint64_t)charge_full / 1000000 / 100;
} else if (capacity_exists && energy_full) {
if (voltage_now != 0) {
charge_full_exists = true;
charge_full = 1000000 * (uint64_t)energy_full / (uint64_t)voltage_now;
charge_now_exists = true;
charge_now = (uint64_t)capacity * 10000 * (uint64_t)energy_full / (uint64_t)voltage_now;
}
energy_now_exists = true;
energy_now = (uint64_t)capacity * (uint64_t)energy_full / 100;
}
}
if (!energy_full_exists && voltage_now_exists) {
if (charge_full_exists) {
energy_full_exists = true;
energy_full = (uint64_t)charge_full * (uint64_t)voltage_now / 1000000;
} else if (charge_now_exists && capacity_exists && capacity != 0) {
charge_full_exists = true;
charge_full = 100 * (uint64_t)charge_now / (uint64_t)capacity;
energy_full_exists = true;
energy_full = (uint64_t)charge_now * (uint64_t)voltage_now / (uint64_t)capacity / 10000;
} else if (capacity_exists && energy_now) {
if (voltage_now != 0) {
charge_now_exists = true;
charge_now = 1000000 * (uint64_t)energy_now / (uint64_t)voltage_now;
}
if (capacity != 0) {
energy_full_exists = true;
energy_full = 100 * (uint64_t)energy_now / (uint64_t)capacity;
if (voltage_now != 0) {
charge_full_exists = true;
charge_full =
100 * 1000000 * (uint64_t)energy_now / (uint64_t)voltage_now / (uint64_t)capacity;
}
}
}
}
if (!power_now_exists && voltage_now_exists && current_now_exists) {
power_now_exists = true;
power_now = (uint64_t)voltage_now * (uint64_t)current_now / 1000000;
}
if (!energy_full_design_exists && voltage_now_exists && charge_full_design_exists) {
energy_full_design_exists = true;
energy_full_design = (uint64_t)voltage_now * (uint64_t)charge_full_design / 1000000;
}
// Show the "smallest" status among all batteries
if (status_gt(status, _status)) status = _status;
if (power_now_exists) {
total_power_exists = true;
total_power += power_now;
}
if (energy_now_exists) {
total_energy_exists = true;
total_energy += energy_now;
}
if (energy_full_exists) {
total_energy_full_exists = true;
total_energy_full += energy_full;
}
if (energy_full_design_exists) {
total_energy_full_design_exists = true;
total_energy_full_design += energy_full_design;
}
if (capacity_exists) {
total_capacity_exists = true;
total_capacity += capacity;
}
}
// Give `Plugged` higher priority over `Not charging`.
// So in a setting where TLP is used, `Plugged` is shown when the threshold is reached
if (!adapter_.empty() && (status == "Discharging" || status == "Not charging")) {
bool online;
std::string current_status;
std::ifstream(adapter_ / "online") >> online;
std::getline(std::ifstream(adapter_ / "status"), current_status);
if (online && current_status != "Discharging") status = "Plugged";
}
float time_remaining{0.0f};
if (status == "Discharging" && time_to_empty_now_exists) {
if (time_to_empty_now != 0) time_remaining = (float)time_to_empty_now / 3600.0f;
} else if (status == "Discharging" && total_power_exists && total_energy_exists) {
if (total_power != 0) time_remaining = (float)total_energy / total_power;
} else if (status == "Charging" && time_to_full_now_exists) {
if (time_to_full_now_exists && (time_to_full_now != 0))
time_remaining = -(float)time_to_full_now / 3600.0f;
// If we've turned positive it means the battery is past 100% and so just report that as no
// time remaining
if (time_remaining > 0.0f) time_remaining = 0.0f;
} else if (status == "Charging" && total_energy_exists && total_energy_full_exists &&
total_power_exists) {
if (total_power != 0)
time_remaining = -(float)(total_energy_full - total_energy) / total_power;
// If we've turned positive it means the battery is past 100% and so just report that as no
// time remaining
if (time_remaining > 0.0f) time_remaining = 0.0f;
}
float calculated_capacity{0.0f};
if (total_capacity_exists) {
if (total_capacity > 0.0f)
calculated_capacity = (float)total_capacity / batteries_.size();
else if (total_energy_full_exists && total_energy_exists) {
if (total_energy_full > 0.0f)
calculated_capacity = ((float)total_energy * 100.0f / (float)total_energy_full);
}
}
// Handle weighted-average
if ((config_["weighted-average"].isBool() ? config_["weighted-average"].asBool() : false) &&
total_energy_exists && total_energy_full_exists) {
if (total_energy_full > 0.0f)
calculated_capacity = ((float)total_energy * 100.0f / (float)total_energy_full);
}
// Handle design-capacity
if ((config_["design-capacity"].isBool() ? config_["design-capacity"].asBool() : false) &&
total_energy_exists && total_energy_full_design_exists) {
if (total_energy_full_design > 0.0f)
calculated_capacity = ((float)total_energy * 100.0f / (float)total_energy_full_design);
}
// Handle full-at
if (config_["full-at"].isUInt()) {
auto full_at = config_["full-at"].asUInt();
if (full_at < 100) calculated_capacity = 100.f * calculated_capacity / full_at;
}
// Handle it gracefully by clamping at 100%
// This can happen when the battery is calibrating and goes above 100%
if (calculated_capacity > 100.f) calculated_capacity = 100.f;
uint8_t cap = round(calculated_capacity);
// If we've reached 100% just mark as full as some batteries can stay stuck reporting they're
// still charging but not yet done
if (cap == 100 && status == "Charging") status = "Full";
return {cap, time_remaining, status, total_power / 1e6};
#endif
} catch (const std::exception& e) {
spdlog::error("Battery: {}", e.what());
return {0, 0, "Unknown", 0};
}
}
const std::string waybar::modules::Battery::getAdapterStatus(uint8_t capacity) const {
#if defined(__FreeBSD__)
int state;
size_t size_state = sizeof state;
if (sysctlbyname("hw.acpi.battery.state", &state, &size_state, NULL, 0) != 0) {
throw std::runtime_error("sysctl hw.acpi.battery.state failed");
}
bool online = state == 2;
std::string status{"Unknown"}; // TODO: add status in FreeBSD
{
#else
if (!adapter_.empty()) {
bool online;
std::string status;
std::ifstream(adapter_ / "online") >> online;
std::getline(std::ifstream(adapter_ / "status"), status);
#endif
if (capacity == 100) {
return "Full";
}
if (online && status != "Discharging") {
return "Plugged";
}
return "Discharging";
}
return "Unknown";
}
const std::string waybar::modules::Battery::formatTimeRemaining(float hoursRemaining) {
hoursRemaining = std::fabs(hoursRemaining);
uint16_t full_hours = static_cast<uint16_t>(hoursRemaining);
uint16_t minutes = static_cast<uint16_t>(60 * (hoursRemaining - full_hours));
auto format = std::string("{H} h {M} min");
if (full_hours == 0 && minutes == 0) {
// Migh as well not show "0h 0min"
return "";
}
if (config_["format-time"].isString()) {
format = config_["format-time"].asString();
}
std::string zero_pad_minutes = fmt::format("{:02d}", minutes);
return fmt::format(fmt::runtime(format), fmt::arg("H", full_hours), fmt::arg("M", minutes),
fmt::arg("m", zero_pad_minutes));
}
auto waybar::modules::Battery::update() -> void {
#if defined(__linux__)
if (batteries_.empty()) {
event_box_.hide();
return;
}
#endif
auto [capacity, time_remaining, status, power] = getInfos();
if (status == "Unknown") {
status = getAdapterStatus(capacity);
}
auto status_pretty = status;
// Transform to lowercase and replace space with dash
std::transform(status.begin(), status.end(), status.begin(),
[](char ch) { return ch == ' ' ? '-' : std::tolower(ch); });
auto format = format_;
auto state = getState(capacity, true);
setBarClass(state);
auto time_remaining_formatted = formatTimeRemaining(time_remaining);
if (tooltipEnabled()) {
std::string tooltip_text_default;
std::string tooltip_format = "{timeTo}";
if (time_remaining != 0) {
std::string time_to = std::string("Time to ") + ((time_remaining > 0) ? "empty" : "full");
tooltip_text_default = time_to + ": " + time_remaining_formatted;
} else {
tooltip_text_default = status_pretty;
}
if (!state.empty() && config_["tooltip-format-" + status + "-" + state].isString()) {
tooltip_format = config_["tooltip-format-" + status + "-" + state].asString();
} else if (config_["tooltip-format-" + status].isString()) {
tooltip_format = config_["tooltip-format-" + status].asString();
} else if (!state.empty() && config_["tooltip-format-" + state].isString()) {
tooltip_format = config_["tooltip-format-" + state].asString();
} else if (config_["tooltip-format"].isString()) {
tooltip_format = config_["tooltip-format"].asString();
}
label_.set_tooltip_text(fmt::format(fmt::runtime(tooltip_format),
fmt::arg("timeTo", tooltip_text_default),
fmt::arg("power", power), fmt::arg("capacity", capacity),
fmt::arg("time", time_remaining_formatted)));
}
if (!old_status_.empty()) {
label_.get_style_context()->remove_class(old_status_);
}
label_.get_style_context()->add_class(status);
old_status_ = status;
if (!state.empty() && config_["format-" + status + "-" + state].isString()) {
format = config_["format-" + status + "-" + state].asString();
} else if (config_["format-" + status].isString()) {
format = config_["format-" + status].asString();
} else if (!state.empty() && config_["format-" + state].isString()) {
format = config_["format-" + state].asString();
}
if (format.empty()) {
event_box_.hide();
} else {
event_box_.show();
auto icons = std::vector<std::string>{status + "-" + state, status, state};
label_.set_markup(fmt::format(
fmt::runtime(format), fmt::arg("capacity", capacity), fmt::arg("power", power),
fmt::arg("icon", getIcon(capacity, icons)), fmt::arg("time", time_remaining_formatted)));
}
// Call parent update
ALabel::update();
}
void waybar::modules::Battery::setBarClass(std::string& state) {
auto classes = bar_.window.get_style_context()->list_classes();
const std::string prefix = "battery-";
auto old_class_it = std::find_if(classes.begin(), classes.end(), [&prefix](auto classname) {
return classname.rfind(prefix, 0) == 0;
});
auto new_class = prefix + state;
// If the bar doesn't have any `battery-` class
if (old_class_it == classes.end()) {
if (!state.empty()) {
bar_.window.get_style_context()->add_class(new_class);
}
return;
}
auto old_class = *old_class_it;
// If the bar has a `battery-` class,
// but `state` is empty
if (state.empty()) {
bar_.window.get_style_context()->remove_class(old_class);
return;
}
// If the bar has a `battery-` class,
// and `state` is NOT empty
if (old_class != new_class) {
bar_.window.get_style_context()->remove_class(old_class);
bar_.window.get_style_context()->add_class(new_class);
}
}